ABSTRACT The objective of our study was to evaluate the effect of the use of legume (Arachis pintoi) or nitrogen fertilization on animal performance, characteristics of carcass and meat, and fatty acids profile of crossbred steers on Megathyrsus maximus cv. Aruana pasture, overseeded with temperate grasses. The experimental design was completely randomized, with three treatments and three replicates. The experiment was carried out from June to October (127 d). The treatments were: Low-N: 100 kg of N/ha; Medium-N: 200 kg of N/ha; and Legume: Arachis pintoi + 100 kg of N/ha. The pasture with higher nitrogen fertilization (N200) showed a more significant forage mass yield. The mixed grass with legumes presented a higher concentration of saturated fatty acids and saturated:unsaturated ratio in the meat. However, the grass pastures resulted in a higher content of unsaturated fatty acids in the meat. The other pasture variables, and characteristics of carcass and meat were not influenced by the treatments. The increase in nitrogen fertilization, from 100 to 200 kg/ha, and Arachis pintoi mixed with Aruana grass pasture overseeded with black oat and ryegrass does not affect the daily weight gain and the carcass and meat characteristics of the steers. The grass-legume mixture decreases the total concentration of unsaturated fatty acids in meat without influencing the concentration of polyunsaturated fatty acids. performance cv grasses randomized replicates 127 (12 d. d . d) LowN Low N Low-N 10 N/ha Nha ha MediumN Medium Medium-N 20 Legume N200 (N200 yield saturatedunsaturated However variables kgha kg/ha grasslegume 12 (1 1 2 N20 (N20 ( N2 (N2 (N

ABSTRACT The objective of this study was to evaluate the growth performance and meat quality of feedlot Aberdeen Angus steers fed high-concentrate diets with or without a natural feed additive composed of a mixture of yeasts and essential oils (EO). A completely randomized design with two diets (with or without natural feed additive) and 12 replicates was used. Twenty-four steers with initial shrunk body weight of 402.62±48.2 kg and average age of 18±2.0 months were used. Steers were fed ad libitum a diet containing 777.3 g of concentrate/kg dry matter (DM) and 222.7 g of corn silage/kg DM for 74 days. The mixture of yeast and EO was supplied at the rate of 10.0 and 0.117 g/animal/day, respectively. Average daily weight gain and feed efficiency in the adaptation period was greater in animals fed natural feed additive; however, there was no difference for the total experimental period. Dry matter intake, carcass weight, carcass yield, proportion of carcass bone, carcass muscle + fat:bone ratio, round thickness, and arm length were not altered by treatments. The inclusion of a natural feed additive in the diet increased the cooling loss (0.98 vs. 1.25%), proportion of carcass muscle (51.32 vs. 54.56%), carcass muscle:fat ratio (1.70 vs. 2.11%), leg length (68.79 vs. 70.71 cm), and arm perimeter (36.70 vs. 37.88 cm) and reduced the proportion of carcass fat (30.17 vs. 25.92%). Carcass length was greater in animals fed the diet with a natural feed additive. Meat color, texture, and marbling were not altered by treatments. The addition of natural feed additive to high concentrate diets does not alter the productive performance of feedlot Aberdeen Angus steers, although it can increase the proportion of lean meat of carcasses.

RESUMO: Os efeitos da suplementação energética e da ervilhaca (Vica sativa L.) foram estudados para avaliar o perfil de ácidos graxos intramusculares de novilhos terminados em pastagens de aveia (Avena sativa L.). Foram avaliados 18 novilhos mestiços com 21 meses de idade. O experimento foi realizado em três tratamentos e seis repetições: pastagem de aveia (OA), pastagem de aveia + ervilhaca (OA + VET) e pastagem de aveia + suplementação (OA + SUP). A suplementação compreendeu a adição de fubá na dose diária de 1% do peso corporal dos animais. Os novilhos que receberam suplementação apresentaram maior teor lipídico no Longissimus lombar do que aqueles alimentados com OA + VET (1,25 contra 1,02%), enquanto aqueles alimentados com AO (1,15%) apresentaram valores intermediários. Os níveis de ácido linoléico conjugado foram maiores em novilhos alimentados com AO (0,57%) e OA + SUP (0,59%), enquanto a maior quantidade de ácidos graxos ômega-3 foi observada em animais alimentados com OA + VET (3,32%). Animais terminados em pastagens sem suplementação apresentaram menor proporção de n-6: n-3 (3,14). Novilhos terminados em pastagem de aveia com ervilhaca apresentaram gordura intramuscular mais saudável do que aqueles terminados com suplementação de milho moído, uma vez que apresentaram maior quantidade de PUFAs e melhor a relação n-6: n-3.

