The Impact of Colostral IgG Levels on Growth and Viability in Piglets

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Thus, the passive transfer through colostrum is essential to establish protection against environmental pathogens and enhance the health and survival of the neonatal piglet. The aim of this study was to investigate how colostrum quality in sows influence growth and survival in piglets and to determine whether higher colostrum quality can compensate for lower colostrum intake. Methods Farrowings were monitored at three-hour intervals through regular visual inspections. Colostrum was manually collected from all teats. Antibody concentration was measured immediately using a digital Brix refractometer (PAL-1 BLT/A + W, Atago, Tokyo, Japan). Piglets were individually marked for identification and weighed immediately after colostrum sampling (birth weight) and again 24 hours after birth. Piglets were subsequently weighed at 5 and 9 weeks of age to assess growth performance. Results The antibody content in colostrum (“Brix”) averaged 27.5%, with a median of 27.2%, a minimum of 24.1% and a maximum of 32.2%. Antibody levels in colostrum had no significant effect on survival. Piglets with a Brix value ≥ 27.5% (n = 149) showed significantly higher average daily weight gain (ADWG) at 5 weeks of age compared to those with values < 27.5% (n = 159). Median AWDG for the two groups were 298 g and 276 g, respectively. Piglets with a Brix value ≥ 27.5% (n = 144) also showed significantly higher average daily weight gain (ADWG) at 9 weeks of age compared to those with values < 27.5% (n = 154). Median AWDG for the two groups were 510 g and 486 g, respectively. Conclusion In conclusion, colostrum quality as measured by a Brix refractometer has a significant impact on piglet growth from birth to 5 and 9 weeks of age, where antibody levels above 27.5% resulted in significantly better growth. Birth weight was shown to be highly important for survival, whereas antibody levels in colostrum had no direct effect. Colostrum Brix sow piglet growth survival Background Reducing pre-weaning piglet mortality can have a substantial impact on both economics and animal welfare ( 1 ). Piglets are born without antibodies, as no transfer of immunoglobulins occur across the sow’s placenta. Thus, the passive transfer through colostrum is essential to establish protection against environmental pathogens and enhance the health and survival of the neonatal piglet ( 2 – 5 ). Colostrum is defined as the first secretion from the mammary gland and is largely produced prior to parturition ( 6 ). It is released during suckling within the first 24 hours after birth of the first piglet. Between 12 and 48 hours postpartum, colostrum gradually transitions into mature milk ( 7 ). Litter size has increased in recent years ( 8 ), but no correlation exists between litter size and the amount of colostrum produced by the sow. Consequently, there is a negative correlation between litter size and the amount of colostrum available per piglet ( 9 ). Previous research has shown that colostrum intake is associated with growth performance; however, as litter sizes continue to increase, the availability of colostrum per piglet may become limited ( 10 ). Despite the well-recognised importance of colostrum, knowledge is still lacking regarding the factors that influence a piglet’s ability to achieve an adequate amount in order to ensure good health and growth. Colostrum is also important for several other reasons. Newborn piglets lack brown adipose tissue. At birth, they have very limited energy reserves, possessing approximately 30–38 g/kg of glycogen and 10–20 g/kg of fat, from which they can derive around 450 kJ/kg of body weight. These reserves are rapidly depleted. A piglet expending the minimum possible energy for feed intake and minimal physical activity requires approximately 275 kJ/kg of body weight to meet basic maintenance needs. However, additional energy is required for thermoregulation, estimated at 2 kJ/kg BW per hour per °C. Just standing, requires about 9.5 kJ/kg BW per hour. Thus, a 1-kg piglet demands between 700 and 950 kJ during the first 24 hours after birth for survival. Colostrum provides the essential energy needed to support thermoregulation, physical activity, and early postnatal growth ( 2 ). Colostrum consists of dry matter, proteins, fat, lactose, minerals, and growth factors, as well as antibacterial components such as cytokines, oligosaccharides, lactoferrin, and lactoperoxidase ( 11 – 15 ). The dry matter and protein content in colostrum are high, whereas lactose and fat are present at lower levels. At parturition, sow colostrum contains approximately 27.3 g of dry matter, 17.7 g of protein, 5.1 g of lipids and 3.5 g of lactose per 100 g ( 16 ). The elevated protein content is primarily due to the high concentration of immunoglobulins present in colostrum ( 11 ). It could thus be of value to gain information on the milk production of the sow and antibody content in her milk. The use of a digital Brix refractometer has been proposed as a practical, on-farm tool to estimate colostral IgG content in sows. It is designed to measure the percentage of sucrose in liquids; when applied to fluids that do not contain sucrose, it provides an approximate estimation of total solids content (TS %) ( 17 ). Hasan et al. ( 18 ) validated this method by comparing Brix values with ELISA-determined IgG concentrations, showing a strong correlation when samples were collected within 3 hours post partum . The authors emphasised that delayed sampling reduced the correlation between Brix values and true IgG levels, as the immunoglobulin content declines more rapidly than the total solids measured by the refractometer. Therefore, early sampling is critical for accurate estimation of colostral IgG content. Hasan et al. ( 18 ) also proposed threshold values for interpreting Brix measurements taken during the first hours of colostrum production. A Brix value below 20% was considered as “Poor”, 20–24% as “Borderline, 25–29% as “Adequate” and value ≥ 30 was considered as “Very good” ( 18 ). The aim of this study was to investigate how colostrum quality in sows influence growth and survival in piglets and to determine whether higher colostrum quality can compensate for lower colostrum intake. The study focused on analysing associations between colostrum intake, birth weight, growth and survival, in relation to colostrum quality as measured by a Brix refractometer. Materials and Methods The study was approved by the Ethics Committee for Animal Experimentation, Uppsala, Sweden (Dnr. 5.2.18–02900/2020). The study was conducted at the Lövsta Agricultural Research Centre’s pig herd, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden. The herd is an SPF-herd and is documented free from AFS, CFS, AD, FMD, SVD, TGE, PED, PRRS, Japanese encephalitis virus, rabies, Brucella spp., Actinobacillus pleuropneumoniae, Mesomycoplasma hyopneumoniae , Atrophic rhinitis, Sarcoptes scabiei, Brachyspira spp., Salmonella spp. and Lawsonia intracellularis. Data were collected between 25th August 2022 and 18th July 2023. Colostral samples were obtained from 34 sows, and birth weight, weight at 24 hours, at 5 weeks of age, and weight at 9 weeks of age were recorded from a total of 372 piglets. Sow parity ranged from 1 to 8, and six breeds or breed combinations were represented: Y (purebred Swedish Yorkshire), LY (Landrace × Yorkshire), LZ (Landrace × Canadian Yorkshire, the “Z-line”), ZY, ZYY (alternating backcross; 25% Z-line and 75% Swedish Yorkshire), and ZZY (Table 1 ). All