ABSTRACT This study was intended to estimate the genetic associations between growth traits and visual scores with possible changes in mature weight (MW) in 397,900 Nellore animals. A bi-character analysis was performed to estimate the (co)variances and genetic parameters for MW, which comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, and WM) and yearling (YC, YP, and YM), birth weight (BW), weight from birth to weaning (WG), weight from weaning to yearling (YG), and final index (FIND). The observed mean MW was 417.6±56.2 kg, and the direct genetic effect mean estimated heritability ( h 2 a 1) of MW was 0.45. Overall, the BW was 31.0±3.7 kg, and the estimated h² was 0.34. The heritability estimate of the maternal additive genetic component ( h 2 m 2) of BW was 0.07. We calculated the mean WG to be 144.1±26.3 and estimated the h 2 a 2 as 0.18 and h 2 m 2 as 0.07. The value for h 2 a YG (0.17) and YW (0.26) were also estimated. The heritability of the weaning WC (0.17), WP (0.19), and WM (0.17) and yearling YC (0.25), YP (0.27), and YM (0.25) were estimated using visual scores. The h 2 m values for weaning WC, WP, and WM (0.06) with visual scores were estimated. The genetic correlations between body weight (BoW) at YC and WC (0.62) were considered moderately high and positive. In addition, YP (0.18), YM (0.15), WP (0.13), and WM (0.14) were considered moderately low compared with MW. The genetic correlation between BW and FIND (0.38) was considered positive and moderate. The heritability estimation indicates that growth traits, visual scores, and weight of adult cows could be changed by selection. Cows that presented the highest h 2 a values for live weight responded rapidly to selection based on growth characteristics, visual scores, and FIND and might result in increased final MW.

ABSTRACT This study aimed at estimating the heritability of age at first calving and of performance traits included in the selection index and the genetic correlations between age at first calving and these performance traits. Data were extracted from the Conexão Delta G database and only data from herds in which heifers were bred younger than 24 months of age were used, resulting in a file with 331,310 evaluated animals. The following traits were included in the analyses: age at first calving, birth to weaning gain, post-weaning weight gain, visual scores of conformation, precocity, and muscling evaluated at weaning and in yearling heifers. Covariance components were obtained by bi-character analyses between traits. An alternative age at first calving was also taken into account, in which all heifers were used, including those that were mated and did not calve. Covariance components and estimates of the effects included in the model were obtained using the software program DMU. Heritability estimates were 0.11 and 0.13 for age at first calving and alternative age at first calving, 0.38 for birth to weaning gain, and 0.13 for post-weaning weight gain. Visual score estimates ranged between 0.16 and 0.18 at weaning and 0.19 and 0.29 in yearlings. Genetic correlation estimates of the traits were low, but in the desirable direction. Selection for birth to weaning gain and visual scores does not have a negative effect on age at first calving or alternative age at first calving.

RESUMO: O peso adulto das vacas (PV) está relacionado com os custos de produção. Em geral, vacas com PV moderados são mais eficientes em ambientes desafiadores, como aqueles disponíveis nos sistemas de produção no Brasil. No presente estudo, o índice de seleção compreende as seguintes características: conformação, precocidade e musculatura nas fases da desmama (CD, PD e MD) e sobreano (CS, PS e MS), circunferência escrotal no sobreano (CE), dias para ganhar 160kg do nascimento até a desmama (D160) e 240kg pós-desmama (D240), que estão relacionadas com os ganhos de peso do nascimento à desmama (GD) e, da desmama ao sobreano (GS). As características PV e PN não foram consideradas no índice de seleção. O objetivo deste estudo foi estimar os valores das tendências genéticas (TG) das importantes características de seleção (PV) e econômicas (PN). Para estimar os componentes de (co)variâncias e os dados genéticos, foram realizadas análises bi-caracter de PV com as demais características. Os resultados de TG obtidos para PV foram nulos (0,0065% ou 0,02718kg por ano) no período de 1990 á 2007. Os valores de TG foram estimados para PN (-0,0650% ou -0,02017kg), GD (0,0758% ou 0,0865kg), GS (0,1051% ou 0,11377kg) e PF (0,0393% ou 0,11276kg) por ano. Os valores dos escores visuais (em unidades de escore) foram determinados para TG à desmama [CD (0,2310%; 0,00707), PD (0,3624%; 0,3623%) e MD (0,01149; 0,01087)] e sobreano [CS (0,3256%; 0,00990), PS (0,4795%; 0,01496) e MS (0,5041%; 0,01457)] ao ano. A seleção baseada no índice foi efetiva para promover o progresso genético nas características de GD, CD, PD, MD, GS, CS, PS e mantendo PN e PV constantes.

