ABSTRACT The present study aimed to assess the productive performance, ingestive behavior, and thermal condition of crossbred beef heifers in an integrated livestock-forest (ILF) system with different tree-planting designs. Seventy-two ½ Angus ½ Nellore heifers were divided in three treatments—conventional system (CS) without eucalyptus, integrated livestock system with 187 eucalyptus ha−1 (ILF-1L), and integrated livestock system with 446 eucalyptus ha−1 (ILF-3L)—, in the winter and summer. Total dry mass of forage (TDM), chemical analysis of Marandu palisadegrass, average daily gain (ADG), stocking rate (SR), weight gain per area (WGA), behavior, microclimatic variables, and thermal comfort indexes were evaluated. A higher percentage of crude protein and lower TDM and SR were observed in ILF-1L and ILF-3L, with no differences for ADG and WGA. Ambient temperature, temperature-humidity index, black globe-humidity index, and radiant heat load were better in ILF-1L and ILF-3L. Heifers in ILF-1L and ILF-3L carried out grazing, resting, rumination, and other activities in the shade. In the summer, heifers in ILF-1L and ILF-3L spent less time resting and more time in rumination and performing other activities than those in the CS. In conclusion, the better forage quality in ILF-1L and ILF-3L does not alter the performance of heifers or WGA, despite the decreased TDM and SR. Furthermore, ILF-1L and ILF-3L provide better thermal comfort, and heifers that do not have access to shade decrease their activities as a strategy to reduce the use of energy for thermal regulation process.

ABSTRACT: Interest in improving feed efficiency of cattle has been increasing. The residual feed intake (RFI), the most commonly used measurement of feed efficiency, is expensive and can only be used in a small number of animals. The Kleiber Index has also been proposed to measure RFI. In this study, we estimated genetic parameters for the Kleiber Index average daily weight gain and adjusted weights to obtain a more comprehensive understanding of potential responses to selection and support the development of breeding strategies. Genetic analyses were conducted on animal records from a data file with 36,505 animals recorded by ABCZ (Brazilian Association of Zebu Breeders). Restricted maximum likelihood estimates of genetic parameters were computed with Wombat software. Heritabilities ranged from 0.24 to 0.22 for adjusted weights, from 0.12 to 0.26 for Kleiber Indexes and from 0.15 to 0.22 for average daily gains. Correlations between traits ranged from -0.06 to 0.99. Results indicated that Kleiber Indexes at different ages do not constitute a viable solution for the selection of bulls and cows for Brazilian Brahman populations in terms of feeding efficiency.

RESUMO. Objetivou-se com o estudo avaliar os efeitos de diferentes tempos de maturação sobre as características da carne de búfalos Murrah jovens abatidos com 20-24 meses de idade (experimento I; n=10) e novilhas bubalinas Murrah abatidas com 32-36 meses de idade (experimento II; n=10), com a finalidade de determinar o melhor tempo de maturação para ambos os experimentos. As amostras do músculo longissimus thoracis foram maturadas durante 7, 14 e 21 dias (0 ± 1°C). Após esse período, foi realizada análise de colesterol, pH, perdas de peso por cocção, força de cisalhamento, índice de fragmentação miofibrilar, cor da carne e perfil de ácidos graxos. A maturação melhorou a maciez (p < 0,05), no entanto, modificou a cor da carne (p < 0,05), a qual, mesmo sem diferença entre os tratamentos para percepção subjetiva da cor (ΔE; p > 0,05), foi considerada como muito perceptível ao olho humano. Além disso, a maturação reduziu os ácidos graxos polinsaturados (p < 0,05) e não afetou os níveis de colesterol (p > 0,05) na carne de búfalos jovens e novilhas bubalinas com idade avançada. Com base nas características avaliadas, conclui-se que sete dias de maturação são suficientes para as novilhas bubalinas mais velhas, mas 21 dias de maturação são necessários para o grupo de búfalos mais jovens.