sows were group-housed on deep straw-litter bedding during gestation, and they were not confined in the farrowing pens. Table 1 Parities and breeds of sows included in the study Parity 1 2 3 4 5 6 7 8 Breed Y 1 LY 2 LZ 1 ZY 3 2 2 2 ZYY 2 2 1 ZZY 2 1 3 1 1 1 1 Y (purebred Swedish Yorkshire), LY (Landrace × Yorkshire), LZ (Landrace × Canadian Yorkshire, the “Z-line”), ZY, ZYY (alternating backcross; 25% Z-line and 75% Swedish Yorkshire), and ZZY Farrowings were monitored at three-hour intervals through regular visual inspections, during which sows were directly observed for signs of imminent parturition. The temperature in the creep area on the day of the expected farrowing was measured to 32.9°C. The temperature in the farrowing unit was measured to 22.7°C. Sows from which colostrum samples could be collected within 3 hours after the onset of farrowing were included in the study. Colostrum was manually collected from all teats. Antibody concentration was measured immediately using a digital Brix refractometer (PAL-1 BLT/A + W, Atago, Tokyo, Japan). Briefly, 0,3 ml colostrum was placed on the prism and measured on a 0–53% scale with an accuracy of ± 0.2%. The prism was wiped clean with a paper tissue between each measurement. Colostrum intake was calculated using the method described by Devillers et al .( 7 ) $$\:CI=-217.4+0.217\cdot\:t+1861019\cdot\:B{W}_{t}+BWB\cdot\:(54.80-1861019\cdot\:t)\cdot\:(0.9985-3.7\times\:{10}^{-4}\cdot\:{t}_{FS}+6.1\times\:{10}^{-7}\cdot\:{t}_{FS}^{2})$$ where CI = colostrum intake, BW = body weight at 24 hours of age, BWB = birth weight, \(\:{t}_{FS}\) = estimated time of first suckling (30 min), and \(\:t=25\:\) h. Piglets were individually marked for identification and weighed using a digital scale with an accuracy of ± 2 g (WE2108, Profilvågen, 2010, Borlänge, Sweden) immediately after colostrum sampling (birth weight) and again 24 hours after birth. Piglets were subsequently weighed at 5 and 9 weeks of age to assess growth performance. The mean age at weaning was 32 days and the pigs were transferred to the fattening unit at ~ 9 weeks of age. Survival to weaning was recorded. Growth rate (g/day) was calculated as the difference between weight at 5 and 9 weeks of age, respectively, and birth weight, divided by the piglet’s age in days at weaning. Statistical Analysis Data were processed in R. Descriptive statistics (mean, median, and standard deviation) were calculated for all variables. Pairwise Pearson correlations were used to examine the relationships between birth weight, weight at 24 hours, weights at 5 and 9 weeks, colostrum intake, growth from birth to weaning, growth from birth to 9 weeks of age, and colostrum antibody concentration (Brix %). Non-normally distributed variables were analysed using the Kruskal–Wallis test, including associations between growth (birth to weaning; birth to 9 weeks) and Brix categories ( 30%). The effects of sow breed and parity on Brix values, as well as on growth variables, were analysed using the Kruskal–Wallis test. The association between low colostrum intake (growth during the first 24 hours) and intake of colostrum with low versus high antibody content, and the subsequent impact on growth to weaning, was analysed using the Mann–Whitney U test. Lasso regression was used to identify important predictors and to avoid overfitting. Results Body weight at birth was recorded for 372 piglets, and piglets that were cross-fostered were excluded from the analyses. The number of piglets included in the dataset decreased over time due to both mortality and cross-fostering. Thus, at weaning (5 weeks), 308 piglets remained in the calculations, and 298 remained at 9 weeks of age. The newborn piglets weighed on average 1.42 kg, with a median weight of 1.46 kg, a minimum of 0.5 kg and a maximum of 2.28 kg. The weight after 24 hours averaged 1.49 kg, with a median of 1.51 kg, a minimum of 0.62 kg and a maximum of 2.47 kg. The weaning weight (5 weeks of age) averaged 10.97 kg, with a median of 11.1 kg, a minimum of 3.3 kg and a maximum of 19.1 kg. At 9 weeks of age, the piglets weighed on average 32.45 kg, with a median of 33.2 kg, a minimum of 15.8 kg and a maximum of 45.9 kg (Table 2 ). Birth weight had a strong positive correlation with weight after 24 hours (r = 0.966), weaning weight, and weight at 9 weeks (r = 0.746). Growth from birth to weaning averaged 0.279 kg/day, with a median of 0.285 kg/day, a minimum of 0.221 kg/day and a maximum of 0.492 kg/day. Growth from birth to 9 weeks averaged 0.488 kg/day, with a median of 0.499 kg/day, a minimum of 0.221 kg/day and a maximum of 0.699 kg/day. Piglets that survived had a higher mean birth weight, 1.55 kg, than those that died, 1.18 kg. Table 2 Weight and colostral parameters measured at birth and up to 9 weeks of age Variable N N* Mean Minimum Median Maximum Birth weight, kg 372 0 1,42 0,50 1,46 2,28 Weight 24 hour, kg 358 14 1,49 0,62 1,51 2,47 Weight 5 week, kg 308 64 10,97 3,30 11,10 19,10 Weight 9 week, kg 298 74 32,45 15,80 33,20 45,90 Colostrum intake, mL 355 17 233,4 0,00 218,2 808,3 ADWG 5 week, g 308 64 279 67 285 492 ADWG 9 week, g 298 74 488 221 499 699 Brix% 372 0 27,5 24,1 27,2 32,2 Measurements of birth weight, weight at 24 h, 5 and 9 weeks of age, ADWG = average daily weight gain Brix% - as measured as percentage of total solids content by a Brix refractometer, N = number of pigs. Colostrum intake, as calculated according to the formula by Devillers et al .( 7 ), averaged 233.4 mL, with a median of 218.2 mL, a minimum value of 0 and a maximum of 808.3 mL. The antibody content in colostrum (“Brix”) averaged 27.5%, with a median of 27.2%, a minimum of 24.1% and a maximum of 32.2%. Antibody levels in colostrum had no significant effect on survival. Only a limited number of piglets fell outside the proposed Brix thresholds ( 18 ), with 24 piglets registering values below 25% and 44 piglets above 30%, and therefore the study’s mean value (27.5%) was instead used as the threshold for “low” and “high” antibody content. The antibody content showed weak or no correlation with the weight parameters at birth and 24 hours. Piglets with a Brix value ≥ 27.5% (n = 149) showed significantly higher average daily weight gain (ADWG) at 5 weeks of age compared to those with values < 27.5% (n = 159). Median AWDG for the two groups were 298 g and 276 g, respectively. A Kruskal–Wallis test revealed a statistically significant difference in growth between the groups (Z = − 2.75, p < 0.01), indicating that higher IgG content were associated with improved growth. Piglets with a Brix value ≥ 27.5% (n = 144) also showed significantly higher average daily weight gain (ADWG) at 9 weeks of age compared to those with values < 27.5% (n = 154). Median AWDG for the two groups were 510 g and 486 g, respectively. A Kruskal–Wallis test revealed a statistically significant difference in growth between the groups (Z = − 2.40, p < 0.01), indicating that higher IgG content was associated with improved growth from birth to transition to the fattening unit. A difference was observed between breeds, where LZ had significantly (p < 0.01) higher antibody content in the colostrum (29.9%). However, since the value relates to a single sow, no conclusions can be drawn from this result. Lasso regression showed a weak positive association (r = 0.032) between the antibody level in colostrum and the growth rates from birth to 9 weeks of age. Colostrum intake showed a positive association (r = 0.385) with weaning weight. The weight at 9 weeks was positively associated (r = 0.746) with weaning weight. Discussion The importance of adequate