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ABSTRACT The objective of this study was to assess the effects of high-concentrate diets with and without the inclusion of soybean hull (SH; 0 or 500.8 g/kg) plus corn (whole or ground) on the performance, morphometric traits, and nutritional and metabolic parameters of crossbred dairy calves. We also aimed to assess the costs associated with the experimental diets employed. Thirty-six male calves with an average weight of 89±18.6 kg and age of 3.5 months were allocated to four treatments, with nine replicates of one calf/pen, in a completely randomized experimental design for 198 days. The inclusion of the SH and the physical form of corn did not influence animal performance or morphometric measurements; however, SH inclusion increased the digestibility of neutral detergent fiber and the intakes of dry matter and neutral detergent fiber, but did not affect total digestible nutrient intake. The physical form of corn did not influence nutrient intake or digestibility, which resulted in similar performance across the animals. Blood glucose levels as well as alkaline phosphatase and creatinine remained elevated regardless of the diet. The use of SH reduced the total plasma cholesterol content, and there was an interaction between the physical form of corn and SH inclusion in relation to creatinine levels, which were higher when using diets with whole corn and SH. Although the inclusion of up to 500.8 g/kg of SH in the diet reduces feed efficiency, its use decreases the cost per kilogram of weight gain. Dairy calves can exhibit satisfactory production performance when fed alternative ingredients such as whole corn or SH, which have a lower cost than ground corn, traditionally used in diet formulations.

ABSTRACT The objective of this study was to assess the effects of two levels of soybean hulls (0 and 400.1 g/kg) and whole or ground corn in the diet of newborn crossbred dairy male calves on intake, performance, blood indicators, and feeding cost. Twenty-eight calves with an average weight of 33.0±6.2 kg and four days of age were distributed into four treatment groups in a completely randomized design (n = 7) for 56 days. Weekly samples of feed, diets, and leftovers were collected to determine dry matter and nutrient intakes. To evaluate apparent digestibility, samples were taken using titanium dioxide as a maker. Blood samples were also collected to evaluate blood indicators. The inclusion of soybean hulls resulted in greater neutral detergent fiber intake by the calves, but reduced their non-fibrous carbohydrates intake, which was also reduced by the use of whole corn in the diet. Although the total digestible nutrients content of diets decreased with the use of whole corn and inclusion of soybean hulls, its intake did not vary (0.75 kg/d), regardless of the factors analyzed. The apparent digestibilities of dry matter (0.87 kg/kg) and crude protein (0.89 kg/kg) were similar, resulting in similar performance between the animals, regardless of the factors analyzed. In the quantities evaluated, the use of soybean hulls or whole corn did not affect blood indicators and was insufficient to reduce feed costs; the cost of daily feed was $2.06, while the cost per kilogram of gain was $3.74. The inclusion of up to 400.1 g/kg of soybean hulls or the replacement of ground corn with whole corn does not affect the performance of crossbred dairy calves during the preweaning period, demonstrating that both can be used in animal feed during this phase of production.

Abstract The objective of this work was to evaluate, through meta-analysis, the impact of subcutaneous fat thickness on beef qualitative traits. Combined data from 13 studies were used, comprising 245 carcasses of male bovines slaughtered in Brazil. Effect size for all parameters was calculated as mean difference or standardized mean difference, at 95% probability. The meta-analysis of random and fixed effects was carried out when I2>50% and I26 mm) groups. Carcasses in the “high” group showed greater intramuscular fat deposition, whereas those in the “low” group presented an intramuscular fat deposition similar to that of the control. When the fat thickness was below the recommended threshold of 3 mm, shear force increased. Subcutaneous fat thickness values greater than 6 mm induced a positive change in the perception of tenderness by the panel of evaluators. Beef carcasses with a subcutaneous fat thickness over 6 mm tend to accumulate more intramuscular fat content and are tenderer for consumers’ acceptance. Carcasses with a fat thickness less than 3 mm produce tougher meat.

ABSTRACT Determining what and how much each environmental factor affects pregnancy is crucial to the sustainability and management of beef cow herds. The study evaluated through logistic regression the effect of environmental variables on the increase or reduction in the pregnancy rate of beef cows. The average pregnancy rate in the cows was 73 %, with an average age for the herd of 3.7 years. An increase in age of one year represented a 30 % increase in pregnancy, while a reduction of one year reduced the odds of pregnancy in the cows by 23 %. During the lactation period, an extra seven days’ lactation reduced the odds of pregnancy by 12 %. For every seven days that weaning was brought forward, the cows’ pregnancy odds increased by 14 %. An increase of 0.1 kg in average daily gain represented an increase of 17 % and 15 % in the odds of pregnancy during the first 60 days post-partum and 60 days to the end of the reproductive period. On the other hand, the loss of 0.1 kg in average daily gain resulted in a 14 % and 13 % reduction in the cows’ pregnancy odds, respectively. Factors such as age, the precocity of calving in the calving season, the time the calf remains with the cow and better performance in cows between calving and the end of the mating are strategies that increase the chances of pregnancy in beef cows.

The objective of this study was to examine the effects of behavioral differences in cattle on bruising on different cuts and on carcass yield. A total of 4,061 lots of cattle were evaluated, which corresponded to 199,026 carcasses. Animal temperament was classified as calm, anxious, or excited. The following carcass cuts were evaluated: round, rump, shin, thin flank, tenderloin, and rib. Of the total number of slaughtered animals, 68.26% had at least one type of bruise with complete removal of the affected tissue. There was an interaction effect between sex and temperament on the occurrence of bruises on the different cuts and on carcass yield. In castrated males, bruises on the round, rump, shin, and tenderloin cuts did not differ between temperament classes, but the excited males showed more bruises on the thin flank and rib cuts. Among the females, for all cuts, the number of bruises was higher (P0.05). Additionally, carcass yield relative to plant weight decreased (P0.05). Females and more reactive animals have more bruises on their carcass.

Aspects related to good handling practices have significant impacts on animal behaviour with positive effects on the productivity and profitability of production systems. This study investigated the impact of good handling practices on the modification of stress indicators and the behaviour of beef cattle. Thirty-six male castrated bovines at the growth stage were evaluated for 490 days and submitted to two different production systems in Southern Brazil: good handling practices (GHP) and a traditional handling system of beef-cattle farming (THS). Body weight, reactivity indicators (flight distance and composite behaviour score), and blood indicators of stress (glucose and cortisol) were measured. An analysis of variance was carried out with measurements repeated over time, and Pearson's correlation applied between the variables mentioned above. No differences were found (P>0.05) for body weight in any of the evaluations, with initial weights of 196.2 and 196.3 kg and final weights of 431.0 and 413.8 kg for the GHP and THS steers, respectively. The GHP determined better values for the stress and behavioural indicators compared to THS (P

This study examines the impact of the body mass index (BMI) at calving on the development and postpartum efficiency of cows of Zebu origin. The study involved 87 cows and their calves [pure Nellore (N) or predominant Nellore composition in a cross with Charolais (C) (3/4N1/4C and 5/8N3/8C)]. The mothers were grouped into classes according to their BMI at calving, namely, ‘small’, ‘moderate’ and ‘large’. Body mass index was determined by dividing the body weight of the cows by their length and by hip height and then dividing the result by 10. Cows were weighed at calving, at weaning, at the end of the breeding period and at the diagnosis of pregnancy. Calves were weighed at birth, at early weaning (63 days) and at 210 of age. To evaluate milk yield and quality, milk was collected at 21, 42 and 63 days after calving. Milk yield was measured by the direct method, with manual milking, followed by analysis of the lactose, fat, total solids and crude protein contents. Pregnancy rate was similar between the three BMI groups; however, cows with a lower BMI were more efficient at calving in producing kilograms of calf per kilogram of cow kept. Higher BMI provide higher milk yields, without affecting its quality, as well as heavier calves at early weaning and at 210 days of age.