ABSTRACT. The aim of this study was to evaluate the effects of different aging times on the meat characteristics from young Murrah buffaloes slaughtered at 20-24 months of age (experiment I; n=10) and Murrah buffalo heifers slaughtered at 32-36 months of age (experiment II; n=10), with the purpose of determining the best aging time to tenderize meat from both experiments. Samples of the longissimus thoracis muscle from buffaloes slaughtered at each age were aged for 7, 14, and 21 days (0±1°C). After this period, analysis of cholesterol, pH, cooking loss, shear force, myofibrillar fragmentation index, meat color, and fatty acid profile was performed. Aging greatly improved the tenderness (p < 0.05) but caused a change in color (p < 0.05), which, even without difference between the treatments for subjective perception of the color (ΔE; p > 0.05), was considered very noticeable to the human eye. Furthermore, aging reduced the polyunsaturated fatty acids (p <0.05) and did not affect the levels of cholesterol (p > 0.05) in the meat of young buffalo and buffalo heifers of advanced age. Based on the evaluated meat characteristics, concludes that seven days of aging are sufficient for older buffalo heifers, but 21 days of aging are required for the younger male group.

Resumo O objetivo deste trabalho foi avaliar a produção de forragem de capim-marandu (Urochloa brizantha) e os atributos químicos e físicos do solo, em sistemas integrados de produção. Foram avaliados os sistemas de integração lavoura-pecuária e lavoura-pecuária-floresta, em linhas simples (200 árvores por hectare) e linhas triplas (500 árvores por hectare), além do plantio exclusivo de eucalipto. A resistência mecânica à penetração do solo e a produção de forragem não diferiram entre os sistemas. A infiltração de água no solo foi menor nos sistemas agrossilvipastoris. Após dois anos da implantação dos sistemas, os teores de matéria orgânica, cálcio, magnésio e fósforo, na camada de 0-20 cm, aumentaram.

Abstract The objective of this work was to evaluate the forage production of 'Marandu' palisade grass (Urochloa brizantha) and the soil chemical and physical attributes in integrated agricultural systems. Crop-livestock and crop-livestock-forest integrated systems were evaluated in single (200 trees per hectare) and triple planting lines (500 trees per hectare), besides the exclusive planting of eucalyptus. Soil mechanical resistance to penetration and forage production did not differ between systems. Soil-water infiltration was lower in the agroforestry systems. After two years of the implementation of the systems, the levels of organic matter, calcium, magnesium, and phosphorus increased in the 0-20-cm soil depth.

Objetivou-se com este trabalho avaliar o efeito de duas estratégias de suplementação no período seco sobre o desempenho e características da carcaça de novilhos terminados em capim-marandu. Foram utilizados 36 bovinos Nelore, machos, castrados, com peso inicial de 417 ± 10,7kg e idade média de 20 meses. O delineamento experimental foi inteiramente casualizado com dois tratamentos e dezoito repetições. Os tratamentos foram constituídos de sal mineral proteinado (SMP) fornecido ad libitum e da suplementação com concentrado (SC) com 0,5% do peso corporal (PC). Após abate, as carcaças foram pesadas, identificadas e resfriadas por 24 horas. Foram medidos rendimento de carcaça, área de olho de lombo, espessura de gordura subcutânea, pH e escore de marmorização. Os animais da SC apresentaram maior (P=0,00007) ganho de peso médio diário (0,562kg) e espessura de gordura subcutânea ajustada para 100kg de carcaça (1,7mm) em relação aos animais do SMP (0,395kg; 1,3mm), respectivamente, mas não diferiram (P>0,01) em relação ao peso de carcaça, rendimento de carcaça, área de olho de lombo, pH e marmorização. Conclui-se que a suplementação com concentrado durante o período seco proporciona maior ganho de peso médio diário e espessura de gordura subcutânea ajustada para 100kg de carcaça, antecipando a idade de abate e a utilização de sal mineral proteinado com massa de forragem adequada pode ser uma alternativa de suplementação devido menor exigência de estrutura, controle de consumo, menor mão-de-obra e maior facilidade no fornecimento.