ABSTRACT: Mature weight (MW) of cows is related to the costs of their production. Usually, cows with moderate MW are more efficient in challenging environments, such as those available in the production systems in Brazil. In the present study, the selection index comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, WM) yearling (YC, YP and YM), scrotal circumference at yearling (SC), days to gain 160kg from birth to weaning (D160) and 240kg after weaning (D240). This are related to birth weight gain at weaning (WG) and from weaning to yearling (YG). The mature (MW) and birth weight (BW) traits were not considered in the selection index. The aim of this study was to estimate the values for the genetic trends (GT) of some important selection (MW) and economic traits (BW). A bi-character analysis of MW and other characteristics was performed to estimate the (co)variance components and genetic parameters. The GT results obtained for MW were null (0.0065% or 0.02718kg per year) in the period 1990-2007. The GT values were determined for BW (-0.0650% or -0.02017kg), WG (0.0758% or 0.0865kg), YG (0.1051% or 0.11377kg), and MW (0.0393% or 0.11276kg) per year. The visual score values (in score units) were also determined for GTat weaning [WC (0.2310%; 0.00707), WP (0.3624%; 0.3623%),aWM (0.01149; 0.01087)] yearling [YC (0.3256%; 0.00990), YP (0.4795%; 0.01496),YM (0.5041%; 0.01457)] per year. Index-based selection was effective to promote genetic progress in WG, WC, WP, WM, YG, YC, YP, and YM characteristics keeping BW and MW constant.

Resumo Objetivou-se avaliar a substituição do farelo de soja pela torta de soja sobre as características de carcaça e qualidade da carne de cordeiros Santa Inês. Foram utilizados 29 machos inteiros, com 23,63 ± 2,44 kg de peso vivo, 80 dias de idade, distribuídos de maneira inteiramente casualizada, submetidos a cinco dietas, sendo que as dietas variaram nos teores de substituição do farelo de soja pela torta de soja de 0, 25, 50, 75 e 100%. Para cada teor de substituição foram utilizados seis animais, mas no teor de 25%, cinco animais. Foram realizadas avaliações das carcaças e retirou-se o Longissimus dorsi para análises da qualidade da carne. As características da carcaça não foram afetadas pelos diferentes teores de torta de soja. Observou-se efeito quadrático para a força de cisalhamento e efeito linear decrescente para a intensidade de odor, mas não foram observadas diferenças nos demais parâmetros. A substituição do farelo de soja pela torta de soja pode ser realizada sem prejuízo à maioria das características da carcaça e de carne e altos teores de torta de soja na dieta podem resultar em benefícios às qualidades sensoriais da carne de cordeiros recebendo dietas concentradas.

Abstract The objective of this study was to evaluate the replacement of soybean meal by soybean cake on carcass characteristics and meat quality of Santa Ines lambs. Twenty-nine intact males were used, weighing 23.63 ± 2.44 kg, at 80 days of age, distributed randomly, submitted to five diets, with the diets differing in the levels of substitution of soybean meal by soybean cake (0, 25, 50, 75 and 100%). Each diet was provided to six animals, except the 25% diet, in which five animals were used. Carcass characteristics were evaluated, and the Longissimus dorsi was removed for meat quality analysis. The different levels of soybean cake did not affect carcass characteristics. Regarding the characteristics of meat, there was a quadratic effect for the shear force and negative linear effect on flavor intensity, but no significant differences on the other parameters were observed. Replacement of soybean meal for soybean cake can be made without affecting most of the carcass and meat characteristics, and high levels of soybean cake in the diet can improve the meat sensorial quality of lambs receiving concentrated diets.

