Impact of pen space allowance in outdoor feedlot on cattle performance, and carcass and meat quality traits

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J. R. Paranhos da Costa This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4714140/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 We analyzed the effects of feedlot pen space allowances on cattle performance and carcass and meat quality traits. Bulls (N = 1350) with an average age of 30 ± 6 months and weight of 392 ± 46 kg were assigned to one of three feedlot pen space allowances, 6 (T6), 12 (T12) and 24 (T24) m2/animal. The animals were weighed in the beginning and end of experimental period and individual average daily gain (ADG) was calculated. Hot carcass weight (HCW), fat cover (scored from 1 to 5), carcass bruise occurrences (classified as old or new and superficial, muscular, or severe), and meat pH24 were assessed in a commercial slaughterhouse. Treatment T24 showed higher (P<0.05) ADG than T6 and T12. T6 had lower (P<0.05) HCW than T12 and T24. T6 had the highest (P<0.05) percentage of carcass scored 3 for fat cover, followed by T24 and T12. In all the treatments pH24 were within the range that ensured good meat quality, ranging from 5.60 (T24) to 5.63 (T6). The mean of new bruises per carcass was lowest for T24 (P 0.05). Superficial bruises were more frequent in T24 than in T6 and T12 carcasses (P<0.05), differing from each other, but the mean number of muscular bruises was higher in T6 than in T12 and T24 (P0.05). We conclude that reduced space in feedlot pens lessens beef cattle performance and downgrades carcass quality. Average daily gain hot carcass weight carcass bruises meat pH24 welfare. Figures Figure 1 Figure 2 INTRODUCTION Space is an essential resource in the adequacy of feedlot pens and when it is not appropriately defined, it increases the risk of harming animal welfare (Macitelli et al., 2020 ). Limited space in cattle feedlot pens is usually associated with mud accumulation (Mader, 2011), increased frequency of agonistic behaviors (Kondo et al., 1989 ), and a higher risk of predisposing cattle to more severe effects of pathogens (Stokka et al., 2001 ). Space restriction could also result in physiological and psychological stress, negatively affecting cattle performance (Mader, 2011; Wechsler, 2011; Krawczel et al., 2012 ). Additionally, due to the increasing concern about the welfare of farm animals, high-density feedlots harm consumers’ perceptions of the beef cattle production chain (Vanhonacker et al., 2009 ). Despite the existing knowledge about the relevance of feedlot space for cattle welfare, most of the studies were conducted in indoor feedlots, with a small number of animals kept at high stock densities (Fisher et al., 1997 ; Gygax et al., 2007 ). These conditions do not foster the consideration of many environmental effects, such as exposure to climatic factors (Van Laer et al., 2014 ) and social relationships, which differ between large or small groups of animals (Fraser et al., 2013 ). According to Grandin ( 2016 ), the main problems of outdoor feedlots are: (1) muddy pens and the difficulty of keeping cattle clean, (2) heat stress caused by lack of shade in the pens and (3) problems associated with managing large numbers of cattle, besides the high concentration of dust in the air during the dry period, being expected that this problems are aggravated when animals are kept in high density (Macitelli et al., 2020 ). Although the dust particles emitted by feedlots are dominated by large particles (Guo et al., 2011 ), which are relatively simple to control with irrigation systems, it must be considered that feedlot dust particles harbor antibiotic residues, bacteria, and antibiotic resistance genes (McEachram et al., 2015), which increase the risk of health problems to animals and people exposed to this polluted air. To our knowledge, only one study assessed the impact of space allowance on the performance of beef cattle in commercial outdoor feedlots (Mader, 2011), but it was performed under different conditions (concerning climate, nutrition, confinement period, and breed) than our study. This study aimed to assess the effects of space allowance in outdoor feedlots under tropical conditions on beef cattle performance and carcass and meat quality traits. MATERIALS AND METHODS This study was carried out according to the Brazilian legislation and approved by the Committee of Ethical Use of Animals from the Faculty of Agricultural and Veterinary Sciences, São Paulo State University, Jaboticabal-SP, Brazil, Jaboticabal, SP, Brazil (Certified n. 025961/13). Animals, treatments, and facilities The study was conducted in a commercial feedlot in the municipality of Campo Verde, Mato Grosso State, Brazil (15º32’ S and 55 o 10’ W, 736 meters above the sea level) from August to November 2013, totaling 87 or 111 days in a feedlot. One thousand three hundred and fifty bulls were evaluated, 450 pure Nellore and 900 crossbred Angus or Caracu vs. Nellore cattle. At the beginning of the feedlot period. the animals were around 30 ± 6 months of age and weighed 392 ± 46 kg of body weight, on average. The animals were individually identified with numbered ear tags. All animals were road transported to the farm where the study was carried out two weeks before starting feedlot operations. During this period, cattle were kept on pasture ( Brachiaria ruzizienses ), with free access to mineral supplements and water. Just before entering the feedlot facilities, they were weighed, vaccinated against clostridial diseases, dewormed (Doramectin 1%, Dectomax, Zoetis Brasil, São Paulo, SP, Brazil), and assigned (randomly within breed) to nine batches (with 150 animals each). The batches were sorted in one of the three treatments, defining one batch of pure Nellore and two of crossbred cattle per treatment. The treatments consisted of three pen space availability, 6 (T6), 12 (T12) and 24 (T24) m² per animal. These space allowances were defined considering that 12 m 2 /animal is the average space available per head of cattle in the commercial Brazilian feedlots, compared to halving it (negative control) and doubling the space (positive control). The feedlot pens were enclosed by smooth wire fences, and their surfaces (unpaved ground) had approximately 5% slope. The pen areas were defined by changing their lengths, being 18, 36 and 72 m for T6, T12 and T24, respectively. The water troughs were 1.5 meters in diameter (each serving two feedlot pens), and the feed bunk line was 50 meters long in each feedlot pen, resulting in 33 cm per animal. Diet and feeding management Cattle were fed two diets in the feedlot: the adaptation diet, offered in the first 25 days of confinement; and the finishing diet, offered from the 26th day until the end of the feedlot period (Table 1 ). The RLM® software (Integra Software, a Brazilian nutritional program that considers age, body weight, sexual condition, genetic group, the nutritional composition and digestibility of Brazilian foods, and the market value of ingredients, aiming for maximum profit) was used to formulate the diets. Table 1 Composition (% of DM) of the adaptation and finishing diets offered to the cattle in all treatments during the study period. Ingredients Adaptation diet Finishing diet Corn silage 44.03 14.00 Cotton hulls 00.00 12.50 Corn residue* 07.09 10.20 Milled corn 26.18 40.30 Cotton seed cake 12.67 12.38 Soybean skin 08.13 08.84 Other** 01.90 01.78 Total 100.00 100.00 DM = Dry matter; Dry matter intake = 2.4% live weight. *Residue from corn storage. **14.93% mineral salt, 85% urea and 0.074% monensin sodium salt. The animals were fed four times a day, twice in the morning (07:30h and 10:00h) and in the afternoon (14:30h and 16:30h). Before the first feeding of the day, the person responsible for the feed bunk management applied a 5-points feed bunk scoring (Table 2 ) in each pen, and this score was used to define the amount of food that should be offered for each pen that day. Generally, the animals received 40% of the total amount of food at the last feeding of each day and 20% at each of the other three feeding times. The average daily gain (ADG) expected for the entire feedlot period was 1.6 kg/animal. Table 2 Criteria used for the feed bunk management used to define the amount of food that should be offered for each pen every day Score Feed bunk condition Cattle behavior Amount of food -2 Empty Most of the animals (more than 50%) standing in front of the feed bunk Increase 10% the amount of food in relation to the day before − 1 Empty Few animals (less than 25%) standing in front of the feed bunk Increase 5% the amount of food in relation to the day before 0 Empty or little quantity of food (5 to 10% of the last feeding). It is possible to see the bottom of the feed bunk Most of the animals is calm and not expecting the food at the feed bunk Same amount of food than the last day 1 Little quantity of food. It is not possible to see the bottom of the feed bunk (20% of the last feed) Half of animals standing and half lying down Decrease 5% of the amount of food in relation to the day before 2 Full Most of animals lying and ruminating Decrease 10% of the amount of food in relation to the day before Adapted from Pritchard and Burns (2003). Performance traits The animals were weighed in the beginning (d0, initial body weight = IBW), after 35 days (d35, intermediate body weight = MBW), and at the end of the feedlot period (final body weight = FBW, measured just before loading the animals to the slaughterhouse). Weighing was done always after a fasting period of 12 hours. The average daily weight gains (ADG) were calculated for three periods: from d0 until d35 (ADGi = (MBW – IBW)/dp1), from d35 until the end of the feedlot period (ADGf = (FBW – MBW)/dp2), and from d0 until the end of the feedlot period (ADGt = (FBW – IBW)/dpt), where dp1, dp2 and dp3 are the number of days covered in each period (35, 51, and 86 or 110 days, respectively). Three classes of ADGt were defined and the percentage of cattle with ADG ≤ 1.6 kg/day, from 1.61 to 2.39 kg/day, and ≥ 2.40 kg/day were recorded for each treatment. Cattle were slaughtered in two commercial slaughterhouses, both under the inspection of the Official Veterinary Service of Brazil. The first slaughter was conducted with three batches (one of each treatment) of crossbred bulls 86 days after the beginning of the experiment, and the second occurred 24 days later when the remaining animals were slaughtered. The hot carcass weights (HCW, kg) were provided by the slaughterhouse. Carcass and meat quality traits A trained person recorded the presence of bruises (yes or no) and, when present, the number of bruises per carcass, and their colors and severities. The color of the bruises was classified as fresh (for those presenting bright red color) or old (for those with yellowish-green color), as described by Gracey and Collins ( 1992 ). The bruise severity was scored as superficial, when the damaged area comprises only subcutaneous tissues; muscular, when the damaged area comprises subcutaneous and muscular tissue; and severe, when subcutaneous, muscular tissues and even bones are damaged, including fractures, as described in the Chilean grading system (INN, 2012). The same trained person used a five-point scale (BRASIL, 2004 ) to score the amount of fat cover on carcasses. A slaughterhouse technician measured the meat pH24 with a digital pHmeter. The measurements were done in the 12th rib region (ribeye), inside of the right half-carcass maintained at a temperature of about 2°C for 24 hours after the slaughter. Statistical Analyses The consistency of the database was carried out with the Microsoft Excel software and the extreme values were excluded by applying the criterion of average ± 3 standard deviations. All data were analyzed using SAS software (SAS Inst. Inc. Cary, NC), considering animals as the subjects and the results were considered statistically different when P < 0.05. The normality of data distribution was checked for all continuous dependent variables (IBW, FBW, ADG1, ADG2, ADGt, HCW, and pH24) using the Kolmogorov-Smirnov test. The analysis of variance was conducted using Proc Mixed to evaluate the effect of treatments (space allowance) on IBW, FBW, ADGi, ADGf, ADGt, HCW, and pH24. The model included the fixed effect of treatment and the random effect of genetic groups. When analyzing FBW and HCW, IBW was included in the model as a covariate. For HCW and pH24 analysis, the slaughterhouse was included in the model as a random effect. Means comparisons were performed by post-hoc Tukey test. A chi-square test (using Proc Freq) was applied to assess whether the frequency of fat cover scores of ADGt classes depends on the treatments. Due to the differences in transport distance and conditions between the two slaughterhouses, we considered only the animals slaughtered in the second plant to do the bruises analyses. The effects of the treatments on the number of new, old and total and superficial, muscular and severe bruises per carcass were analyzed using the Glimmix procedure, considering the fixed effect of treatment, the random effect of breed, and a Poison distribution. The effect of treatment on the risk of bruises occurrences was analyzed by applying a logistic regression (Proc Genmod), assuming data binomial distribution with a probit link function to an adjacent normal distribution, assuming T24 as the reference category (RC). RESULTS Performance traits Significant differences among treatments were observed for FBW (F 2, 968 = 9.93), HCW (F 2, 968 = 2.94), ADGi, ADGf and ADGt (F 2, 960 = 13.64, F 2, 959 = 64.14, F 2, 970 = 17.68, respectively), but not for IBW (F 2, 970 = 0.46). The ADGi was lower for T24 and did not differ between T6 and T12. On the other hand, T24 showed higher FBW, ADGf, and ADGt means than T12 and T6 (Table 3 ). There was no difference between HCW means of T24 and T12, which were greater than the T6 mean. The percentages of animals for each class of ADG also differed significantly among treatments for ADGt (DF = 42, \(\:\chi\:\) ² = 106.63), as shown in Fig. 1 . Table 3 Means (± SE) of the cattle performance traits when kept in feedlot pens under three space allowances (6, 12 and 24 m²/animal). Variables Space allowances 6 m²/animal 12 m²/animal 24 m²/animal IBW (kg) 389.16 ± 9.37 a 390.11 ± 9.34 a 386,74 ± 9.36 a FBW (kg) 526.76 ± 10.12 c 535.45 ± 9.96 b 538.22 ± 10.10 a ADGi (kg/d) 2.19 ± 0.08 a 2.14 ± 0.08 a 1.91 ± 0.08 b ADGf (kg/d) 1.30 ± 0.12 c 1.40 ± 0.12 b 1.71 ± 0.12 a ADGt (kg/d) 1.60 ± 0.08 c 1.69 ± 0.08 b 1.77 ± 0.08 a HCW (kg) 291.85 ± 1.29 b 294.42 ± 1.23 a 295.17 ± 1.25 a Initial body weight (IBW), final body weighed (FBW), hot carcass weight (HCW), average daily gain in the first period (ADGi, from d0 to d35), average daily gain in the second period (ADGf, from d36 until the end of the feedlot period), and average daily gain for the total experimental period (ADGt, from d0 until the end of the feedlot period). Means followed by the same letters in the lines did not differ statistically (Tukey test, P > 0.05). Carcass and meat quality traits No carcass was scored as 4 or 5 for fat cover and only one case of severe bruise was recorded, being excluded from the statistical analyzes. The percentages of carcass receiving fat cover scores 1, 2 or 3 vary significantly among treatments (DF = 4, \(\:\chi\:\) ² = 12.89, Fig. 2 ), with a higher percentage of score 3 occurring in T6, followed by T24 and T12 (50.54, 42.28 and 39.16%, respectively). The number of new (F 2, 737 = 11.99), old (F 2, 738 = 8.55) and total (F 2, 737 = 14.58) bruises per carcass differed among treatments. The mean number of new bruises per carcass was lowest for the T24 and did not differ between the T6 and T12. The mean number of old and total bruises per carcass were highest for T12, but T24 and T6 did not differ (Table 4 ). The odds ratios of new and total bruises differed among treatments, as shown in Table 5 . We observed an increased risk of new and total bruises for T6 and T12. However, the risk of old bruises did not differ among treatments. Table 4 Adjusted (± SE) and observed means (between brackets) of the numbers of new, old and total bruises per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m²/animal). Bruises categories Space allowance 6 m²/animal 12 m²/animal 24 m²/animal New -0.38 ± 0.17 a (0.50) -0.20 ± 0.16 a (0.60) -0.91 ± 0.18 b (0.30) Old -2.10 ± 0.18 b (0.12) -1.23 ± 0.11 a (0.29) -1.58 ± 0.14 b (0.20) Total -0.14 ± 0.15 b (0.62) 0.22 ± 0.14 a (0.90) -0.36 ± 0.15 b (0.51) Means followed by the same letters in the lines did not differ statistically (Tukey test, P > 0.05). Table 5 Odds ratios and respective confidence intervals of new, old and total bruises occurrences per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m²/animal). Bruises categories and space allowances N % Odds ratio Confidence Intervals \(\:\varvec{\chi\:}2\) New 6 m²/animal 246 49.59 1.68 1.13–2.46 6.72 * 12 m²/animal 266 60.53 1.77 1.20–2.64 8.02 * 24 m²/animal 229 30.00 1.00 RC . Old 6 m²/animal 246 12.19 0.68 0.41–1.17 1.92 12 m²/animal 266 29.32 1.51 0.95–2.41 3.05 24 m²/animal 229 20.00 1.00 RC . Total 6 m²/animal 246 61.78 1.40 0.92–2.03 3.23 * 12 m²/animal 266 89.85 1.72 1.20–2.46 8.52 * 24 m²/animal 229 50.00 1.00 RC . \(\:\chi\:\) 2 test, all P > 0.05. N = total number of evaluated animals; (%) = percentage of animals with bruises, and RC = reference class. The number of superficial (F 2, 737 = 20.13) and muscular bruises (F 2, 737 = 4.32) differed among treatments. T24 had the lowest mean of superficial bruises per carcass, followed by T6 (N = 0.48) and T12 (N = 0.65), respectively; and T6 had the lowest mean of muscular bruises per carcass, with T24 and T12 not differing from each other (Table 6 ). The odds ratios of superficial and muscular bruises differed between treatments (P < 0.05). There was a pronounced increase in the risk of superficial bruises for T6 and T12 compared to the reference class (T24). On the other hand, the risk of muscular bruises was lower for T6 (Table 7 ). Table 6 Adjusted (± SE) and observed means (between brackets) of the number of superficial and muscular bruises per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m²/animal). Bruises severity Space allowances 6 m²/animal 12 m²/animal 24 m²/animal Superficial -0.10 ± 0.18 b (0.48) 0.17 ± 0.16 a (0.65) -0.79 ± 0.19 c (0.25) Muscular -2.00 ± 0.19 b (0.14) -1.48 ± 0.15 a (0.23) -1.40 ± 0.15 a (0.25) Means followed by the same letters in the lines did not differ statistically (Tukey test, P > 0.05). Table 7 Odds ratios and respective confidence intervals of superficial and muscular bruises occurrences per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m²/animal). Bruise categories and space allowance N % Odds ratios Confidence intervals \(\:\varvec{\chi\:}2\) Superficial 6 m²/animal 381 37.00 2.37 1.55–3.60 15.99 * 12 m²/animal 403 35.70 2.72 1.13–2.46 23.48 * 24 m²/animal 399 24.89 1.00 RC . Muscular 6 m²/animal 381 10.97 0.50 0.30–0.83 7.27* 12 m²/animal 403 21.43 0.81 0.51–1.27 0.84 24 m²/animal 399 15.28 1.00 RC . \(\:\chi\:\) 2 test, all P > 0.05. N = total number of carcasses evaluated; (%) = percentage of carcass with bruises. RC = reference class. There were differences among treatments for meat pH (F 2, 960 = 5.40), with the highest mean observed for the T6 (5.63 ± 0.03) followed by T12 and T24 (5.61 ± 0.03 and 5.60 ± 0.04, respectively), which did not differ between each other (P > 0.05). DISCUSSION There is a tendency to reduce the space allowance for beef cattle housed in outdoor feedlots in Brazil, as evidenced by some recommendations, indicating the use of 8 m 2 per animal in outdoor feedlot pens (Souza et al., 2003 ). Such guidance ignores the risks of causing a negative environmental impact and impoverishing cattle welfare, raising worrisome ethical issues. Despite this, few studies addressed the effect of reducing space allowance per animal in outdoor feedlots. In this study, we evaluated the impact of three pen space allowances on performance and carcass and meat quality traits of cattle housed in outdoor feedlots by halving and doubling the area commonly used in