The objective of this study was evaluate the effect of two supplementation strategies in the dry season on performance and carcass traits of steers finished on marandu grass. The experimental design was completely randomized with two treatments and eighteen repetitions per treatment. The treatments consisted of ad libitum protein mineral salt (PMS) and supplementation with concentrate (SC) with 0.5% of body weight. It was used 36 Nelore steers with initial weight of 417kg and 20 months of age. After slaughter, carcasses were weighted, identified and cooled for 24 hours. Carcass yield, ribeye, fat thickness, pH and marbling score were measured. The animals supplemented with concentrate had higher (P<0.01) average daily weight gain (0.562kg) and higher fat thickness adjusted to 100kg carcass than animals supplemented with protein mineral salt (0.395kg), but did not differed (P>0.01) in relation to carcass weight, carcass yield, ribeye, pH and marbling. The results show that the supplementation with concentrate accelerates gains, allowing early and better condition of slaughter and the use of protein mineral salt with adequate forage mass may be an alternative supplementation because less need for structure, control consumption, lower labor and greater ease in supply.

The objective of this study was to evaluate the effects of feeding cattle with isoprotein and isoenergetic diets, with and without the addition of polyclonal antibody preparation (PAP), yeasts (YST) or monensin sodium (MON) on performance, carcass characteristics and gain cost in feedlot. Ninety-five 20-month old bullocks (323.3±21.8 kg) were distributed in 25 pens. The completely randomized experimental design had a 2 × 2 + 1 factorial arrangement and the treatments were replicated 5 times. There was no effect of MON for DMI throughout the feedlot period; however, MON reduced the dry matter intake (DMI) in g/kg of BW in the first 28 days when compared with the other treatments. The gain cost decreased with MON addition in relation to the other treatments. Inclusion of YST decreased average daily gain (ADG), final body weight, hot carcass weight, carcass weight, gain to feed ratio and DMI in g/kg body weight, worsening feed conversion and increasing the gain cost in the feeding periods. Inclusion of PAP increased ADG and decreased the gain cost, besides improving feed conversion. For MON and PAP, a difference was found for kidney-pelvic fat and kidney-pelvic fat per 100 kg of hot carcass weight. For MON and YST, there was a difference in ADG, feed conversion, gain cost and carcass yield and kidney-pelvic fat per 100 kg of hot carcass. Treatment YST worsened performance in relation to the non-supplemented treatments. Feeding PAP to animals did not influence performance and carcass characteristics of bullocks in feedlot negatively. Thus, PAP shows potential to substitute MON in cattle feeding using isoprotein and isoenergetic diets.

The objective of this study was to evaluate the association of visual scores of body structure, precocity and muscularity with production (body weight at 18 months and average daily gain) and reproductive (scrotal circumference) traits in Brahman cattle in order to determine the possible use of these scores as selection criteria to improve carcass quality. Covariance components were estimated by the restricted maximum likelihood method using an animal model that included contemporary group as fixed effect. A total of 1,116 observations of body structure, precocity and muscularity were used. Heritability was 0.39, 043 and 0.40 for body structure, precocity and muscularity, respectively. The genetic correlations were 0.79 between body structure and precocity, 0.87 between body structure and muscularity, and 0.91 between precocity and muscularity. The genetic correlations between visual scores and body weight at 18 months were positive (0.77, 0.57 and 0.59 for body structure, precocity and muscularity, respectively). Similar genetic correlations were observed between average daily gain and visual scores (0.60, 0.57 and 0.48, respectively), whereas the genetic correlations between scrotal circumference and these scores were low (0.13, 0.02, and 0.13). The results indicate that visual scores can be used as selection criteria in Brahman breeding programs. Favorable correlated responses should be seen in average daily gain and body weight at 18 months. However, no correlated response is expected for scrotal circumference.