ABSTRACT: The effects of energetic supplementation and mixture vetch (Vica sativa L.) were studied to evaluate the intramuscular fatty acid profile of steers finished on oat (Avena sativa L.) pastures. Eighteen 21-month-old crossbred steers were evaluated. The experiment was carried out in three treatments and six repetitions: oat pasture (OA), oat pasture + vetch (OA + VET), and oat pasture + supplementation (OA + SUP). Supplementation comprised the addition of corn meal at a daily dose of 1% of the animals’ body weight. Steers receiving supplementation had higher lipid content in Longissimus lumborum than did those fed with OA + VET (1.25 vs 1.02%), whereas those fed with OA (1.15%) showed intermediate values. Conjugated linoleic acid levels were higher in steers fed OA (0.57%) and OA + SUP (0.59%), whereas the highest amount of omega-3 fatty acids was observed in animals fed OA + VET (3.32%). Pasture-finishing without supplementation resulted in a lower ratio of n-6:n-3 (3.14). Steers finished in oat mixture with vetch showed healthier intramuscular fat than did those finished with cornmeal supplementation; importantly, the higher the amount of PUFAs, the better n-6:n-3 ratio.

ABSTRACT The objective of this study was to investigate the effects of slaughter body weight (SW) on the performance, carcass characteristics, and meat quality of Jersey bulls in feedlots from weaning to slaughter. Eighteen Jersey bulls (125.7±15.9 kg; 5±0.6 months old) were used in the study. The treatments corresponded to three slaughter-weights: L360 – light weight, SW of 360 kg, M390 – medium weight, SW of 390 kg, and H420 – heavy weight, SW of 420 kg (n = 6/treatment); the animals were slaughtered at 368, 392, and 422 kg, respectively. The average daily gain was not influenced by SW. The M390 and H420 groups remained in feedlot, on average, 6 and 51 d longer, respectively, to reach a similar SW in relation to the L360 group. The increase in SW did not influence dry matter intake. However, the L360 group exhibited greater dry matter intake relative to body weight compared with the other two groups (29 vs. 26 g/kg). The increase in SW resulted in heavier and longer carcasses, with higher hot carcass yields. However, animals with greater SW had lower fat thickness. In addition, the increase in SW led to greater pistol cut, bone, and muscle weight for the carcasses. Although the meat color of Jersey bulls was darker in the H420 group, the meat was considered softer and more palatable by the consumer panel compared with the meat from the L360 group. The L360 group exhibited less fluid loss during thawing and cooking. Shear force measured by Warner Blatzer Shear was lower for H420. Animals slaughtered in the L390 group had an intermediate carcass weight, similar carcass yield, better cover fat and meat quality (color and shear) than animals slaughtered in the H420. Combining these factors with a shorter feedlot time compared with that of heavier animals, the SW of feedlot Jersey bulls is recommended at 390 kg.

RESUMO: O objetivo deste trabalho foi avaliar o efeito da espessura de gordura subcutânea (EGS) nas características de carcaça e qualidade de carne em novilhos, com até 24 meses de idade, britânicos ou suas cruzas terminados no sistema de confinamento. Para isso foi utilizado o sistema de meta-análise com dados extraídos de 46 artigos publicados, totalizando 2,695 unidades experimentais. Foi encontrado que a GS influencia no aumento linear no peso de carcaça quente (PCC) e fria (PCF) e em seus rendimentos. Além disso as frações de osso decaem enquanto as frações de músculo e gordura aumentam em altos níveis de GS. Não foi encontrada diferença significativa, mas variáveis de qualidade de carne. Assim a GS apresenta influência direta em PCC, PCF e nos pesos e rendimento de osso, músculo e gordura da carcaça de novilhos castrados. Um valor uniforme de gordura subcutânea de 6,00 mm é capaz de padronizar uma qualidade de carcaça e de produtos aos consumidores.