Objetivou-se com este estudo avaliar o desempenho de tourinhos de três grupos genéticos, ½ Brangus x ½ Nelore (BRN), Nelore (NEL) e ½ Canchim x ½ Nelore (CAN), recriados à pasto e suplementados com mineral (SM) ou energético-mineral (SEM). Foram utilizados 81 tourinhos, com idade média de 12 meses e peso corporal médio de 252 ± 33 kg. O experimento foi conduzido em delineamento inteiramente ao acaso em esquema fatorial 3x2. Cada grupo genético foi subdividido em seis parcelas experimentais, em que três delas receberam SM e três receberam SEM. Os animais foram manejados em sistema de lotação rotacionada em pasto de capim Tifton 85. O consumo de SM foi semelhante entre os grupos genéticos com média de 0,073 kg animal-1 dia-1, já o consumo de SEM foi maior para o BRN com 2,10 kg animal-1 dia-1, seguido pelo CAN com 1,57 kg animal-1 dia-1 e menor para o NEL com 1,28 kg animal-1 dia-1. O ganho de peso médio diário (GMD) foi maior para os animais que receberam SEM em relação aos que receberam SM. Para os animais que receberam SM, o grupo BRN apresentou GMD de 0,64 kg animal-1, enquanto os grupos NEL e CAN foram semelhantes com média de 0,46 kg animal-1. Para os animais que receberam SEM o grupo CAN apresentou maior GMD com 0,97 kg animal-1, enquanto os grupos NEL e BRN foram semelhantes com média de 0,86 kg animal-1. Os níveis sanguíneos de proteína total, albumina, creatinina, glicose e colesterol não foram alterados em função dos tipos de suplementos utilizados ou entre os grupos genéticos. Maiores níveis séricos de ureia foram observados nos animais NEL e CAN que receberam SM. Os níveis séricos de aspartato aminotransferase foram maiores em animais BRN e CAN que receberam SEM. Os ganhos de altura de garupa, altura de cernelha, comprimento, largura de garupa, perímetro torácico e largura de peito foram maiores em animais que receberam SEM. Em sua maioria, os ganhos de medidas morfométricas foram maiores para os animais mestiços do que para o NEL. O fornecimento de suplemento energético-mineral em pasto de capim Tifton 85 durante o período das águas é recomendado apenas para tourinhos Nelore e ½ Canchim x ½ Nelore. Tourinhos mestiços apresentam maiores ganhos em medidas morfométricas que tourinhos Nelore durante a recria.

Abstract The aim of this study was to evaluate the effects of conception weight and gestational weight gain on performance and productive efficiency in beef cows and their calves. Eighty-eight primiparous, three-year old Braford females were used, divided according to weight at conception and gestational performance (High and Low): cows with a low conception weight and low gestational weight gain (LL), cows with low conception weight and high gestational weight gain (LH), cows with high conception weight and low gestational weight gain (HL), and cows with high conception weight and high gestational weight gain (HH). At calving, HH cows were heavier than LH and HL and these were heavier than LL cows. Male calves born to HH cows were superior in body weight to those born to LL cows at 150, 210 and 365 days. Female calves born to HH, HL or LH cows were superior to those born to LL cows in pregnancy at 14 months of age. The LL and HL cows were more efficient in calf production. Actual fertility was influenced by the nutritional level of the herd, where HH cows were superior than LL cows. Better cow herd nutrition increases the development and performance of the progeny.

Abstract: The objective of this work was to evaluate the influence of lairage periods on the temperament, physiological indicators of stress, and meat quality of beef cattle. Thirty-two castrated Aberdeen Angus x Nellore crossbred steers were distributed into four lairage periods: 12, 18, 24, and 48 hours. The following variables were evaluated: serum levels of the physiological indicators of stress glucose and cortisol (upon arrival at the slaughterhouse, after the lairage period, and at bleeding), animal temperament (movement, resistance to approach, and aggressiveness), and meat quality (final pH, water-holding capacity, color parameters, and tenderness). With a longer lairage period, the temperament score was higher, indicating that the animals were more agitated and resistant to human approach. Serum cortisol and glucose levels correlate positively with animal temperament and negatively with meat quality. At bleeding, an increase was observed in glucose and cortisol levels, respectively, for lairage periods longer than 24 hours and of 12 hours. The lairage of 48 hours reduces meat tenderness and water-holding capacity.

ABSTRACT: Heterosis plays an important role on yield and profitability of beef production systems. This study evaluates the morphometrics of purebred Nellore (N) and Charolais (C) animals and of the second (G2) and third (G3) generations of their alternating crosses, regarding the effects of genetic group and heterosis from birth to 365 days of age. The experiment comprised 159 calves (C = 29, N = 22, G2 - 3/4C 1/4N = 21, 3/4N 1/4C = 9, G3-5/8C 3/8N = 44 and 5/8N 3/8C = 34). The foreshank girth (FG), thoracic girth (TG), body length (BL), and hip height (HH) were measured after birth, and at 63, 210, and 365 days of age, and the total increases were calculated. The Charolais animals had greater FG, TG, and BL values than Nellore, while the latter had greater HH. For the offspring generations, the predominance of Charolais genes in the genotypes resulted in greater measurements for FG and TG in G2, whereas the predominance of Nellore genes resulted in higher HH values in both generations. The crossbred animals had greater values for all measurements than the purebreds, with more significant differences in FG, TG, and BL compared to Nellore purebreds and in HH compared to Charolais. Charolais animals show higher values for muscularity; while, Nellore animals are taller. Crossbred animals show greater development compared to purebreds, indicating a significant effect of heterosis.

O objetivo deste trabalho foi avaliar a qualidade químico-fermentativa da silagem de dois híbridos de sorgo nos diferentes estratos da face do silo e a interferência do tempo de exposição aeróbia da face do silo estruturada e/ou desestruturada (após desensilagem). A silagem do híbrido AG-2005E apresentou maior teor de proteína bruta e pH mais elevado em comparação à do híbrido AG-60298 (6,33% e 4,0 contra 6,06% e 3,8, respectivamente). As silagens do estrato de 0 a 20 cm tinham o menor teor de matéria seca e o maior teor de proteína bruta (38% e 6,35%, respectivamente). O pH não diferiu entre os estratos e o teor de NH3 foi maior no estrato de 60 a 80 cm (4,5%). Com o avanço das 72 horas de exposição aeróbia, a silagem desestruturada apresentou maior incremento de temperatura em relação à silagem da face estruturada, mas esse tempo não foi suficiente para mostrar diferenças entre os teores de matéria seca, matéria mineral, NH3 e pH. O híbrido de sorgo e o estrato do silo interferem diretamente na qualidade químico-fermentativa da silagem. Após a exposição aeróbia, a silagem do painel do silo estruturado parece sofrer menor interferência em relação à silagem após ser desensilada. Palavras-chave: avaliação a campo; degradação aeróbia; pós-abertura do silo; qualidade nutricional; massa específica da silagem.