O Brasil ocupa as posições de maior produtor e exportador mundial de carne bovina, com a região Centro-Oeste respondendo por 35% do abate nacional, em 2010. Entretanto, faz-se necessário valorizar o planejamento, o controle e a gestão empresarial nas propriedades produtoras, visando ao lucro na atividade. O presente estudo objetivou analisar e avaliar a viabilidade econômica da produção de bovinos de corte, em Camapuã (MS), a fim de identificar os itens relevantes aos custos da atividade. Como direcionador dos custos variáveis, no custo operacional efetivo, o suplemento mineral fornecido aos animais e a mão de obra mostraram-se relevantes para a gestão do sistema de produção, representando, aproximadamente, 71% dos custos. Com base nos resultados apresentados, pôde-se concluir que a propriedade apresenta boa lucratividade (superior a 20%). Verificou-se, ainda, com base no fluxo de caixa, taxa interna de retorno de 13,13% e capital inicial investido retornando em, aproximadamente, 7 anos, com resultados atrativos para o investimento, neste segmento agropecuário. O estudo proporcionou um parâmetro de custo para o produtor pecuarista, podendo contribuir para um melhor planejamento de atividades, em que, apesar dos altos investimentos iniciais, possivelmente, poderá reduzir seus custos, com o manejo racional no sistema produtivo, o que seria mais atrativo para o mercado, tornando mais viáveis as suas atividades de produção e comercialização do produto.

Brazil is the world largest producer and exporter of beef, with its Middle West region accounting for 35% of the national cattle killing, in 2010. However, it is necessary to value the planning, control, and business management in rural properties, aiming to profit from this activity. This study aimed to analyze and evaluate the economic viability of beef cattle production in Camapuã, Mato Grosso do Sul State, Brazil, in order to identify relevant items to the activity costs. As a guide of variable costs in the effective operational cost, the mineral supplement rationed to animals and labor were relevant to the management of the production system, representing approximately 71% of the costs. Based on the results, it was possible to conclude that the property shows a good profitability (above 20%). Based on cash flows, it was observed an internal rate of return of 13.13% and that the initial capital returns in about 7 years, with attractive results for the investment in this agriculture segment. The study provided a cost parameter to cattle breeders, contributing to improve how activities are planned and how costs can be reduced, despite the high initial investment, with the rational management of the production system, which would be more attractive to the market, making its production activities and product commercialization more viable.

Objetivou-se avaliar o crescimento de novilhas de diferentes grupos genéticos no sistema de produção superprecoce. Utilizaram-se 132 novilhas dos seguintes grupos genéticos: 18 ¾ Canchim × ¼ Nelore (¾ CN); 18 ½ Canchim × ½ Nelore (½ CN); 24 Simbrasil -⅝ Simental × ⅜ Nelore; e 72 Three-cross ¼ Simental × ¼ Nelore × ½ Angus. As novilhas foram desmamadas aos 210 dias de idade, com 247,4 ± 16,5 kg de peso vivo (PV), mantidas em creep-feeding durante a fase de cria e confinadas por 132 ± 14 dias até atingirem 350 kg PV e 5 mm de gordura subcutânea, quando, então, foram abatidas. Os grupos genéticos não influenciaram o ganho de peso médio diário, porém a espessura de gordura subcutânea do dorso (EGS) e da garupa (EGG) foi maior nos animais Three-cross, que apresentaram os maiores valores iniciais (1,07 kg/dia). Não houve diferença na área de olho-de-lombo (AOL) inicial, porém a os animais Three-cross apresentaram os maiores valores iniciais. Nos animais do grupo Three-cross, a área de olho-de-lombo (AOL) final e ajustada para 100 kg de peso vivo (PV) foi inferior à observada nos demais grupos, porém o peso final foi superior ao do grupo Simbrasil, com tempo intermediário de confinamento. Ajustando-se os valores de AOL e EGG para o menor número de dias de confinamento (114 dias), animais Simbrasil apresentam maior valor de AOL final e os animais Three-cross e Simbrasil, maior EGG final.