RESUMO O objetivo foi avaliar o comportamento ingestivo, características de carcaça e a qualidade da carne de novilhas Nelore, alimentadas com torta de girassol em substituição ao farelo de algodão. Foram utilizadas 30 novilhas, com peso médio inicial de 274 kg ± 28 kg e idade média de 24 meses, confinadas por 76 dias. O delineamento foi inteiramente casualizado com cinco tratamentos (0; 150; 300; 450 e 600 g kg-1 MS) e seis repetições por tratamento. Ao completar 24 h após o abate, avaliou-se conformação muscular e grau de acabamento realizada no músculo Longissimus dorsi na 13ª costela. Amostra representativa entre a 10ª e 12ª costelas foi coletada para avaliações dos componentes físicos das carcaças. Assim como as demais variáveis estudadas, o peso de carcaça quente, rendimento de carcaça, comprimento de carcaça e área de olho de lombo não foram influenciados pelos diferentes teores de torta nas rações. Os valores médios de porcentagem de músculo, osso e gordura da carcaça foram de 53,45; 16,14 e 29,46%, respectivamente, semelhantes entre tratamentos. Portanto, a utilização de até 600g kg-1 de torta de girassol em substituição ao farelo de algodão, como principal fonte proteica, não alterou as características de carcaça e a qualidade da carne de novilhas Nelore.

ABSTRACT The aim was to evaluate the feeding behavior, carcass characteristics and meat quality of Nelore heifers fed sunflower pie replacing cottonseed meal. They were used 30 heifers with average initial weight of 274 kg ± 28 kg and average age of 24 months, confined for 76 days. The design was completely randomized with five treatments (0, 150, 300, 450 and 600 g kg-1 DM) and six replicates per treatment. By completing 24 hours after slaughter, it evaluated muscle conformation and degree of finish made the Longissimus dorsi at the 13th rib. A representative sample between the 10th and 12th ribs was collected for evaluation of the physical components of carcasses. As well as the other variables, the hot carcass weight, dressing percentage, carcass length and rib eye area were not influenced by different pie levels in feed. The mean percentage of muscle, bone and fat from the carcass were 53.45; 16.14 and 29.46%, respectively, similar among treatments. Therefore, the use of up to 600 g kg-1 of sunflower pie replacing cottonseed meal as the main protein source, did not affect the carcass characteristics and meat quality of Nelore heifers.

The objective of this study was to evaluate the characteristics of wool produced by ewes of different genetic groups, ages, and reproductive statuses. A total of 115 ewes, of the following genetic groups, were used: 10 Corriedale, 37 Hampshire Down, 26 1/2 Hampshire Down + 1/2 Corriedale, 24 1/2 Ile de France + 1/2 Corriedale, and 18 1/2 Suffolk + 1/2 Corriedale. Age was determined by the number of permanent incisors, ranging from four teeth to eight teeth. Ewes were further classified by their reproductive status into: lambed, having reared one lamb; and not-lambed. Hampshire and half-blood Suffolk ewes were heavier (53.2 and 52.7 kg, respectively), while Corriedale animals were lighter (40.1 kg). Older ewes and not-lambed ewes were heavier as well. Fleece weight was higher for the Corriedale and its crossbred ewes (average of 2.9 kg). Genetic group did not affect yield after scouring (61.6%). Ewe age, reproductive status, and year of evaluation did not affect greasy fleece weight or yield. Fiber diameter and number of crimps were not affected by any tested variables, with mean values of 29.8 μm and 5.8 crimps per centimeter, respectively. Staple length was influenced only by genetic group, in which the Hampshire ewes showed the shortest staple (6.2 cm). In general, the character was classified as good to regular, and the worst was found in the Hampshire. That genetic group grew rough wool, while the others were rated as slightly soft to rough. All genetic groups presented wools with some medullation. The majority of the samples were classified from "Cruza 1" to "Cruza 3" in all five groups and, for quality, the majority of the samples were rated as Good. Wool produced by meat breeds presents variations of quantity and quality that should be considered by producers and industry.

