{"paper_id":"0b554284-e72d-4016-9c4a-812d31f7a299","body_text":"Impact of prepartum hindlimb hoof lesions and other risk factors on the lameness status of sows at weaning: A prospective cohort study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Impact of prepartum hindlimb hoof lesions and other risk factors on the lameness status of sows at weaning: A prospective cohort study Junbiao Wang, Meng Li, Ziyang Liu, Shuyu Tian, Bolan Sun, Yupeng Mo, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6538207/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Sow lameness represents a significant challenge to both animal welfare and economic efficiency in swine production, with hoof lesions identified as a major contributing factor. In China, research addressing sow lameness and its associated risk factors remains limited, particularly regarding longitudinal studies on risk factors for lameness in weaned sows. This study utilized a prospective cohort design to investigate the effects of pre-farrowing hindlimb hoof lesions and other factors including breed and parity on the development of lameness by weaning. Materials and methods A prospective cohort study was conducted from July to September 2024 on a multiplier sow farm (herd size = 5,159 sows) in Guangxi, China. The study cohort consisted of 311 non-lame sows, representing two genetic lines: Danish Yorkshire (YY) and Landrace (LL). At 110 days of gestation, one trained veterinarian performed standardized scoring for seven hindlimb conditions: overgrown toe (OT), overgrown dewclaw (ODC), heel overgrowth and erosion (HOE), heel-sole crack (HSC), white line crack (WLC), cracked wall horizontal (CWH) and cracked wall vertical (CWV). Lameness assessment were conducted during two key transition points: (1) pre-farrowing (transfer from gestation to farrowing rooms at 110 days of gestation) and (2) post-weaning (return to gestation rooms after weaning). Sows were monitored throughout lactation, with data collected on genetic line, parity, backfat thickness, and the requirement for farrowing assistance. Univariate analysis was conducted to identify candidate variables (hoof lesion types, genetic line, parity, backfat thickness, and farrowing assistance requirement). Then, these selected variables were incorporated into a multivariate logistic regression model to determine risk factors for lameness in sows at weaning. Variables with p -values < 0.1 were subsequently included in a multivariate logistic regression model to identify independent risk factors for lactation-associated lameness. Results Among sows that were non-lame at pre-farrowing assessment, 44.7% (139/311) developed lameness by weaning. Bilateral OT exhibited the highest adjusted odds ratio for incident lameness (OR = 42.5, 95% CI: 10.9-165.5; P < 0.001), followed by unilateral OT (OR = 28.0, 95% CI: 9.4–83.7; P < 0.001), bilateral HOE (OR = 10.0, 95% CI: 3.5–29.0; P < 0.001), and bilateral ODC (OR = 7.3, 95% CI: 2.5–21.2, P < 0.001). YY sows demonstrated a borderline significantly elevated risk compared to LL sows (OR = 2.3, 95% CI: 0.9–5.5; P = 0.070). Conclusions Pre-farrowing hindlimbs lesions-including bilateral OT, ODC, HOE, and unilateral OT, were significant predictors of incident lameness at weaning. Biomechanical stresses during lactation may exacerbate pre-existing subclinical hoof lesions, leading to overt lameness at weaning. Prepartum hoof lesion scoring may thus serve as a valuable tool for risk stratification and early intervention strategies for improving sow welfare and farm productivity. Sow lameness Hindlimb hoof lesions Lactation Purebred Danish sows Prospective cohort study Figures Figure 1 Figure 2 Figure 3 Background Sow lameness poses a critical welfare challenge in the global swine industry, accounting for 10–29% of culling and mortality events [ 1 – 5 ]. Cross-sectional studies have estimated the prevalence of sow lameness at 8–27% across various production systems [ 6 – 9 ]. A 2023 study from the United States identified lameness as the primary contributor to 28.78% of sow mortality-related culls [ 1 ]. Beyond welfare impact, lameness also incurs substantial economic losses by reducing productive longevity [ 5 , 10 , 11 ]. Emerging evidence highlights hoof lesion dynamics as pivotal contributors to pathogenesis of lameness [ 12 – 15 ]. Jorgensen’s work has established associations between hoof lesions and clinical outcomes such as lameness, forelimb stiffness, and hindlimb postural instability [ 12 , 13 ]. Hoof lesions are estimated to account for 5–20% of sow lameness [ 14 , 15 ], with approximately 90% of sows exhibiting at least one type of lesion [ 16 , 17 ]. Lameness manifestation has been shown to be lesion location-specific [ 18 ] and dose-dependent with respect to lesion pathological severity [ 19 ], particularly for hindlimb lesions [ 7 , 20 ] In China, sow lameness remains a significant challenge within intensive pig production systems, accounting for 10–23% of sow mortality [ 4 , 5 ]. Previous studies [ 10 , 21 , 22 ] have shown that lameness-related mortality and culling rates peaked during the weaning-to-rebreeding period, likely due to increased lameness during lactation and common culling practices after weaning. Lameness-associated culling leads to a shortened herd lifespan for affected sows, resulting in fewer litters, and markedly reduced production efficiency [ 2 ]. However, research on sow lameness and its associated risk factors in China remains limited. Most existing studies have employed cross-sectional designs, which inherently limit the ability to comprehensively identify risk factors of lameness and thereby hinder the development of effective prevention and control strategies. The present prospective cohort study therefore investigates the influence of prepartum hindlimb hoof lesions and other risk factors on the development of incident lameness at weaning, with the goal of informing evidence-based prevention strategies. Materials and methods Research farm and animals This study was conducted on a sow farm in Guangxi, China, housing a herd of 5,159 sows, from July to September 2024. All sows tested negative for porcine reproductive and respiratory syndrome virus, pseudorabies, and porcine parvovirus based on both antigen and antibody detection. Previous investigations on this farm reported a sow lameness prevalence rate of approximately 25%. A total of 576 sows at 110 days of gestation were initially included in the study, without interfering the farm's production schedule. Prenatal lameness assessments were conducted at 110 days of gestation. Lame sows (n = 159) were excluded, and non-lame sows (n = 417) were retained for follow-up study. These non-lame sows were monitored throughout lactation and subsequently transferred back to the gestation barn. Due to unavoidable management factors, some sows were reassigned as nursing sows to different farrowing rooms for fostering fallback piglets, while others died during the study. Consequently, data for 106 sows were missing and were excluded for the final analysis (Fig. 1). Sows were transferred from the gestation barn to the farrowing room at 110 days of gestation. Each farrowing room contained 48 farrowing crates, accommodating 40 ± 2 sows; with the remaining crates reserved for nursing sows. Each crate measured 215 cm in length, 45 cm in width, and 110 cm in height. The flooring was made of cast iron with a 1 cm-wide gap between slats. Environmental conditions were regulated by a computerized climate control system (307 Pro Climate Control computers, Big Dutchman), which operated water curtains and negative-pressure fans to maintain optimal temperature based on real-time monitoring. Sows were fed via an automated feeding system, and had free access to individual drinking nipples throughout lactation. Figure 1 Flowchart of sow selection for the study Data Collection During the study period, the following data were recorded for each sow: ear tag number, parity, breed [Yorkshire (YY), Landrace (LL)], backfat thickness, hoof lesions, and lameness status (Fig. 2). Backfat thickness was measured at the P2 point, located 65 mm from the midline at the last rib [ 23 ], using a B-mode ultrasound instrument (SONO V6+, Shenzhen Shengnuowei Technology Co., Ltd.) at three time points: on the 110th day of gestation (BT-G110), the 15th day after entering the farrowing room (BT-FR15), and the day of weaning (BT-WD). Upon entry into the farrowing room on the 110th day of gestation, hindlimb hoof lesions were assessed while the sows were either standing or lying down. The scoring system included the following lesion types: overgrowth toe (OT: toe length > 5.5 cm [ 24 ]), overgrowth dewclaw length (ODC: The dewclaw extends beyond the level of the coronary band [ 24 ]), heel overgrowth and erosion (HOE), heel-sole crack (HSC), white line crack (WLC), cracked wall horizontal (CWH) and cracked wall vertical (CWV), recorded separately for each hindlimb. Lesions were evaluated using a modified version of the Zinpro Feet First scoring system [ 25 ]. Lesions were scored as follows: 0 indicated no lesions on either hind hoof; 1 indicated lesions on one hind hoof; 2 indicated lesions on both hind hooves. Each sow could exhibit up to seven types of hoof lesions, scored individually. The total hoof lesion score, calculated by summing all individual lesion scores, ranged from 0 to 14. Lameness was assessed based on walking behavior on the 110th day of gestation and again the day of weaning. This evaluation, adapted from Main et al. (2000) [ 26 ], used the following scoring: 0 = normal walking and standing (non-lame); 1 = lameness (slight abnormality without affecting normal activities; restricted walking, minimal force on the affected limb or frequent tiptoeing with difficulty in walking and standing; the affected limb is held high or unable to touch the ground). Parities were categorized as primiparous (0) and multiparous (1). Farrowing assistance [When an interval of 30 to 60 min elapsed from the birth of the last piglet, or when the sow showed intermit-tent straining accompanied by paddling of the legs or when the sow expelled small quantities of fetal fluid together with marked tail switching for 30 to 60 min without any piglet being born. Birth assistance is performed by stimulating uterine contraction through palpation of the dorsal wall of the vagina (Ferguson reflex) and manually extracting the piglets.] was scored as 0 (no) or 1 (yes) (Table 1 ). Table 1 Classification and scoring of breed, parity, lameness, farrowing assistance, backfat thickness, and hindlimb hoof lesions in sows. Variables Classification Breed Yorkshire (YY), Landrace (LL) Parity 0: primiparity;1: multiparity Lameness a 0: Non-lame; 1: Lame Farrowing assistance 0: No;1: Yes Backfat thickness mm Sow hindlimb hoof lesions b 0: No lesions in both hind hooves 1: Lesions in one hind hoof 2: Lesions in both hind hooves a Scoring definition modified after Main et al [ 26 ]. (2000) b Scoring definition modified after Zinpro's Feet First Team [ 25 ]. (2009) Statistical analysis All data were analyzed using R (Version 4.3.0, Auckland, NZ, 2014). Descriptive statistics were generated for all the variables in the dataset. Univariate analyses were performed for continuous variables using independent t -tests (absence of heteroscedasticity suggested by an F test) to compare backfat thickness between sows with different weaning lameness statuses (lameness vs. non-lameness). To control for type I error inflation caused by multiple comparisons, the Bonferroni correction was applied to adjust the significance threshold. The normality assumption was visually examined by using a Quantile-Quantile (q-q) plot based on the studentized residuals. For categorical variables, including breed, parity, dystocia, lameness at weaning, and hoof lesions, the Chi-square test was preliminarily employed to evaluate associations with lameness at weaning. Multivariable logistic regression was used to analyze the associations between variables, with the dependent variable being the weaning lameness status (lameness or non-lameness). A stepwise backward selection method was employed for model construction. First, a full model including potential risk factors with P < 0.25 in univariate analysis was established. Then, the degrees-of-freedom-adjusted generalized variance inflation factor [ \\(\\:{GVIF}^{\\frac{1}{2\\times\\:df}}\\) ] coefficients were calculated for the initial model. If a coefficient was > 2, it indicated the presence of multicollinearity, requiring further treatment; if ≤ 2, there was no significant multicollinearity. Subsequently, non-significant variables with P > 0.05 were removed step-by-step, and it was checked whether removing a variable would cause a change of over 20% in the effects of other variables. This process was repeated until all retained variables were either statistically significant ( P < 0.05) or affected the effects of other variables. Variables eliminated during backward elimination were step-by-step re-introduced into the model to ensure that no confounding or omitted factors were present (variables with P < 0.05 or causing a change of over 20% in the coefficients of other variables upon reintroduction were retained). Finally, the Hosmer-Lemeshow test was used to evaluate the calibration of the final model, and non-significant ( P > 0.05) indicated a good fit. Results Descriptive statistics The study population comprised 36% (111/311) LL sows and 64% (200/311) YY sows. Parity distribution indicated that 41% (128/311) were primiparous and 59% (183/311) were multiparous sows. Regarding farrowing characteristics, 69% (216/311) of sows required assisted farrowing, while 31% (95/311) farrowed without assistance. At weaning, 44.7% (139/311) of sows exhibited lameness, while 55.3% (172/311) were non-lame (Table 2 ). Table 2 Descriptive statistics for continuous and categorical variables (N = 311) Continuous variables No-lame Lame Total sows N Mean (SD) Median (MAD) Mean (SD) Median (MAD) Mean (SD) Median (MAD) BT-G110 14.8(3.5) 14.3(2.8) 14.9(3.8) 14.4(3) 14.8(3.6) 14.4(2.9) BT-FR15 14.7(3.5) 14.1(2.8) 14.6(3.9) 13.8(3.1) 14.7(3.7) 14(3) BT-WD 14.3(3.3) 13.6(2.7) 13.6(3.5) 13.3(2.7) 14(3.4) 13.2(2.7) Categorical variables No-lame (%) Lame (%) Total sows N (%) Breed 72 (65%) 39(35%) 111(36%) 100(50%) 100(50%) 200(64%) Parity 75(59%) 53(41%) 128(41%) 97(53%) 86(47%) 183(59%) Farrowing assistance 54(57%) 41(43%) 95(31%) 118(55%) 98(45%) 216(69%) OT 163(85%) 29(15%) 192(62%) 6(12%) 46(88%) 52(17%) 3(4%) 64(96%) 67(22%) ODC 134(84%) 25(16%) 159(51%) 28(41%) 40(59%) 68(22%) 10(12%) 74(88%) 84(27%) HOE 96(91%) 10(9%) 106(34%) 52(58%) 37(42%) 89(29%) 24(21%) 92(79%) 116(37%) HSC 38(72%) 15(28%) 53(17%) 41(58%) 30(42%) 71(23%) 93(50%) 94(50%) 187(60%) WLC 99(72%) 39(28%) 138(44%) 55(50%) 55(50%) 110(35%) 18(29%) 45(71%) 63(20%) CWH 100(73%) 37(27%) 137(44%) 58(51%) 56(49%) 114(37%) 14(23%) 46(77%) 60(19%) CWV 112(64%) 63(36%) 175(56%) 48(51%) 47(49%) 95(31%) 12(29%) 29(71%) 41(13%) OT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion; HSC: Heel-Sole Crack; WLC: White Line Crack; CWH: Cracked Wall Horizontal; CWV: Cracked Wall Vertical. BT-G110: Backfat thickness at gestation 110th days; BT-FR15: Backfat thickness on the 15th day in the farrowing room; BT-WD: Backfat thickness on the day of weaning. SD: Standard Deviation; MAD: Mean Absolute Deviation A stacked bar chart (Fig. 2) were plotted to visualize the relationship between prepartum hindlimb hoof lesion scores and lameness status at weaning. The chart illustrates the frequency distribution of sows by lameness status across different hoof lesion scores. As shown in the figure, non-lame sows were more frequent at lower hoof lesion scores, while the frequency of lame sows increased progressively with higher hoof lesion scores. For the three continuous variables-backfat thickness at gestation 110th days (BT-G110), on the 15th day in the farrowing room (BT-FR15), and at weaning (BT-WD) —the mean and median values were similar between lame and non-lame groups. Specifically, for BT-G110, the mean (± SD: Standard Deviation) was 14.8 ± 3.5 mm in non-lame sows and 14.9 ± 3.8 mm in lame sows, with a median (MAD: Mean Absolute Deviation): 14.3 (2.8) mm and 14.4 (3) mm respectively. For BT-FR15, the mean (± SD) was 14.7 ± 3.5 mm for non-lame sows and 14.6 ± 3.9 mm for lame sows, with a median (MAD) of 14.1 (2.8) mm and 13.8 (3.1) mm, respectively. For BT-WD, the mean (± SD) was 14.3 ± 3.3 mm for non-lame sows and 13.6 ± 3.5 mm for lame sows, with a median (MAD) of 13.6 (2.7) mm and 13.3 (2.7) mm, respectively. Figure 2 Frequency distribution of prepartum hindlimb hoof lesion scores and lameness status at weaning Univariable analysis Association between the backfat thickness of sows at different stages and the lameness status at weaning The t- test was used to evaluate the association between sow lameness status at weaning and backfat thickness at three stages (Table 3 and Fig. 3): BT-G110, BT-FR15, and BT-WD. No significant differences were observed between the non-lame sows and lame sows for backfat thickness. However, there was a trend of difference in BT-WD ( P = 0.06) between lame and non-lame sows, with non-lame sows at weaning having higher backfat levels than lame sows. Consequently, BT-WD ( P < 0.25) was included in subsequent multivariate logistic regression analysis. Table 3 The t-test for sow lameness status at weaning and backfat thickness Variable Mean Median F test-P T test-P Bonferroni BT-G110 Non-lame 14.8 14.3 0.27 0.75 0.02 Lame 14.9 14.4 BT-FR15 Non-lame 14.7 14.1 0.17 0.73 0.02 Lame 14.6 13.8 BT-WD Non-lame 14.4 13.6 0.68 0.06 0.02 Lame 13.6 13 BT-G110: Backfat thickness at gestation 110th days; BT-FR15: Backfat thickness on the 15th day in the farrowing room; BT-WD: Backfat thickness on the day of weaning Figure 3 Box plots of backfat thickness at three-time points and lameness status at weaning Chi-square test for the association between categorical variables and lame ness at weaning Based on the chi-square test results (Table 4 ), parity and farrowing assistance ( P > 0.05) have no significant link with post-weaning lameness. Breed (OR = 1.8, 95%CI: 1.1-3.0; P < 0.05) is significantly associated; its risk is 1.8 times that of the reference breed. Among hindlimb hoof lesions before farrowing, all are significant risk factors for post-weaning lameness. Notably, OT (OR = 43.1, 95%CI: 16.9-110.1; P < 0.001), ODC (OR = 7.7, 95%CI: 4.0-14.6; P < 0.001), and HOE (OR = 6.8, 95%CI: 3.1–14.8; P < 0.001) pose particularly high risks. Overall, OT, ODC, HOE, WLC and CWH of the hindlimb hoof lesions are key factors, Breed and HSC are less influential, and Parity ( P > 0.05) and farrowing assistance ( P > 0.05) aren't. Seven hoof lesions of the hindlimb hoof lesions and breed ( P < 0.25) were used to build the initial multivariable logistic regression model. Table 4 Univariate analysis of categorical variables (Chi-Square Test) Variable Chi-Square DF P -value OR 95%CI Parity 0.7 1 0.39 1.3 0.8-2.0 Breed 5.8 1 < 0.05 a 1.8 1.1-3.0 Farrowing assistance 0.1 1 0.81 1.1 0.7–1.8 OT 178.3 2 < 0.001 a 43.1 16.9-110.1 ODC 123.5 2 < 0.001 a 7.7 4.0-14.6 HOE 109.9 2 < 0.001 a 6.8 3.1–14.8 HSC 8.3 2 < 0.05 a 1.9 0.9-4.0 WLC 34.5 2 < 0.001 a 2.5 1.5–4.3 CWH 43.1 2 < 0.001 a 2.6 1.5–4.4 CWV 17.5 2 < 0.05 a 1.7 1.0-2.9 OT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion; HSC: Heel-Sole Crack; WLC: White Line Crack; CWH: Cracked Wall Horizontal; CWV: Cracked Wall Vertical. a Used in the multivariable model. Multivariable analysis During the multicollinearity tests performed on both the initial full-fledged model, the degrees-of-freedom-adjusted generalized variance inflation factor of all variables was below 2 [ \\(\\:{GVIF}^{\\frac{1}{2\\times\\:df}}\\) ]. This demonstrates that there are no multicollinearity problems within the models. The initial model included OT, ODC, HOE, HSC, WLC, CWH, CWV, BT-WD, and Breed. Subsequently, backward elimination was performed, and finally, OT, ODC, HOE and breed (kept as its removal changed other variables' coefficients by over 20%) were retained. In the test of adding back the eliminated variables one by one, no variables were retained. Finally, OT, ODC, HOE, and breed were retained (Table 5 ). Meanwhile, the Hosmer-Lemeshow test for the final model was insignificant ( P = 0.147), indicating a good model fit. Interactions between significant risk factors were not analyzed because including interaction terms in the model resulted in small subgroups and poor model convergence. Table 5 Multivariable logistic regression analysis results: Risk factors for lameness at weaning (n = 310) Variables OR 95%CI P -value OT 0 - - - 1 28 9.4–83.7 < 0.001 2 42.5 10.9-165.5 < 0.001 ODC 0 - - - 1 1.6 0.6–4.2 0.343 2 7.3 2.5–21.2 < 0.001 HOE 0 - - - 1 2.5 0.9–7.5 0.096 2 10 3.5–29.0 < 0.001 Breed LL - - - YY 2.3 0.9–5.5 0.07 OT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion. AIC:187; BIC: 217 The final result shows that significant risk factors were OT, ODC, and HOE among the hindlimb hoof lesions before farrowing. For the OT, compared with normal hooves, OT on a single hindlimb hoof increased the risk of lameness by approximately 28-fold (OR = 28.0, 95%CI: 9.4–83.7; P < 0.001), and when both hindlimb hooves had OT, compared with the reference level, the risk further increased to about 42-fold (OR = 42.5, 95%CI: 10.9-165.5; P < 0.001) compared with the reference level. For ODC and HOE, lesions on a single hindlimb hoof ( P > 0.05) were not significantly different from the reference level, but when both hindlimb hooves had lesions, there was a significant difference. ODC on both hindlimb hooves significantly increased the risk of lameness in sows by approximately 7-fold (OR = 7.3, 95%CI: 2.5–21.2; P < 0.001), while HOE on both hindlimb hooves significantly increased the risk of lameness in sows by approximately 10-fold (OR = 10.0, 95%CI: 3.5–29.0; P < 0.001). At the same time, compared with LL sows, YY sows had a marginally elevated risk of lameness (OR = 2.3, 95%CI: 0.9–5.5; P = 0.070), which implies potential genetic influences requiring further investigation. Discussion This prospective cohort study offers new perspectives on the risk factors associated with lameness development in sows during lactation, with a particular focus on prepartum hindlimb hoof lesions. Lactation may represent a critical period for the development of lameness in sows. In the present study, the incidence of lameness at weaning (44.7%, 139/311) was significantly higher than that recorded at the 110th day of gestation (27.6%, 159/576), suggesting that sows are at a relatively high risk of lameness during the lactation. Similarly, Díaz et al. (2014) [ 27 ] reported that sows had an increased risk of lameness after being transferred to farrowing crates compared to when housed in gestation stalls. Furthermore, the peak culling rate for lame sows during the weaning-re-breeding period also supports the notion that lactation is a high-risk phase for lameness [ 10 , 21 , 28 ]. During lactation, the metabolic demands on sows rise substantially to support milk production [ 29 ], which may disrupt calcium-phosphorus homeostasis, weaken skeletal integrity [ 30 ] and impair hoof horn strength [ 31 ]. Additionally, in most farms, farrowing crates typically have semi-slatted or fully slatted floors with a high void ratio compared to gestation housing. When sows are moved into these crates, the flooring increases the pressure per unit area exerted on hooves [ 18 ], potentially leading to new hoof lesions or exacerbating existing ones, thereby contributing to a higher risk of lameness in sows during lactation. Compared with previous studies, we also found that the lameness risk was positively correlated with overgrown toe (OT), overgrown dewclaw (ODC), and heel overgrowth and erosion (HOE) [ 32 ]. The most frequent lesions observed were HOE, OT and ODC [ 32 ]. HOE, closely linked to the abrasiveness of floor surface [ 33 , 34 ], can cause heel abrasions or erosions, facilitating pathogen entry, infection, and pain, ultimately resulting in lameness. Excessive hoof growth, whether in the toes or dewclaws, can alter the hoof structure and impair sow mobility [ 35 , 36 ]. On fully slatted floors, overgrown toes or dewclaws increases the contact area between the claws and the slat, raising the risk of claw injuries, fractures, and lameness due to pain [ 32 ]. Moreover, the combined length of the main toes of the rear feet has been corelated with the presence of all types of rear foot lesions [ 36 ]. Among the available prevention and control measures, supplementation with organic minerals in sow diets may help prevent lesions in the