The objective of this study was to evaluate the growth of young heifers from different genetic groups in an intensive meat production system. One hundred and thirty two heifers from four different genetics groups were used: 18 - ¾ Canchim × ¼ Nellore (¾ CN), 18 - ½ Canchim × ½ Nellore (½ CN), 24 Simbrasil - ⅝ Simmental × ⅜ Nellore (SIMB) and 72 - Three way cross ¼ Simmental × ¼ Nellore × ½ Angus. The heifers were weaned at 210 days of age with 247.4 ± 16.5 kg live weight (LW), from creep-feeding during the rearing phase and 132 ± 14 days in feedlot system. The animals were slaughtered when they reached 350 kg LW and 5 mm backfat thickness (BFT). There was no difference among the genetic groups for average daily weight gain but the three way cross heifers presented the highest values (1.07 kg/day). There were no differences for initial ribeye area (REA), but the three cross animals obtained larger values of initial backfat thickness (BFT) and initial rump fat thickness (RFT). In the animals in the three – cross group, the final ribeye area and adjusted to 100 kg live weight (LW) was lower than that observed in the other groups, but the final body weight was superior to the Simbrasil group, with intermediate feedlot time. When the REA and RFT values are fitted to the smallest number of days in feedlot (114 days), the Simbrasil animals present greater REA and the three-cross and Simbrasil higher RFT.

Os objetivos neste trabalho foram estimar as correlações entre medidas obtidas por ultrassonografia e na carcaça e acompanhar o desenvolvimento da área de olho-de-lombo e a deposição de gordura de búfalos em diferentes períodos de confinamento. Foram utilizados 20 bubalinos da raça Murrah, castrados, abatidos aos 75, 100, 125 ou 150 dias de confinamento. As medidas realizadas foram área de olho-de-lombo, espessura de gordura subcutânea do dorso e espessura de gordura da garupa, mensuradas por ultrassonografia quando os búfalos atingiram o tempo de abate e na carcaça, após o abate. A espessura de gordura subcutânea da carcaça foi avaliada utilizando-se paquímetro e a área de olho-de-lombo da carcaça, régua do quadrante de pontos. O período de confinamento apresentou efeito linear crescente na área de olho-de-lombo e nas espessuras de gordura do dorso e da garupa avaliadas por ultrassom e na carcaça. O efeito linear positivo entre 75 e 150 dias de confinamento, tanto para a área de olho-de-lombo como para espessura de gordura medidas no dorso e na garupa, comprovou que os animais ainda não haviam atingido a maturidade. As correlações entre as medidas obtidas por ultrassom e na carcaça foram 0,82 para área de olho-de-lombo e 0,85 para espessura de gordura subcutânea no dorso. As características de carcaça medidas por ultrassom em bubalinos apresentam boas correlações com as medidas realizadas na carcaça no momento do abate, o que permite, em bubalinos da raça Murrah castrados e oriundos de rebanho leiteiro, acompanhar as alterações dessas características durante o desenvolvimento.

The objective of this study was to evaluate the correlations between the measurements obtained by ultrasound and from the carcass and follow the development of the ribeye and fat thickness in buffaloes at different feedlot stages. Twenty castrated, hornless Murrah buffaloes were used. The buffaloes were separated into four groups that were slaughtered at 75, 100, 125, 150 days of feedlot. The measurements taken by ultrasound when the buffaloes reached the slaughter point and from the carcass after the slaughter were ribeye, back fat thickness and rump fat thickness. The fat thickness was evaluated using a paquimeter and the ribeye was evaluated by using a quadrant grade ruler. The ribeye, back fat thickness and rump fat thickness presented a linear increase effect in function of the feedlot stages. The linear increase from 75 to 150 days of feedlot for ribeye, back fat thickness and rump fat thickness showed that the buffaloes had not reached maturity. The increase in the fat thickness measurement obtained in days of feedlot from the carcass and by ultrasound was similar between the back and rump. The correlations measured by ultrasound and from the carcass were 0.82 for ribeye and 0.85 for back fat thickness. The characteristics of the measurements taken by ultrasound, in buffaloes, correlated well with measurements at the time of slaughter, so that the alterations could be followed in these characteristics in castrated Murrah buffaloes from a dairy herd during their development.