ResumoO objetivo deste trabalho foi avaliar o efeito da substituição do farelo de soja pela torta de soja em dietas para cordeiros Santa Inês confinados, avaliando o desempenho, consumo de nutrientes, comportamento ingestivo e medidas biométricas. Foram utilizados 30 cordeiros machos não castrados, com 23,63 ± 2,44kg de peso corporal, distribuídos de maneira inteiramente casualizada em cinco tratamentos, sendo assim 6 repetições por tratamento, os quais foram os teores de substituição do farelo de soja pela torta de soja de 0; 25; 50; 75 e 100%. O comportamento ingestivo foi avaliado através de observações pontuais a cada 10 minutos durante 24 horas. Não foi observado efeito significativo sobre os parâmetros de desempenho, consumo de matéria seca e de comportamento ingestivo. O ganho de peso médio diário foi de 312,73g, o consumo médio de matéria seca foi de 1,44kg/dia. A inclusão da torta de soja levou a um aumento linear no consumo de extrato etéreo em gramas/dia, em porcentagem do peso corporal e em porcentagem do peso metabólico. Foi observado efeito cúbico sobre parâmetros de consumo de fibra em detergente ácido. Os tempos de ruminação, alimentação e ócio foram de 425,85; 194,50 e 789,29min/dia, respectivamente. Em relação às medidas biométricas, não foi encontrado efeito da substituição do farelo de soja pela torta de soja. A torta de soja pode ser utilizada na substituição do farelo de soja, devendo-se atentar ao teor de extrato etéreo residual presente neste coproduto da indústria do biodiesel.

AbstractThe objective of this study was to evaluate the effect of replacing soybean meal by soybean cake in diets for feedlot Santa Ines lambs, evaluating performance, nutrient intake, ingestive behavior and biometric measures. Thirty intact males were used, weighing 23.63 ± 2.44kg, distributed randomly in five treatments, with 6 animals each, with the treatments being the levels of substitution of soybean meal for soybean cake, by 0; 25; 50; 75 and 100%. The ingestive behavior was assessed by visual observations every 10 minutes, during 24 hours. No significant effects were found on the parameters of performance, DM intake, and ingestive behavior. The average daily weight gain was 312,73g, and the average dry matter intake was 1,44kg/day. The inclusion of soybean cake led to a significant linear increase in ether extract intake in grams/day, in percentage of body weight and in percentage of metabolic weight. Cubic effects were observed in the parameters of acid detergent fiber intake. The rumination, feed intake and idleness time observed were 425,85; 194,50 e 789,29 min/day, respectively. Regarding biometric measurements, there was no significant effect of replacing soybean meal with soybean cake. The soybean cake can be used in replacement of soybean meal, but is important to pay attention on the content of residual lipids present in this byproduct of the biodiesel industry.

The objective of this study was to evaluate the performance, the carcass and meat characteristics of ewes supplemented with magnesium oxide. Eighteen 6-year-old Santa Ines ewes were used in a completely randomized experimental design, where three levels of supplementation (0.0, 0.1 and 0.2% magnesium oxide in the concentrate) were tested, with six replicates. Final weight, weight gain, feed intake and feed conversion were not affected by levels of magnesium supplementation. Hot and cold carcass weights showed linear increasing and quadratic responses, respectively, according to supplementation with magnesium. Carcass measurements such as length, depth, and measures of arm and leg were not affected by supplementation. Depth and width of the longissimus muscle and rib-eye area were not affected; however, marbling and ether extract increased linearly with supplementation. Water loss and color were not affected. Lipid oxidation and shear force were not affected by supplementation, while the myofibrillar fragmentation index showed a quadratic regression. There was a linear decrease in pH with magnesium supplementation. Supplementation with magnesium can improve carcass and meat pH, but can act negatively by increasing the amount of marbling and ether extract of meat.