ABSTRACT The incidence of bruising in bovine carcases is a consequence of several potentially stressful and aggressive factors to which the animals are subjected during pre-slaughter handling. The aim of this study was to identify pre-slaughter factors associated with the severe bruising in different regions of the bovine carcass. The study evaluated 5,028 batches of slaughtered cattle from 154,100 animals. The carcases were analysed for gender, handling on the farm, condition of farm infrastructure, type of truck, distance and journey time from the farm to the slaughterhouse, loading density and time of year in which the animals were slaughtered. The results showed that the sidecut and forequarter are the areas most affected by bruising, with females being the most vulnerable. Loading densities above excess of 401 kg m-2 cause an increase in the number of bruises. The use of larger vehicles results in an increase in bruising, as does the use of poor farming facilities. A decrease in the number of bruises was seen for journey times of more than three hours. All the variables under evaluation are potential causes of injury to bovine carcases. As such, improving the handling conditions and facilities for loading cattle, as well as reducing the stress of transport, are factors which determine a smaller number of bruises in bovine carcases.

The objective of this study was to evaluate the effect of live weight at first mating on reproductive performance in the first and second reproductive years. For that purpose, the reproductive history of 221 heifers mated for the first time between the years of 2003 and 2012 was evaluated. Heifers were grouped into three weight classes at the age of 24 months: 50-59.9% (55%), 60-69.9% (65%), and 70-80% (75%). The pregnancy rate in the first reproductive year in heifers from weight classes 55%, 65%, and 75% was 38.0%, 56.4%, and 69.0%, respectively. The pregnancy rate in the second reproductive year was not affected by weight at first mating (p > 0.05) and corresponded to 41.6%; 42.1%, and 50.4% in the three weight classes, respectively. The weight class of heifers before mating at the age of 24 months affected reproductive performance at first mating but did not increase the pregnancy rate in the second reproductive year.

Abstract: The objective of this work was to assess the effect of genetic group and heterosis on the relationship between body weight and morphometric measurements, in purebred and crossbred animals from the second (G2) and third (G3) generations of Nellore and Charolais calves. Body weight (BW), average daily weight gain (ADG), foreleg circumference (FC), thoracic girth (TG), body length (BL), and croup height (CH) were measured at birth and at 63, 210, and 365 days of age in animals from G2 and G3. Charolais animals were superior to Nellore ones for gains BW, ADG, BL, and TG, as well as for the ratio between BW gain and CH gain; Nellore animals were superior for CH gains. Crossbred animals of both generations were superior to the purebred animals for gains of BW, BL, and CH. In G2, the predominance of Charolais genes resulted in greater gains of BW, ADG, FC, and TG. The G3 animals were superior to the purebred animals for ADG, FC, and TG. No differences were found for the ratio between gains of weight and morphometric measurements. Heterosis and complementarity are apparent for weight and body measurements of crossbred calves from rotational crossings.

Cattle farming becomes more intensive when the productive efficiency of the cows is increased, and nutrition is adjusted to the animal biotype. Eighty purebred Charolais and Nellore cows and their crosses between 3 and 7 years of age, were grouped for body weight at calving into Light (332.6 kg), Moderate (385.3 kg) and Heavy (444.6 kg). Cows and their calves were weighed at calving, at 63 days (early weaning) and at 210 days. The estimated milk production of the cows was evaluated by manual milking at 21, 42 and 63 days postpartum. The difference in the weight of the cows at calving was maintained during lactation and at 210 days postpartum. The body size of the cow did not influence milk production. Heavier cows produce heavier calves up to 365 days of age compared to lighter cows. The reproductive performance of the cows is not affected by their weight. The production of kilograms of calf for every 100 kilograms of cow at calving and weaning is higher in Light cows. The production of kilograms of calf adjusted for the pregnancy rate of the cows is higher in Heavy cows. Production efficiency in kilograms of calf per area is lower in Heavy cows.

ABSTRACT The objective of this study was to evaluate performance, apparent digestibility, blood parameters, and quantitative characteristics of carcass and internal organs of crossbred dairy calves fed different levels of crude glycerin in corn grain-based diets. Twenty-four calves of three months of age and average initial weight of 95.5±11.8 kg were used. The experimental design was completely randomized with four treatments (0, 80, 160, and 240 g kg−1 of crude glycerin of DM of diets). The calves were fed in feedlot until six months of age (195.68±2.38 kg of BW). Dry matter (4.14, 4.11, 3.80, and 3.49 kg day−1) and apparent digestible energy intake (0.43, 0.41, 0.37, and 0.35 MJ kg−1 BW) decreased with increasing levels of glycerin in the diets. There was no effect on the apparent digestibility of nutrients, average daily gain, feed efficiency, carcass characteristics, and blood parameters. The diets did not influence the weights [g kg−1 of empty body weight (EBW)] of lungs, heart, kidneys, liver, omasum, abomasum, and large intestine. The reticulorumen weight (g kg−1 EBW) increased, whereas the small intestine weight decreased with increased levels of glycerin in the diets. The area, height, and width of the rumen papillae were not changed with increasing levels of glycerin. The rumen wall thickness increased with increasing levels of glycerin in the diets. The inclusion up to 240 g kg−1 DM of crude glycerin of in corn grain-based diets for the production of dairy calves does not alter animal performance, carcass characteristics, and weights of internal organs.

The calving period influences productivity and reproductive efficiency the herds. The objective of this study was to evaluate two calving months (October and November) and their effect on the efficiency of a breeding herd for three consecutive years. A total of 298 Braford cows were evaluated at three, four, and five years of age, with their calves early-weaned at 148 days of age. The performance characteristics of the cow/calf pairs were evaluated with the calving month and calf sex as the independent variables. The animals were kept as a single group for the three years of observation. Cows calving in November were heavier and had a higher body condition score at calving. Cows calving in October were heavier and produced heavier calves at weaning. Male calves were heavier at birth and weaning than females (30.8 vs 28.6 kg and 118.9 vs 114.7 kg, respectively). The pregnancy rate was 82.35 and 69.23% for cows calving in October and November, respectively. Calving intervals were shorter in cows calving in November. Cows calving in October were more efficient compared with those calving in November, with a higher actual fertility rate. The production of kilograms of the calf/cow pair was higher for cows calving in October. Key Words: actual fertility; bovine; milk production; productivity; reproductive performance

Abstract This study aimed to evaluate the performance in feedlot and temperament of Nellore bulls classified by residual feed intake. The residual feed intake was calculated as the difference between the observed and predicted dry matter intake. Bulls classified as low residual feed intake had lower dry matter intake (kg day−1) and dry matter intake (g kg−1 d−1) of body weight, and were more efficient in feed conversion ratio than those classified as medium and high. The average daily gain didn’t differ among residual feed intake classes and was 1.69 kg day−1, 1.82 kg day−1 and 1.71 kg day−1 for bulls classified as low, medium, or high, respectively. The residual feed intake was positively associated with dry matter intake, feed conversion ratio and subcutaneous fat thickness. The subcutaneous fat thickness was lower in bulls classified as low residual feed intake than in those with medium and high. No differences were observed in flight speed and reactivity score among residual feed intake classes. Overall, we concluded that bulls classified as low residual feed intake consumed less dry matter than high, with no differences in average daily gain, temperamentand had better feed efficiency, albeit their subcutaneous fat thickness was lower.

O clima interfere de maneira marcante na produtividade animal, característica que tem sua importância ressaltada no tocante às recentes mudanças climáticas verificadas e às previsões de aumento no aquecimento global. Neste contexto, a presente revisão visa abordar os efeitos do clima sobre o conforto térmico, aspectos comportamentais e desempenho produtivo em ovinos. As condições climáticas acarretam respostas fisiológicas e comportamentais relevantes nos ovinos, e, quando essas condições atingem graus elevados de estresse, acabam impactando fortemente nos índices de produtividade. É necessário adequar práticas de manejo, instalações e alimentação de tal forma que permitam melhores condições de bem-estar dos animais frente às condições climáticas estressantes, bem como selecionar biótipos mais adaptados às características climáticas, as quais serão explorados, buscando permitir que expressem todo seu potencial produtivo.