commercial Brazilian feedlots. The results showed that increasing the space allowance resulted in better performance and carcass quality traits. Performance traits It is well known that many factors affect cattle ADG, including pen space allowances for feedlot cattle (Andersen et al., 1997 ; Fisher et al., 1997 ; Gygax et al., 2007 ; Herva et al., 2009 ). Our results corroborated these previous findings, showing that ADG differed between treatments in all feedlot periods, with a lower ADGi mean for T24 than for T6 and T12 and a higher ADGf and ADGt means for T24 than T6 and T12. The observed reduction in ADG after the adaptation phase in the feedlot was not expected. Newly arrived feedlot cattle usually face numerous stressors that change their behavior and physiological state, leading to lower performance (Loerch and Fluharty, 1999 ). However, the changes in the weather conditions during our study, resulting in increased rainfall during the second period, probably contributed to the ADG reduction. Rainfall increases mud accumulation in the feedlot pens (Macitelli et al., 2020 ), which leads to lower food consumption and cattle performance (Mader, 2011). Our results also show that high density in feedlots harms the individual performance of beef cattle, as indicated by the ADGf and ADGt means, and the distribution of weight gain observed for T6 and compared to T12 and T24 animals. We should also consider that reducing space allowance in feedlot pens can impair cattle health and causes behavioral disorders, also negatively affecting cattle performance (Andersen et al., 1997 ; Gygax et al., 2007 ). Although weight gain is widely used as a performance indicator, it is also important to regard the distribution of weight gain as a piece of complementary information since, with this information, it will be possible to compare the homogeneity of ADG between batches and to identify the percentages of animals at the lower extreme of the ADG’s curve. In this study, all treatments were under the same conditions, varying only in density. Our results show that 69.00% of animals in T24, 54.94% in T12, and 44.89% in T6 had a higher average daily weight gain than expected (> 1.60 kg/day, Fig. 1 ). According to the production cost calculation, animals should gain a minimum of 1.30 kg/day; otherwise, they would incur losses. Most of the 156 animals, which did not achieve the expected ADG were housed in T6 and T12 (41.03%, 44.23%, and 14.74%, for T6, T12, and T24 treatments, respectively). These results corroborate the outcomes from previous studies showing that the reduced space in indoor feedlots negatively affects cattle performance (Ingvartsen and Andersen, 1993 ; Fisher et al., 1997 ; Gygax et al., 2007 ) and feed conversion ratio (Cortese et al., 2020 ), strengthening the idea that the individual space in feedlots is an important resource for beef cattle. Carcass and meat quality traits Several factors affect the fat deposition in cattle carcasses, and the source of energy and its concentration in the diet are considered the most relevant factors, especially during the finishing period (Drackley et al., 2014 ). Once the animals of all treatments tested in this study received the same diet, other factors caused the differences in carcass fat cover between treatments. Interestingly, despite T6 showing the lowest ADFf and ADGt, a higher percentage of cattle from this treatment scored 3 for fat cover than T12 and T24. Carcass fat cover is indirectly associated with the meat quality because it controls the speed of temperature drop down and the action of enzymes that transform glycogen into lactic acid, lowering meat pH (McGilchrist et al., 2012 ). Despite the significant differences among the treatments found for carcass fat cover and meat pH, all the results were within the acceptable range for good carcass and meat quality (EU, 2007; BRASIL, 2017 ). Based on our results, we suggest that the stress caused by the space restriction altered the metabolism of energy nutrients, corroborating the results observed in several previous cattle studies, which showed that animals kept under limited space conditions displayed high concentrations of glucocorticoids in the blood (Friend et al., 1979 ). Our results are conflicting with what is expected of the metabolism and distribution of adipose tissue since we expected lower fat cover T6 cattle but, as pointed out by Peckett et al. ( 2011 ), “…the acute and long-term effects of glucocorticoids on adipose tissue lipolysis remain unclear…”. A well and standardized fat cover is desired. However, it depends on many factors, such as diet and genetics, besides being affected by metabolic disorders caused by stress. As already reported (Finger et al., 2012 ; Lee et al., 2014 ), chronic stress conditions increase the adipocyte cells, mainly the visceral fat deposition, which points to a lower efficiency of diet utilization by the animal to deposit tissues that are profitable. To our knowledge, there is no result about how chronic stress may increase fat accumulation in beef cattle adipocyte cells. The studies addressing this subject were conducted mainly with rats and humans because of the direct relationship between abdominal fat and metabolic and cardiovascular diseases in humans (Finger et al., 2012 ; Lee et al., 2014 ). Thus, there is a need to conduct further studies addressing the association between indicators of chronic stress and those related to visceral and fat cover deposition in cattle. Another variable used to assess the carcass quality was the occurrence of bruises. We expected that T6 cattle would show the highest number of old and muscular bruises in the carcasses since it is known that space restriction potentially increases physical contact and, consequently, the frequency of agonistic behavior (Lindberg, 2001; Rodenburg and Koene, 2007 ), as also described by Kondo et al. ( 1989 ), who reported a significant negative correlation between space allowance and agonistic behavior in feedlot cattle. However, this was not the case, probably because, as reported by Macitelli et al. ( 2020 ), T6 and T12 cattle reduced their locomotion over time, and a higher percentage of T6 cattle showed health problems and hooves alteration (three times higher than T12 and twice than T24), besides deeper mud in the pens. Therefore, we assume that since T6 cattle were not physically well, diminished the frequency and intensity of agonistic interactions, thus reducing the risk of old and muscular bruiser occurrences. On the other hand, T24 cattle had more space allowance and better health (Macitelli et al., 2020 ) and thus were more efficient in avoiding social confronts, preventing the risk of bruise occurrence. T12 cattle were apparently in an intermediate situation, where the space did not allow them to avoid agonistic encounters despite being in a better physical condition than those from T6. Then, we could suppose that the lower number of new and superficial bruises observed in T24 cattle was associated with their apparent tranquility during pre-slaughter handling procedures. Nevertheless, we should also consider other factors, not controlled in this study, that are relevant to consider when recording new bruises’ occurrence and severity, such as poor pre-slaughter handling and transport, bad facilities design, and cattle with excited temperament (Strappini et al., 2010 ; Paranhos da Costa et al., 2012 ; Schwartzkopf-Genswein et al., 2012 ). Muscular bruise occurrences were higher for T12 and T24 than for T6, which could reduce HCW. According to Huertas et al. ( 2015 ), bruises cause economic losses since, when muscular and severe, they are trimmed from the carcasses, downgrading meat cuts. Bruises have a direct effect on consumer perception of meat quality (Strappini et al., 2009 ) since bruised meat decomposes quickly (Chambers and Grandin, 2001 ), leading to poor taste and a shorter shelf-life. We conclude that pen space allowance for beef cattle kept in outdoor feedlots has a role in their performance and carcass quality and that reduced space in feedlot pens lessens cattle performance and downgrades carcass quality. STATEMENTS AND DECLARATIONS CONFLICT OF INTERESTS The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Funding The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Competing Interests The authors have no relevant financial or non-financial interests to disclose. Author Contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Fernanda Macitelli. The first draft of the manuscript was written by Fernanda Macitelli and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. 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Applied Animal Behaviour Science 24:127–135. https://doi.org/10.1016/0168-1591(89)90040-3 Krawczel PD, Klaiber LB, Butzler RE, Klaiber LM, Dann HM, Mooney CS, Grant RJ (2012) Short-term increases in stocking density affect the lying and social behavior, but not the productivity, of lactating Holstein dairy cows. Journal of Dairy Science 95:4298–4308. https://doi.org/10.3168/jds.2011-4687 Lee MJ, Pramyothin P, Karastergiou K, Fried SK (2014) Deconstructing the roles of glucocorticoids in adipose tissue biology and the development of central obesity. Biochimica et Biophysica Acta - Molecular Basis of Disease 1842:473–481. https://doi.org/10.1016/j.bbadis.2013.05.029 Loerch SC, Fluharty FL (1999) Physiological changes and digestive capabilities of newly received feedlot cattle. Journal of Animal Science 77:1113–1119. https://doi.org/10.2527/1999.7751113x Macitelli F, Braga JS, Gellatly D, Paranhos da Costa MJR (2020) Reduced space in outdoor feedlot impacts beef cattle welfare. 