The objectives of this work were to evaluate the environmental effects (age of dam, type of birth and sex of lamb) and genetic groups (Hampshire Down and Ile de France, ½ and ¾ Hampshire Down, Ile de France and Suffolk, and ½ Texel) on performance and morphometric characteristics (height, length and heart girth) of lambs; to test regressions to predict live weight of lambs from body measurements; and to describe the growth type of the measurements as function of the weight. Weights and measurements were collected from birth to weaning, every 14 days. For evaluations of performance in relation to environmental effects and genetic groups, only data from birth and from weaning were used; for type of growth all collected data were used. Lambs from younger ewes (2 teeth) presented smaller average for weight at birth, heart girth and height at weaning. Single-birth lambs presented greater averages than twins. Genetic group influenced all traits evaluated, except heart girth at birth and average heart girth gain. Means for birth weight were higher in ¾ Ile de France (3.93±0.16 kg) and lower in ½ Texel lambs (3.04±0.24 kg), and for weaning, they were higher in ½ Texel (14.86±0.87 kg) and lower in Ile de France lambs (11.66±0.83 kg). Year of birth influenced all traits. Heart girth and length showed a negative allometric growth in relation to weight, while between weight and height the relation was positive allometric. The factors that most influenced the performance of lambs from birth to weaning are the type of birth, genetic group and year of birth. Correlations between body weight and morphometric measurements are significant, so it is possible to predict one from the other.

The objectives of this study were to evaluate the environmental effects (age of dam at lambing, type of birth and sex of lamb) and genetic groups (Santa Inês and ½ Santa Inês) on weight and morphometric measurements (heart girth, body length and height) of lambs; to test linear and allometric regressions to predict the weight through the measurements; and to describe the type of growth of the measurements from weight. Weight and morphometric measurements were sampled from birth to 154 days of age, at every 14 days. For the evaluation of the environmental factors and to predict the regressions the data of birth, weaning and 154 days of age were used; and to determine the type of growth all the data collected were used. The lambs derived from younger (two-tooth) ewes recorded lower averages than the ones from eight-tooth ewes for weight, heart girth and body length at birth and length at weaning. The animals born from single births presented higher average weight from birth to weaning, as well as of all the measurements from birth to 154 days of age than those from twin births. There was no difference between the genetic groups Santa Inês and ½ Santa Inês. The correlations between the weight and measurements were significant, and it was possible to predict the weight from the morphometric measurements through regressions. The type of weight gain with heart girth was isometric, while with length it was positive allometric, and with height it was negative allometric. Thereby, in the absence of a scale it is possible to predict the weight from the morphometric measurements, and the type of birth is the most important factor that affects the development of lambs from birth to weaning.

The objective of this study was to evaluate the influence of feeding energy levels during the last third of gestation and lactation on performance of ewes and lambs up to weaning. The experiment was carried out in the sheep raising sector of Universidade Estadual de Londrina (UEL), from August to December of 2007. Thirty-two adult lambs with 105 days of gestation, average live weight of 57.55 kg and average body condition scores of 3.42 were used in the beginning of the experiment. The animals were confined in collective pens, distributed randomly in three treatments: 2.4; 2.2 and 2.0 Mcal of metabolizable energy (ME)/kg of dry matter (DM). Feed supply was ad libitum during the last third of gestation and lactation. Weaning occurred at 70 days. Body weight, body condition score and milk production of ewes and body weight of the lambs were analyzed. There were no significant differences for body weight and body condition of ewes at lambing; however, the level of 2.4 Mcal enabled better results for those characteristics at weaning and higher gain in weight and body condition scoring during the experiment. Severe energetic restriction (2.0 Mcal ME/kg DM) determined lower average daily milk production. Lambs from levels 2.4 and 2.2 presented similar weights in all measurements and were superior to those in level 2.0. Lambs from level 2.4 presented higher average weight gain from birth to weaning. The energetic restriction upon lambs at the end of gestation and during lactation limits the performance of ewes and lambs up to weaning.