Utilizaram-se 32 bubalinos machos não-castrados, da raça Mediterrâneo, divididos aleatoriamente em cinco categorias. Os animais de uma categoria foram abatidos imediatamente, enquanto os demais foram alimentados, à vontade, com ração contendo 70% de concentrado (na matéria seca) e abatidos ao atingirem 450, 480, 510 ou 540 kg de peso corporal. Adotou-se a equação de regressão do logaritmo da quantidade corporal de carcaça e de seus tecidos (muscular, adiposo e ósseo) em função do logaritmo do peso de corpo vazio. A carcaça apresentou valor de alometria, o que indica desenvolvimento proporcionalmente igual ao do peso corporal vazio. Derivando as equações, obtiveram-se as equações de predição da participação dos componentes corporais no ganho de 1 kg de peso de corpo vazio. Na carcaça, o tecido adiposo teve maior impulso de crescimento em idade mais tardia, enquanto os tecidos ósseo e muscular tiveram maior impulso para crescimento em idade mais precoce.

Thirty-two non castrated Mediterranean male buffaloes were used, being divided into five groups (categories). One group was randomly assigned to immediate slaughter, four groups were fully fed with ration containing 70% of concentrate, dry matter basis until reaching the slaughter weights of 450, 480, 510 and 540 kg. Regression equations of log content of carcass and their tissues (muscle, adipose tissue and bone) were adopted as a function of log empty-body-weight. Carcass presented positive allometry value close to 1, reflecting development proportionally equal to the empty-body-weight. Deriving the equations above, the prediction equations of body components in the body gain of 1 kg of the empty-body-weight were obtained. In the carcass, the adipose tissue presented late growth while bone and muscular tissues developed in an earlier age.

Objetivou-se avaliar as características físicas, químicas e sensoriais da carne de búfalos abatidos em diferentes períodos de confinamento. Foram utilizados 20 bubalinos da raça Murrah, castrados, descornados, com idade média inicial de 15 meses, abatidos aos 75, 100, 125 ou 150 dias de confinamento. Após o abate, as carcaças foram identificadas e resfriadas por 24 horas. Durante a desossa, foram colhidas amostras do contrafilé entre a 10ª e 11ª costelas para análise das características sensoriais e das perdas por cocção; entre a 11ª e 12ª costelas para avaliação da composição centesimal, do valor calórico, do pH e do índice de fragmentação miofibrilar (IFM); e entre a 12ª e 13ª costelas para a avaliação do escore de marmorização e da força de cisalhamento. A composição centesimal, o pH, a força de cisalhamento, o valor calórico, as perdas por cocção e o IFM não diferiram estatisticamente entre os períodos de confinamento. O grau de marmorização diferiu entre as idades de abate, uma vez os animais abatidos aos 75 dias de confinamento apresentaram escore de 1,25; os abatidos aos 100 e 125 dias, escore 2; e aqueles abatidos aos 150 dias de confinamento, escore 2,2. Em todos os períodos de confinamento, a carne bubalina foi classificada como macia (média 3,94 kgf) e apresentou com características que não diferiram pelo painel sensorial entre os 75 e 150 dias de confinamento. O abate de bubalinos aos 75 e 150 dias de confinamento não influencia as características sensoriais sabor, aroma e cor da carne bubalina.