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Journal of Animal Science 81:133–138. https://doi.org/10.2527/2003.8114_suppl_2E133x Rodenburg TB, Koene P (2007) The impact of group size on damaging behaviours, aggression, fear, and stress in farm animals. Applied Animal Behaviour Science 103:205–214. https://doi.org/10.1016/j.applanim.2006.05.024 Schwartzkopf-Genswein KS, Faucitano L, Dadgar S, Shand P, González LA, Crowe TG (2012) Road transport of cattle, swine and poultry in North America and its impact on animal welfare, carcass, and meat quality: A review. Meat Science 92:227–243. https://doi.org/10.1016/j.meatsci.2012.04.010 Souza CF, Tinoco IFF, Sartor V (2003) Informações Básicas para Projetos de Construções de Currais – Unidade 2. Bovinos de Corte. Universidade Federal de Viçosa: Viçosa-MG. http://www.ufv.br/dea/ambiagro/arquivos/instala%C3%A7%C3%B5esgadocorte.pdf . Strappini AC, Metz J, Gallo C, Kemp B (2009) Origin and assessment of bruises in beef cattle at slaughter. Animal 3:728–736. http://doi.org/10.1017/S1751731109004091 Strappini AC, Frankena K, Metz JHM, Gallo C, Kemp B (2010) Prevalence and risk factors for bruises in Chilean bovine carcasses. Meat Science 86:859–864. https://doi.org/10.1016/j.meatsci.2010.07.010 Stokka GL, Lechtenberg K, Edwards T, MacGregor S, Voss K, Griffin D, Grotelueschen DM, Smith RA. Perino LJ (2001) Lameness in feedlot cattle. Veterinary Clinics of North America: Food Animal Practice 17:189–207. https://doi.org/10.1016/S0749-0720(15)30062-1 Van Laer E, Moons CPH, Sonck B, Tuyttens FAM (2014) Importance of outdoor shelter for cattle in temperate climates. Livestock Science 159:87–101. https://doi.org/10.1016/j.livsci.2013.11.003 Vanhonacker F, Verbeke W, Van Poucke E, Buijs S, Tuyttens FAM (2009) Societal concern related to stocking density, pen size and group size in farm animal production. Livestock Science 123:16–22. https://doi.org/10.1016/j.livsci.2008.09.023 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-4714140","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":328841732,"identity":"cd7cf371-772c-45bd-a260-fddd458f6bc9","order_by":0,"name":"Fernanda Macitelli","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIiWNgGAWjYBAC9gYwxczAIAFm2IBFmPFp4TmAqiUNKMJMmpbDRGhh73324OcOa3kG6eZjDz78OZ/YI3b+AHPhHjxaeI6bG/aeSTdskDmWbjiD53Zij3QyA/OMZ7i12EuksUnwth1mbJDIMZPmkbiduB+kBepe7LbIP2OT/Nt22L5BIv+b9B+DcxBb8GqRYGOTBtqSCLSFTZoh4QARWnjS2KRl29KT22SOmUn2HEg2BmoxODwDnxb2Y2ySb9usbfulm59J/PhjJ9sjnfjwcQEeLXDAhswhRsMoGAWjYBSMAjwAAJ2ASWGzs4OQAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0006-8075-8613","institution":"Universidade Federal de Mato Grosso - Campus Sinop","correspondingAuthor":true,"prefix":"","firstName":"Fernanda","middleName":"","lastName":"Macitelli","suffix":""},{"id":328841733,"identity":"6b9bffc3-6394-4d06-b472-6c1653da59e0","order_by":1,"name":"M. J. R. Paranhos da Costa","email":"","orcid":"","institution":"Universidade Estadual Paulista: Universidade Estadual Paulista Julio de Mesquita Filho","correspondingAuthor":false,"prefix":"","firstName":"M.","middleName":"J. R. Paranhos da","lastName":"Costa","suffix":""}],"badges":[],"createdAt":"2024-07-09 19:34:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4714140/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4714140/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":62658493,"identity":"aac1b8b8-52f9-4342-a5ee-01672f0ddeeb","added_by":"auto","created_at":"2024-08-17 02:16:55","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":22200,"visible":true,"origin":"","legend":"\u003cp\u003ePercentages of feedlot cattle kept under three space allowances (6, 12 and 24 m²/animal) according to the ADGt classes (£ 1.60kg/day; from 1.61 to 2.39 kg/day, and ³ 2.40 kg/day)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4714140/v1/ff57311e1761509055c8c2c8.png"},{"id":62658492,"identity":"8fa4bcd6-dc75-48fd-9a93-32c97bac80eb","added_by":"auto","created_at":"2024-08-17 02:16:55","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":14284,"visible":true,"origin":"","legend":"\u003cp\u003ePercentages of carcasses for each fat cover scored according to the three space allowances (6, 12 and 24 m²/animal). Fat cover scores ranged from 1 to 5, but scores 4 and 5 were not observed\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4714140/v1/5a40cb7a072c25e0c17577b0.png"},{"id":64286253,"identity":"28ced48a-cf40-401b-bc60-ddedc0b5ca79","added_by":"auto","created_at":"2024-09-11 08:50:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":712917,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4714140/v1/09d895bd-ef2f-42b3-bed7-d9d059b69c2c.pdf"}],"financialInterests":"","formattedTitle":"Impact of pen space allowance in outdoor feedlot on cattle performance, and carcass and meat quality traits","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eSpace is an essential resource in the adequacy of feedlot pens and when it is not appropriately defined, it increases the risk of harming animal welfare (Macitelli et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Limited space in cattle feedlot pens is usually associated with mud accumulation (Mader, 2011), increased frequency of agonistic behaviors (Kondo et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1989\u003c/span\u003e), and a higher risk of predisposing cattle to more severe effects of pathogens (Stokka et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). Space restriction could also result in physiological and psychological stress, negatively affecting cattle performance (Mader, 2011; Wechsler, 2011; Krawczel et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Additionally, due to the increasing concern about the welfare of farm animals, high-density feedlots harm consumers\u0026rsquo; perceptions of the beef cattle production chain (Vanhonacker et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDespite the existing knowledge about the relevance of feedlot space for cattle welfare, most of the studies were conducted in indoor feedlots, with a small number of animals kept at high stock densities (Fisher et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Gygax et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). These conditions do not foster the consideration of many environmental effects, such as exposure to climatic factors (Van Laer et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) and social relationships, which differ between large or small groups of animals (Fraser et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). According to Grandin (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), the main problems of outdoor feedlots are: (1) muddy pens and the difficulty of keeping cattle clean, (2) heat stress caused by lack of shade in the pens and (3) problems associated with managing large numbers of cattle, besides the high concentration of dust in the air during the dry period, being expected that this problems are aggravated when animals are kept in high density (Macitelli et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlthough the dust particles emitted by feedlots are dominated by large particles (Guo et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), which are relatively simple to control with irrigation systems, it must be considered that feedlot dust particles harbor antibiotic residues, bacteria, and antibiotic resistance genes (McEachram et al., 2015), which increase the risk of health problems to animals and people exposed to this polluted air.\u003c/p\u003e \u003cp\u003eTo our knowledge, only one study assessed the impact of space allowance on the performance of beef cattle in commercial outdoor feedlots (Mader, 2011), but it was performed under different conditions (concerning climate, nutrition, confinement period, and breed) than our study. This study aimed to assess the effects of space allowance in outdoor feedlots under tropical conditions on beef cattle performance and carcass and meat quality traits.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003e This study was carried out according to the Brazilian legislation and approved by the Committee of Ethical Use of Animals from the Faculty of Agricultural and Veterinary Sciences, S\u0026atilde;o Paulo State University, Jaboticabal-SP, Brazil, Jaboticabal, SP, Brazil (Certified n. 025961/13).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eAnimals, treatments, and facilities\u003c/h2\u003e \u003cp\u003eThe study was conducted in a commercial feedlot in the municipality of Campo Verde, Mato Grosso State, Brazil (15\u0026ordm;32\u0026rsquo; S and 55\u003csup\u003eo\u003c/sup\u003e10\u0026rsquo; W, 736 meters above the sea level) from August to November 2013, totaling 87 or 111 days in a feedlot. One thousand three hundred and fifty bulls were evaluated, 450 pure Nellore and 900 crossbred Angus or Caracu vs. Nellore cattle. At the beginning of the feedlot period. the animals were around 30\u0026thinsp;\u0026plusmn;\u0026thinsp;6 months of age and weighed 392\u0026thinsp;\u0026plusmn;\u0026thinsp;46 kg of body weight, on average. The animals were individually identified with numbered ear tags.\u003c/p\u003e \u003cp\u003eAll animals were road transported to the farm where the study was carried out two weeks before starting feedlot operations. During this period, cattle were kept on pasture (\u003cem\u003eBrachiaria ruzizienses\u003c/em\u003e), with free access to mineral supplements and water. Just before entering the feedlot facilities, they were weighed, vaccinated against clostridial diseases, dewormed (Doramectin 1%, Dectomax, Zoetis Brasil, S\u0026atilde;o Paulo, SP, Brazil), and assigned (randomly within breed) to nine batches (with 150 animals each). The batches were sorted in one of the three treatments, defining one batch of pure Nellore and two of crossbred cattle per treatment.\u003c/p\u003e \u003cp\u003eThe treatments consisted of three pen space availability, 6 (T6), 12 (T12) and 24 (T24) m\u0026sup2; per animal. These space allowances were defined considering that 12 m\u003csup\u003e2\u003c/sup\u003e/animal is the average space available per head of cattle in the commercial Brazilian feedlots, compared to halving it (negative control) and doubling the space (positive control).\u003c/p\u003e \u003cp\u003eThe feedlot pens were enclosed by smooth wire fences, and their surfaces (unpaved ground) had approximately 5% slope. The pen areas were defined by changing their lengths, being 18, 36 and 72 m for T6, T12 and T24, respectively. The water troughs were 1.5 meters in diameter (each serving two feedlot pens), and the feed bunk line was 50 meters long in each feedlot pen, resulting in 33 cm per animal.