ABSTRACT: The objective of this research was to examine the effect of subcutaneous fat thickness (SFT) on carcass characteristics and meat quality in 24-month-old British and crossbred British steers finished in feedlot systems. It was assessed using meta-analysis performed on data that was extracted from 46 published studies and comprising a total of 2,695 experimental units. We found that SFT was influenced by and increased linearly with hot carcass weights (HCWs) and cold carcass weights (CCWs) and their yields; moreover, the bone fraction decreased whereas the muscle and fat fractions increased with higher levels of SFT. No significant differences were detected in meat quality variables. Thus, SFT appeared to have a direct influence on HCW, CCW, and the weight and yield of bone, muscle, and fat of castrated steers. A uniform fat thickness level of 6.0 mm SFT was determined to be the standard of quality of carcasses and meat products for consumers.

Resumo O objetivo deste trabalho foi avaliar a eficiência biológica do sucedâneo em substituição ao leite, na fase de cria e recria de bezerros da raça Holandesa. O trabalho foi realizado na Universidade Tecnológica Federal do Paraná (UTFPR), Dois Vizinhos, entre maio de 2011 e abril de 2012. A pesquisa foi realizada com 32 animais, adotando-se o delineamento inteiramente casualizado com quatro tratamentos e oito repetições: 100% leite; 34% sucedâneo + 66% leite; 66% sucedâneo + 34% leite; e 100% sucedâneo. Os dados foram submetidos à analise de variância e de regressão a 5% de significância. Dentre as medidas morfométricas realizadas, apenas o ganho de perímetro torácico apresentou diferença significativa. A utilização de sucedâneo em substituição ao leite durante a fase de aleitamento apresentou uma resposta linear negativa para os níveis 100%, 66%, 34% sucedâneo, porém durante a fase de recria ocorreu um ganho compensatório dos animais submetidos aos tratamentos 34% e 66% sucedâneo. A utilização de 100% de sucedâneo na alimentação de bezerros holandeses na fase de cria não foi eficiente durante o aleitamento. Durante a fase de recria, a substituição parcial do leite por sucedâneo (66% sucedâneo + 34% leite) mostrou ser a opção mais eficiente, pois apresentou um ganho compensatório favorável.

Abstract The objective of this study was to evaluate the biological efficiency of the milk replacer in the substitution of whole milk for calves at the first months of age and at rearing fase. This study was conducted in Universidade Tecnológica Federal do Paraná (UTFPR), Campus Dois Vizinhos, from May 2011 to April 2012. This research was carried out on 32 animals, assigned in a completely randomized design with four treatments (100% whole milk, 34% milk replacer + 66% whole milk, 66% milk replacer + 34% whole milk and 100% milk replacer) and eight replications.The data were analyzed by analysis of variance and regression at 5% of significance. Regarding the morphometric measurements, only the gain of chest circumference presented significant difference. The use of milk replacer in the substitution of whole milk during pre-weaning phase showed negative linear response for levels 100%, 66%, 34% milk replacer, nevertheless during the post-weaning phase there was a compensatory gain for the animals fed with 34% and 66 % milk replacer. The use of 100% milk replacer for Holstein calves at pre-weaning phase was not efficient during lactation, althoug, during post-weaning phase, partial replacement of milk by milk replacer (66% + 34% milk replacer) was an efficient option because there was a favorable compensatory growth.