The objective was to evaluate the physical, chemical and sensory of buffaloes meat slaughtered in different periods of feedlot. Twenty castrated, hornless Murrah buffaloes with initial average age of 15 months old were slaughtered at 75, 100, 125 or 150 days of feedlot. After slaughter, the carcasses were identified and cooled for 24 hours. During the deboning, samples were taken from striploin between the 10th and 11st ribs for sensory characteristics analyses and cooking losses; between 11st and 12nd ribs for centesimal composition, caloric value, pH and myofibril fragmentation index (MFI); and between the 12nd and 13rd ribs for marbling score and shear force analysis. Centesimal composition, pH, shear force, caloric value, cooking losses and MFI did not differ among feedlot periods. Marbling score differed among slaughter ages since animals slaughtered at 75 days of feedlot showed marbling score of 1.25, and that slaughtered at 100 and 125 days, marbling score of 2, and those slaughtered at 150 days of feedlot, score 2.2. In all feedlot periods, buffaloes meat was classified as soft (3.94 kgf), with characteristics that did not differ among sensory panel at 75 and 150 days of feedlot. Buffalo slaughter at 75 and 150 days of feedlot does not influence the sensory characteristics as flavor, aroma and color of Buffalo meat.

O comportamento sexual foi avaliado em 88 touros das raças Angus, Gir, Guzerá e Nelore, com 5 anos de idade, em média, peso médio de 906 kg e circunferência escrotal média de 41 cm, submetidos ao manejo reprodutivo em central de coleta e processamento de sêmen. Os touros da raça Angus apresentaram menor tempo de reação se comparados aos das raças zebuínas. O tipo de estímulo manequim em movimento influenciou positivamente o tempo de reação em todas as raças estudadas. Touros mais velhos tiveram maior tempo de reação em comparação aos mais jovens. A ordem do salto no dia não influenciou o tempo de reação dos touros. Todos os eventos comportamentais dos touros Angus ocorreram próximo ao serviço completo em vagina artificial. Os eventos comportamentais cheirar e lamber genitália, golpear o manequim com a cabeça ou o chifre, gotejamento de líquido seminal, ereção e protusão de pênis e monta abortada foram realizados em maior freqüência pelos touros zebuínos que pelos Angus. Na espécie indiana, os padrões comportamentais contração prepucial e monta abortada foram mais realizados pelos touros Nelore que pelos Guzerá. O evento serviço completo sem arranque final, no entanto, foi mais observado nos Nelore e nos Guzerá que nos touros Gir.

This study aimed to evaluate the sexual behavior of 88 bulls of the Angus and Zebu (Gyr, Guzerat and Nellore) breeds managed for collection and processing of semen at an artificial insemination center. On average, bulls were at 5 years of age, 906 kg of live weight and 41 cm for scrotal circumference. Reaction time in all breeds was positively influenced by the "moving" stimuli teaser. Reaction time in Angus bulls was smaller than in bulls of the zebu breeds and longer in older than in younger bulls. The daily mount order did not influence the reaction time. All sexual behavior traits in the Angus bulls were close to complete mount with artificial vagina. The behavior for "smelling and licking the genitalia", "beating using the head or the horn", "drip of seminal liquid", "erection and penis protrusion" and "aborted mount" were more usual in zebu than in Angus bulls. Among zebu breeds "prepuce contraction" and "aborted mount" were more frequent in Nellore than in Guzerat bulls and "complete mount without end force" was more observed in Nellore and Guzerat than in Gyr bulls.

Objetivou-se estudar o efeito das diferentes proporções de sangue Simental e Nelore sobre as características da carcaça e da carne de bovinos superprecoces. Foram utilizados 72 bovinos jovens inteiros (18 Nelore; 18 ½ Simental × Nelore; 18 Simbrasil e 18 Simental), com 8 meses de idade e 250 kg PV médio inicial. Os animais foram desmamados aos 8 meses de idade em sistema creep-feeding e posteriormente confinados durante 150 dias até atingirem o peso de abate, acima de 465 kg, e abatidos em frigorífico comercial. Os valores de pH e temperatura durante o resfriamento das carcaças foi semelhante para todos os grupos genéticos. Da mesma forma, as variáveis carcaça fria, dianteiro e traseiro, não apresentaram diferenças entre os grupos genéticos. Os cortes foram bastante homogêneos, com excessão do contrafilé e do filé-mignon, que foram maiores nos animais Simental. Os animais da raça Nelore e ½ Simental apresentaram maior força de cisalhamento (4,98 e 4,45 kgf) em relação aos Simental e Simbrasil (3,13 e 3,33 kgf). No entanto, após a maturação da carne durante sete dias, não se constataram diferenças entre os valores de maciez entre os grupos. As perdas por evaporação e gotejamento foram maiores na carne in natura para os animais Simental e Simbrasil, no entanto, aos sete dias de maturação se tornaram semelhantes. O sistema de produção de bovinos superprecoces produz carcaças e cortes semelhantes entre as diferentes raças estudadas. Aos sete dias de maturação, a maciez da carne de animais Nelore foi semelhante à dos demais grupos genéticos utilizados neste estudo.