colostrum intake for neonatal piglet survival, health and growth has been demonstrated across numerous studies ( 2 , 10 , 19 ). Our findings support this general understanding by showing that colostrum quality, as measured as percentage of total solid contents, had a significant impact on growth, whereas survival was primarily associated with birth weight. This aligns with Jourquin et al. and Le Dividich et al ., who argue that piglets with a high birth weight have better changes of survival regardless of colostrum intake ( 19 , 20 ). While this interpretation fits with studies emphasising the importance of early energy supply, it contrasts with research highlighting colostrum’s essential immunological role. Given that piglets are born immunocompetent but without prior antigen exposure, our results suggest that—under low pathogen pressure, as is the case in an SPF-herd—high-quality colostrum may contribute more to optimising growth potential than to immediate survival. Our findings that low colostrum intake is associated with reduced growth also complement previous work demonstrating the critical role of energy acquisition in the neonatal period ( 10 ). Starvation remains one of the most frequent causes of pre-weaning mortality, together with crushing (Rangstrup-Christensen et al. 2018; Kielland et al. 2018). Further, insufficient energy intake is often implicated in death by crushing, as weakened piglets are less able to avoid the sow. Environmental conditions also influence early energy expenditure, and higher environmental temperatures may reduce piglet heat loss, thereby reducing the energy losses. In the present study, the rather high environmental temperature (22.7°C) might have contributed to the low mortality during the first 24 hours p.p. Our study also indicates that genetic and litter-related factors substantially affected both growth and survival, reinforcing earlier observations that colostral IgG concentrations vary greatly both between and within herds ( 2 , 10 , 19 ). These variations suggest that housing system and management practices strongly influence colostrum production and intake. Factors promoting optimal hormonal profiles—such as nest-building behaviour and provision of nesting material—have been shown to improve oxytocin and progesterone release, support calmer nursing behaviour, and lengthen milk let-down in loose-housed sows (Yun et al. 2014). These behavioural and hormonal influences may help explain part of the variability observed in our dataset. However, this was not investigated in the present study. Increasing litter sizes remain an important challenge. Larger litters may reduce individual birth weights, prolong farrowing, and increase competition at the udder, increasing the likelihood that later-born piglets access less colostrum and of lower IgG concentration ( 21 ). However, the relationship between the order at birth and IgG content in colostrum was not investigated in the present study. Our results, showing that higher Brix values (> 27.5%) were associated with improved growth, support the notion that colostrum quality could partially compensate for limited volume intake. This highlights the value of monitoring colostrum quality at the herd level. The Brix refractometer provides a simple, objective, and practical method for estimating colostrum quality on-farm ( 18 ). In addition to offering rapid results, it enables evaluation of whether management interventions have a measurable effect on colostrum composition. However, obtaining samples within the optimal time frame requires continuous farrowing surveillance ( 18 ), which is highly labour-intensive and may not be feasible in smaller herds. As such, Brix testing may be better suited for spot-sampling during daytime farrowings, or for use in larger herds with sufficient staffing to support 24-hour farrowing supervision. In contrast, estimating colostrum intake remains labour-intensive, requiring repeated weighing within the first 24 hours. Nevertheless, periodic weighing of selected litters may still be feasible as part of a herd-monitoring programme. Considering that up to one-third of the sows may produce insufficient colostrum for their litters ( 10 ), breeding for improved colostrum production and quality could further strengthen neonatal resilience. Overall, our results demonstrate that both biological and management-related factors interact to shape early piglet performance. Effective herd strategies should therefore combine improved colostrum management, enhanced farrowing supervision, optimisation of environmental conditions, and consideration of genetic influences. Conclusions In conclusion, colostrum quality as measured by a Brix refractometer has a significant impact on piglet growth from birth to 5 and 9 weeks of age, where antibody levels above 27.5% resulted in significantly better growth. Birth weight was shown to be highly important for survival, whereas antibody levels in colostrum had no direct effect. Based on the results of this study, genetics may affect the antibody content in colostrum. However, the effect of genetics warrants further studies. Declarations Acknowledgements The authors gratefully acknowledge the staff at the University Research Farm, Lövsta, for skilful assistance. We would also like to acknowledge Razaw Al-Sarraj for skilful help with the statistical analyses. Author’s contribution MJ was responsible for the design of the study. AC and ES performed the clinical parts of the study. AC wrote the manuscript and all authors contributed in scrutinizing the text. All authors read and approved the final manuscript. Funding This study was financed by grants from the Royal Swedish Academy of Agriculture and Forestry, and from the Swedish University of Agricultural Sciences. Data availability The datasets used and analysed during the current study are available from the corresponding author upon request. Ethics approval The study was approved by the Swedish Board of Agriculture and the Ethics Committee for Animal Experimentation, Uppsala, Sweden (approval no. 5.2.18-02900/2020). All procedures were conducted in accordance with the Swedish Animal Welfare Act (SFS 2018:1192), the Animal Welfare Ordinance (SFS 2019:66), and EU animal welfare legislation, including Directive 2010/63/EU on the protection of animals used for scientific purposes. Consent for publication Not applicable Declarations -conflict of interest The authors declare no conflict of interests References Stygar AH, Chantziaras I, Maes D, Aarestrup Moustsen V, De Meyer D, Quesnel H et al. Economic feasibility of interventions targeted at decreasing piglet perinatal and pre-weaning mortality across European countries. Porcine Health Manage. 2022;8(1). Dividich JL, Rooke JA, Herpin P. Nutritional and immunological importance of colostrum for the new-born pig. J Agricultural Sci. 2005;143(6):469–85. Milon A, Aumaitre A, Le Dividich J, Franz J, Metzger J, editors. Influence of birth prematurity on colostrum composition and subsequent immunity of piglets. Annales de recherches vétérinaires; 1983. Rooke JA, Bland IM. The acquisition of passive immunity in the new-born piglet. Livest Prod Sci. 2002;78(1):13–23. Bandrick M, Ariza-Nieto C, Baidoo SK, Molitor TW. Colostral antibody-mediated and cell-mediated immunity contributes to innate and antigen-specific immunity in piglets. Dev Comp Immunol. 2014;43(1):114–20. Quesnel H, Farmer C, Theil PK. Colostrum and milk production. Brill | Wageningen Academic; 2015. pp. 173–92. Devillers N, Van Milgen J, Prunier A, Le Dividich J. Estimation of colostrum intake in the neonatal pig. Anim Sci. 2004;78(2):305–13. Prunier A, Heinonen M, Quesnel H. High physiological demands in intensively raised pigs: impact on health and welfare. Animal. 