O objetivo deste experimento foi avaliar as características da carcaça de bezerros holandeses terminados em confinamento ou em pastagem com suplementação e abatidos com diferentes pesos de abate. Os animais confinados foram alimentados com volumoso e concentrado comercial, na proporção de 40:60, sendo a silagem de milho utilizada como volumoso. O delineamento experimental foi o inteiramente casualizado, em arranjo fatorial 2x4 (dois sistemas de terminação x quatro pesos de abate). Os animais foram abatidos à medida que atingiam os pesos de abate pré-determinados (140, 180, 220 e 260kg). O sistema de acabamento não teve influência sobre o peso e rendimento de carcaça quente e fria e as perdas de carcaça, mas os animais confinados apresentaram maior espessura de gordura. Animais confinados apresentaram melhor conformação, comparados com os terminados em pastagem. À medida que aumentou o peso de abate, houve crescimento linear para peso de carcaça quente e fria, rendimento de carcaça quente e fria, conformação, medidas métricas e peso dos cortes comerciais da carcaça. O percentual do corte traseiro decresceu com o aumento do peso de abate, enquanto que a espessura de gordura apresentou resposta quadrática. Os sistemas de abate apresentaram rendimento de carcaça semelhante. As características da carcaça melhoram com o aumento do peso de abate, mas, em percentagem, são semelhantes

A bovinocultura de leite apresenta grande importância económica para várias regiões do Brasil e nos últimos anos houve mudanças significativas no setor. O presente trabalho teve por objetivo realizar uma revisão da utilização da modelação para a determinação de genótipos de milho mais indicados para a produção de silagem e, por conseguinte, produção de leite. Com a utilização de técnicas como o uso de modelos matemáticos e softwares, é possível planear as atividades da propriedade rural de forma rápida, minimizando esforços e possibilitando a redução de tempo para a tomada de decisão. Uma dessas formas é a utilização de folhas de cálculo que permitem a estimativa de produção de leite a partir de parâmetros bromatológicos e da produção de milho para silagem. Essa ferramenta é importante, pois no Brasil a dinâmica de produção de milho faz com que exista uma grande quantidade de genótipos disponíveis no mercado.

The dairy cattle present great economic importance for many regions in Brazil and in recent years there have been significant changes in the industry. This paper aims to review the use of modelling for the determination of maize genotypes more suitable for silage production and hence milk production. With the use of techniques, such as mathematical models and software, is possible to plan the activities of the rural property quickly, minimizing effort and time for decision making. One of these ways is to use spreadsheets which allow estimates of milk production based on parameters of production and nutritional qualities of maize for silage. This tool is important because in Brazil the production dynamics of maize genotypes means that there is a large amount of genotypes available in the market.

O objetivo deste trabalho foi avaliar o desempenho ponderal e reprodutivo de vacas de corte submetidas a diferentes manejos de amamentação. Durante a estação de monta, de 85 dias, foram avaliadas 161 vacas de corte da raça Purunã, de acordo com os seguintes manejos de amamentação: desmame precoce, vacas separadas dos seus bezerros aos 75 dias pós-parto; amamentação controlada, vacas separadas de seus bezerros aos 75 dias de idade, mas colocadas para amamentar uma vez ao dia durante a estação de monta; e desmame convencional, vacas mantidas com seus bezerros ao pé até o final da estação de monta, aos 160 dias de idade dos bezerros, em média. As taxas de prenhez não foram significativamente afetadas pelos manejos de amamentação, tendo sido de 97% no desmame precoce, de 96% na amamentação controlada e de 90% no desmame convencional. No entanto, o desmame precoce resultou em menor eficiência reprodutiva (28,26 kg), quando comparado à amamentação controlada (35,09 kg) e ao desmame convencional (35,34 kg). Vacas de corte mantidas em boas condições corporais ao parto e ao início da estação de monta apresentam alta taxa de fertilidade, independentemente do manejo de amamentação dos bezerros.

The objective of this work was to evaluate the weight and reproductive performance of beef cows subjected to different nursing managements. During the breeding season of 85 days, 161 beef cows of the Purunã breed were evaluated, according to the following feeding managements: early weaning, cows separated from their calves at 75 days postpartum; controlled nursing, cows separated from their calves at 75 days of age, but taken to nurse once a day during the breeding season; and conventional weaning, cows kept with their calves until the end of the breeding season, at 160 days of age of calves, in average. Fertility rates were not significantly affected by weaning managements, being 97% for early weaning, 96% for controlled nursing, and 90% for conventional weaning. However, early weaning resulted in lower reproductive efficiency (28.26 kg), when compared to controlled nursing (35.09 kg) and conventional weaning (35.34 kg). Beef cows maintained in good body conditions at birth and at the beginning of the breeding season have a high fertility rate, regardless of calf-feeding management.