heel, sole, and hoof wall but appears less effective in preventing overgrowth of the toe or dewclaws, which are likely influenced by a combination of genetics, housing, flooring, and age-related factors [ 37 ]. Functional claw trimming remains the most effective intervention for managing overgrown claws, thereby maintaining hoof health and reducing the risk of lameness [ 24 ]. However, in contrast to previous study [ 18 ], we did not find an association between WLC and risk of lameness. Unlike earlier studies that typically investigated the relationship between hoof lesions and lameness within the same time frame [ 27 , 32 ], our research specifically assessed the impact of prepartum hoof lesions on lameness at weaning. This difference in study design may partly explain why WLC was not significantly associated with lameness in our findings. Additionally, our study was conducted in a single pig population, which may have further contributed to this discrepancy. Prepartum hindlimb hoof lesion scores may potentially serve as a predictive indicator for sow lameness at weaning. In the present study, we observed a strong association between higher prepartum hindlimb hoof lesion scores and an increased risk of lameness at weaning (Fig. 2). Consistent with previous findings [ 32 ], the presence of multiple lesion sites on a sow's feet markedly increased the likelihood of lameness. This phenomenon may be attributed to the cumulative effect of hoof lesions [ 32 ], where multiple lesion can compromise the overall stability of the hoof structure, and thus elevate the risk of lameness. The link between hoof lesions and lameness is thought to be mediated by pain [ 7 ], with greater numbers of hoof lesions likely causing more severe greater pain. Although some individual lesions may not immediately result in lameness, their progressive worsening over time may exacerbate pain levels, and which ultimately lead to lameness. Therefore, a higher prepartum hoof lesion score may reflect an increased risk of lameness at weaning. In addition, Yorkshire (YY) sows exhibited a marginally higher risk of lameness compared to Landrace (LL) sows. This trend may be related to the breed-specific differences in bone characteristics and growth rates reported in other pig populations [ 36 , 38 ]. Grandhi et al. (1986) [ 39 ] found LL gilts and sows had larger femur and third metacarpal shaft diameters but lower bone strength, elastic modulus, and cortex thickness compared to YY pigs, which may influence susceptibility to lameness. Additionally, Papadopoulos et al. (2021) [ 36 ] observed differences in claw and dewclaw length and their associations with claw lesions among different genetic lines, such as PIC, Danbred, and Topigs. These findings suggest that future breeding strategies may need to focus on optimizing skeletal and hoof structures, as well as improving resistance to injuries to enhance sow welfare and production efficiency in pig farming. Regarding parity, previous studies [ 4 , 5 , 40 ] have demonstrated that low-parity sows are more likely to develop lameness and be subsequently culled compared to high-parity sows. Lame sows with lower parities often fail to complete their production cycles due to the progression of lameness, leading to earlier culling [ 41 ]. However, in the present study, no association was found between parity and the occurrence of lameness at weaning. This discrepancy may be attributed to the uneven distribution of sows’ parities in our study population, where primiparous sow accounted for 41% of the sample. Furthermore, when analyzing the parity variable, sows were categorized simply as primiparous or multiparous, which may have masked the potential differences across finer parity levels. While conducting this study on a single sow farm allowed for control over external variables and ensured a consistent research environment, it also introduced certain limitations. The homogeneity of management, housing, and environmental conditions may not fully capture the variability seen across different commercial production systems, thereby limiting the generalizability of the findings. Future multi-farm studies are warranted to account for variability in factors such as seasonal fluctuations, feeding protocols, housing designs, flooring materials, and management practices, all of which can differ substantially between farms and may influence the applicability of results. Conclusions In conclusion, the lactation period may serve as a crucial stage for the occurrence of lameness in sows. Sows with bilateral overgrown toe (OT), overgrown dewclaw (ODC) and heel overgrowth and erosion (HOE) on their hindlimbs, along with those having unilateral OT on the hindlimbs, face a greater risk of lameness at weaning. The prepartum hindlimb hoof lesion score may potentially serve as a predictive criterion for sow lameness at weaning. Declarations Ethics approval and consent to participate This study was approved by the Institutional Animal Care and Use Committee of Nanjing Agricultural University (NJAULLSC2024035). All experimental procedures involving animals were conducted in accordance with the relevant guidelines and regulations for animal welfare. Consent for publication All authors have approved the final manuscript for publication and consent to its submission to this journal. Availability of data and materials The datasets/materials used in this study are available from the corresponding author, Zhen Yang, upon reasonable request via email at [email protected] . Competing interests The authors declare no competing interests. Funding Funding for this work was provided by China Agriculture Research System of MOF and MARA (CARS-35) and Zhen Yang’s NJAU Research Startup Fund No.090-804126. Authors' contributions Z. Yang designed the experimental protocols, supervised research progress, and provided critical guidance on manuscript preparation. J.B. Wang conducted the experiments, collected and analyzed data, and drafted the manuscript under Z. Yang’s supervision. M. Li critically reviewed the manuscript, corrected content and methodological errors, and revised it to improve scientific rigor. Z.Y. Liu and S.Y. Tian assisted with data collection and experimental procedures. B.R. Sun and Y.P. Mo contributed to experimental design, supervised research progress, and advised on technical and analytical strategies. All authors reviewed and approved the final manuscript. Acknowledgement We thank Prof. Danchen Yang for guidance on data analysis, Dr. Ke Dai and Mr. Hongzhi Ma for experimental assistance, Changjie Qian, Ting Zhang and Wenjiao Guo for support with operations and experiments. References Paiva RC, Moura CA, Thomas P, Haberl B, Greiner L, Rademacher CJ, et al. Risk factors associated with sow mortality in breeding herds under one production system in the Midwestern United States. Prev Vet Med. 2023;213:105883.doi:10.1016/j.prevetmed.2023.105883. Hallowell A, Pierdon M. Effects of lameness on productivity and longevity for sows in pen gestation. 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Livest Sci. 2017;195:53-7.doi:10.1016/j.livsci.2016.10.013. Deen J, Schuttert, M., van Amstel, S., Ossent, P., van Barneveld, R., Stalder, K. FeetFirst from Zinpro: Lesion Scoring Guide. Eden Prairie, MN, USA: Zinpro Corporation; 2009. Main DCJ, Clegg J, Spatz A, Green LE. Repeatability of a lameness scoring system for finishing pigs. Vet Rec. 2000;147(20):574-6.doi:10.1136/vr.147.20.574. Díaz JAC, Fahey AG, Boyle LA. Effects of gestation housing system and floor type during lactation on locomotory ability; body, limb, and claw lesions; and lying-down behavior of lactating sows. J Anim Sci. 2014;92(4):1673-83.doi:10.2527/jas.2013-6279. Pluym LM, Van Nuffel A, Van Weyenberg S, Maes D. Prevalence of lameness and claw lesions during different stages in the reproductive cycle of sows and the impact on reproduction results. Animal. 2013;7(7):1174-81.doi:10.1017/s1751731113000232. Costermans NGJ, Soede NM, Middelkoop A, Laurenssen BFA, Koopmanschap RE, Zak LJ, et al. Influence of the metabolic state during lactation on milk production in modern sows. Animal. 2020;14(12):2543-53.doi:10.1017/s1751731120001536. van Riet MMJ, Millet S, Liesegang A, Nalon E, Ampe B, Tuyttens FAM, et al. Impact of parity on bone metabolism throughout the reproductive cycle in sows. Animal. 2016;10(10):1714-21.doi:10.1017/s1751731116000471. van Riet MMJ, Millet S, Aluwé M, Janssens GPJ. Impact of nutrition on lameness and claw health in sows. Livest Sci. 2013;156(1-3):24-35.doi:10.1016/j.livsci.2013.06.005. Lisgara M, Skampardonis V, Kouroupides S, Leontides L. Hoof lesions and lameness in sows in three Greek swine herds. J Swine Health Prod. 2015;23(5):244-51. Bos EJ, Maes D, van Riet MMJ, Millet S, Ampe B, Janssens GPJ, et al. Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups. Plos One. 2016;11(9).doi:10.1371/journal.pone.0163625. Gillman CE, KilBride AL, Ossent P, Green LE. A cross-sectional study of the prevalence of foot lesions in post-weaning pigs and risks associated with floor type on commercial farms in England. Prev Vet Med. 2009;91(2-4):146-52.doi:10.1016/j.prevetmed.2009.05.023. Fitzgerald RF, Stalder KJ, Karriker LA, Sadler LJ, Hill HT, Kaisand J, et al. The effect of hoof abnormalities on sow behavior and performance. Livest Sci. 2012;145(1-3):230-8.doi:10.1016/j.livsci.2012.02.009. Papadopoulos GA, Chalvatzi S, Kroustallas F, Skampardonis V, Cernat M, Marouda C, et al. Claw Characteristics of Culled Sows from Three Farrow-to-Finish Greek Farms. Part 1: Claw Length Measurements, Lesion Scores and Their Association. Vet Sci. 2021;8(7).doi:10.3390/vetsci8070126. Lisgara M, Skampardonis V, Leontides L. Effect of diet supplementation with chelated zinc, copper and manganese on hoof lesions of loose housed sows. Porcine health management. 2016;2:6.doi:10.1186/s40813-016-0025-2. Jiang B, Wang M, Tang Z, Du X, Feng S, Ma G, et al. Genome-wide association study of bone mineral density trait among three pig breeds. Animal. 2020;14(12):2443-51.doi:10.1017/s1751731120001111. Grandhi RR, Thorntontrump AB, Doige CE. INFLUENCE OF DIETARY CALCIUM-PHOSPHORUS LEVELS ON CERTAIN MECHANICAL, PHYSICAL AND HISTOLOGICAL PROPERTIES AND CHEMICAL-COMPOSITION OF BONES IN GILTS AND 2ND LITTER SOWS. Can J Anim Sci. 1986;66(2):495-503.doi:10.4141/cjas86-051. Engblom L, Lundeheim N, Strandberg E, Schneider MDP, Dalin AM, Andersson K. Factors affecting length of productive life in Swedish commercial sows. J Anim Sci. 2008;86(2):432-41.doi:10.2527/jas.2007-0310. USDA. Swine 2006, part I: reference of swine health and management practices in the United States, 2006. Swine 2006, part I: reference of swine health and management practices in the United States, 2006. 2007. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-6538207\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":452286870,\"identity\":\"b59be327-2f44-4675-bf02-7936009c7014\",\"order_by\":0,\"name\":\"Junbiao Wang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing Agricultural University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Junbiao\",\"middleName\":\"\",\"lastName\":\"Wang\",\"suffix\":\"\"},{\"id\":452286872,\"identity\":\"55f136f0-4c45-41e5-9074-eb9a0b50e624\",\"order_by\":1,\"name\":\"Meng Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing Agricultural University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Meng\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":452286874,\"identity\":\"043aede9-428e-4ad6-b13e-43a226324e47\",\"order_by\":2,\"name\":\"Ziyang Liu\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing Agricultural University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Ziyang\",\"middleName\":\"\",\"lastName\":\"Liu\",\"suffix\":\"\"},{\"id\":452286875,\"identity\":\"6cad1b68-abff-4cd5-ad20-a4d0db46d5c3\",\"order_by\":3,\"name\":\"Shuyu Tian\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing Agricultural University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Shuyu\",\"middleName\":\"\",\"lastName\":\"Tian\",\"suffix\":\"\"},{\"id\":452286876,\"identity\":\"5fb724bc-f4a5-4f79-b1dd-f7cdeca2c99e\",\"order_by\":4,\"name\":\"Bolan Sun\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guilin Liyuan Grain and Oil Food Group Co. 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Ltd.