We examined the production performance of Nellore heifers fed high-concentrate (90%) diets in which ground corn (GC) was substituted by ground soybean hulls (SH) at increasing levels (0, 33, 66, and 100%), in the concentrate portion. A total of 144 heifers (263.40 ± 13.90 kg average initial weight; 27 months old) received the test diets in a feedlot for 112 days. The experiment was set up as a completely randomised design with four treatments. Data were subjected to ANOVA and orthogonal contrasts, adopting ? = 5%. The sum of squares of treatments in the contrast analysis was decomposed into two orthogonal contrasts (L - linear and Q - quadratic effect) for the level of SH substituting GC. Dry matter intake was not changed by the GC substitution levels, averaging 2.51% of body weight. There was a linear increase in neutral detergent fibre intake (1.08, 2.03, 2.92, 3.78, 4.85 kg/day) and feed conversion (6.20, 7.08, 7.77, and 8.67 kg/kg); and a linear decrease in total digestible nutrient intake (5.78, 5.16, 5.03, 5.12, and 3.66 kg/day), average daily gain (1.24, 1.11, 1.02, and 0.89 kg/day), and slaughter weight (383.52, 374.71, 363.25, and 366.27 kg) as the substitution level was increased (0, 33, 66, and 100%, respectively). Subcutaneous fat thickness and loin-eye area were not influenced (P > 0.05), averaging 5.30 mm and 53.09 cm2, respectively. Substituting ground corn by ground soybean hulls in high-concentrate diets determined a reduction in production performance of feedlot-finished Nellore heifers.

ABSTRACT: The goal of the present study was to assess the economic viability relating to the risk of replacing corn with pearl millet in diets with 80% concentration for feedlot cattle confined for 89 days. Replacement levels were: 0, 33, 66, and 100%. The risk was estimated using Monte Carlo simulation, Spearman’s rank correlation test between input variables, stochastic dominance, and analysis of sensitivity. The expected average values ± standard deviation for net present value (R$/animal) were ± 71.74 ± 283.32, 91.23 ± 285.18, 196.05 ± 273.79, and 223.80 ± 267.96 for diets containing 0, 33, 66, and 100% of pearl millet, respectively. The probability of ≥0 net present value was 63.4, 66.1, 78.4, and 82.4%, respectively. The net present values were statistically different (P

This study aimed to evaluate the production, reproductive performance, and productive efficiency of predominantly Charolais cows and their calves (Straightbred, ¾ C, ¼ N) according to body size at calving. Sixty-three cow-calf pairs were used and classified into three weight groups: Light (331.3±5.8 kg), Moderate (385.9±5.3 kg), and Heavy (424.4±6.2 kg). The classes were formed using half standard deviations above or below the average weight of the cows at calving. For each pair, the body weight was evaluated at calving, at weaning (63 days), at the beginning and at end of the reproductive period, and at 9 months for the calves. Pregnancy rates were similar (P > 0.05) between weight groups. The calves did not differ (P > 0.05) in terms of body weight and weight gain from calving until pregnancy diagnosis (210 days). The heavy cows had greater weight variations from 210 days to 270 days than the light cows. The calf production rate (kg calf/cow kept in herds) did not differ between weight groups. However, in relation to the weight of the cows at 210 days, light cows were 11.28% and 13.02% more productive (P < 0.05), than moderate and heavy cows, respectively. Light cows were more efficient than the other classes of cows at calving and at 210 days old. Our simulations showed that there were more kilograms for sale in herds of light cows (53.085 kg) than moderate and heavy cows (52.310 and 52.870 kg, respectively), while maintaining the structures of the herd constant. The size of the Charolais cow did not influence the weight of calves from calving until 7 months of age or their reproductive performance provided they were weaned early. The need for space for the maintenance of the cow-calf pair increased as the weight of the cows increased. In herds with smaller cows, higher numbers and a higher production of weight for sale are observed than in herds with moderate and heavy cows. Light cows were the most efficient at calving and during pregnancy diagnosis at 210 days.

The objective of this study was to evaluate the replacement of 0, 25, 50, 75 and 100% of ground corn (GC) with pelleted soybean hulls (SH) in the concentrate portion of cattle diets. The evaluation was conducted using five 13-month-old Nellore steers cannulated in the rumen, with a mean body weight of 265.00 + 11.60 kg. The steers received a diet composed of 90% concentrate and 10% sugarcane bagasse as the only source of roughage. The statistical design used was a 5x5 Latin square. There was no effect (p > 0.05) of replacement levels or interaction (p > 0.05) between replacement levels and sampling time on ruminal pH, which ranged from 5.8 to 6.0. The apparent digestibility of DM, CP, EE, CHOT and CHONF were not influenced (p > 0.05) by the replacement levels, showing mean values of 67.88 + 2.02; 67.43 + 2.89; 68.29 + 4.11; 70.54 + 1.68 and 80.21 + 1.85%, respectively. The NDF digestibility increased linearly (p < 0.05) with the replacement of corn with soybean hulls. There was no effect (p > 0.05) of replacement levels on time spent feeding (F) and total idle time (TI), with mean values of 10.51 and 4.61% of the day, respectively. However there was a quadratic effect (p < 0.05) of soybean hull inclusion on the time spent ruminating. It was concluded that although the replacement of corn with soybean hull does not improve the ruminal pH of steers fed diets with a high proportion of concentrate, pelleted soybean hulls improve the digestibility of the fibrous fraction of the diet and increase the time spent ruminating, indicating that this ingredient can be included in high-concentrate diets to improve economic efficiency.

This study aimed to evaluate the cholesterol content, ?-tocopherol and fatty acids in the meat of Nellore young bulls or steers castrated at different ages, 13 or 18 months. The animals were confined for 100 days and slaughtered at 22 months of age. The experimental design was completely randomized with three treatments, using 12 repetitions. The levels of palmitic acid (26.39%), stearic (24.39%), myristic (3.01%) and total saturated fatty acids were not altered by sexual condition or castration age. Oleic was the fatty acid with the highest average participation in the meat (34.54%), and lower content in the meat of young bulls in relation to the castrated. The content of total unsaturated fatty acids was lower in the young bulls in relation to castrated at 18 months, which did not differ from castrated at 12 months. The content of total polyunsaturated fatty acids was increased by elevation of the castration age, being similar between young bulls and castrated at 18 months. The ratio ?6/?3 was not altered by sexual condition or castration age. Castration at the beginning of the finishing period increases the content of beneficial fatty acids to health in relation to castrated in the first third of backgrounding.

Assessment of carcass and meat characteristics of Nellore young bulls or dairy crossbred young bulls fed two levels of grass-Convert silage in the rations (400 and 100 g kg-1 of dry matter). Sixteen Nellore young bulls and 16 dual-purpose dairy young bulls (Holstein x Gir and Holstein x Guzerá) with average initial body weight of 378.8±13.8 kg were used. The experimental design was completely randomized with treatments in a 2x2 factorial arrangement. The proportion of silage and the genetic group did not change the percentage of muscle, fat and bone of the carcass. The yield of the primary commercial cuts was not altered by the level of silage. The pistol cut weight was higher in Nellore young bulls compared to dairy crossbred young bulls (125.8 vs. 119.5 kg), while the relative weight of short ribs was higher in dairy crossbreds (11.9 vs. 11.5%). Only the muscle cut of the pistol was altered by silage proportion in the rations, being higher in those with the lowest proportion of grass silage. On the other hand, only the relative weight of flat, rump cap and edible lean trims were altered by genetic group, which were higher in Nellore young bulls. Among the characteristics of the meat, only marbling was significantly changed, being higher in dairy crossbreds fed rations with a lower grass-silage proportion. The genetic group did not alter the other meat characteristics. Nellore young bulls produce carcasses with higher yield of valuable meat cuts in relation to dairy crossbred young bulls.