Objetivou-se avaliar os efeitos ambientais (idade da mãe ao parto, tipo de nascimento, sexo do cordeiro e ano de nascimento) e os grupos genéticos sobre o peso e medidas morfométricas de cordeiros, ao nascimento e ao desmame; testar regressões para predizer peso por meio das medidas e descrever o tipo de crescimento das medidas. Os filhos de ovelhas mais jovens (dois dentes) apresentaram médias menores para todas as características, exceto altura ao desmame. As médias de peso ao nascimento variaram de 3,34 ± 0,14kg nos filhos de ovelhas de dois dentes a 3,94 ± 0,09kg nos filhos de ovelhas de oito dentes, e as de peso ao desmame variaram de 12,19 ± 0,72kg nos filhos de ovelhas de dois dentes a 14,79 ± 0,62 nos filhos de ovelhas de seis dentes. Os cordeiros nascidos de partos simples apresentaram maiores médias que os gêmeos. As médias de peso ao nascer foram de 3,24 ± 0,11kg a 4,08 ± 0,06kg e para peso ao desmame foram de 11,18 ± 0,59kg a 15,81 ± 0,35kg, as médias menores foram dos cordeiros gêmeos e as maiores dos cordeiros simples. O grupo genético influenciou o peso, o comprimento e a altura ao nascimento, os Santa Inês puros apresentaram médias maiores que os ½ Santa Inês. O ano de nascimento influenciou todas as características. Todas as correlações entre pesos e medidas foram significativas, e assim foi possível prever o peso em função das medidas.

The objective of this study was to evaluate the environmental effects (age of dam, type of birth, sex of the lamb and year of birth) and genetic groups on the weight and morphometric measurements of lamb at birth and at weaning; test regressions for predicting weight of lambs by the measurements and describe the type of growth of the measures. Lambs of young ewes (2 teeth) had lower average for all characteristics except height at weaning. The average birth weight ranged from 3.34 ± 0.14kg in the offspring of two teeth ewes to 3.94 ± 0.09kg in the lambs of eight teeth ewes, and for weaning weight ranged from 12.19 ± 0.72kg in the offspring of two teeth ewes, and 14.79 ± 0.62 in the lambs of six teeth ewes. The single birth lambs had highter averages than the twins. Means for birth weight ranged from 3.24 ± 0.11kg to 4.08 ± 0.06kg and for weaning weight from 11.18 ± 0.59kg to 15.81 ± 0.35kg, the averages were lower for twins and greater for single lambs. The genetic group affected the weight and the length and height at birth, where purebred Santa Inês lambs presented greater averages than ½ Santa Inês lambs. The year of birth influenced all traits. All correlations between weights and measures were significant. It is possible to predict the weight on the basis of measures.