\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Yupeng\",\"middleName\":\"\",\"lastName\":\"Mo\",\"suffix\":\"\"},{\"id\":452286878,\"identity\":\"06464b6a-36bb-4420-af56-97dbbf8f110f\",\"order_by\":6,\"name\":\"Zhen Yang\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7UlEQVRIiWNgGAWjYLACxgYGBn4GhgQYm0gtkg0kazE4gGDjBwbHzx5++XOHTZ7x7YaHn3kYbGQ3HGB+9gCvljN5aRaSZ9KKze4cSJbmYUgz3nCAzdwAr5YDOWYGhm2HE7fdSEgAajmcuOEAD5sEXi3n35gZJLb9T9w8IyH5Nw/DfyK03MgxfnCw7UDiBomENKAtBwhrkbzxxoyxsS05ccaNhDTLOQbJxjMPs5nh1cJ3Psf44882u8T+GTnJN95U2Mn2HW9+hleLwgEGmDN4EoDuBNLM+NQDgXwDA/MHCJP9AAG1o2AUjIJRMFIBAGoaUNzYodBNAAAAAElFTkSuQmCC\",\"orcid\":\"\",\"institution\":\"Nanjing Agricultural University\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Zhen\",\"middleName\":\"\",\"lastName\":\"Yang\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-04-27 05:38:21\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-6538207/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-6538207/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":82045284,\"identity\":\"dec4c5e1-0797-4828-a7ca-35f653e1e960\",\"added_by\":\"auto\",\"created_at\":\"2025-05-06 09:34:12\",\"extension\":\"jpg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":2285822,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eFlowchart of sow selection for the study\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig.1Flowchartofsowselectionforthestudy.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6538207/v1/f8367509cc039d3981821488.jpg\"},{\"id\":82045285,\"identity\":\"a28af372-9f17-4502-b874-7e05c97cd8a3\",\"added_by\":\"auto\",\"created_at\":\"2025-05-06 09:34:12\",\"extension\":\"jpg\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":249572,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eFrequency distribution of prepartum hindlimb hoof lesion scores and lameness status at weaning\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig.2Frequencydistributionofprepartumhindlimbhooflesionscoresandlamenessstatusatweaning.tiff.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6538207/v1/8379cc183d7eef9535f720d7.jpg\"},{\"id\":82045286,\"identity\":\"e4bb4ae7-2914-48c5-bbd0-0a4e12de3c85\",\"added_by\":\"auto\",\"created_at\":\"2025-05-06 09:34:12\",\"extension\":\"jpg\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":413685,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eBox plots of backfat thickness at three-time points and lameness status at weaning\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig.3Boxplotsofbackfatthicknessatthreetimepointsandlamenessstatusatweaning.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6538207/v1/5b4a11b504dad667a02721e0.jpg\"},{\"id\":86141084,\"identity\":\"26b0c46b-aba5-4b0f-8bba-76cb228e7019\",\"added_by\":\"auto\",\"created_at\":\"2025-07-07 08:24:19\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":3974677,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6538207/v1/ca608783-a647-4de4-808d-7a4020312635.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Impact of prepartum hindlimb hoof lesions and other risk factors on the lameness status of sows at weaning: A prospective cohort study\",\"fulltext\":[{\"header\":\"Background\",\"content\":\"\\u003cp\\u003eSow lameness poses a critical welfare challenge in the global swine industry, accounting for 10\\u0026ndash;29% of culling and mortality events [\\u003cspan additionalcitationids=\\\"CR2 CR3 CR4\\\" citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Cross-sectional studies have estimated the prevalence of sow lameness at 8\\u0026ndash;27% across various production systems [\\u003cspan additionalcitationids=\\\"CR7 CR8\\\" citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. A 2023 study from the United States identified lameness as the primary contributor to 28.78% of sow mortality-related culls [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e]. Beyond welfare impact, lameness also incurs substantial economic losses by reducing productive longevity [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eEmerging evidence highlights hoof lesion dynamics as pivotal contributors to pathogenesis of lameness [\\u003cspan additionalcitationids=\\\"CR13 CR14\\\" citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. Jorgensen\\u0026rsquo;s work has established associations between hoof lesions and clinical outcomes such as lameness, forelimb stiffness, and hindlimb postural instability [\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e]. Hoof lesions are estimated to account for 5\\u0026ndash;20% of sow lameness [\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e], with approximately 90% of sows exhibiting at least one type of lesion [\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]. Lameness manifestation has been shown to be lesion location-specific [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] and dose-dependent with respect to lesion pathological severity [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e], particularly for hindlimb lesions [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e]\\u003c/p\\u003e \\u003cp\\u003eIn China, sow lameness remains a significant challenge within intensive pig production systems, accounting for 10\\u0026ndash;23% of sow mortality [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Previous studies [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e] have shown that lameness-related mortality and culling rates peaked during the weaning-to-rebreeding period, likely due to increased lameness during lactation and common culling practices after weaning. Lameness-associated culling leads to a shortened herd lifespan for affected sows, resulting in fewer litters, and markedly reduced production efficiency [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e]. However, research on sow lameness and its associated risk factors in China remains limited. Most existing studies have employed cross-sectional designs, which inherently limit the ability to comprehensively identify risk factors of lameness and thereby hinder the development of effective prevention and control strategies.\\u003c/p\\u003e \\u003cp\\u003eThe present prospective cohort study therefore investigates the influence of prepartum hindlimb hoof lesions and other risk factors on the development of incident lameness at weaning, with the goal of informing evidence-based prevention strategies.\\u003c/p\\u003e\"},{\"header\":\"Materials and methods\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eResearch farm and animals\\u003c/h2\\u003e \\u003cp\\u003eThis study was conducted on a sow farm in Guangxi, China, housing a herd of 5,159 sows, from July to September 2024. All sows tested negative for porcine reproductive and respiratory syndrome virus, pseudorabies, and porcine parvovirus based on both antigen and antibody detection. Previous investigations on this farm reported a sow lameness prevalence rate of approximately 25%.\\u003c/p\\u003e \\u003cp\\u003eA total of 576 sows at 110 days of gestation were initially included in the study, without interfering the farm's production schedule. Prenatal lameness assessments were conducted at 110 days of gestation. Lame sows (n\\u0026thinsp;=\\u0026thinsp;159) were excluded, and non-lame sows (n\\u0026thinsp;=\\u0026thinsp;417) were retained for follow-up study. These non-lame sows were monitored throughout lactation and subsequently transferred back to the gestation barn. Due to unavoidable management factors, some sows were reassigned as nursing sows to different farrowing rooms for fostering fallback piglets, while others died during the study. Consequently, data for 106 sows were missing and were excluded for the final analysis (Fig.\\u0026nbsp;1).\\u003c/p\\u003e \\u003cp\\u003eSows were transferred from the gestation barn to the farrowing room at 110 days of gestation. Each farrowing room contained 48 farrowing crates, accommodating 40\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2 sows; with the remaining crates reserved for nursing sows. Each crate measured 215 cm in length, 45 cm in width, and 110 cm in height. The flooring was made of cast iron with a 1 cm-wide gap between slats.\\u003c/p\\u003e \\u003cp\\u003eEnvironmental conditions were regulated by a computerized climate control system (307 Pro Climate Control computers, Big Dutchman), which operated water curtains and negative-pressure fans to maintain optimal temperature based on real-time monitoring. Sows were fed via an automated feeding system, and had free access to individual drinking nipples throughout lactation.\\u003c/p\\u003e \\u003cp\\u003e \\u003cb\\u003eFigure\\u0026nbsp;1\\u003c/b\\u003e Flowchart of sow selection for the study\\u003c/p\\u003e \\u003c/div\\u003e\\n\\u003ch3\\u003eData Collection\\u003c/h3\\u003e\\n\\u003cp\\u003eDuring the study period, the following data were recorded for each sow: ear tag number, parity, breed [Yorkshire (YY), Landrace (LL)], backfat thickness, hoof lesions, and lameness status (Fig.\\u0026nbsp;2). Backfat thickness was measured at the P2 point, located 65 mm from the midline at the last rib [\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e], using a B-mode ultrasound instrument (SONO V6+, Shenzhen Shengnuowei Technology Co., Ltd.) at three time points: on the 110th day of gestation (BT-G110), the 15th day after entering the farrowing room (BT-FR15), and the day of weaning (BT-WD).\\u003c/p\\u003e \\u003cp\\u003eUpon entry into the farrowing room on the 110th day of gestation, hindlimb hoof lesions were assessed while the sows were either standing or lying down. The scoring system included the following lesion types: overgrowth toe (OT: toe length\\u0026thinsp;\\u0026gt;\\u0026thinsp;5.5 cm [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e]), overgrowth dewclaw length (ODC: The dewclaw extends beyond the level of the coronary band [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e]), heel overgrowth and erosion (HOE), heel-sole crack (HSC), white line crack (WLC), cracked wall horizontal (CWH) and cracked wall vertical (CWV), recorded separately for each hindlimb. Lesions were evaluated using a modified version of the Zinpro Feet First scoring system [\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. Lesions were scored as follows: 0 indicated no lesions on either hind hoof; 1 indicated lesions on one hind hoof; 2 indicated lesions on both hind hooves. Each sow could exhibit up to seven types of hoof lesions, scored individually. The total hoof lesion score, calculated by summing all individual lesion scores, ranged from 0 to 14.\\u003c/p\\u003e \\u003cp\\u003eLameness was assessed based on walking behavior on the 110th day of gestation and again the day of weaning. This evaluation, adapted from Main et al. (2000) [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e], used the following scoring: 0\\u0026thinsp;=\\u0026thinsp;normal walking and standing (non-lame); 1\\u0026thinsp;=\\u0026thinsp;lameness (slight abnormality without affecting normal activities; restricted walking, minimal force on the affected limb or frequent tiptoeing with difficulty in walking and standing; the affected limb is held high or unable to touch the ground). Parities were categorized as primiparous (0) and multiparous (1). Farrowing assistance [When an interval of 30 to 60 min elapsed from the birth of the last piglet, or when the sow showed intermit-tent straining accompanied by paddling of the legs or when the sow expelled small quantities of fetal fluid together with marked tail switching for 30 to 60 min without any piglet being born. Birth assistance is performed by stimulating uterine contraction through palpation of the dorsal wall of the vagina (Ferguson reflex) and manually extracting the piglets.] was scored as 0 (no) or 1 (yes) (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eClassification and scoring of breed, parity, lameness, farrowing assistance, backfat thickness, and hindlimb hoof lesions in sows.