2010;4(6):886–98. Devillers N, Le Dividich J, Farmer C, Mounier AM. Le Huërou-Luron I. Variability of colostrum yield and colostrum intake in pigs. 2005;54(4):313–24. Quesnel H, Farmer C, Devillers N. Colostrum intake: Influence on piglet performance and factors of variation. Livest Sci. 2012;146(2):105–14. Klobasa F, Werhahn E, Butler JE. Composition of Sow Milk During Lactation. J Anim Sci. 1987;64(5):1458–66. Albera E, Kankofer M. Antioxidants in Colostrum and Milk of Sows and Cows. Reprod Domest Anim. 2009;44(4):606–11. Tan L, Wei T, Yuan A, He J, Liu J, Xu D, et al. Dietary Supplementation of Astragalus Polysaccharides Enhanced Immune Components and Growth Factors EGF and IGF-1 in Sow Colostrum. J Immunol Res. 2017;2017:1–6. Jahan M, Francis N, Wang B. Milk lactoferrin concentration of primiparous and multiparous sows during lactation. J Dairy Sci. 2020;103(8):7521–30. Nuntapaitoon M, Juthamanee P, Theil PK, Tummaruk P. Impact of sow parity on yield and composition of colostrum and milk in Danish Landrace × Yorkshire crossbred sows. Prev Vet Med. 2020;181:105085. Theil PK, Lauridsen C, Quesnel H. Neonatal piglet survival: impact of sow nutrition around parturition on fetal glycogen deposition and production and composition of colostrum and transient milk. animal. 2014;8(7):1021–30. Quigley JD, Lago A, Chapman C, Erickson P, Polo J. Evaluation of the Brix refractometer to estimate immunoglobulin G concentration in bovine colostrum. J Dairy Sci. 2013;96(2):1148–55. Hasan S, Rydhmer L, Jonsson L, Gustafsson H, Wattrang E, Johansson G et al. Validation of Brix refractometer to estimate colostrum immunoglobulin G content and composition in the sow. 2016;58(1):1–7. Le Dividich J, Charneca R, Thomas F. Relationship between birth order, birth weight, colostrum intake, acquisition of passive immunity and pre-weaning mortality of piglets. Span J Agricultural Res. 2017;15(2):e0603. Jourquin J, Morales J, Bokenkroger C. Impact of piglet birth weight increase on survivability and days to market, a simulation model. J Anim Sci. 2016;94:34. Oliviero C, Junnikkala S, Peltoniemi O. The challenge of large litters on the immune system of the sow and the piglets. Reprod Domest Anim. 2019;54(S3):12–21. Additional Declarations No competing interests reported. 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14:51:35","extension":"html","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":71779,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8213260/v1/c399df7d8819ce68df2b15fa.html"},{"id":104397483,"identity":"e067ddfe-2e5b-4039-b4ab-c765d4587d1a","added_by":"auto","created_at":"2026-03-11 11:49:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":462518,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8213260/v1/9bc2968c-25b2-40f4-b05c-bd2e57f45205.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Colostral IgG Levels on Growth and Viability in Piglets","fulltext":[{"header":"Background","content":"\u003cp\u003eReducing pre-weaning piglet mortality can have a substantial impact on both economics and animal welfare (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Piglets are born without antibodies, as no transfer of immunoglobulins occur across the sow\u0026rsquo;s placenta. Thus, the passive transfer through colostrum is essential to establish protection against environmental pathogens and enhance the health and survival of the neonatal piglet (\u003cspan additionalcitationids=\"CR3 CR4\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Colostrum is defined as the first secretion from the mammary gland and is largely produced prior to parturition (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). It is released during suckling within the first 24 hours after birth of the first piglet. Between 12 and 48 hours postpartum, colostrum gradually transitions into mature milk (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eLitter size has increased in recent years (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), but no correlation exists between litter size and the amount of colostrum produced by the sow. Consequently, there is a negative correlation between litter size and the amount of colostrum available per piglet (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Previous research has shown that colostrum intake is associated with growth performance; however, as litter sizes continue to increase, the availability of colostrum per piglet may become limited (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Despite the well-recognised importance of colostrum, knowledge is still lacking regarding the factors that influence a piglet\u0026rsquo;s ability to achieve an adequate amount in order to ensure good health and growth. Colostrum is also important for several other reasons. Newborn piglets lack brown adipose tissue. At birth, they have very limited energy reserves, possessing approximately 30\u0026ndash;38 g/kg of glycogen and 10\u0026ndash;20 g/kg of fat, from which they can derive around 450 kJ/kg of body weight. These reserves are rapidly depleted. A piglet expending the minimum possible energy for feed intake and minimal physical activity requires approximately 275 kJ/kg of body weight to meet basic maintenance needs. However, additional energy is required for thermoregulation, estimated at 2 kJ/kg BW per hour per \u0026deg;C. Just standing, requires about 9.5 kJ/kg BW per hour. Thus, a 1-kg piglet demands between 700 and 950 kJ during the first 24 hours after birth for survival. Colostrum provides the essential energy needed to support thermoregulation, physical activity, and early postnatal growth (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eColostrum consists of dry matter, proteins, fat, lactose, minerals, and growth factors, as well as antibacterial components such as cytokines, oligosaccharides, lactoferrin, and lactoperoxidase (\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). The dry matter and protein content in colostrum are high, whereas lactose and fat are present at lower levels. At parturition, sow colostrum contains approximately 27.3 g of dry matter, 17.7 g of protein, 5.1 g of lipids and 3.5 g of lactose per 100 g (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). The elevated protein content is primarily due to the high concentration of immunoglobulins present in colostrum (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). It could thus be of value to gain information on the milk production of the sow and antibody content in her milk. The use of a digital Brix refractometer has been proposed as a practical, on-farm tool to estimate colostral IgG content in sows. It is designed to measure the percentage of sucrose in liquids; when applied to fluids that do not contain sucrose, it provides an approximate estimation of total solids content (TS %) (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Hasan et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) validated this method by comparing Brix values with ELISA-determined IgG concentrations, showing a strong correlation when samples were collected within 3 hours \u003cem\u003epost partum\u003c/em\u003e. The authors emphasised that delayed sampling reduced the correlation between Brix values and true IgG levels, as the immunoglobulin content declines more rapidly than the total solids measured by the refractometer. Therefore, early sampling is critical for accurate estimation of colostral IgG content. Hasan et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) also proposed threshold values for interpreting Brix measurements taken during the first hours of colostrum production. A Brix value below 20% was considered as \u0026ldquo;Poor\u0026rdquo;, 20\u0026ndash;24% as \u0026ldquo;Borderline, 25\u0026ndash;29% as \u0026ldquo;Adequate\u0026rdquo; and value\u0026thinsp;\u0026ge;\u0026thinsp;30 was considered as \u0026ldquo;Very good\u0026rdquo; (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe aim of this study was to investigate how colostrum quality in sows influence growth and survival in piglets and to determine whether higher colostrum quality can compensate for lower colostrum intake. The study focused on analysing associations between colostrum intake, birth weight, growth and survival, in relation to colostrum quality as measured by a Brix refractometer.