Avaliaram-se as características da carcaça de 43 vacas de descarte da raça Purunã com idade média de 68,02 ± 17,36 meses em diferentes pesos de abate. O delineamento experimental foi inteiramente casualizado e os pesos de abate avaliados foram de 401; 434; 461; 476 e 522 kg. A elevação do peso de abate de 401 para 522 promoveu aumento do peso e rendimento de carcaça quente e fria de 34,7; 36,6; 2,1 e 5,13, respectivamente. A espessura de gordura subcutânea (mm) aumentou linearmente com o avanço do peso de abate, passando de 1,11 para 4,79 mm. A área do Longissimus dorsi expressa em função do peso de carcaça fria variou de forma quadrática com o avanço do peso de abate, com o menor valor estimado para o peso de abate de 440 kg. A quantidade de músculo, gordura e osso aumentaram 300; 330 e 69 g a cada quilograma a mais no peso de abate, respectivamente. A porção comestível da carcaça aumentou 34,1% com a elevação do peso de abate de 401 para 522 kg. A elevação do peso de abate representa grande potencial para o aumento da produção de carne no país, dado ao número expressivo de fêmeas de descarte que são abatidas anualmente. No entanto, para o sistema de produção, considerando o atual método de remuneração, o peso de abate de vacas de descarte não deve exceder as exigências mínimas dos frigoríficos, tendo em vista a redução da eficiência alimentar com o avanço da deposição de gordura corporal.

The carcass characteristics of 43 livestock cows of the Purunã breed, with an average age of 68.02 ± 17.36 months and of different weights at slaughter, were evaluated. The experimental design was completely randomized, with slaughter weights of 401; 434; 461; 476 and 522 kg being evaluated. The increase in slaughter weight from 401 to 522 kg, promoted a gain in weight and in the hot and cold carcass yield of 34.7; 36.6; 2.1 and 5.13 respectively. The subcutaneous fat thickness (mm) increased linearly with increasing slaughter weight, going from 1.11 to 4.79 mm. The area of the Longissimus dorsi, expressed as a function of the cold-carcass weight varied quadratically with increasing slaughter weight, with the smallest value being estimated for a slaughter weight of 440 kg. The amount of muscle, fat and bone increased by 300; 330 and 69g for each additional kilogram of slaughter weight respectively. The edible portion of the carcass increased by 34.1% with the increase in slaughter weight from 401 to 522 kg. Raising the slaughter weight represents a great potential for increasing meat production in the country, given the significant number of female livestock slaughtered annually. However, based on the production system, and considering the current method of remuneration, the slaughter weight of livestock cows should not exceed the minimum requirements of slaughterhouses, in view of the reduced feed efficiency which accompanies increasing body-fat deposits.

The objective of this study was to evaluate the effect of inclusion of lipid residue of biodiesel originated in the processing of palm oil (Elaeis guineensis) in the diet on the digestibility of feedlot lambs. Twenty-five crossbred male castrated lambs, weighing 20±1.61 kg, were distributed in randomized blocks with five treatments and five replications. The experimental period lasted 22 days; 15 for diet adaptation, 2 for the adaptation to the indicator LIPE (lignin from Eucalyptus grandis isolated, purified and enriched, UFMG, Minas Gerais) and 5 for fecal sampling. Diets were formulated with 64% concentrate based on corn and soybean meal, 31% Massai grass (Panicum maximum cv. Massai) hay and 5% lipid supplementation from increasing levels of substitution of 0, 25, 50, 75 and 100% of palm oil for biodiesel oil from palm residue. The lambs were offered two meals a day, at 7h00 and 16h00. There was linear effect of inclusion of the residue from palm oil biodiesel on dry matter intake. There was no change in digestibility of nutrients except for ether extract. The use of biodiesel from palm oil residue up to 100% replacement for the lipid supplementation of sheep positively influences the consumption without altering the digestibility of nutrients.