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"2\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVariables\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eClassification\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBreed\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eYorkshire (YY), Landrace (LL)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eParity\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0: primiparity;1: multiparity\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eLameness \\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0: Non-lame; 1: Lame\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eFarrowing assistance\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0: No;1: Yes\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBackfat thickness\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003emm\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eSow hindlimb hoof lesions \\u003csup\\u003eb\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0: No lesions in both hind hooves\\u003c/p\\u003e \\u003cp\\u003e1: Lesions in one hind hoof\\u003c/p\\u003e \\u003cp\\u003e2: Lesions in both hind hooves\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c2\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003e\\u003csup\\u003ea\\u003c/sup\\u003e Scoring definition modified after Main et al [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e]. (2000)\\u003c/p\\u003e \\u003cp\\u003e\\u003csup\\u003eb\\u003c/sup\\u003e Scoring definition modified after Zinpro's Feet First Team [\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. (2009)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eStatistical analysis\\u003c/h2\\u003e \\u003cp\\u003eAll data were analyzed using R (Version 4.3.0, Auckland, NZ, 2014). Descriptive statistics were generated for all the variables in the dataset. Univariate analyses were performed for continuous variables using independent \\u003cem\\u003et\\u003c/em\\u003e-tests (absence of heteroscedasticity suggested by an F test) to compare backfat thickness between sows with different weaning lameness statuses (lameness vs. non-lameness). To control for type I error inflation caused by multiple comparisons, the Bonferroni correction was applied to adjust the significance threshold. The normality assumption was visually examined by using a Quantile-Quantile (q-q) plot based on the studentized residuals. For categorical variables, including breed, parity, dystocia, lameness at weaning, and hoof lesions, the Chi-square test was preliminarily employed to evaluate associations with lameness at weaning.\\u003c/p\\u003e \\u003cp\\u003eMultivariable logistic regression was used to analyze the associations between variables, with the dependent variable being the weaning lameness status (lameness or non-lameness). A stepwise backward selection method was employed for model construction. First, a full model including potential risk factors with \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.25 in univariate analysis was established. Then, the degrees-of-freedom-adjusted generalized variance inflation factor [\\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:{GVIF}^{\\\\frac{1}{2\\\\times\\\\:df}}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e] coefficients were calculated for the initial model. If a coefficient was \\u0026gt;\\u0026thinsp;2, it indicated the presence of multicollinearity, requiring further treatment; if\\u0026thinsp;\\u0026le;\\u0026thinsp;2, there was no significant multicollinearity. Subsequently, non-significant variables with \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05 were removed step-by-step, and it was checked whether removing a variable would cause a change of over 20% in the effects of other variables. This process was repeated until all retained variables were either statistically significant (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05) or affected the effects of other variables. Variables eliminated during backward elimination were step-by-step re-introduced into the model to ensure that no confounding or omitted factors were present (variables with \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05 or causing a change of over 20% in the coefficients of other variables upon reintroduction were retained). Finally, the Hosmer-Lemeshow test was used to evaluate the calibration of the final model, and non-significant (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05) indicated a good fit.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eDescriptive statistics\\u003c/h2\\u003e \\u003cp\\u003eThe study population comprised 36% (111/311) LL sows and 64% (200/311) YY sows. Parity distribution indicated that 41% (128/311) were primiparous and 59% (183/311) were multiparous sows. Regarding farrowing characteristics, 69% (216/311) of sows required assisted farrowing, while 31% (95/311) farrowed without assistance. At weaning, 44.7% (139/311) of sows exhibited lameness, while 55.3% (172/311) were non-lame (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eDescriptive statistics for continuous and categorical variables (N\\u0026thinsp;=\\u0026thinsp;311)\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"7\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c7\\\" colnum=\\\"7\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eContinuous variables\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eNo-lame\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003eLame\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003eTotal sows N\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eMean (SD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eMedian (MAD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eMean (SD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eMedian (MAD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003eMean (SD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003eMedian (MAD)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBT-G110\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14.8(3.5)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.3(2.8)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14.9(3.8)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e14.4(3)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e14.8(3.6)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e14.4(2.9)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBT-FR15\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14.7(3.5)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.1(2.8)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14.6(3.9)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e13.8(3.1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e14.7(3.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e14(3)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBT-WD\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14.3(3.3)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e13.6(2.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13.6(3.5)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e13.3(2.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e14(3.4)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e13.2(2.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003eCategorical variables\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003eNo-lame (%)\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003eLame (%)\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003eTotal sows N (%)\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eBreed\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e72 (65%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e39(35%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e111(36%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e100(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e100(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e200(64%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eParity\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e75(59%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e53(41%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e128(41%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e97(53%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e86(47%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e183(59%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eFarrowing assistance\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e54(57%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e41(43%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e95(31%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e118(55%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e98(45%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e216(69%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eOT\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e163(85%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e29(15%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e192(62%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e6(12%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e46(88%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e52(17%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e3(4%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e64(96%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e67(22%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eODC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e134(84%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e25(16%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e159(51%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e28(41%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e40(59%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e68(22%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e10(12%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e74(88%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e84(27%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eHOE\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e96(91%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e10(9%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e106(34%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e52(58%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e37(42%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e89(29%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e24(21%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e92(79%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e116(37%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eHSC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e38(72%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e15(28%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e53(17%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e41(58%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e30(42%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e71(23%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e93(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e94(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e187(60%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eWLC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e99(72%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e39(28%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e138(44%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e55(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e55(50%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e110(35%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e18(29%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e45(71%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e63(20%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eCWH\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e100(73%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e37(27%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e137(44%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e58(51%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e56(49%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e114(37%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e14(23%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e46(77%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e60(19%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eCWV\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e112(64%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e63(36%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e175(56%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e48(51%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e47(49%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e95(31%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003e12(29%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003e29(71%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c7\\\" namest=\\\"c6\\\"\\u003e \\u003cp\\u003e41(13%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"7\\\" nameend=\\\"c7\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eOT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion; HSC: Heel-Sole Crack; WLC: White Line Crack; CWH: Cracked Wall Horizontal; CWV: Cracked Wall Vertical.