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e The study was approved by the Ethics Committee for Animal Experimentation, Uppsala, Sweden (Dnr. 5.2.18\u0026ndash;02900/2020). The study was conducted at the L\u0026ouml;vsta Agricultural Research Centre\u0026rsquo;s pig herd, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden. The herd is an SPF-herd and is documented free from AFS, CFS, AD, FMD, SVD, TGE, PED, PRRS, Japanese encephalitis virus, rabies, \u003cem\u003eBrucella\u003c/em\u003e spp., \u003cem\u003eActinobacillus pleuropneumoniae, Mesomycoplasma hyopneumoniae\u003c/em\u003e, Atrophic rhinitis, \u003cem\u003eSarcoptes scabiei, Brachyspira\u003c/em\u003e spp., \u003cem\u003eSalmonella\u003c/em\u003e spp. and \u003cem\u003eLawsonia intracellularis.\u003c/em\u003e Data were collected between 25th August 2022 and 18th July 2023. Colostral samples were obtained from 34 sows, and birth weight, weight at 24 hours, at 5 weeks of age, and weight at 9 weeks of age were recorded from a total of 372 piglets. Sow parity ranged from 1 to 8, and six breeds or breed combinations were represented: Y (purebred Swedish Yorkshire), LY (Landrace \u0026times; Yorkshire), LZ (Landrace \u0026times; Canadian Yorkshire, the \u0026ldquo;Z-line\u0026rdquo;), ZY, ZYY (alternating backcross; 25% Z-line and 75% Swedish Yorkshire), and ZZY (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All sows were group-housed on deep straw-litter bedding during gestation, and they were not confined in the farrowing pens.\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\u003eParities and breeds of sows included in the study\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParity\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003e8\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLZ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eZY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eZYY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eZZY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e1\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\u003eY (purebred Swedish Yorkshire), LY (Landrace \u0026times; Yorkshire), LZ (Landrace \u0026times; Canadian Yorkshire, the \u0026ldquo;Z-line\u0026rdquo;), ZY, ZYY (alternating backcross; 25% Z-line and 75% Swedish Yorkshire), and ZZY\u003c/p\u003e\u003cp\u003eFarrowings were monitored at three-hour intervals through regular visual inspections, during which sows were directly observed for signs of imminent parturition. The temperature in the creep area on the day of the expected farrowing was measured to 32.9\u0026deg;C. The temperature in the farrowing unit was measured to 22.7\u0026deg;C. Sows from which colostrum samples could be collected within 3 hours after the onset of farrowing were included in the study. Colostrum was manually collected from all teats. Antibody concentration was measured immediately using a digital Brix refractometer (PAL-1 BLT/A\u0026thinsp;+\u0026thinsp;W, Atago, Tokyo, Japan). Briefly, 0,3 ml colostrum was placed on the prism and measured on a 0\u0026ndash;53% scale with an accuracy of \u0026plusmn;\u0026thinsp;0.2%. The prism was wiped clean with a paper tissue between each measurement.\u003c/p\u003e\u003cp\u003eColostrum intake was calculated using the method described by Devillers \u003cem\u003eet al\u003c/em\u003e.(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:CI=-217.4+0.217\\cdot\\:t+1861019\\cdot\\:B{W}_{t}+BWB\\cdot\\:(54.80-1861019\\cdot\\:t)\\cdot\\:(0.9985-3.7\\times\\:{10}^{-4}\\cdot\\:{t}_{FS}+6.1\\times\\:{10}^{-7}\\cdot\\:{t}_{FS}^{2})$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ewhere CI\u0026thinsp;=\u0026thinsp;colostrum intake, BW\u0026thinsp;=\u0026thinsp;body weight at 24 hours of age, BWB\u0026thinsp;=\u0026thinsp;birth weight, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{FS}\\)\u003c/span\u003e\u003c/span\u003e= estimated time of first suckling (30 min), and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:t=25\\:\\)\u003c/span\u003e\u003c/span\u003eh.\u003c/p\u003e\u003cp\u003ePiglets were individually marked for identification and weighed using a digital scale with an accuracy of \u0026plusmn;\u0026thinsp;2 g (WE2108, Profilv\u0026aring;gen, 2010, Borl\u0026auml;nge, Sweden) immediately after colostrum sampling (birth weight) and again 24 hours after birth. Piglets were subsequently weighed at 5 and 9 weeks of age to assess growth performance. The mean age at weaning was 32 days and the pigs were transferred to the fattening unit at ~\u0026thinsp;9 weeks of age. Survival to weaning was recorded. Growth rate (g/day) was calculated as the difference between weight at 5 and 9 weeks of age, respectively, and birth weight, divided by the piglet\u0026rsquo;s age in days at weaning.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eData were processed in R. Descriptive statistics (mean, median, and standard deviation) were calculated for all variables. Pairwise Pearson correlations were used to examine the relationships between birth weight, weight at 24 hours, weights at 5 and 9 weeks, colostrum intake, growth from birth to weaning, growth from birth to 9 weeks of age, and colostrum antibody concentration (Brix %).\u003c/p\u003e\u003cp\u003eNon-normally distributed variables were analysed using the Kruskal\u0026ndash;Wallis test, including associations between growth (birth to weaning; birth to 9 weeks) and Brix categories (\u0026lt;\u0026thinsp;25%, 27.5%, and \u0026gt;\u0026thinsp;30%). The effects of sow breed and parity on Brix values, as well as on growth variables, were analysed using the Kruskal\u0026ndash;Wallis test.\u003c/p\u003e\u003cp\u003eThe association between low colostrum intake (growth during the first 24 hours) and intake of colostrum with low versus high antibody content, and the subsequent impact on growth to weaning, was analysed using the Mann\u0026ndash;Whitney U test.\u003c/p\u003e\u003cp\u003eLasso regression was used to identify important predictors and to avoid overfitting.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eBody weight at birth was recorded for 372 piglets, and piglets that were cross-fostered were excluded from the analyses. The number of piglets included in the dataset decreased over time due to both mortality and cross-fostering. Thus, at weaning (5 weeks), 308 piglets remained in the calculations, and 298 remained at 9 weeks of age.