In order to evaluate the effect of the different percentages of zebu blood in the genotype of crossbred steers on carcass traits, a meta-analysis was carried out, using 30 studies conducted in Brazil that have been published since the year 2000. The parameters evaluated were hot carcass weight (221 estimates), cold carcass weight (232), hot carcass (236) and cold carcass yield (223), subcutaneous fat thickness (238) and the percentages of saw cut (233), forequarter (234) and sidecut (246 estimates). Initially, exploratory analysis was performed for each of the variables for detection of publication vices through the dispersion of observations by pointing out the outliers eliminated. Normality tests were normal and the data were subjected to analysis of variance for the regression study, which were assessed to the third degree. Weights of hot carcass and cold carcass, hot and cold carcass yield and the percentage of saw cut had a quadratic effect on animals with the presence of zebu blood, indicating superiority of crossbred animals. The regression equation showed that 66; 50; 72; 81 and 59% of zebu in crossbred animals showed higher hot and cold carcass weight, hot and cold carcass percentage and saw cut, respectively. Fat thickness was not influenced by the degree of zebu in the genotype. The percentage of forequarter has a positive response by increasing the degree of zebu in the genotype, while the sidecut has a negative answer. The crossbreeding between zebu and European breeds provides carcasses with better quality than purebred animals.

The objective of the experiment was to study the carcass physical composition and meat qualitative characteristics of different categories of Charolais cattle, feedlot finished. Nine steers (ST), ten heifers (HE), with average age of 20 months, and ten cull cows (CO) with average age of 87 months, taken from the same herd, were used. Diet contained 13% of crude protein for ST and HE and 10% for CO, with roughage:concentrate relation of 50:50, on a dry matter basis. The animals of the three categories were slaughtered with similar degree of finishing, with average subcutaneous fat thickness of 3.8 mm. HE showed carcasses with greater pistolcut percentage (52.8%) than ST (51.0%) and CO (51.4%). The carcass physical composition was similar among the categories evaluated, with 66.5; 67.0 and 67.3% of muscle, 19.1; 18.5 and 18.7% of fat, and 14.9; 15.0; and 14.6% of bone, respectively, for ST, HE and CO. The marbling score was lower for HE (4.6 points) than ST (7.1 points) and CO (6.5 points). However, when this characteristic was adjusted for 100 kg of cold carcass, the means were similar among the categories. CO showed higher cooking losses (27.8%) than ST (21.4%) and HE (23.5%). Meat color, texture, tenderness, shear force, palatability and juiciness were similar among the categories. Charolais cows have the potential for the production of carcass and meat with quality similar to steers and heifers.

Avaliaram-se as características sensoriais da carne de novilhos não-castrados ou castrados terminados em confinamento e abatidos aos 16 (superjovens) ou 26 (jovens) meses de idade. A dieta com relação volumoso:concentrado de 50:50 continha 11,8% de proteína bruta e 2,83 Mcal de energia digestível/kg de matéria seca. A maior amplitude do pH final da carne foi observada nos novilhos jovens e a menor, nos superjovens. A carne dos animais não-castrados, independentemente da idade de abate, foi mais escura, mais grosseira e com menor grau de marmorização em comparação à dos castrados. A carne dos animais castrados teve maior perda de líquidos durante o processo de descongelamento em relação à dos não-castrados (8,55 vs 4,99%). Ocorreu interação entre categoria e sexo do animal para perda de líquido durante a cocção, palatabilidade e suculência. Novilhos jovens não-castrados apresentaram maior quebra à cocção, carne menos palatável e menos suculenta em relação aos jovens castrados e aos superjovens castrados e não-castrados. A redução da idade de abate de 26 para 16 meses de idade, independentemente da condição sexual, melhora a maciez da carne avaliada pelo painel de degustadores.