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"7\\\" nameend=\\\"c7\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eBT-G110: Backfat thickness at gestation 110th days; BT-FR15: Backfat thickness on the 15th day in the farrowing room; BT-WD: Backfat thickness on the day of weaning.\\u003c/p\\u003e \\u003cp\\u003eSD: Standard Deviation; MAD: Mean Absolute Deviation\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eA stacked bar chart (Fig.\\u0026nbsp;2) were plotted to visualize the relationship between prepartum hindlimb hoof lesion scores and lameness status at weaning. The chart illustrates the frequency distribution of sows by lameness status across different hoof lesion scores. As shown in the figure, non-lame sows were more frequent at lower hoof lesion scores, while the frequency of lame sows increased progressively with higher hoof lesion scores.\\u003c/p\\u003e \\u003cp\\u003eFor the three continuous variables-backfat thickness at gestation 110th days (BT-G110), on the 15th day in the farrowing room (BT-FR15), and at weaning (BT-WD) \\u0026mdash;the mean and median values were similar between lame and non-lame groups. Specifically, for BT-G110, the mean (\\u0026plusmn;\\u0026thinsp;SD: Standard Deviation) was 14.8\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.5 mm in non-lame sows and 14.9\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.8 mm in lame sows, with a median (MAD: Mean Absolute Deviation): 14.3 (2.8) mm and 14.4 (3) mm respectively. For BT-FR15, the mean (\\u0026plusmn;\\u0026thinsp;SD) was 14.7\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.5 mm for non-lame sows and 14.6\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.9 mm for lame sows, with a median (MAD) of 14.1 (2.8) mm and 13.8 (3.1) mm, respectively. For BT-WD, the mean (\\u0026plusmn;\\u0026thinsp;SD) was 14.3\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.3 mm for non-lame sows and 13.6\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.5 mm for lame sows, with a median (MAD) of 13.6 (2.7) mm and 13.3 (2.7) mm, respectively.\\u003c/p\\u003e \\u003cp\\u003e \\u003cb\\u003eFigure\\u0026nbsp;2\\u003c/b\\u003e Frequency distribution of prepartum hindlimb hoof lesion scores and lameness status at weaning\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec8\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eUnivariable analysis\\u003c/h2\\u003e \\u003cp\\u003e \\u003cb\\u003eAssociation between the backfat thickness of sows at different stages and the lameness status at weaning\\u003c/b\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe \\u003cem\\u003et-\\u003c/em\\u003etest was used to evaluate the association between sow lameness status at weaning and backfat thickness at three stages (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e and Fig.\\u0026nbsp;3): BT-G110, BT-FR15, and BT-WD. No significant differences were observed between the non-lame sows and lame sows for backfat thickness. However, there was a trend of difference in BT-WD (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.06) between lame and non-lame sows, with non-lame sows at weaning having higher backfat levels than lame sows. Consequently, BT-WD (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.25) was included in subsequent multivariate logistic regression analysis.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eThe t-test for sow lameness status at weaning and backfat thickness\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"7\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c7\\\" colnum=\\\"7\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c2\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eVariable\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eMean\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eMedian\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eF test-P\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003eT test-P\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003eBonferroni\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eBT-G110\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eNon-lame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.27\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.75\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e0.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eLame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.9\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14.4\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eBT-FR15\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eNon-lame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.17\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.73\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e0.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eLame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eBT-WD\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eNon-lame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.4\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.68\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.06\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e0.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eLame\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e13.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"7\\\" nameend=\\\"c7\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eBT-G110: Backfat thickness at gestation 110th days; BT-FR15: Backfat thickness on the 15th day in the farrowing room; BT-WD: Backfat thickness on the day of weaning\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cb\\u003eFigure\\u0026nbsp;3\\u003c/b\\u003e Box plots of backfat thickness at three-time points and lameness status at weaning\\u003c/p\\u003e \\u003c/div\\u003e\\n\\u003ch3\\u003eChi-square test for the association between categorical variables and lame\\u003c/h3\\u003e\\n\\u003cdiv id=\\\"Sec10\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eness at weaning\\u003c/h2\\u003e \\u003cp\\u003eBased on the chi-square test results (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e), parity and farrowing assistance (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05) have no significant link with post-weaning lameness. Breed (OR\\u0026thinsp;=\\u0026thinsp;1.8, 95%CI: 1.1-3.0; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05) is significantly associated; its risk is 1.8 times that of the reference breed. Among hindlimb hoof lesions before farrowing, all are significant risk factors for post-weaning lameness. Notably, OT (OR\\u0026thinsp;=\\u0026thinsp;43.1, 95%CI: 16.9-110.1; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), ODC (OR\\u0026thinsp;=\\u0026thinsp;7.7, 95%CI: 4.0-14.6; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), and HOE (OR\\u0026thinsp;=\\u0026thinsp;6.8, 95%CI: 3.1\\u0026ndash;14.8; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001) pose particularly high risks. Overall, OT, ODC, HOE, WLC and CWH of the hindlimb hoof lesions are key factors, Breed and HSC are less influential, and Parity (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05) and farrowing assistance (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05) aren't. Seven hoof lesions of the hindlimb hoof lesions and breed (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.25) were used to build the initial multivariable logistic regression model.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab4\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 4\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eUnivariate analysis of categorical variables (Chi-Square Test)\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"6\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVariable\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eChi-Square\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eDF\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eOR\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e95%CI\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eParity\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.39\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e1.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.8-2.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBreed\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.05\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e1.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e1.1-3.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eFarrowing assistance\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.81\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e1.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.7\\u0026ndash;1.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eOT\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e178.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e43.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e16.9-110.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eODC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e123.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e7.7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e4.0-14.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eHOE\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e109.9\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e6.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e3.1\\u0026ndash;14.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eHSC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e8.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.05\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e1.9\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e0.9-4.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eWLC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e34.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e2.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e1.5\\u0026ndash;4.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCWH\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e43.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e2.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e1.5\\u0026ndash;4.4\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCWV\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e17.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.05\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e1.7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e1.0-2.9\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"6\\\" nameend=\\\"c6\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eOT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion; HSC: Heel-Sole Crack; WLC: White Line Crack; CWH: Cracked Wall Horizontal; CWV: Cracked Wall Vertical.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"6\\\" nameend=\\\"c6\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003e\\u003csup\\u003ea\\u003c/sup\\u003e Used in the multivariable model.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec11\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eMultivariable analysis\\u003c/h2\\u003e \\u003cp\\u003eDuring the multicollinearity tests performed on both the initial full-fledged model, the degrees-of-freedom-adjusted generalized variance inflation factor of all variables was below 2 [\\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:{GVIF}^{\\\\frac{1}{2\\\\times\\\\:df}}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e]. This demonstrates that there are no multicollinearity problems within the models. The initial model included OT, ODC, HOE, HSC, WLC, CWH, CWV, BT-WD, and Breed. Subsequently, backward elimination was performed, and finally, OT, ODC, HOE and breed (kept as its removal changed other variables' coefficients by over 20%) were retained. In the test of adding back the eliminated variables one by one, no variables were retained. Finally, OT, ODC, HOE, and breed were retained (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). Meanwhile, the Hosmer-Lemeshow test for the final model was insignificant (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.147), indicating a good model fit. Interactions between significant risk factors were not analyzed because including interaction terms in the model resulted in small subgroups and poor model convergence.