\u003c/p\u003e\u003cp\u003eThe newborn piglets weighed on average 1.42 kg, with a median weight of 1.46 kg, a minimum of 0.5 kg and a maximum of 2.28 kg. The weight after 24 hours averaged 1.49 kg, with a median of 1.51 kg, a minimum of 0.62 kg and a maximum of 2.47 kg. The weaning weight (5 weeks of age) averaged 10.97 kg, with a median of 11.1 kg, a minimum of 3.3 kg and a maximum of 19.1 kg. At 9 weeks of age, the piglets weighed on average 32.45 kg, with a median of 33.2 kg, a minimum of 15.8 kg and a maximum of 45.9 kg (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eBirth weight had a strong positive correlation with weight after 24 hours (r\u0026thinsp;=\u0026thinsp;0.966), weaning weight, and weight at 9 weeks (r\u0026thinsp;=\u0026thinsp;0.746). Growth from birth to weaning averaged 0.279 kg/day, with a median of 0.285 kg/day, a minimum of 0.221 kg/day and a maximum of 0.492 kg/day.\u003c/p\u003e\u003cp\u003eGrowth from birth to 9 weeks averaged 0.488 kg/day, with a median of 0.499 kg/day, a minimum of 0.221 kg/day and a maximum of 0.699 kg/day. Piglets that survived had a higher mean birth weight, 1.55 kg, than those that died, 1.18 kg.\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\u003eWeight and colostral parameters measured at birth and up to 9 weeks of age\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=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\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\u003eN\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eN*\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMinimum\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eMedian\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eMaximum\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBirth weight, kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e372\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1,42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1,46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2,28\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight 24 hour, kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e358\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1,49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0,62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1,51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2,47\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight 5 week, kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e308\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e10,97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e3,30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e11,10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e19,10\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight 9 week, kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e32,45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e15,80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e33,20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e45,90\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eColostrum intake, mL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e355\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e233,4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e218,2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e808,3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eADWG 5 week, g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e308\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e279\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e285\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e492\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eADWG 9 week, g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e488\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e221\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e499\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e699\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBrix%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e372\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e27,5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e24,1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e27,2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e32,2\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\u003cem\u003eMeasurements of birth weight, weight at 24 h, 5 and 9 weeks of age, ADWG\u0026thinsp;=\u0026thinsp;average daily weight gain Brix% - as measured as percentage of total solids content by a Brix refractometer, N\u0026thinsp;=\u0026thinsp;number of pigs.\u003c/em\u003e\u003c/p\u003e\u003cp\u003eColostrum intake, as calculated according to the formula by Devillers \u003cem\u003eet al\u003c/em\u003e.(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), averaged 233.4 mL, with a median of 218.2 mL, a minimum value of 0 and a maximum of 808.3 mL. The antibody content in colostrum (\u0026ldquo;Brix\u0026rdquo;) averaged 27.5%, with a median of 27.2%, a minimum of 24.1% and a maximum of 32.2%.\u003c/p\u003e\u003cp\u003eAntibody levels in colostrum had no significant effect on survival. Only a limited number of piglets fell outside the proposed Brix thresholds (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e), with 24 piglets registering values below 25% and 44 piglets above 30%, and therefore the study\u0026rsquo;s mean value (27.5%) was instead used as the threshold for \u0026ldquo;low\u0026rdquo; and \u0026ldquo;high\u0026rdquo; antibody content.\u003c/p\u003e\u003cp\u003eThe antibody content showed weak or no correlation with the weight parameters at birth and 24 hours. Piglets with a Brix value\u0026thinsp;\u0026ge;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;149) showed significantly higher average daily weight gain (ADWG) at 5 weeks of age compared to those with values\u0026thinsp;\u0026lt;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;159). Median AWDG for the two groups were 298 g and 276 g, respectively. A Kruskal\u0026ndash;Wallis test revealed a statistically significant difference in growth between the groups (Z = \u0026minus;\u0026thinsp;2.75, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), indicating that higher IgG content were associated with improved growth.\u003c/p\u003e\u003cp\u003ePiglets with a Brix value\u0026thinsp;\u0026ge;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;144) also showed significantly higher average daily weight gain (ADWG) at 9 weeks of age compared to those with values\u0026thinsp;\u0026lt;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;154). Median AWDG for the two groups were 510 g and 486 g, respectively. A Kruskal\u0026ndash;Wallis test revealed a statistically significant difference in growth between the groups (Z = \u0026minus;\u0026thinsp;2.40, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), indicating that higher IgG content was associated with improved growth from birth to transition to the fattening unit.\u003c/p\u003e\u003cp\u003eA difference was observed between breeds, where LZ had significantly (p\u0026thinsp;\u0026lt;\u0026thinsp;0.01) higher antibody content in the colostrum (29.9%). However, since the value relates to a single sow, no conclusions can be drawn from this result.\u003c/p\u003e\u003cp\u003eLasso regression showed a weak positive association (r\u0026thinsp;=\u0026thinsp;0.032) between the antibody level in colostrum and the growth rates from birth to 9 weeks of age. Colostrum intake showed a positive association (r\u0026thinsp;=\u0026thinsp;0.385) with weaning weight. The weight at 9 weeks was positively associated (r\u0026thinsp;=\u0026thinsp;0.746) with weaning weight.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe importance of adequate colostrum intake for neonatal piglet survival, health and growth has been demonstrated across numerous studies (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Our findings support this general understanding by showing that colostrum quality, as measured as percentage of total solid contents, had a significant impact on growth, whereas survival was primarily associated with birth weight. This aligns with Jourquin \u003cem\u003eet al.