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eDiet and feeding management\u003c/h2\u003e \u003cp\u003eCattle were fed two diets in the feedlot: the adaptation diet, offered in the first 25 days of confinement; and the finishing diet, offered from the 26th day until the end of the feedlot period (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The RLM\u0026reg; software (Integra Software, a Brazilian nutritional program that considers age, body weight, sexual condition, genetic group, the nutritional composition and digestibility of Brazilian foods, and the market value of ingredients, aiming for maximum profit) was used to formulate the diets.\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\u003eComposition (% of DM) of the adaptation and finishing diets offered to the cattle in all treatments during the study period.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIngredients\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAdaptation diet\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFinishing diet\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorn silage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e44.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCotton hulls\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e00.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorn residue*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e07.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMilled corn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e40.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCotton seed cake\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12.38\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoybean skin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e08.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e08.84\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e01.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e01.78\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eDM\u0026thinsp;=\u0026thinsp;Dry matter; Dry matter intake\u0026thinsp;=\u0026thinsp;2.4% live weight. *Residue from corn storage. **14.93% mineral salt, 85% urea and 0.074% monensin sodium salt.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe animals were fed four times a day, twice in the morning (07:30h and 10:00h) and in the afternoon (14:30h and 16:30h). Before the first feeding of the day, the person responsible for the feed bunk management applied a 5-points feed bunk scoring (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) in each pen, and this score was used to define the amount of food that should be offered for each pen that day. Generally, the animals received 40% of the total amount of food at the last feeding of each day and 20% at each of the other three feeding times. The average daily gain (ADG) expected for the entire feedlot period was 1.6 kg/animal.\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\u003eCriteria used for the feed bunk management used to define the amount of food that should be offered for each pen every day\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScore\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFeed bunk condition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCattle behavior\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAmount of food\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEmpty\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMost of the animals (more than 50%) standing in front of the feed bunk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIncrease 10% the amount of food in relation to the day before\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026minus;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEmpty\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFew animals (less than 25%) standing in front of the feed bunk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIncrease 5% the amount of food in relation to the day before\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEmpty or little quantity of food (5 to 10% of the last feeding). It is possible to see the bottom of the feed bunk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMost of the animals is calm and not expecting the food at the feed bunk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSame amount of food than the last day\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLittle quantity of food. It is not possible to see the bottom of the feed bunk (20% of the last feed)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHalf of animals standing and half lying down\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDecrease 5% of the amount of food in relation to the day before\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFull\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMost of animals lying and ruminating\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDecrease 10% of the amount of food in relation to the day before\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eAdapted from Pritchard and Burns (2003).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003ePerformance traits\u003c/h2\u003e \u003cp\u003eThe animals were weighed in the beginning (d0, initial body weight\u0026thinsp;=\u0026thinsp;IBW), after 35 days (d35, intermediate body weight\u0026thinsp;=\u0026thinsp;MBW), and at the end of the feedlot period (final body weight\u0026thinsp;=\u0026thinsp;FBW, measured just before loading the animals to the slaughterhouse). Weighing was done always after a fasting period of 12 hours.\u003c/p\u003e \u003cp\u003eThe average daily weight gains (ADG) were calculated for three periods: from d0 until d35 (ADGi = (MBW \u0026ndash; IBW)/dp1), from d35 until the end of the feedlot period (ADGf = (FBW \u0026ndash; MBW)/dp2), and from d0 until the end of the feedlot period (ADGt = (FBW \u0026ndash; IBW)/dpt), where dp1, dp2 and dp3 are the number of days covered in each period (35, 51, and 86 or 110 days, respectively). Three classes of ADGt were defined and the percentage of cattle with ADG \u0026le; 1.6 kg/day, from 1.61 to 2.39 kg/day, and \u0026ge; 2.40 kg/day were recorded for each treatment.\u003c/p\u003e \u003cp\u003eCattle were slaughtered in two commercial slaughterhouses, both under the inspection of the Official Veterinary Service of Brazil. The first slaughter was conducted with three batches (one of each treatment) of crossbred bulls 86 days after the beginning of the experiment, and the second occurred 24 days later when the remaining animals were slaughtered. The hot carcass weights (HCW, kg) were provided by the slaughterhouse.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eCarcass and meat quality traits\u003c/h2\u003e \u003cp\u003eA trained person recorded the presence of bruises (yes or no) and, when present, the number of bruises per carcass, and their colors and severities. The color of the bruises was classified as fresh (for those presenting bright red color) or old (for those with yellowish-green color), as described by Gracey and Collins (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1992\u003c/span\u003e). The bruise severity was scored as superficial, when the damaged area comprises only subcutaneous tissues; muscular, when the damaged area comprises subcutaneous and muscular tissue; and severe, when subcutaneous, muscular tissues and even bones are damaged, including fractures, as described in the Chilean grading system (INN, 2012). The same trained person used a five-point scale (BRASIL, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2004\u003c/span\u003e) to score the amount of fat cover on carcasses.\u003c/p\u003e \u003cp\u003eA slaughterhouse technician measured the meat pH24 with a digital pHmeter. The measurements were done in the 12th rib region (ribeye), inside of the right half-carcass maintained at a temperature of about 2\u0026deg;C for 24 hours after the slaughter.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analyses\u003c/h2\u003e \u003cp\u003eThe consistency of the database was carried out with the Microsoft Excel software and the extreme values were excluded by applying the criterion of average\u0026thinsp;\u0026plusmn;\u0026thinsp;3 standard deviations. All data were analyzed using SAS software (SAS Inst. Inc. Cary, NC), considering animals as the subjects and the results were considered statistically different when P\u0026thinsp;\u0026lt;\u0026thinsp;0.05. The normality of data distribution was checked for all continuous dependent variables (IBW, FBW, ADG1, ADG2, ADGt, HCW, and pH24) using the Kolmogorov-Smirnov test.\u003c/p\u003e \u003cp\u003eThe analysis of variance was conducted using Proc Mixed to evaluate the effect of treatments (space allowance) on IBW, FBW, ADGi, ADGf, ADGt, HCW, and pH24. The model included the fixed effect of treatment and the random effect of genetic groups. When analyzing FBW and HCW, IBW was included in the model as a covariate. For HCW and pH24 analysis, the slaughterhouse was included in the model as a random effect. Means comparisons were performed by post-hoc Tukey test. A chi-square test (using Proc Freq) was applied to assess whether the frequency of fat cover scores of ADGt classes depends on the treatments.\u003c/p\u003e \u003cp\u003eDue to the differences in transport distance and conditions between the two slaughterhouses, we considered only the animals slaughtered in the second plant to do the bruises analyses. The effects of the treatments on the number of new, old and total and superficial, muscular and severe bruises per carcass were analyzed using the Glimmix procedure, considering the fixed effect of treatment, the random effect of breed, and a Poison distribution. The effect of treatment on the risk of bruises occurrences was analyzed by applying a logistic regression (Proc Genmod), assuming data binomial distribution with a probit link function to an adjacent normal distribution, assuming T24 as the reference category (RC).