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab5\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 5\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eMultivariable logistic regression analysis results: Risk factors for lameness at weaning (n\\u0026thinsp;=\\u0026thinsp;310)\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"5\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVariables\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eOR\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e95%CI\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eOT\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e28\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e9.4\\u0026ndash;83.7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e42.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e10.9-165.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eODC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.6\\u0026ndash;4.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.343\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e7.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e2.5\\u0026ndash;21.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eHOE\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.9\\u0026ndash;7.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.096\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e10\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e3.5\\u0026ndash;29.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eBreed\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eLL\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eYY\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.9\\u0026ndash;5.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.07\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"5\\\" nameend=\\\"c5\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eOT: Overgrown Toes; ODC: Overgrown Dew Claws; HOE: Heel Overgrowth and Erosion.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"5\\\" nameend=\\\"c5\\\" namest=\\\"c1\\\"\\u003e \\u003cp\\u003eAIC:187; BIC: 217\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe final result shows that significant risk factors were OT, ODC, and HOE among the hindlimb hoof lesions before farrowing. For the OT, compared with normal hooves, OT on a single hindlimb hoof increased the risk of lameness by approximately 28-fold (OR\\u0026thinsp;=\\u0026thinsp;28.0, 95%CI: 9.4\\u0026ndash;83.7; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), and when both hindlimb hooves had OT, compared with the reference level, the risk further increased to about 42-fold (OR\\u0026thinsp;=\\u0026thinsp;42.5, 95%CI: 10.9-165.5; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001) compared with the reference level. For ODC and HOE, lesions on a single hindlimb hoof (\\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.05) were not significantly different from the reference level, but when both hindlimb hooves had lesions, there was a significant difference. ODC on both hindlimb hooves significantly increased the risk of lameness in sows by approximately 7-fold (OR\\u0026thinsp;=\\u0026thinsp;7.3, 95%CI: 2.5\\u0026ndash;21.2; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), while HOE on both hindlimb hooves significantly increased the risk of lameness in sows by approximately 10-fold (OR\\u0026thinsp;=\\u0026thinsp;10.0, 95%CI: 3.5\\u0026ndash;29.0; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001). At the same time, compared with LL sows, YY sows had a marginally elevated risk of lameness (OR\\u0026thinsp;=\\u0026thinsp;2.3, 95%CI: 0.9\\u0026ndash;5.5; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.070), which implies potential genetic influences requiring further investigation.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eThis prospective cohort study offers new perspectives on the risk factors associated with lameness development in sows during lactation, with a particular focus on prepartum hindlimb hoof lesions.\\u003c/p\\u003e \\u003cp\\u003eLactation may represent a critical period for the development of lameness in sows. In the present study, the incidence of lameness at weaning (44.7%, 139/311) was significantly higher than that recorded at the 110th day of gestation (27.6%, 159/576), suggesting that sows are at a relatively high risk of lameness during the lactation. Similarly, D\\u0026iacute;az et al. (2014) [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e] reported that sows had an increased risk of lameness after being transferred to farrowing crates compared to when housed in gestation stalls. Furthermore, the peak culling rate for lame sows during the weaning-re-breeding period also supports the notion that lactation is a high-risk phase for lameness [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eDuring lactation, the metabolic demands on sows rise substantially to support milk production [\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e], which may disrupt calcium-phosphorus homeostasis, weaken skeletal integrity [\\u003cspan citationid=\\\"CR30\\\" class=\\\"CitationRef\\\"\\u003e30\\u003c/span\\u003e] and impair hoof horn strength [\\u003cspan citationid=\\\"CR31\\\" class=\\\"CitationRef\\\"\\u003e31\\u003c/span\\u003e]. Additionally, in most farms, farrowing crates typically have semi-slatted or fully slatted floors with a high void ratio compared to gestation housing. When sows are moved into these crates, the flooring increases the pressure per unit area exerted on hooves [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e], potentially leading to new hoof lesions or exacerbating existing ones, thereby contributing to a higher risk of lameness in sows during lactation.\\u003c/p\\u003e \\u003cp\\u003eCompared with previous studies, we also found that the lameness risk was positively correlated with overgrown toe (OT), overgrown dewclaw (ODC), and heel overgrowth and erosion (HOE) [\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e]. The most frequent lesions observed were HOE, OT and ODC [\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e]. HOE, closely linked to the abrasiveness of floor surface [\\u003cspan citationid=\\\"CR33\\\" class=\\\"CitationRef\\\"\\u003e33\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR34\\\" class=\\\"CitationRef\\\"\\u003e34\\u003c/span\\u003e], can cause heel abrasions or erosions, facilitating pathogen entry, infection, and pain, ultimately resulting in lameness. Excessive hoof growth, whether in the toes or dewclaws, can alter the hoof structure and impair sow mobility [\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e]. On fully slatted floors, overgrown toes or dewclaws increases the contact area between the claws and the slat, raising the risk of claw injuries, fractures, and lameness due to pain [\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e]. Moreover, the combined length of the main toes of the rear feet has been corelated with the presence of all types of rear foot lesions [\\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e]. Among the available prevention and control measures, supplementation with organic minerals in sow diets may help prevent lesions in the heel, sole, and hoof wall but appears less effective in preventing overgrowth of the toe or dewclaws, which are likely influenced by a combination of genetics, housing, flooring, and age-related factors [\\u003cspan citationid=\\\"CR37\\\" class=\\\"CitationRef\\\"\\u003e37\\u003c/span\\u003e]. Functional claw trimming remains the most effective intervention for managing overgrown claws, thereby maintaining hoof health and reducing the risk of lameness [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eHowever, in contrast to previous study [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e], we did not find an association between WLC and risk of lameness. Unlike earlier studies that typically investigated the relationship between hoof lesions and lameness within the same time frame [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e], our research specifically assessed the impact of prepartum hoof lesions on lameness at weaning. This difference in study design may partly explain why WLC was not significantly associated with lameness in our findings. Additionally, our study was conducted in a single pig population, which may have further contributed to this discrepancy.\\u003c/p\\u003e \\u003cp\\u003ePrepartum hindlimb hoof lesion scores may potentially serve as a predictive indicator for sow lameness at weaning. In the present study, we observed a strong association between higher prepartum hindlimb hoof lesion scores and an increased risk of lameness at weaning (Fig.\\u0026nbsp;2). Consistent with previous findings [\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e], the presence of multiple lesion sites on a sow's feet markedly increased the likelihood of lameness. This phenomenon may be attributed to the cumulative effect of hoof lesions [\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e], where multiple lesion can compromise the overall stability of the hoof structure, and thus elevate the risk of lameness. The link between hoof lesions and lameness is thought to be mediated by pain [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e], with greater numbers of hoof lesions likely causing more severe greater pain. Although some individual lesions may not immediately result in lameness, their progressive worsening over time may exacerbate pain levels, and which ultimately lead to lameness. Therefore, a higher prepartum hoof lesion score may reflect an increased risk of lameness at weaning.\\u003c/p\\u003e \\u003cp\\u003eIn addition, Yorkshire (YY) sows exhibited a marginally higher risk of lameness compared to Landrace (LL) sows. This trend may be related to the breed-specific differences in bone characteristics and growth rates reported in other pig populations [\\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR38\\\" class=\\\"CitationRef\\\"\\u003e38\\u003c/span\\u003e]. Grandhi et al. (1986) [\\u003cspan citationid=\\\"CR39\\\" class=\\\"CitationRef\\\"\\u003e39\\u003c/span\\u003e] found LL gilts and sows had larger femur and third metacarpal shaft diameters but lower bone strength, elastic modulus, and cortex thickness compared to YY pigs, which may influence susceptibility to lameness. Additionally, Papadopoulos et al. (2021) [\\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e] observed differences in claw and dewclaw length and their associations with claw lesions among different genetic lines, such as PIC, Danbred, and Topigs. These findings suggest that future breeding strategies may need to focus on optimizing skeletal and hoof structures, as well as improving resistance to injuries to enhance sow welfare and production efficiency in pig farming.\\u003c/p\\u003e \\u003cp\\u003eRegarding parity, previous studies [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR40\\\" class=\\\"CitationRef\\\"\\u003e40\\u003c/span\\u003e] have demonstrated that low-parity sows are more likely to develop lameness and be subsequently culled compared to high-parity sows. Lame sows with lower parities often fail to complete their production cycles due to the progression of lameness, leading to earlier culling [\\u003cspan citationid=\\\"CR41\\\" class=\\\"CitationRef\\\"\\u003e41\\u003c/span\\u003e]. However, in the present study, no association was found between parity and the occurrence of lameness at weaning. This discrepancy may be attributed to the uneven distribution of sows\\u0026rsquo; parities in our study population, where primiparous sow accounted for 41% of the sample. Furthermore, when analyzing the parity variable, sows were categorized simply as primiparous or multiparous, which may have masked the potential differences across finer parity levels.