\u003c/em\u003e and Le Dividich \u003cem\u003eet al\u003c/em\u003e., who argue that piglets with a high birth weight have better changes of survival regardless of colostrum intake (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). While this interpretation fits with studies emphasising the importance of early energy supply, it contrasts with research highlighting colostrum\u0026rsquo;s essential immunological role. Given that piglets are born immunocompetent but without prior antigen exposure, our results suggest that\u0026mdash;under low pathogen pressure, as is the case in an SPF-herd\u0026mdash;high-quality colostrum may contribute more to optimising growth potential than to immediate survival.\u003c/p\u003e\u003cp\u003eOur findings that low colostrum intake is associated with reduced growth also complement previous work demonstrating the critical role of energy acquisition in the neonatal period (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Starvation remains one of the most frequent causes of pre-weaning mortality, together with crushing (Rangstrup-Christensen et al. 2018; Kielland et al. 2018). Further, insufficient energy intake is often implicated in death by crushing, as weakened piglets are less able to avoid the sow. Environmental conditions also influence early energy expenditure, and higher environmental temperatures may reduce piglet heat loss, thereby reducing the energy losses. In the present study, the rather high environmental temperature (22.7\u0026deg;C) might have contributed to the low mortality during the first 24 hours \u003cem\u003ep.p.\u003c/em\u003e\u003c/p\u003e\u003cp\u003eOur study also indicates that genetic and litter-related factors substantially affected both growth and survival, reinforcing earlier observations that colostral IgG concentrations vary greatly both between and within herds (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). These variations suggest that housing system and management practices strongly influence colostrum production and intake. Factors promoting optimal hormonal profiles\u0026mdash;such as nest-building behaviour and provision of nesting material\u0026mdash;have been shown to improve oxytocin and progesterone release, support calmer nursing behaviour, and lengthen milk let-down in loose-housed sows (Yun et al. 2014). These behavioural and hormonal influences may help explain part of the variability observed in our dataset. However, this was not investigated in the present study.\u003c/p\u003e\u003cp\u003eIncreasing litter sizes remain an important challenge. Larger litters may reduce individual birth weights, prolong farrowing, and increase competition at the udder, increasing the likelihood that later-born piglets access less colostrum and of lower IgG concentration (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). However, the relationship between the order at birth and IgG content in colostrum was not investigated in the present study. Our results, showing that higher Brix values (\u0026gt;\u0026thinsp;27.5%) were associated with improved growth, support the notion that colostrum quality could partially compensate for limited volume intake. This highlights the value of monitoring colostrum quality at the herd level.\u003c/p\u003e\u003cp\u003eThe Brix refractometer provides a simple, objective, and practical method for estimating colostrum quality on-farm (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). In addition to offering rapid results, it enables evaluation of whether management interventions have a measurable effect on colostrum composition. However, obtaining samples within the optimal time frame requires continuous farrowing surveillance (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e), which is highly labour-intensive and may not be feasible in smaller herds. As such, Brix testing may be better suited for spot-sampling during daytime farrowings, or for use in larger herds with sufficient staffing to support 24-hour farrowing supervision. In contrast, estimating colostrum intake remains labour-intensive, requiring repeated weighing within the first 24 hours. Nevertheless, periodic weighing of selected litters may still be feasible as part of a herd-monitoring programme. Considering that up to one-third of the sows may produce insufficient colostrum for their litters (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e), breeding for improved colostrum production and quality could further strengthen neonatal resilience.\u003c/p\u003e\u003cp\u003eOverall, our results demonstrate that both biological and management-related factors interact to shape early piglet performance. Effective herd strategies should therefore combine improved colostrum management, enhanced farrowing supervision, optimisation of environmental conditions, and consideration of genetic influences.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn conclusion, colostrum quality as measured by a Brix refractometer has a significant impact on piglet growth from birth to 5 and 9 weeks of age, where antibody levels above 27.5% resulted in significantly better growth.\u003c/p\u003e\u003cp\u003eBirth weight was shown to be highly important for survival, whereas antibody levels in colostrum had no direct effect.\u003c/p\u003e\u003cp\u003eBased on the results of this study, genetics may affect the antibody content in colostrum. However, the effect of genetics warrants further studies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors gratefully acknowledge the staff at the University Research Farm, L\u0026ouml;vsta, for skilful assistance. We would also like to acknowledge Razaw Al-Sarraj for skilful help with the statistical analyses.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMJ was responsible for the design of the study. AC and ES performed the clinical parts of the study. AC wrote the manuscript and all authors contributed in scrutinizing the text. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was financed by grants from the Royal\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eSwedish Academy of Agriculture and Forestry, and from the Swedish University of Agricultural Sciences.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analysed during the current study are available from the corresponding author upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Swedish Board of Agriculture and the Ethics Committee for Animal Experimentation, Uppsala, Sweden (approval no. 5.2.18-02900/2020). All procedures were conducted in accordance with the Swedish Animal Welfare Act (SFS 2018:1192), the Animal Welfare Ordinance (SFS 2019:66), and EU animal welfare legislation, including Directive 2010/63/EU on the protection of animals used for scientific purposes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations -conflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interests\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eStygar AH, Chantziaras I, Maes D, Aarestrup Moustsen V, De Meyer D, Quesnel H et al. Economic feasibility of interventions targeted at decreasing piglet perinatal and pre-weaning mortality across European countries. Porcine Health Manage. 2022;8(1).