O presente estudo teve por objetivo avaliar o efeito heterótico sobre as características da carcaça e da carne de novilhos do cruzamento entre as raças Charolês (Ch) e Nelore (Ne) e cruzados entre essas raças de quinta (21/32Ch 11/32Ne; 21/32Ne 11/32Ch) e sexta (43/64Ch 21/64Ne; 43/64Ne 21/64Ch) gerações, terminados em confinamento. A dieta cotinha relação volumoso: concentrado de 39: 61 (base na matéria seca).Para o total de músculos na carcaça, o efeito heterótico foi significativo na quinta e sexta gerações, com valores de 14,7 e 15,8 kg, e para os pesos de gordura e osso apenas na quinta geração, com valores de 5,90 e 4,49, citados na mesma ordem. Quando os tecidos foram expressos por 100 kg de carcaça fria, assim como para as relações entre os tecidos, o efeito heterótico não foi significativo em nenhuma das gerações do cruzamento. Entre os definidos, novilhos da raça Charolês foram superiores aos Nelore no total de músculo na carcaça (145,7 contra 116,0 kg) e no percentual desse tecido na carcaça (67,7 e 62,2%), sendo que os animais zebuínos apresentaram maiores peso (41,7 e 37,9 kg) e participação de gordura na carcaça em relação aos taurinos (22,3 contra 17,5%). Para as perdas de líquido, houve efeito heterótico para as perdas ao descongelar na quinta geração (2,95%) e para perdas ao cozimento na sexta geração (-5,07%), porém para a perda total de líquidos e para as características organolépticas da carne não houve efeito heterótico em nenhuma das gerações.

Assessment of carcass bruises in steers and cull females, classified during truck unloading at the slaughterhouse according to genetic dominance in zebu and taurine cattle, and the presence of horns, including polled, horned and mixed batches. We considered horned the batches that included more than 20% of horned animals and mixed the batches that included less than 20% horned animals. The data were collected in a commercial slaughterhouse and included 93 batches, with a total of 2,520 animals, from different regions of South Brazil. After evisceration, the bruises were identified and recorded in the different carcass regions: hip, round, ribs, forequarter and loin area per animal and batch. The weights of the removed tissue due to bruising was based on the average weights of various samples of bruises according to their degree of severity. Regarding the number of bruises per animal, no differences (P> 0.05) were observed between genetic groups, however, when comparing the total bruises per batch, differences were observed in all carcass regions, except for the forequarter, with more number of injuries in zebu than in taurine carcasses. The individual assessment showed 86.2% (P

The objective of this study was to evaluate the fatty acid profile of duodenal digesta (experiment I) and of meat of beef cattle (experiment II) fed diets containing different levels of concentrate (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The experiment I was conducted with four Charolais-Nellore steers (460 ± 18.2 kg of BW), with a T-shaped duodenal cannula, using a double 4 × 4 Latin square as an experimental design. In experiment II, 16 crossbred Charolais-Nellore young bulls (192.44 ± 18.2 kg of BW) were randomly distributed in the experimental treatments (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The diets were isonitrogenous (120 g of crude protein/kg of dry matter). The intramuscular fat content was used as a covariant for the statistical analysis of the meat fatty acid profile. The duodenal content of fatty acid C17:0 decreased with increase of concentrate levels, while its content in the meat presented a quadratic variation with the increase of the concentrate levels of the diets, being the lowest values observed for the diet with 400 g of concentrate. The duodenal content of fatty acid C18:1 trans-11 decreased, whereas the content of this fatty acid in the meat increased with the increase of the dietary concentrate levels. The increase in the level of concentrate reduced the content of polyunsaturated fatty acids C18:3 n-3, C20:3 n-6, C20:4 n-6, and C20:5 n-3 EPA in both the duodenal digesta and meat. No difference was observed in the n-6/n-3 fatty acids ratio (mean of 13.96) of the meat between diets. The elevation of the level of concentrate in confinement diets reduces the nutraceutical quality of the meat of Charolais-Nellore young bulls slaughtered at 14-16 months of age due to the reduction of the polyunsaturated fatty acids content important for human health.

Resumo: Objetivou-se avaliar o desempenho animal, as características de carcaça e a qualidade da carne de novilhos e novilhas F1 Angus-Nelore terminados em confinamento com similar grau de acabamento de carcaça. O delineamento experimental foi o inteiramente casualizado, com dois tratamentos (novilhos e novilhas) e 11 repetições (animais). Foram utilizados 22 bovinos com 18 meses de idade inicial, 11 novilhos e 11 novilhas, com peso corporal inicial de 354,86±43,66 e 353,82±39,80 kg, respectivamente. Os animais foram terminados em confinamento (114 dias) com dieta contendo 200 g kg-1 de silagem de milho e 800 g kg-1 de concentrado composto principalmente por grão de milho moído e farelo de soja. O consumo de matéria seca (9,42 vs. 9,24 kg dia-1), o ganho de peso médio diário (1,44 vs. 1,38 kg dia-1), a conversão alimentar (6,49 vs. 7,05 kg de matéria seca kg-1 de ganho de peso), o peso de carcaça quente (284,62 vs. 268,16 kg) e a espessura de gordura subcutânea (12,09 vs. 13,05 mm) foram similares entre novilhos e novilhas (respectivamente). O rendimento de carcaça quente foi maior (P < 0,05) nos novilhos (58,14 vs. 55,53%). Os novilhos apresentaram maior proporção de dianteiro (39,26 vs. 37,53%), enquanto as novilhas apresentaram maior proporção do traseiro especial (49,87 vs. 48,85%). A carne dos novilhos apresentou coloração mais escura (P < 0,05). A força de cisalhamento da carne e o marmoreio não diferiram entre as condições sexuais, com valores médios de, 5,43 kgf cm-2 e 10,14 pontos (mediano), respectivamente. Exceto em relação à proporção dos cortes primários, rendimento de carcaça e cor da carne, novilhas jovens F1 Angus-Nelore apresentam similar desempenho animal, características de carcaça e de carne em relação aos novilhos abatidos com similar grau de acabamento.

Avaliou-se o desenvolvimento de bezerros de corte, do nascimento aos 12 meses de idade, filhos de vacas Charolês (CH), Nelore (N) e mestiças com predominância Charolês e Nelore (PCH, PN), respectivamente, agrupadas em três classes de idade: primíparas, jovens e adultas. Adicionalmente, foram avaliadas as exigências de energia líquida de mantença e de ganho dos bezerros, bem como a produção e a disponibilidade de energia no leite das vacas avaliadas. Foram utilizados 93 pares de vacas e bezerros contemporâneos mantidos em pastagem natural. Do nascimento aos 21 dias de idade, e dos 21 aos 42 dias de idade, os bezerros filhos de vacas adultas apresentaram maior ganho de peso médio diário (GMD), já os bezerros filhos das vacas jovens e primíparas obtiveram GMD similar. A maior exigência de ELm e ELg foram para os bezerros cruzados e puros Charolês, sendo estes últimos semelhantes aos bezerros Nelore. A energia disponível no leite das vacas adultas foi 33% superior à energia disponível no leite das vacas primíparas. O ganho de peso dos bezerros foi influenciado pela idade da vaca até o desmame. Os pesos pré e pós-desmama dos bezerros são afetados pelo grupo genético das vacas. Vacas adultas e jovens produzem bezerros mais pesados no período pré-desmama do que vacas primíparas.