\\u003c/p\\u003e \\u003cp\\u003eWhile conducting this study on a single sow farm allowed for control over external variables and ensured a consistent research environment, it also introduced certain limitations. The homogeneity of management, housing, and environmental conditions may not fully capture the variability seen across different commercial production systems, thereby limiting the generalizability of the findings. Future multi-farm studies are warranted to account for variability in factors such as seasonal fluctuations, feeding protocols, housing designs, flooring materials, and management practices, all of which can differ substantially between farms and may influence the applicability of results.\\u003c/p\\u003e\"},{\"header\":\"Conclusions\",\"content\":\"\\u003cp\\u003eIn conclusion, the lactation period may serve as a crucial stage for the occurrence of lameness in sows. Sows with bilateral overgrown toe (OT), overgrown dewclaw (ODC) and heel overgrowth and erosion (HOE) on their hindlimbs, along with those having unilateral OT on the hindlimbs, face a greater risk of lameness at weaning. The prepartum hindlimb hoof lesion score may potentially serve as a predictive criterion for sow lameness at weaning.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eEthics approval and consent to participate\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis study was approved by the Institutional Animal Care and Use Committee of Nanjing Agricultural University (NJAULLSC2024035). All experimental procedures involving animals were conducted in accordance with the relevant guidelines and regulations for animal welfare.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConsent for publication\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll authors have approved the final manuscript for publication and consent to its submission to this journal.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAvailability of data and materials\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe datasets/materials used in this study are available from the corresponding author, Zhen Yang, upon reasonable request via email at yangzhen@njau.edu.cn.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCompeting interests\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare no competing interests.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFunding\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eFunding for this work was provided by China Agriculture Research System of MOF and MARA (CARS-35) and Zhen Yang\\u0026rsquo;s NJAU Research Startup Fund No.090-804126.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthors\\u0026apos; contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eZ. Yang designed the experimental protocols, supervised research progress, and provided critical guidance on manuscript preparation. J.B. Wang conducted the experiments, collected and analyzed data, and drafted the manuscript under Z. Yang\\u0026rsquo;s supervision. M. Li critically reviewed the manuscript, corrected content and methodological errors, and revised it to improve scientific rigor. Z.Y. Liu and S.Y. Tian assisted with data collection and experimental procedures. B.R. Sun and Y.P. Mo contributed to experimental design, supervised research progress, and advised on technical and analytical strategies. All authors reviewed and approved the final manuscript.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgement\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eWe thank Prof. Danchen Yang for guidance on data analysis, Dr. Ke Dai and Mr. Hongzhi Ma for experimental assistance, Changjie Qian, Ting Zhang and Wenjiao Guo for support with operations and experiments.\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003ePaiva RC, Moura CA, Thomas P, Haberl B, Greiner L, Rademacher CJ, et al. Risk factors associated with sow mortality in breeding herds under one production system in the Midwestern United States. Prev Vet Med. 2023;213:105883.doi:10.1016/j.prevetmed.2023.105883.\\u003c/li\\u003e\\n\\u003cli\\u003eHallowell A, Pierdon M. Effects of lameness on productivity and longevity for sows in pen gestation. 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Animal. 2013;7(7):1174-81.doi:10.1017/s1751731113000232.\\u003c/li\\u003e\\n\\u003cli\\u003eCostermans NGJ, Soede NM, Middelkoop A, Laurenssen BFA, Koopmanschap RE, Zak LJ, et al. Influence of the metabolic state during lactation on milk production in modern sows. Animal. 2020;14(12):2543-53.doi:10.1017/s1751731120001536.\\u003c/li\\u003e\\n\\u003cli\\u003evan Riet MMJ, Millet S, Liesegang A, Nalon E, Ampe B, Tuyttens FAM, et al. Impact of parity on bone metabolism throughout the reproductive cycle in sows. Animal. 2016;10(10):1714-21.doi:10.1017/s1751731116000471.\\u003c/li\\u003e\\n\\u003cli\\u003evan Riet MMJ, Millet S, Aluw\\u0026eacute; M, Janssens GPJ. Impact of nutrition on lameness and claw health in sows. Livest Sci. 2013;156(1-3):24-35.doi:10.1016/j.livsci.2013.06.005.\\u003c/li\\u003e\\n\\u003cli\\u003eLisgara M, Skampardonis V, Kouroupides S, Leontides L. Hoof lesions and lameness in sows in three Greek swine herds. J Swine Health Prod. 2015;23(5):244-51.\\u003c/li\\u003e\\n\\u003cli\\u003eBos EJ, Maes D, van Riet MMJ, Millet S, Ampe B, Janssens GPJ, et al. Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups. Plos One. 2016;11(9).doi:10.1371/journal.pone.0163625.\\u003c/li\\u003e\\n\\u003cli\\u003eGillman CE, KilBride AL, Ossent P, Green LE. A cross-sectional study of the prevalence of foot lesions in post-weaning pigs and risks associated with floor type on commercial farms in England. Prev Vet Med. 2009;91(2-4):146-52.doi:10.1016/j.prevetmed.2009.05.023.\\u003c/li\\u003e\\n\\u003cli\\u003eFitzgerald RF, Stalder KJ, Karriker LA, Sadler LJ, Hill HT, Kaisand J, et al. The effect of hoof abnormalities on sow behavior and performance. Livest Sci. 2012;145(1-3):230-8.doi:10.1016/j.livsci.2012.02.009.\\u003c/li\\u003e\\n\\u003cli\\u003ePapadopoulos GA, Chalvatzi S, Kroustallas F, Skampardonis V, Cernat M, Marouda C, et al. Claw Characteristics of Culled Sows from Three Farrow-to-Finish Greek Farms. Part 1: Claw Length Measurements, Lesion Scores and Their Association. Vet Sci. 2021;8(7).doi:10.3390/vetsci8070126.\\u003c/li\\u003e\\n\\u003cli\\u003eLisgara M, Skampardonis V, Leontides L. Effect of diet supplementation with chelated zinc, copper and manganese on hoof lesions of loose housed sows. Porcine health management. 2016;2:6.doi:10.1186/s40813-016-0025-2.\\u003c/li\\u003e\\n\\u003cli\\u003eJiang B, Wang M, Tang Z, Du X, Feng S, Ma G, et al. Genome-wide association study of bone mineral density trait among three pig breeds. Animal. 2020;14(12):2443-51.doi:10.1017/s1751731120001111.\\u003c/li\\u003e\\n\\u003cli\\u003eGrandhi RR, Thorntontrump AB, Doige CE. INFLUENCE OF DIETARY CALCIUM-PHOSPHORUS LEVELS ON CERTAIN MECHANICAL, PHYSICAL AND HISTOLOGICAL PROPERTIES AND CHEMICAL-COMPOSITION OF BONES IN GILTS AND 2ND LITTER SOWS. Can J Anim Sci. 1986;66(2):495-503.doi:10.4141/cjas86-051.\\u003c/li\\u003e\\n\\u003cli\\u003eEngblom L, Lundeheim N, Strandberg E, Schneider MDP, Dalin AM, Andersson K. Factors affecting length of productive life in Swedish commercial sows. J Anim Sci. 2008;86(2):432-41.doi:10.2527/jas.2007-0310.\\u003c/li\\u003e\\n\\u003cli\\u003eUSDA. Swine 2006, part I: reference of swine health and management practices in the United States, 2006. Swine 2006, part I: reference of swine health and management practices in the United States, 2006. 2007.\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Sow lameness, Hindlimb hoof lesions, Lactation, Purebred Danish sows, Prospective cohort study\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-6538207/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-6538207/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eBackground\\u003c/h2\\u003e \\u003cp\\u003eSow lameness represents a significant challenge to both animal welfare and economic efficiency in swine production, with hoof lesions identified as a major contributing factor. In China, research addressing sow lameness and its associated risk factors remains limited, particularly regarding longitudinal studies on risk factors for lameness in weaned sows. This study utilized a prospective cohort design to investigate the effects of pre-farrowing hindlimb hoof lesions and other factors including breed and parity on the development of lameness by weaning.\\u003c/p\\u003e\\u003ch2\\u003eMaterials and methods\\u003c/h2\\u003e \\u003cp\\u003eA prospective cohort study was conducted from July to September 2024 on a multiplier sow farm (herd size\\u0026thinsp;=\\u0026thinsp;5,159 sows) in Guangxi, China. The study cohort consisted of 311 non-lame sows, representing two genetic lines: Danish Yorkshire (YY) and Landrace (LL). At 110 days of gestation, one trained veterinarian performed standardized scoring for seven hindlimb conditions: overgrown toe (OT), overgrown dewclaw (ODC), heel overgrowth and erosion (HOE), heel-sole crack (HSC), white line crack (WLC), cracked wall horizontal (CWH) and cracked wall vertical (CWV). Lameness assessment were conducted during two key transition points: (1) pre-farrowing (transfer from gestation to farrowing rooms at 110 days of gestation) and (2) post-weaning (return to gestation rooms after weaning). Sows were monitored throughout lactation, with data collected on genetic line, parity, backfat thickness, and the requirement for farrowing assistance. Univariate analysis was conducted to identify candidate variables (hoof lesion types, genetic line, parity, backfat thickness, and farrowing assistance requirement). Then, these selected variables were incorporated into a multivariate logistic regression model to determine risk factors for lameness in sows at weaning. Variables with \\u003cem\\u003ep\\u003c/em\\u003e-values\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.1 were subsequently included in a multivariate logistic regression model to identify independent risk factors for lactation-associated lameness.\\u003c/p\\u003e\\u003ch2\\u003eResults\\u003c/h2\\u003e \\u003cp\\u003eAmong sows that were non-lame at pre-farrowing assessment, 44.7% (139/311) developed lameness by weaning. Bilateral OT exhibited the highest adjusted odds ratio for incident lameness (OR\\u0026thinsp;=\\u0026thinsp;42.5, 95% CI: 10.9-165.5; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), followed by unilateral OT (OR\\u0026thinsp;=\\u0026thinsp;28.0, 95% CI: 9.4\\u0026ndash;83.7; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), bilateral HOE (OR\\u0026thinsp;=\\u0026thinsp;10.0, 95% CI: 3.5\\u0026ndash;29.0; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001), and bilateral ODC (OR\\u0026thinsp;=\\u0026thinsp;7.3, 95% CI: 2.5\\u0026ndash;21.2, \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001). YY sows demonstrated a borderline significantly elevated risk compared to LL sows (OR\\u0026thinsp;=\\u0026thinsp;2.3, 95% CI: 0.9\\u0026ndash;5.5; \\u003cem\\u003eP\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.070).\\u003c/p\\u003e\\u003ch2\\u003eConclusions\\u003c/h2\\u003e \\u003cp\\u003ePre-farrowing hindlimbs lesions-including bilateral OT, ODC, HOE, and unilateral OT, were significant predictors of incident lameness at weaning. Biomechanical stresses during lactation may exacerbate pre-existing subclinical hoof lesions, leading to overt lameness at weaning. Prepartum hoof lesion scoring may thus serve as a valuable tool for risk stratification and early intervention strategies for improving sow welfare and farm productivity.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Impact of prepartum hindlimb hoof lesions and other risk factors on the lameness status of sows at weaning: A prospective cohort study\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-05-06 09:34:07\",\"doi\":\"10.21203/rs.3.rs-6538207/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"ff44c75b-f432-415f-948a-0853f3558dfa\",\"owner\":[],\"postedDate\":\"May 6th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-07-07T08:23:38+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-05-06 09:34:07\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-6538207\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-6538207\",\"identity\":\"rs-6538207\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}