\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003ePerformance traits\u003c/h2\u003e \u003cp\u003eSignificant differences among treatments were observed for FBW (F\u003csub\u003e2, 968\u003c/sub\u003e = 9.93), HCW (F\u003csub\u003e2, 968\u003c/sub\u003e = 2.94), ADGi, ADGf and ADGt (F\u003csub\u003e2, 960\u003c/sub\u003e = 13.64, F\u003csub\u003e2, 959\u003c/sub\u003e = 64.14, F\u003csub\u003e2, 970\u003c/sub\u003e = 17.68, respectively), but not for IBW (F\u003csub\u003e2, 970\u003c/sub\u003e = 0.46). The ADGi was lower for T24 and did not differ between T6 and T12. On the other hand, T24 showed higher FBW, ADGf, and ADGt means than T12 and T6 (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). There was no difference between HCW means of T24 and T12, which were greater than the T6 mean. The percentages of animals for each class of ADG also differed significantly among treatments for ADGt (DF\u0026thinsp;=\u0026thinsp;42, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\chi\\:\\)\u003c/span\u003e\u003c/span\u003e\u0026sup2; = 106.63), as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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\u003eMeans (\u0026plusmn;\u0026thinsp;SE) of the cattle performance traits when kept in feedlot pens under three space allowances (6, 12 and 24 m\u0026sup2;/animal).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSpace allowances\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIBW (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e389.16\u0026thinsp;\u0026plusmn;\u0026thinsp;9.37\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e390.11\u0026thinsp;\u0026plusmn;\u0026thinsp;9.34\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e386,74\u0026thinsp;\u0026plusmn;\u0026thinsp;9.36\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFBW (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e526.76\u0026thinsp;\u0026plusmn;\u0026thinsp;10.12\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e535.45\u0026thinsp;\u0026plusmn;\u0026thinsp;9.96\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e538.22\u0026thinsp;\u0026plusmn;\u0026thinsp;10.10\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eADGi (kg/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eADGf (kg/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eADGt (kg/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHCW (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e291.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e294.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e295.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.25\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eInitial body weight (IBW), final body weighed (FBW), hot carcass weight (HCW), average daily gain in the first period (ADGi, from d0 to d35), average daily gain in the second period (ADGf, from d36 until the end of the feedlot period), and average daily gain for the total experimental period (ADGt, from d0 until the end of the feedlot period). Means followed by the same letters in the lines did not differ statistically (Tukey test, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eCarcass and meat quality traits\u003c/h3\u003e\n\u003cp\u003eNo carcass was scored as 4 or 5 for fat cover and only one case of severe bruise was recorded, being excluded from the statistical analyzes. The percentages of carcass receiving fat cover scores 1, 2 or 3 vary significantly among treatments (DF\u0026thinsp;=\u0026thinsp;4, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\chi\\:\\)\u003c/span\u003e\u003c/span\u003e\u0026sup2; = 12.89, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), with a higher percentage of score 3 occurring in T6, followed by T24 and T12 (50.54, 42.28 and 39.16%, respectively).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe number of new (F\u003csub\u003e2, 737\u003c/sub\u003e = 11.99), old (F\u003csub\u003e2, 738\u003c/sub\u003e = 8.55) and total (F\u003csub\u003e2, 737\u003c/sub\u003e = 14.58) bruises per carcass differed among treatments. The mean number of new bruises per carcass was lowest for the T24 and did not differ between the T6 and T12. The mean number of old and total bruises per carcass were highest for T12, but T24 and T6 did not differ (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The odds ratios of new and total bruises differed among treatments, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. We observed an increased risk of new and total bruises for T6 and T12. However, the risk of old bruises did not differ among treatments.\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\u003eAdjusted (\u0026plusmn;\u0026thinsp;SE) and observed means (between brackets) of the numbers of new, old and total bruises per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m\u0026sup2;/animal).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eBruises categories\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSpace allowance\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNew\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003csup\u003ea\u003c/sup\u003e (0.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003csup\u003ea\u003c/sup\u003e (0.60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-0.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003csup\u003eb\u003c/sup\u003e (0.30)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOld\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003csup\u003eb\u003c/sup\u003e (0.12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003csup\u003ea\u003c/sup\u003e (0.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-1.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003csup\u003eb\u003c/sup\u003e (0.20)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003csup\u003eb\u003c/sup\u003e (0.62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003csup\u003ea\u003c/sup\u003e (0.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003csup\u003eb\u003c/sup\u003e (0.51)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eMeans followed by the same letters in the lines did not differ statistically (Tukey test, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \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\u003eOdds ratios and respective confidence intervals of new, old and total bruises occurrences per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m\u0026sup2;/animal).\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=\"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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBruises categories and space allowances\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\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOdds ratio\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eConfidence\u003c/p\u003e \u003cp\u003eIntervals\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varvec{\\chi\\:}2\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNew\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e49.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.13\u0026ndash;2.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e6.72\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.20\u0026ndash;2.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.02\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e229\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOld\u003c/b\u003e\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.41\u0026ndash;1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e29.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.95\u0026ndash;2.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e229\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e61.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.92\u0026ndash;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.23\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e89.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.20\u0026ndash;2.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.52\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e229\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e50.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\chi\\:\\)\u003c/span\u003e\u003c/span\u003e\u003csup\u003e2\u003c/sup\u003e test, all P\u0026thinsp;\u0026gt;\u0026thinsp;0.05. N\u0026thinsp;=\u0026thinsp;total number of evaluated animals; (%)\u0026thinsp;=\u0026thinsp;percentage of animals with bruises, and RC\u0026thinsp;=\u0026thinsp;reference class.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe number of superficial (F\u003csub\u003e2, 737\u003c/sub\u003e = 20.13) and muscular bruises (F\u003csub\u003e2, 737\u003c/sub\u003e = 4.32) differed among treatments. T24 had the lowest mean of superficial bruises per carcass, followed by T6 (N\u0026thinsp;=\u0026thinsp;0.48) and T12 (N\u0026thinsp;=\u0026thinsp;0.65), respectively; and T6 had the lowest mean of muscular bruises per carcass, with T24 and T12 not differing from each other (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). The odds ratios of superficial and muscular bruises differed between treatments (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). There was a pronounced increase in the risk of superficial bruises for T6 and T12 compared to the reference class (T24). On the other hand, the risk of muscular bruises was lower for T6 (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAdjusted (\u0026plusmn;\u0026thinsp;SE) and observed means (between brackets) of the number of superficial and muscular bruises per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m\u0026sup2;/animal).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eBruises severity\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSpace allowances\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSuperficial\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003csup\u003eb\u003c/sup\u003e (0.48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003csup\u003ea\u003c/sup\u003e (0.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003csup\u003ec\u003c/sup\u003e (0.25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMuscular\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-2.