Carcass and meat characteristics of 48 Nellore heifers at 24 to 30 months of age, with an initial weight of 263.4 ± 13.9 kg, were evaluated. The experiment was set up as a completely randomized design with four treatments, which consisted of four slaughter-weight classes, namely 400 kg. Back fat thickness was not influenced (p > 0.05) by slaughter weight in any of the forms it was expressed (mm or %), averaging 5.3 mm. Loin eye area in cm2 increased (p < 0.05) with the increase in slaughter weight. Animals slaughtered at a live weight (LW) of more than 400 kg showed better (p < 0.05) carcass conformation than the other experimental groups (9.8 points). Heifers slaughtered at over 400 kg LW had a more compact (p < 0.05) carcass (1.65 cm kg-1 cold carcass). The marbling degree of meat was lower (p < 0.05) in the animals slaughtered at less than 340 kg LW. In conclusion, cull heifers must not be slaughtered at a LW of less than 340 kg and slaughter weights greater than 400 kg have positive implications on important carcass characteristics, notably conformation and marbling.

Assessment of carcass and meat characteristics of Holstein-Zebu crossbred young bulls finished in feedlot with crude glycerin levels (0, 60, 120, and 240 g kg-1 dry matter) in replace of ground pearl millet grain and babassu mesocarp bran mixture-based diets. Twenty four bulls 30-month-old and initial average body weight of 390 ± 31.5 kg were used. The animals were distributed in a completely randomized design with four treatments and six replicates. The absolute weight (kg) of commercial cuts did not fit any of the tested regression models. However, the weight of the short ribs and the pistol cut were higher for animals fed with crude glycerin in relation to those fed without inclusion of this food in the diet. The proportion of the commercial cuts, however, was not changed. The increase of the crude glycerin levels linearly increased the proportion of carcass fat and reduced the muscle proportion, without changing the proportion of bone and the edible portion of the carcasses. The ratio muscle/fat reduced linearly with the advance of crude glycerin level of diets. The color of the meat, evaluated subjectively, increased linearly with the advance of crude glycerin levels of the diets, from dark red to slightly dark red. The texture, marbling, shear force, thawing loss and cooking loss were not changed by dietary levels of crude glycerin. The inclusion of up to 240 g kg-1 of crude glycerin in the diets increases the proportion of fat without changing the marketable portion of carcasses. The benefits to the meat quality refer to the improvement of color, without changing the other characteristics of economic interest.

Assessment of carcass and meat characteristics of Nellore young bulls finished in feedlot with crude glycerin levels (0, 60, 120, and 240 g kg-1 dry matter) in millet-based diets. Twenty-eight young bulls with mean age of 18 months and average weight of 357 ± 23.56 kg were used. The animals were distributed in a completely randomized design with four treatments and seven replicates. It was observed that the physical composition and edible portion of the carcass were not affected by crude glycerin levels in the diets. However, the increased dietary crude glycerin level raised the weights of the forequarters (kg and % of cold carcass weight), but not that of the pistol cut and short ribs. Among the commercial cuts prepared to marketing of the pistol cut, only the weight of the rump cap (% cold carcass weight) was changed, decreasing linearly with increasing dietary crude glycerin levels. Additionally, meat characteristics remained unaltered by the increased levels of crude glycerin. It was concluded that inclusion of up to 240 g kg-1 of crude glycerin in millet grain-based diets for Nellore young bulls finished in feedlot does not alter the main carcass and meat characteristics or affect their economic value.

In the present study, the effects of genetic group and heterosis on body measurements of purebreds (Charolais - C and Nellore - N), first-generation crossbreds (G1) (1/2C1/2N and 1/2N1/2C), and second-generation crossbreds (G2) (3/4C1/4N and 3/4N1/4C) males from rotational crossbreeding were evaluated at 8, 12, 18, and 24 months of age. Among the purebreds, the Nellore displayed greater rump height than the Charolais. The Charolais had greater thoracic perimeter than the Nellore, however this difference decreased gradually with advancing age, being equal between the two genetic groups at 24 months. For width of the rump, ischial opening and thoracic perimeter crossbred animals showed higher values than the purebred animals at all ages, but less pronounced at eight months of age. For all morphometric measurements, with exception of rump height, the differences of crossbreds males in relation to the purebreds, were more evident in relation to the Nellore. Heterosis was significant for morphometric measurements in male beef cattle. Morphometric measurements showed high correlation with each other and with body weight, thereby indicating that they are good indicators of body development.

ABSTRACT The objective of this study was to assess the effects of including crude glycerin in the diet on intake, performance, rumen development, and carcass traits of dairy crossbred veal calves fed starter concentrate containing 0, 80, 160, and 240 g kg−1 crude glycerin. Twenty-eight calves with an average weight of 38.03±6.7 kg and five days of age were distributed in a completely randomized design with four treatments with seven replications. Calves were individually housed in covered stalls equipped with feeders and drinkers for 56 days. The calf response to inclusion of crude glycerin in the concentrate changed over the weeks and the inclusion level of 240 g kg−1 resulted in greater dry matter intake and average daily gain. There was no effect on the final weight and total weight gain of the animals, with mean values of 73.60 and 35.16 kg, respectively. The weight of the rumen-reticulum adjusted for body weight, empty body weight, and total stomach weight increased linearly with the inclusion of crude glycerin. Blood total protein, globulin, urea, cholesterol, gamma glutamyl transferase, aspartate aminotransferase, and alkaline phosphatase concentrations did not differ among treatments. Carcass traits and meat color were not affected. Crude glycerin can be added to dairy calf starter concentrate up to 240 g kg−1 dry matter because it benefits concentrate intake, performance, and rumen development without affecting animal health.

Assessment of carcass physical composition and physicochemical characteristics of meat from Nellore males distributed randomly into three treatments: males castrated at 13 months of age at puberty (n=26); castrated at 18 months of age, 15 days before confinement (n=26); and young bulls (n=25). For the evaluation of meat chemical characteristics, we used samples of 12 animals taken at random from each treatment. The experimental design was completely randomized. Animals were slaughtered at 22 months of age after 100 days of confinement. The carcasses of young bulls showed higher contents of muscle (66.46 %) and bone (16.03 %), and lower fat content (17.66 %), in relation to that of steers castrated at 13 (62.83,15.28, and 22.11 %, respectively) or 18 months (63.99, 15.29, and 21.53%, respectively), which did not differ amongst themselves. The meat of young bulls was darker (3.07 points) than the meat from those castrated at 13 months of age (3.43 points), while the meat from those castrated at 18 months displayed an intermediate color (3.29 points), not differing from the others. Young bulls yielded meat with lower content of intramuscular fat (3.18 points) and lipids (3.81%) in relation to those castrated at 13 (4.58 points and 6.77%, respectively) or 18 months (4.52 points and 5.66%, respectively). Protein content was higher (P 0.05) by the age of castration, with young bulls having lower values in relation to the castrated males. Castration of Nellore young bulls in early puberty increases the edible portion of the carcass due to the higher body fat deposit.

This study aimed to evaluate carcass and meat characteristics of feedlot-finished steers of dairy origin fed with pearl millet grain-based diets, containing inclusion levels of babassu mesocarp bran (BMB) (0, 12, 24, 36 and 48%). A total of 30 Holstein-Zebu crossbred steers with an average initial weight of 371.02 ± 27 kg were randomly divided into six groups fed with different experimental diets (five pearl millet-based diets containing inclusion levels of BMB and one standard corn-based diet). Each diet had five replications. Isonitrogenous diets had a roughage/concentrate ratio of 20/80. BMB inclusion level in the diet reduced slaughter and carcass weight from 488.4 and 242.2 kg to 454.0 and 226.7 kg, respectively. The subcutaneous fat thickness, conformation, and pistol cut weight were also reduced to 38.8, 13.6, and 9%, respectively, as the BMB inclusion level in the diet increased. Meat characteristics were not affected by BMB inclusion levels in the diet. Regarding carcass and meat characteristics, no difference was observed in the analysis of contrasts between BMB diets and corn- or millet-based diets, or between corn- or millet-based diets. The inclusion of BMB in millet-based diets should consider the cost/benefit ratio, as it reduces slaughter and carcass weight, while the main meat characteristics remain unchanged. However, total substitution of corn by millet grains in feedlot diets does not alter bovine carcass and meat characteristics.