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDividich JL, Rooke JA, Herpin P. Nutritional and immunological importance of colostrum for the new-born pig. J Agricultural Sci. 2005;143(6):469\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMilon A, Aumaitre A, Le Dividich J, Franz J, Metzger J, editors. Influence of birth prematurity on colostrum composition and subsequent immunity of piglets. Annales de recherches v\u0026eacute;t\u0026eacute;rinaires; 1983.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRooke JA, Bland IM. The acquisition of passive immunity in the new-born piglet. Livest Prod Sci. 2002;78(1):13\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBandrick M, Ariza-Nieto C, Baidoo SK, Molitor TW. Colostral antibody-mediated and cell-mediated immunity contributes to innate and antigen-specific immunity in piglets. Dev Comp Immunol. 2014;43(1):114\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQuesnel H, Farmer C, Theil PK. Colostrum and milk production. Brill | Wageningen Academic; 2015. pp. 173\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDevillers N, Van Milgen J, Prunier A, Le Dividich J. Estimation of colostrum intake in the neonatal pig. Anim Sci. 2004;78(2):305\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePrunier A, Heinonen M, Quesnel H. High physiological demands in intensively raised pigs: impact on health and welfare. Animal. 2010;4(6):886\u0026ndash;98.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDevillers N, Le Dividich J, Farmer C, Mounier AM. Le Hu\u0026euml;rou-Luron I. Variability of colostrum yield and colostrum intake in pigs. 2005;54(4):313\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQuesnel H, Farmer C, Devillers N. Colostrum intake: Influence on piglet performance and factors of variation. Livest Sci. 2012;146(2):105\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlobasa F, Werhahn E, Butler JE. Composition of Sow Milk During Lactation. J Anim Sci. 1987;64(5):1458\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlbera E, Kankofer M. Antioxidants in Colostrum and Milk of Sows and Cows. Reprod Domest Anim. 2009;44(4):606\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTan L, Wei T, Yuan A, He J, Liu J, Xu D, et al. Dietary Supplementation of Astragalus Polysaccharides Enhanced Immune Components and Growth Factors EGF and IGF-1 in Sow Colostrum. J Immunol Res. 2017;2017:1\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJahan M, Francis N, Wang B. Milk lactoferrin concentration of primiparous and multiparous sows during lactation. J Dairy Sci. 2020;103(8):7521\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNuntapaitoon M, Juthamanee P, Theil PK, Tummaruk P. Impact of sow parity on yield and composition of colostrum and milk in Danish Landrace \u0026times; Yorkshire crossbred sows. Prev Vet Med. 2020;181:105085.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTheil PK, Lauridsen C, Quesnel H. Neonatal piglet survival: impact of sow nutrition around parturition on fetal glycogen deposition and production and composition of colostrum and transient milk. animal. 2014;8(7):1021\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQuigley JD, Lago A, Chapman C, Erickson P, Polo J. Evaluation of the Brix refractometer to estimate immunoglobulin G concentration in bovine colostrum. J Dairy Sci. 2013;96(2):1148\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHasan S, Rydhmer L, Jonsson L, Gustafsson H, Wattrang E, Johansson G et al. Validation of Brix refractometer to estimate colostrum immunoglobulin G content and composition in the sow. 2016;58(1):1\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLe Dividich J, Charneca R, Thomas F. Relationship between birth order, birth weight, colostrum intake, acquisition of passive immunity and pre-weaning mortality of piglets. Span J Agricultural Res. 2017;15(2):e0603.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJourquin J, Morales J, Bokenkroger C. Impact of piglet birth weight increase on survivability and days to market, a simulation model. J Anim Sci. 2016;94:34.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOliviero C, Junnikkala S, Peltoniemi O. The challenge of large litters on the immune system of the sow and the piglets. Reprod Domest Anim. 2019;54(S3):12\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e\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":"[email protected]","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":"Colostrum, Brix, sow, piglet, growth, survival","lastPublishedDoi":"10.21203/rs.3.rs-8213260/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8213260/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003ePiglets are born without antibodies, as no transfer of immunoglobulins occur across the sow\u0026rsquo;s placenta. Thus, the passive transfer through colostrum is essential to establish protection against environmental pathogens and enhance the health and survival of the neonatal piglet. The aim of this study was to investigate how colostrum quality in sows influence growth and survival in piglets and to determine whether higher colostrum quality can compensate for lower colostrum intake.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eFarrowings were monitored at three-hour intervals through regular visual inspections. Colostrum was manually collected from all teats. Antibody concentration was measured immediately using a digital Brix refractometer (PAL-1 BLT/A\u0026thinsp;+\u0026thinsp;W, Atago, Tokyo, Japan). Piglets were individually marked for identification and weighed immediately after colostrum sampling (birth weight) and again 24 hours after birth. Piglets were subsequently weighed at 5 and 9 weeks of age to assess growth performance.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe antibody content in colostrum (\u0026ldquo;Brix\u0026rdquo;) averaged 27.5%, with a median of 27.2%, a minimum of 24.1% and a maximum of 32.2%. Antibody levels in colostrum had no significant effect on survival. Piglets with a Brix value\u0026thinsp;\u0026ge;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;149) showed significantly higher average daily weight gain (ADWG) at 5 weeks of age compared to those with values\u0026thinsp;\u0026lt;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;159). Median AWDG for the two groups were 298 g and 276 g, respectively. Piglets with a Brix value\u0026thinsp;\u0026ge;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;144) also showed significantly higher average daily weight gain (ADWG) at 9 weeks of age compared to those with values\u0026thinsp;\u0026lt;\u0026thinsp;27.5% (n\u0026thinsp;=\u0026thinsp;154). Median AWDG for the two groups were 510 g and 486 g, respectively.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eIn conclusion, colostrum quality as measured by a Brix refractometer has a significant impact on piglet growth from birth to 5 and 9 weeks of age, where antibody levels above 27.5% resulted in significantly better growth. Birth weight was shown to be highly important for survival, whereas antibody levels in colostrum had no direct effect.\u003c/p\u003e","manuscriptTitle":"The Impact of Colostral IgG Levels on Growth and Viability in Piglets","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-01 14:51:30","doi":"10.21203/rs.3.rs-8213260/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","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":"d3041999-e857-4b6c-a0a2-9b3ae4198f01","owner":[],"postedDate":"December 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-25T17:25:02+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-01 14:51:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8213260","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8213260","identity":"rs-8213260","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}