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003csup\u003eb\u003c/sup\u003e (0.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003csup\u003ea\u003c/sup\u003e (0.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003csup\u003ea\u003c/sup\u003e (0.25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eMeans followed by the same letters in the lines did not differ statistically (Tukey test, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eOdds ratios and respective confidence intervals of superficial and muscular bruises occurrences per carcass of beef cattle kept in feedlots under three space allowances (6, 12 and 24 m\u0026sup2;/animal).\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=\"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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBruise categories and space allowance\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\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOdds ratios\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eConfidence intervals\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varvec{\\chi\\:}2\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuperficial\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e381\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e37.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.55\u0026ndash;3.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e15.99\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e403\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e35.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.13\u0026ndash;2.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e23.48\u003cb\u003e*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e399\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMuscular\u003c/b\u003e\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e381\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.30\u0026ndash;0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e7.27*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e403\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.51\u0026ndash;1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24 m\u0026sup2;/animal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e399\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\chi\\:\\)\u003c/span\u003e\u003c/span\u003e\u003csup\u003e2\u003c/sup\u003e test, all P\u0026thinsp;\u0026gt;\u0026thinsp;0.05. N\u0026thinsp;=\u0026thinsp;total number of carcasses evaluated; (%)\u0026thinsp;=\u0026thinsp;percentage of carcass with bruises. RC\u0026thinsp;=\u0026thinsp;reference class.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThere were differences among treatments for meat pH (F\u003csub\u003e2, 960\u003c/sub\u003e = 5.40), with the highest mean observed for the T6 (5.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03) followed by T12 and T24 (5.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 and 5.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04, respectively), which did not differ between each other (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThere is a tendency to reduce the space allowance for beef cattle housed in outdoor feedlots in Brazil, as evidenced by some recommendations, indicating the use of 8 m\u003csup\u003e2\u003c/sup\u003e per animal in outdoor feedlot pens (Souza et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Such guidance ignores the risks of causing a negative environmental impact and impoverishing cattle welfare, raising worrisome ethical issues. Despite this, few studies addressed the effect of reducing space allowance per animal in outdoor feedlots. In this study, we evaluated the impact of three pen space allowances on performance and carcass and meat quality traits of cattle housed in outdoor feedlots by halving and doubling the area commonly used in commercial Brazilian feedlots. The results showed that increasing the space allowance resulted in better performance and carcass quality traits.\u003c/p\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003ePerformance traits\u003c/h2\u003e \u003cp\u003eIt is well known that many factors affect cattle ADG, including pen space allowances for feedlot cattle (Andersen et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Fisher et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Gygax et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Herva et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Our results corroborated these previous findings, showing that ADG differed between treatments in all feedlot periods, with a lower ADGi mean for T24 than for T6 and T12 and a higher ADGf and ADGt means for T24 than T6 and T12.\u003c/p\u003e \u003cp\u003eThe observed reduction in ADG after the adaptation phase in the feedlot was not expected. Newly arrived feedlot cattle usually face numerous stressors that change their behavior and physiological state, leading to lower performance (Loerch and Fluharty, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e1999\u003c/span\u003e). However, the changes in the weather conditions during our study, resulting in increased rainfall during the second period, probably contributed to the ADG reduction. Rainfall increases mud accumulation in the feedlot pens (Macitelli et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), which leads to lower food consumption and cattle performance (Mader, 2011). Our results also show that high density in feedlots harms the individual performance of beef cattle, as indicated by the ADGf and ADGt means, and the distribution of weight gain observed for T6 and compared to T12 and T24 animals. We should also consider that reducing space allowance in feedlot pens can impair cattle health and causes behavioral disorders, also negatively affecting cattle performance (Andersen et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Gygax et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlthough weight gain is widely used as a performance indicator, it is also important to regard the distribution of weight gain as a piece of complementary information since, with this information, it will be possible to compare the homogeneity of ADG between batches and to identify the percentages of animals at the lower extreme of the ADG\u0026rsquo;s curve.\u003c/p\u003e \u003cp\u003eIn this study, all treatments were under the same conditions, varying only in density. Our results show that 69.00% of animals in T24, 54.94% in T12, and 44.89% in T6 had a higher average daily weight gain than expected (\u0026gt;\u0026thinsp;1.60 kg/day, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). According to the production cost calculation, animals should gain a minimum of 1.30 kg/day; otherwise, they would incur losses. Most of the 156 animals, which did not achieve the expected ADG were housed in T6 and T12 (41.03%, 44.23%, and 14.74%, for T6, T12, and T24 treatments, respectively).\u003c/p\u003e \u003cp\u003eThese results corroborate the outcomes from previous studies showing that the reduced space in indoor feedlots negatively affects cattle performance (Ingvartsen and Andersen, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e1993\u003c/span\u003e; Fisher et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Gygax et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) and feed conversion ratio (Cortese et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), strengthening the idea that the individual space in feedlots is an important resource for beef cattle.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eCarcass and meat quality traits\u003c/h2\u003e \u003cp\u003eSeveral factors affect the fat deposition in cattle carcasses, and the source of energy and its concentration in the diet are considered the most relevant factors, especially during the finishing period (Drackley et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Once the animals of all treatments tested in this study received the same diet, other factors caused the differences in carcass fat cover between treatments. Interestingly, despite T6 showing the lowest ADFf and ADGt, a higher percentage of cattle from this treatment scored 3 for fat cover than T12 and T24.\u003c/p\u003e \u003cp\u003eCarcass fat cover is indirectly associated with the meat quality because it controls the speed of temperature drop down and the action of enzymes that transform glycogen into lactic acid, lowering meat pH (McGilchrist et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Despite the significant differences among the treatments found for carcass fat cover and meat pH, all the results were within the acceptable range for good carcass and meat quality (EU, 2007; BRASIL, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eBased on our results, we suggest that the stress caused by the space restriction altered the metabolism of energy nutrients, corroborating the results observed in several previous cattle studies, which showed that animals kept under limited space conditions displayed high concentrations of glucocorticoids in the blood (Friend et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1979\u003c/span\u003e). Our results are conflicting with what is expected of the metabolism and distribution of adipose tissue since we expected lower fat cover T6 cattle but, as pointed out by Peckett et al. (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), \u0026ldquo;\u0026hellip;the acute and long-term effects of glucocorticoids on adipose tissue lipolysis remain unclear\u0026hellip;\u0026rdquo;.