ABSTRACT - The objective of this study was to find the best level of inclusion of crude glycerin (0, 60, 120, and 240 g kg−1 of dry matter of diet) in substitution of pearl millet in a feedlot diet. Twenty-eight Nellore young bulls with mean age of 18 months and average weight of 357±23.56 kg were used. The animals were distributed in a completely randomized design with four treatments and seven replications. The intakes of dry matter, crude protein, neutral detergent fiber, and total digestible nutrients were similar among the dietary levels of crude glycerin. The ether extract intake decreased with increase in the levels of crude glycerol in the diets. Apparent digestibility of dry matter, crude protein, and extract ether was similar among the dietary crude glycerin levels. Apparent digestibility of neutral detergent fiber was lower in the diets with inclusion of crude glycerin in relation the other diets. The increase in the levels of crude glycerin did not affect the total digestible nutrients content of the diets. Average daily gain increased linearly with the increase in crude glycerin. Feed conversion was not altered by the increase in the levels of crude glycerin in the diets. The dietary increase in crude glycerin level did not affect the carcass characteristics. The inclusion of up to 240 g kg−1 of crude glycerin in pearl millet grain-based diets for feedlot-finished Nellore young bulls increases average daily gain, but does not change the main carcass characteristics of economic importance.

ABSTRACT The objective of this study was to evaluate the feeding behavior and feedlot productive performance of dairy-origin steers fed for 84 days ground pearl millet grain-based diets with 0, 120, 240, 360, and 480 g kg-1 of babassu mesocarp bran (BMB) and a standard diet based on ground corn. Thirty Holstein-Zebu steers with average initial body weight of 371.02±27 kg were used. The experimental design was completely randomized, with five replications. Dry matter intake showed better fit with the quadratic regression equation with the inclusion of BMB, reaching a maximum value in diets with 360 g of this by-product. There was no difference for dry matter intake between pearl millet- and corn-based diets. There was no difference in total digestible nutrients intake between diets. The digestibility coefficient of organic matter decreased linearly with the increase in the dietary level of BMB. The digestibility coefficient of organic matter was not different between corn and millet diets. There was no difference in feeding time between diets. Total requirement of metabolizable energy increased linearly with inclusion of BMB. However, total requirements of metabolizable energy did not differ between the corn- and pearl millet-based diets. Average daily gain decreased linearly with the increase in BMB, with adjustment forced by the sharp decline of this variable in diets with 480 g of BMB. There was no difference in average daily gain between corn- and pearl millet-based diets. The inclusion of levels above 360 g of babassu mesocarp bran in pearl millet-based diets reduces the supply of metabolizable energy and the productive performance of feedlot dairy steers.

Objetivou-se avaliar o efeito do peso de abate sobre o desempenho animal, cortes comerciais da carcaça e características da carne de vacas Purunã terminadas em confinamento. Foram utilizadas 28 vacas de descarte com 68,02±17,36 meses de idade abatidas com pesos distintos (434; 461; 476 e 522 kg). O delineamento experimental foi o inteiramente casualizado com quatro tratamentos (pesos de abate) e sete repetições (animais). O consumo de matéria seca, expresso em kg dia-1 e % do peso corporal, apresentou variação quadrática em função do avanço do peso de abate, sendo os maiores valores observados para o peso de abate de 461 kg. O ganho de peso médio diário diminuiu linearmente, enquanto que o peso absoluto do dianteiro, ponta de agulha e traseiro especial aumentou linearmente com avanço do peso de abate. Em termos relativos somente o corte ponta de agulha foi alterado pelo avanço do peso de abate, aumentando linearmente. Entre as proporções dos cortes cárneos preparados para comercialização, elevações lineares foram verificadas para o acém e contra filé. O aumento do peso de abate promoveu incrementos lineares nos escores de coloração, marmoreio e palatabilidade, mas não alterou a maciez da carne. O avanço do peso de abate de vacas de descarte da raça Purunã reduz o desempenho animal, aumentando as perdas pelo recorte de gordura, com benefícios importantes apenas para a palatabilidade da carne.

This study was developed to evaluate productive efficiency during the lactation period of cows with predominant Nellore genetic composition based on their body size. Cows were divided into the following categories: light (≤ 316 kg), moderate (≥ 317 and ≤ 400 kg), or heavy (≥ 401 kg). Body weight change and total gain from birth to 210 days of age of calves born from heavy cows (0.155±0.03 and 111.6±5.1 kg) were higher than those of calves born from light (0.064±0.03 and 91.0±4.3 kg) and moderate (0.144±0.03 and 97.7±4.0 kg) cows. Calf production index differed (p < 0.05) with the herd of heavy cows (93.5±3.2 kg), producing 57.4 and 19.7% more kilograms of calf than light (59.4±2.7 kg) and moderate (78.1±2.4 kg) cows, respectively. Heavy Nellore cows produce heavier calves and have a better reproductive performance, which lead to a better calf production index. However, they require a larger area for the same herbage allowance. Calves born from heavier Nellore cows gain more weight from birth to 210 days of age and are heavier from 210 to 270 days of age.

The objective of the experiment was to evaluate byproducts yield of non-castrated Nellore males slaughtered at different weights. Forty Nellore males with average weight of 350 kg at the beginning of the feedlot were used. In a completely randomized design, the animals were divided into four groups: 0 to 2-teeth animals with carcass weight up to 238.0 kg (young and light carcasses); 2-teeth animal with carcass weights ranging from 238.1 to 258.0 kg (young and middle weight carcasses); 2-teeth animal with carcass weight over 258.0 kg (young and heavy carcasses) and animals with four or six teeth, regardless of carcass weight (adults). Animals were fed during 84 days with diet calculated to reach average weight gain of 1.2 kg/day. Hide weight was higher for young and heavy animals in relation to young and light and adult animals. Regarding the noncarcass components yield, we verified difference for liver percentage, which was higher for young and heavy animals (1.91%) in relation to young with middle weight carcasses (1.49%). Economic analysis showed that the non-carcass components of young animals with heavy carcass result in higher income (R$ 208.00), followed by young animals with middle weight carcasses (R$ 193.56), and the incomes of adult and of young and light animals, respectively, R$ 21.42 and R$ 23.42 lower than the first one. No carcass components add to industry from R$ 0.71 to R$ 0.80 per carcass kilogram.

The aim of this study was to evaluate the productive and reproductive performance of primiparous zebu cows supplemented on Brachiaria brizantha cv. Marandu with supplements of low intake composed of different energy sources in the postpartum period. Sixty cow-calf pairs were divided into three treatments, a standard mineral salt supplement, a supplement based on ground corn and another containing protected fat, under the same conditions of pasture. The cows had an average initial age of 36 months and 295.9 ± 20 kg of initial body weight. The evaluation period lasted from November 2006 to May 2007, the 24 days after delivery until weaning of calves to 192 days of age. Cows fed the supplement based on ground corn (351 g day-1) and protected fat (357 g day-1) showed a similar increase in body weight, which was higher in relation cows fed with the mineral mixture (179 g day-1). Mineral mixture supplementation resulted in body condition score loss of cows between 80 and 136 days after calving. Cows fed energy supplements of low consumption produced more milk, weaned heavier calves and showed higher pregnancy rate than those fed only with the mineral mixture. The use of 3% calcium salts of fatty acids in energy supplements of low consumption did not alter the productive and reproductive performance of primiparous Zebu cows.