The aim of this work was to study the effect of the different proportions of blood Simmental and Nellore on meat and carcass characteristics of bovine young bulls. Seventy two young bulls were used (18 Nellore; 18 ½ Simmental x Nellore; 18 Simbrasil and 18 Simmental), with medium age of 8 months and with average 250 kg LW initial. The animals were weaned at 8 months of age in system creep-feeding and later confined for 150 days until they reach the slaughter weight above 465 kg and slaughtered in commercial abattoir. The pH values and temperature during carcass cooling was similar for all of the genetic groups. In the same way, the variables cold carcass, forequarter and hindquarter, did not show any differences among the genetic groups. The beef cuts were quite homogeneous, excepting the strip loin and the tenderloin that were larger perceptually for Simmental. The Nellore and ½ Simmental breeds presented larger shear force (4.98 and 4.45 kgf) than Simmental and Simbrasil (3.13 and 3.33 kgf). However, after the meat ageing for 7 days, no differences were verified among the groups for tenderness values. The losses by evaporation and leaking were higher for non aged Simmental and Simbrasil beef cuts; however, seven days of ageing those losses showed no differences. The system of production of young bulls bovines produces carcasses and cuts similar among the different breed studied. With seven days of maturation Nellore meat tenderness was similar to the other genetic groups used in this study.

Avaliaram-se as características de carcaça de búfalos Murrah castrados terminados em confinamento. Foram utilizados 20 bubalinos Murrah (15 meses de idade e peso inicial de 207 kg), castrados e descornados, divididos em quatro grupos homogêneos e abatidos aos 75, 100, 125, 150 dias de confinamento, após período de adaptação. Ao abate, as carcaças foram identificadas, resfriadas por 24 horas para pesagem e cálculo dos rendimentos das meias-carcaças, dos cortes dianteiro, ponta-de-agulha, traseiro total e serrote. Não houve diferença estatística para o rendimento de carcaça. Os pesos de traseiro total, serrote e dianteiro apresentaram aumento linear, porém, observou-se efeito cúbico do período de confinamento sobre os rendimentos de traseiro total e dianteiro. Verificou-se ainda aumento linear dos pesos de filé-mignon, contrafilé, fraldinha, coxão mole, coxão duro, lagarto, sebo, porção comestível e ossos. O período de confinamento promoveu efeito linear decrescente sobre os rendimentos de patinho, músculo traseiro e maminha + alcatra e linear crescente para fraldinha e sebo.

The objective of this trial was to evaluate the carcass traits of feedlot castrated Murrah buffaloes. Twenty castrated hornless Murrah buffaloes averaging 15 months of age and initial body weight of 207 kg were used. Animals were divided in four groups and slaughtered at 75, 100, 125 or 150 days of feedlot after an adaptation period. At slaughter, carcasses were identified, cooled for 24 hours, and weighed for calculation of yields of half carcass, hindquarter, spare ribs, forequarter, and sawcut. There was no significant difference for carcass yield comparing the different periods of feedlot. Weights of sawcut, forequarter, hindquarter, tenderloin, strip loin, thin skirt, topside, outside flat, eye round, tallow, retail beef cuts, and bones all increased linearly while significant cubic effects were observed for yields of forequarter and hindquarter by increasing the days in feedlot. However, yields of knuckle, shank, and beef loin + tri-tip decreased linearly while those of thin skirt and tallow increased linearly when the feedlot period went from 75 to 150 days.