\u003c/p\u003e \u003cp\u003eA well and standardized fat cover is desired. However, it depends on many factors, such as diet and genetics, besides being affected by metabolic disorders caused by stress. As already reported (Finger et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Lee et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), chronic stress conditions increase the adipocyte cells, mainly the visceral fat deposition, which points to a lower efficiency of diet utilization by the animal to deposit tissues that are profitable. To our knowledge, there is no result about how chronic stress may increase fat accumulation in beef cattle adipocyte cells. The studies addressing this subject were conducted mainly with rats and humans because of the direct relationship between abdominal fat and metabolic and cardiovascular diseases in humans (Finger et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Lee et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Thus, there is a need to conduct further studies addressing the association between indicators of chronic stress and those related to visceral and fat cover deposition in cattle.\u003c/p\u003e \u003cp\u003eAnother variable used to assess the carcass quality was the occurrence of bruises. We expected that T6 cattle would show the highest number of old and muscular bruises in the carcasses since it is known that space restriction potentially increases physical contact and, consequently, the frequency of agonistic behavior (Lindberg, 2001; Rodenburg and Koene, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), as also described by Kondo et al. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1989\u003c/span\u003e), who reported a significant negative correlation between space allowance and agonistic behavior in feedlot cattle. However, this was not the case, probably because, as reported by Macitelli et al. (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), T6 and T12 cattle reduced their locomotion over time, and a higher percentage of T6 cattle showed health problems and hooves alteration (three times higher than T12 and twice than T24), besides deeper mud in the pens. Therefore, we assume that since T6 cattle were not physically well, diminished the frequency and intensity of agonistic interactions, thus reducing the risk of old and muscular bruiser occurrences. On the other hand, T24 cattle had more space allowance and better health (Macitelli et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) and thus were more efficient in avoiding social confronts, preventing the risk of bruise occurrence. T12 cattle were apparently in an intermediate situation, where the space did not allow them to avoid agonistic encounters despite being in a better physical condition than those from T6.\u003c/p\u003e \u003cp\u003eThen, we could suppose that the lower number of new and superficial bruises observed in T24 cattle was associated with their apparent tranquility during pre-slaughter handling procedures. Nevertheless, we should also consider other factors, not controlled in this study, that are relevant to consider when recording new bruises\u0026rsquo; occurrence and severity, such as poor pre-slaughter handling and transport, bad facilities design, and cattle with excited temperament (Strappini et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Paranhos da Costa et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Schwartzkopf-Genswein et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2012\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMuscular bruise occurrences were higher for T12 and T24 than for T6, which could reduce HCW. According to Huertas et al. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), bruises cause economic losses since, when muscular and severe, they are trimmed from the carcasses, downgrading meat cuts. Bruises have a direct effect on consumer perception of meat quality (Strappini et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) since bruised meat decomposes quickly (Chambers and Grandin, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2001\u003c/span\u003e), leading to poor taste and a shorter shelf-life.\u003c/p\u003e \u003cp\u003eWe conclude that pen space allowance for beef cattle kept in outdoor feedlots has a role in their performance and carcass quality and that reduced space in feedlot pens lessens cattle performance and downgrades carcass quality.\u003c/p\u003e \u003c/div\u003e"},{"header":"STATEMENTS AND DECLARATIONS","content":"\u003cp\u003e\u003cstrong\u003eCONFLICT OF INTERESTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare the following financial interests/personal relationships which may be considered as potential competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Fernanda Macitelli. The first draft of the manuscript was written by Fernanda Macitelli and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe dataset that is generated or used to perform statistical analyzes in this study are available upon request to corresponding author.\u003cstrong\u003e\u003cbr\u003e \u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAndersen HR, Jensen LR, Munksgaard L, Ingvartsen KL (1997) Influence of floor space allowance and access sites to feed trough on the production of calves and young bulls and on the carcass and meat quality of young bulls. Acta Agriculturae Scandinavica, Section A \u0026ndash; Animal Science 47:48\u0026ndash;56. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/09064709709362369\u003c/span\u003e\u003cspan address=\"10.1080/09064709709362369\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBRASIL (2004) Instru\u0026ccedil;\u0026atilde;o Normativa n\u0026ordm; 9, de 4 de maio de 2004. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.defesa.agricultura.sp.gov.br/www/legislacoes/popup.php?action=view\u0026amp;idleg=643\u003c/span\u003e\u003cspan address=\"http://www.defesa.agricultura.sp.gov.br/www/legislacoes/popup.php?action=view\u0026amp;idleg=643\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBRASIL (2017) Decreto N\u0026ordm; 9.013, de 29 de mar\u0026ccedil;o de 2017. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.gov.br/agricultura/pt-br/assuntos/mpa/legislacao/legislacao-geral-da-pesca/decreto-no-9-013-de-29-03-2017.pdf/view\u003c/span\u003e\u003cspan address=\"https://www.gov.br/agricultura/pt-br/assuntos/mpa/legislacao/legislacao-geral-da-pesca/decreto-no-9-013-de-29-03-2017.pdf/view\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChambers PG, Grandin T (2001) Effects of stress and injury on meat and by-product quality. In: G. Heinz; T. Srisuvan (Eds.) Guidelines for Humane Handling, Transport and Slaughter of Livestock. FAO Regional Office for Asia and The Pacific: Bangkok, Thailand. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.fao.org/3/x6909e/x6909e.pdf\u003c/span\u003e\u003cspan address=\"https://www.fao.org/3/x6909e/x6909e.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCortese M, Brščić M, Ughelini N, Andrighetto I, Caontiero B, Marchesini G (2020) Effectiveness of stocking density reduction on mitigating lameness in a Charolais finishing beef cattle farm. Animals 10:1147. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/ani10071147\u003c/span\u003e\u003cspan address=\"10.3390/ani10071147\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDrackley JK, Wallace RL, Graugnard D, Vasquez J, Richards BF, Loor JJ (2014). Visceral adipose tissue mass in nonlactating dairy cows fed diets differing in energy density. Journal of Dairy Science 97:3420\u0026ndash;3430. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3168/jds.2014-8014\u003c/span\u003e\u003cspan address=\"10.3168/jds.2014-8014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEU (European Union) (2007) Council Regulation (EC) No 1234/2007 of 22 October 2007. 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Livestock Science 123:16\u0026ndash;22. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.livsci.2008.09.023\u003c/span\u003e\u003cspan address=\"10.1016/j.livsci.2008.09.023\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\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":"Average daily gain, hot carcass weight, carcass bruises, meat pH24, welfare.","lastPublishedDoi":"10.21203/rs.3.rs-4714140/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4714140/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe analyzed the effects of feedlot pen space allowances on cattle performance and carcass and meat quality traits. Bulls (N = 1350) with an average age of 30 ± 6 months and weight of 392 ± 46 kg were assigned to one of three feedlot pen space allowances, 6 (T6), 12 (T12) and 24 (T24) m2/animal. The animals were weighed in the beginning and end of experimental period and individual average daily gain (ADG) was calculated. Hot carcass weight (HCW), fat cover (scored from 1 to 5), carcass bruise occurrences (classified as old or new and superficial, muscular, or severe), and meat pH24 were assessed in a commercial slaughterhouse. Treatment T24 showed higher (P\u0026lt;0.05) ADG than T6 and T12. T6 had lower (P\u0026lt;0.05) HCW than T12 and T24. T6 had the highest (P\u0026lt;0.05) percentage of carcass scored 3 for fat cover, followed by T24 and T12. In all the treatments pH24 were within the range that ensured good meat quality, ranging from 5.60 (T24) to 5.63 (T6). The mean of new bruises per carcass was lowest for T24 (P \u0026lt; 0.05) and did not differ between T6 and T12 (P\u0026gt;0.05). Superficial bruises were more frequent in T24 than in T6 and T12 carcasses (P\u0026lt;0.05), differing from each other, but the mean number of muscular bruises was higher in T6 than in T12 and T24 (P\u0026lt;0.05), which did not differ from each other (P\u0026gt;0.05). We conclude that reduced space in feedlot pens lessens beef cattle performance and downgrades carcass quality.\u003c/p\u003e","manuscriptTitle":"Impact of pen space allowance in outdoor feedlot on cattle performance, and carcass and meat quality traits","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-17 02:16:50","doi":"10.21203/rs.3.rs-4714140/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":"1b4e27aa-906e-4585-bc92-acbf2e42bff1","owner":[],"postedDate":"August 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-09-11T08:41:47+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-17 02:16:50","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4714140","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4714140","identity":"rs-4714140","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}