It was evaluated in this work the sensorial characteristics of the meat of non-castrate or castrated males feedlot finished and slaughtered at 16 (young steers) or 26 (steers) months old. The diet with 50 roughage: 50concentrate contained 11.8% of crude protein and 2.83 Mcal of digestible energy/kg of dry matter. The highest amplitude of the final pH of the meat was noted on the steers, and the lowest on the young steers. The meat of the non-castrate males, regardless to the age at slaughter, was darker, coarser and showed lower marbling degree than the meat of the castrated animals. Thawing loss was higher for the meat of the castrated animals(8.55 vs 4.99%). There was interaction among categories and sex for cooking loss, palatability and juiciness. Meat of the older non-castrate males showed higher cooking loss, it was less palatable and less juicy regarded to the meat of the older castrated and the younger castrated or non-castrate males. Reduction of slaughtering age from 26 to 16 months old, regardless to sexual condition, improves meat tenderness evaluated by taste panel.

Foram avaliados o peso e o rendimento de carcaça quente, os pesos dos cortes primários, os pesos dos componentes físicos dos cortes primários e os pesos dos principais cortes comerciais do traseiro especial de 20 bovinos machos não-castrados dos grupos genéticos Nelore, ½ Guzerá + ½ Nelore (½ G + ½ N), ½ Red Angus + ½ Nelore (½ R + ½ N) e ½ Marchigiana + ½ Nelore (½ M + ½ N) terminados em confinamento. O experimento durou em média 114 dias, período no qual os animais foram alimentados com silagem de sorgo à vontade e concentrado composto de 73,5% de grão de milho, 25% de caroço de algodão e 1,5% de ureia, perfazendo 13,5 MJ de EM e 18% de PB por kg de MS, fornecido à base de 1% do peso vivo do animal por dia. O grupo genético influenciou os pesos de carcaça quente, do dianteiro, da carne do costilhar e os pesos da carne e dos ossos do dianteiro. Animais do grupo ½ M + ½ N superaram os Nelore e os ½ G + ½ N em peso de carcaça quente e em peso do corte dianteiro e da porção de carne do costilhar. O grupo ½ M + ½ N distinguiu-se também do ½ R + ½ N quanto ao peso de dianteiro e do ½ G + ½ N quanto ao peso da carne do dianteiro. Por outro lado, a quantidade de ossos do dianteiro dos animais ½ M + ½ N foi superior à dos animais dos grupos Nelore e ½ R + ½ N. Não houve efeito de grupo genético sobre os cortes resultantes do desdobramento do traseiro especial, exceto pelo fato de os animais ½ M + ½ N apresentarem maior peso de músculo em comparação aos ½ G + ½ N e maior peso de patinho em comparação aos Nelore.

Data on hot carcass weight, hot carcass yield, hindquarter weights and physical components, forequarter and spare ribs, and the weights of the main commercial cuts from the hindquarters of twenty young intact bulls were assessed. The animals, belonging to four genetic groups (Nellore, ½ Guzerath + ½ Nellore (½ G + ½ N), ½ Red Angus + ½ Nellore (½ R + ½ N) and ½ Marchigiana + ½ Nellore (½ M + ½ N)), were raised on pastures, finished in dry lot and slaughtered at live weights ranging from 445 to 517 kg, and at ages ranging from 679 to 863 days. During the dry lot period, which lasted 114 days, animals were fed sorghum silage offered ad libitum, and a concentrate (13.5 MJ of ME, 18% CP in the DM) at 1% live weight per day. Genetic group influenced hot carcass weight, forequarter weight, meat weight in the spare ribs, as well as meat and bone weights in the forequarter. Animals in the ½ M + ½ N group were superior both to those in the Nellore and in the ½ G + ½ N groups for hot carcass weight, forequarter weight and meat weight in the spare ribs. The ½ M + ½ N group also differed from the ½ R + ½ N and from the ½ G + ½ N groups in terms of forequarter weight and meat weight in the forequarter, respectively. Conversely, forequarter bone weight of ½ M + ½ N animals was higher than in animals from the Nellore and the ½ R + ½ N groups, respectively. There was no effect of genetic group on hindquarter cuts, except for higher shank and knuckle weights in the ½ M + ½ N group compared to the ½ G + ½ N and Nellore groups, respectively.