Este trabalho foi realizado com o objetivo de avaliar as características de carcaça e a qualidade da carne de animais puros das raças Tabapuã, Bonsmara e mestiços ½ Bonsmara + ½ Nelore e mestiços ½ Bonsmara + ¼ Red Angus + ¼ Nelore. Foram utilizados cinco bovinos castrados de cada grupo genético, com idade média de 22 meses e peso vivo de 394±21 kg ao início do experimento. A dieta, para todos os animais, continha silagem de cana-de-açúcar e ração comercial na proporção de 55% e 45% (base seca), respectivamente, com 14,99% de proteína bruta (PB) e 59,84% de nutrientes totais digestíveis (NDT). Ao abate, não foram observadas diferenças no peso de carcaça fria nem nos pesos e percentuais dos cortes comerciais (traseiro, costilhar e dianteiro) entre os grupos genéticos. Os animais puros Bonsmara apresentaram maior área de olho-de-lombo, maior percentual de músculo e menor percentual de gordura na carcaça. Nos animais mestiços ½ Bonsmara + ½ Nelore, a espessura de gordura de cobertura (EGC) foi maior que os Bonsmara e Tabapuã, porém todos os grupos genéticos apresentaram EGC acima do mínimo (3 mm) exigido pelos frigoríficos. Não foi observada diferença na composição centesimal da carne entre os grupos genéticos. A carne dos animais Bonsmara e mestiços ½ Bonsmara + ½ Nelore e ½ Bonsmara + ¼ Red Angus + ¼ Nelore foi mais macia que a dos animais Tabapuã. O perfil de ácidos graxos no músculo longissimus dorsi não diferiu entre os grupos genéticos estudados. A carne dos animais Bonsmara e mestiços ½ Bonsmara + ½ Nelore e ½ Bonsmara + ¼ Red Angus + ¼ Nelore apresentou melhor qualidade se comparada à dos Tabapuã.

The objective of this study was to evaluate carcass traits and meat quality of Tabapuã and Bonsmara purebred steers, and crossbred ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore steers. Five animals were used in each genetic group. The average age and weight at the beginning of the experiment were 22 months and 394±21 kg. All animals received the same diet, which was composed of sugar cane silage and a commercial ration, in a ratio of 55 and 45% (dry matter basis), respectively, with 14.99 crude protein and 59.84% total digestible nutrients. There were no differences between the genetic groups for cold carcass weight or percentages of commercial cuts (forequarter, hindquarter and sidequarter) at slaughter. Bonsmara steers presented the greatest ribeye area and percentage of muscle, and the lowest percentage of fat in the carcass. Crossbred ½ Bonsmara + ½ Nellore animals presented greater back fat thickness (BFT) than Bonsmara and Tabapuã animals; however, all genetic groups presented BFT greater than the minimum (3 mm) required by the meat industry. There was no difference in the meat centesimal composition between genetic groups. Meat from Bonsmara, ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore presented greater tenderness than that from Tabapuã steers. The longissimus fat acid profile did not differ between the genetic groups studied. Meat from Bonsmara and crossbred ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore animals presented greater quality than that from Tabapuã steers.

Este trabalho foi desenvolvido com o objetivo de avaliar o desempenho em confinamento de animais puros das raças Tabapuã (T), Bonsmara (B), mestiços ½ Bonsmara + ½ Nelore (B1) e mestiços ½ Bonsmara + ¼ Red Angus + ¼ Nelore (B2). Foram utilizados cinco bovinos castrados de cada grupo genético, com idade média de 22 meses e peso vivo de 394 ± 21 kg, ao início do experimento. A dieta para todos os animais continha silagem de cana-de-açúcar e ração comercial na proporção de 55 e 45% (base seca), respectivamente, com 14,99% de PB e 59,84% de NDT. Os animais foram abatidos quando atingiram escore visual de acabamento de 3, numa escala de 1 = magros a 5 = obesos. Houve efeito significativo dos grupos genéticos sobre o consumo de matéria seca, cujas médias foram de 1,9; 2,1; 2,2 e 2,2% do PV, respectivamente, para os animais Tabapuã, Bonsmara, B1 e B2. O ganho médio diário em peso vivo dos animais cruzados B1 (0,925 kg) e B2 (1,122 kg) e puros Bonsmara (1,035 kg) foi superior ao dos animais da raça Tabapuã (0,630 kg), que foram mais tardios para atingir escore corporal de abate. O consumo de nutrientes, como porcentagem do peso vivo ou por unidade de peso metabólico, não diferiu entre grupos genéticos. Carcaças de animais Bonsmara apresentaram melhor escore de conformação, porém as carcaças dos animais da raça Tabapuã tiveram melhores médias para rendimento de carcaça quente (56,2%) e fria (55,2%). Não houve diferença no peso de carcaça fria entre os grupos genéticos. Animais Bonsmara puros, B1 e B2, apresentam melhor desempenho em confinamento em comparação aos Tabapuã.