This study aimed to assess the rumen papillae keratinization, cellular levels of liver and muscle glycogen, and the chemical composition of meat from feedlot-finished Nellore young bulls fed with levels of concentrate and babassu mesocarp bran. Twenty-eight animals with initial age of 21 months and initial body weight of 356.7 ± 19 kg were randomized to the following treatments: two levels of concentrate in the diet (65% and 71%), with or without inclusion of 35% of babassu mesocarp bran. Fragments of liver, muscle and rumen were obtained after slaughter of the animals. Levels of concentrate and babassu mesocarp bran in the diet did not affect the quantities of liver and muscle glycogen, and did not induce hyperkeratinization of rumen papillae. The chemical composition of the meat was not affected by the studied factors. The inclusion of 35% babassu mesocarp bran in high concentrate diets does not induce hyperkeratinization of rumen papillae, and does not change the amount of muscle and liver glycogen or the chemical characteristics of meat of Nellore young bulls.

This study aimed to assess the carcass and meat characteristics of European crossbred young bulls or Zebu crossbred young bulls feedlot finished with diets with high percentage of concentrate (80%) containing different levels of grounded millet grain as replacement for grounded corn grain (0, 33, 66 and 100%). Forty-five young bulls with genotype predominance of Aberdeen Angus and forty-four young bulls with genotype predominance Nellore with average initial weight of 317.8 and 320.7 kg, respectively, and average age of 21 month, were allocated in 16 collective pens. At the end of the finishing period were slaughtered six animals of each genetic group, chosen according to the body weight and degree of finishing each treatment. The experimental design was the completely randomized design with treatments in a 4x2 factorial arrangement using six replicates. The replacement of corn grain by millet grain did not significantly influence slaughter weight (480.4 kg), hot carcass weight (259.5 kg), carcass yield (54.1%) and subcutaneous fat thickness (3.95 mm). Young bulls with genotype predominance of Aberdeen Angus showed significantly higher values for slaughter weight (507.6 vs. 453.3 kg), hot carcass weight (269.6 vs. 249.3 kg) and longissimus dorsi area (65.34 vs 56.83 cm2), however, were lower in carcass yield (53.2 vs. 55.00%). Millet grain can be used in substitution to corn grain for finishing steers since it does not change carcass traits of economic interest.

The joint analysis of indicators of the investment project is very relevant in making decisions, resulting in more consistent information regarding risk assessment and its confrontation with the possibility of return. This research aimed to evaluate the economic feasibility of Red Angus young steers finished in feedlot, slaughtered at 340, 373, 396 or 430kg with use of various financial indicators, marketed with or without bonus. The purchase of feeder cattle and feeding were variable costs with a higher share in the total cost. In the analysis with bonus, the regression analysis to gross margin, net margin, net present value, benefit:cost index and additional return on investment showed quadratic behavior, with the point of maximum at 406kg (R$ 185.17), 406kg (R$ 161.76) , 393kg (R$ 128.29), 392kg (1.12), 392kg (11.98%), respectively. In the analysis without bonus, gross margin and net margin showed a quadratic response (346kg, with R$ 110.31 and R$ 86.90, respectively), while for the other indicators, there was a linear reduction as an increase in slaughter weight.

The objective of this study was to assess the income and revenues from the sale of boneless cuts of the carcass of 84 Holstein x Zebu crossbred males, non-castrated or submitted to different castration methods at twelve month of age. The animals were randomly divided into four treatments with 21 replications each: castrated with burdizzo, castrated by removing the scrotum apex, castrated with lateral incisions in the scrotum and non-castrated. The slaughter of animals occurred on the same date, at 30 months of age. Carcass primary cuts analysis showed higher forequarter yield in the non-castrated and lower rib cut yield in relation to the castrated animals. Non-castrated animals showed higher weights and yields of deboned chuck and eye round cuts than the castrated animals. Industrial sale revenue of primary cuts analysis showed that the animals castrated by removing scrotum apex were 13.3% less profitable than non-castrated males. However, sale revenues of boneless cuts analysis showed that the lowest revenue income was from animals castrated by lateral incision in relation to non-castrated males (-9.9 %),

The objective of the present study was to evaluate the effects of corn milling and the inclusion of babassu mesocarp bran (BMB) on productive performance, digestibility of dietary nutrients, and blood parameters of dairy crossbred (Holstein-Gyr) bulls finished in confinement. Twenty-four bulls were fed four different experimental diets, containing two levels of inclusion of BMB (0 and 41.24%) and corn supplied in two different forms (ground and whole), for 98 days (77 days of data collection and 21 days of adaptation). The intakes and digestibility coefficients of the dry matter (DM) and nutrients were determined. There were no significant interaction effects of the BMB inclusion level and the form of corn used on the performance and digestibility variables. The intakes of DM, crude protein (CP), and neutral detergent fibre (NDF) increased with the inclusion of BMB in the diets. However, the inclusion of BMB in the diets decreased the ether extract intake, the NDF apparent digestibility, and the feed efficiency of DM and CP. Dry matter and NDF intakes also increased with the use of ground corn in the diet, which promoted an increase in the intake of total digestible nutrients (TDN), digestibility of non-fibrous carbohydrates, and average daily gain. However, the supply of ground corn reduced the feed efficiency of TDN. The remaining measured variables did not vary with the tested diets. The levels of plasma protein and albumin remained normal, but glucose concentrations were always high, irrespective of the tested diet. The form of corn supplied and the level of BMB inclusion had a significant interaction effect on the levels of triglycerides, urea, aspartate aminotransferase, and alkaline phosphatase. Babassu mesocarp bran can be included up to 41.24% in the diet of confined bulls without a negative effect on the animal weight gain. Corn should be supplied ground because this form improves the performance of crossbred bulls

The objective of this study was to assess the effects of different castration methods applied to dairy crossbred males on carcass and meat traits, compared with noncastrated animals. Eighty-four males, with average age of ten months, were randomized into four groups of 21 animals: castrated using burdizzo tool, castrated by lateral incision in scrotum, castrated by cap removing (scrotum apex) or kept intact (non-castrated). The slaughter of animals occurred in commercial slaughterhouse, at 30 months of age. Non-castrated animals showed higher cold carcass weight (208.0±6.2 kg) than the males castrated by different methods (mean 192.0±6.4 kg). There was no difference in subcutaneous fat thickness among the groups, but when the measure was adjusted for carcass weight, there was a higher fat cover in animals castrated with burdizzo (.79± .08 mm/100 kg) or lateral incision (.86± .09 mm/100 kg) than non-castrated (.61± .05 mm/100 kg). Longissimus dorsi area was higher in noncastrated males (60.47±1.94 cm2 ) than males castrated with burdizzo tool (50.41±3.18 cm2 ). There was not statistical difference for muscle/bone and muscle+fat/bone ratios among the groups, but the muscle/fat ratio was higher in non-castrated animals compared to castrated by cap removing and these were greater than castrated by lateral incision. There was no difference of meat sensorial characteristics, but the marbling score was higher in castrated with burdizzo tool (2.33± .20 points) or castrated by cap removing (2.39± .20 points) than the non castrated (1.77 ± 0.12 points). Castration method in crossbred dairy cattle males slaughtered with low weight does not promote changes in carcass and meat quality, but noncastrated animals have higher slaughter and cold carcass weights, and higher muscle percentage and muscle / fat ratio than castrated males.