The objective of this work was to evaluate feedlot performance of Tabapuã (T) and Bonsmara (B) purebreed animals, and ½ Bonsmara + ½ Nelore (B1) and ½ Bonsmara + ¼ Red Angus + ¼ Nelore (B2) crossbred animals. It was used five castrated bovines from each genetic group at average age of 22 months and live weight of 394 ± 21 kg at the beginning of the experiment. The diet for all the animals contained sugar cane silage and commercial ration at the proportion of 55 and 45% (dry matter basis), respectively, with 14.99% CP and 59.84% TDN. Animals were slaughtered when they reached a visual finishing body score of 3, in a scale from 1 = thin to 5 = obese. There was a significant effect of genetic groups on dry matter intake, whose averages were 1.9, 2.1, 2.2 and 2.2% BW for Tabapuã, Bonsmara, B1 and B2 animals, respectively. Average daily gain in live weight of crossbred animals B1 (0.925 kg) and B2 (1.122 kg) and purebred Bonsmara (1.035 kg) were greater than the ones of Tabapuã (0.630 kg), which were the latest to reach body condition score for slaughtering. Nutrient intake, as percentage of the body weight or per unit of metabolic weight, did not differ among genetic groups. Carcasses of Bonsmara animals presented the best conformation score, but carcasses of Tabapuã animals obtained the best means for hot (56.2%) and for cold (55.2%) dressing percentages. There was no difference for cold carcass weight among the genetic groups. Purebred Bonsmara steers, B1 and B2, presented better fedlot performances in comparison to Tabapuã steers.

Avaliaram-se as características quantitativas e a composição regional e tecidual de carcaças de cordeiros submetidos a três níveis de energia (2,23; 2,54 ou 2,85 Mcal de energia metabolizável/kg MS) na alimentação e abatidos aos 32,2 ± 3,8 kg de peso corporal e 145,6 ± 20,1 dias de idade. As rações eram isoproteicas (16,70% PB) e foram fornecidas a 18 cordeiros não-castrados, mestiços Texel, confinados em baias individuais em aprisco com piso elevado do solo e ripado. As meias-carcaças esquerdas foram separadas em paleta, perna, lombo, costelas e pescoço e, em cada um desses cortes, foi avaliada a composição tecidual (osso, músculo e gordura). Com exceção da porcentagem de lombo, os níveis de energia apresentaram efeito quadrático sobre os demais cortes. Com o nível intermediário de energia, foram obtidas as maiores porcentagens de paleta e pescoço e os menores valores de perna e costelas. O nível energético da dieta influenciou a distribuição dos cortes na carcaça, mas não afetou sua composição tecidual média. A paleta foi o corte com a maior variação tecidual decorrente dos níveis de energia. Os cortes analisados podem ser usados para estimar a composição tecidual média das carcaças, no entanto, a paleta é o menos indicado.

The objective of this study was to evaluate quantitative characteristics and carcass regional and tissue composition of lambs submitted to different energy levels (2.23, 2.54 and 2.85 Mcal ME/kg DM) in the diet and slaughtered with 32.2 ± 3.8 kg body weight and at average age of 145.6 ± 20.1 days. The diets were isoproteic (16.70% CP) and fed to 18 no castrated crossbred Texel male lambs. The lambs were confined in individual pens, in a slotted floor sheep barn. The half left-side carcasses were splitted into the shoulder, leg, loin, ribs and neck. The tissue composition (bone, muscle and fat) was also evaluated in each cut. Except for loin percentage, energy levels presented a quadratic effect on the other cuts. The percentages of shoulder and neck were greatest at the middle energy level and the percentages of leg and ribs were lowest at this level. The energy level of the diet influenced the distribution of the cuts in the carcass, but it did not affect the average tissue composition of the carcass. The shoulder was the cut with the greatest tissue variation. The different cuts can be used to predict the average tissue composition of the carcass but the shoulder is the least indicated.