SANTOS, M. S. dos; NOGUEIRA, H. C.; FERREIRA, R. R.; SANTOS, P. B. dos; LEÃO, E. de S.; OLIVEIRA, A. P. de; SANTANA JÚNIOR, H. A. de. Qualidade da carne de bovinos terminados em pastejo. Arq. Ciênc. Vet. Zool. UNIPAR, Umuarama, v. 18, n. 2, p. 109-114, abr./jun. 2015. RESUMO:A carne bovina é uma importante fonte de proteína para alimentação humana, e as exportações de carne contribuem significativamente com a balança comercial brasileira. Entretanto, a conquista e consolidação de novos mercados depende da compreensão que o consumidor tem da qualidade da carne. Com o consumidor mais consciente, o foco da qualidade da carne vem passando do produtor e da indústria (peso da carcaça, rendimento de carcaça, etc.) para o consumidor, com avaliação das características organolépticas e valor nutricional. Apesar do confinamento de bovinos ter crescido nos últimos anos, a terminação a pasto é predominante no país e o rebanho é composto basicamente por animais zebuínos. Esta modalidade de terminação garante a carne características qualitativas particulares, e embora animais terminados em pastejo apresentem carne menos macia e com menos marmoreio, tais características podem ser melhoradas por meio do manejo nutricional e cruzamentos. Já o valor nutritivo da carne tende a ser melhor em animais terminados em pastejo, apresentando menor teor de gordura, e com melhor perfil lipídico, com maior concentração de ácidos graxos insaturados, ácido linoleico conjugado (CLA) e menor relação Ω6:Ω3. Tais características tornam a carne de animais produzidos em pastejo um alimento funcional, podendo ser trabalhado para agregar valor à carne brasileira, que poderá atender a nichos específicos de mercado. PALAVRAS-CHAVE: Marmoreio. Maciez. Ácido linoleico conjugado. Ω6:Ω3. QUALITY OF BOVINE MEAT FINISHED IN GRAZING ABSTRACT:Beef is an important source of protein for human consumption, and meat exports significantly contribute to the Brazilian trade balance. However, the conquest and consolidation of new markets depend on the understanding the consumer has of the quality of meat. With consumers being more aware, the focus of quality meat is shifting from the producer and the industry (carcass weight, carcass yield, etc.) to the consumer, with the evaluation of organoleptic characteristics and nutritional value. Despite the growth in cattle confinement in recent years, the termination in grazing is prevalent in the country and the flock is basically composed of zebu animals. This form of termination ensures the meat presents particular quality characteristics, and although animals finished on grazing have less soft flesh and less marbling, such characteristics can be improved through nutrition management and cross-breeding. The nutritional value of the meat, on the other hand, tends to be better in animals finished on grazing, with less fat, and better lipid profile with higher concentration of unsaturated fatty acids, conjugated linoleic acid (CLA) and lower Ω6:Ω3 relationship. These characteristics make the meat produced from animals in grazin...

ABSTRACT. An experiment was conducted to evaluate the feeding behavior of feedlot-finished bulls and cull cows in the Cerrado region of Piauí State, Brazil. Forty Zebu cattle were used, of which 20 steers averaging 283.0 ± 20.82 kg initial body weight and 30 months of age; and 20 cull cows averaging 296.1 ± 17.80 kg initial body weight and 100 months of age. Animals were grouped according to the following treatments: bulls and cull cows, using a completely randomized design. Feeding behavior was evaluated by means of visual observations every five minutes during 24h. Results were subjected to analysis of variance by the F test (p < 0.05) using the System for Statistical and Genetic Analysis -SAEG (version 9.1). The feeding behavior was expected not to affect the feed intake of cull cows and bulls, so that feed management can be the same for both categories. For all variables, there were differences between the categories (p > 0.05), showing that feeding behavior is influenced by the cattle category.

ABSTRACT. This study was realized to evaluate the production and economic viability of finished beef cattle in feedlot in the Cerrado biome of Piauí State, Brazil. One hundred and fifty cattle -50 bulls (B) with an body weight of 283.0 ± 20.82 kg, at 30 months of age; and 100 cull cows (CC) with an body weight of 296.1 ± 17.80 kg, at 100 months of age-were used in a completely randomized design. The animal performance indicators for the evaluation of economic viability were initial age (months), slaughter age (months), was initial body weight (kg), final body weight (kg), daily feed intake (kg animal produced), and average price of the kg of meat for finishing (R$). The CC consumed more sorghum silage and concentrate than B (p < 0.05).There was a difference between the categories (p < 0.05) for gross revenue, balance, opportunity cost, and net revenue per animal, with higher values found for the steer category. The animal category did not affect the profitability of the system, although the bulls provided lower revenues than cull cows.Keywords: performance, production systems, rate of return.Produção e economicidade de categorias de bovinos de corte em confinamento RESUMO. Objetivou-se avaliar a produção e a viabilidade econômica de bovinos de corte confinados no bioma Cerrado do estado do Piauí, Brasil. Cento e cinquenta bovinos -50 novilhos não castrados (NNC) com peso corporal de 283,0 ± 20,82 kg, aos 30 meses de idade; e100 vacas de descarte (VD) com peso corporal de 296,1 ± 17,80 kg, aos 100 meses de idade -foram utilizados em delineamento inteiramente casualizado. Os indicadores de desempenho animal para a avaliação da viabilidade econômica foram idade inicial (meses), idade de abate (meses), peso corporal inicial (kg), peso corporal final (kg), ingestão diária de alimento (kg animal produzido) e preço médio do kg de carne para acabamento. Essas variáveis foram obtidas a partir da coleta de dados realizada durante o experimento. As VD consumiram mais silagem e concentrado de sorgo do que os NNC (p < 0,05). Houve diferença entre as categorias (p < 0,05) para a receita bruta, o saldo, o custo de oportunidade e a receita líquida por animal, com maiores valores encontrados para NNC. A categoria de animais não afetou a rentabilidade do sistema, embora os novilhos tenham fornecido menores receitas do que as vacas de descarte.Palavras-chave: desempenho, sistemas de produção, taxa de retorno.

The effects of growing pinto peanut mixed with elephant grass-based pastures are still little known. The aim of the current research was to evaluate the performance of herbage yield, nutritive value of forage and animal responses to levels of pinto peanut forage mass mixed with elephant grass in low-input systems. Three grazing systems were evaluated: (i) elephant grass-based (control); (ii) pinto peanut, low-density forage yield (63 g/kg of dry matter – DM) + elephant grass; and (iii) pinto peanut, high-density dry matter forage yield (206 g/kg DM) + elephant grass. The experimental design was completely randomized with the three treatments (grazing systems) and three replicates (paddocks) in split-plot grazing cycles. Forage samples were collected to evaluate the pasture and animal responses. Leaf blades of elephant grass and the other companion grasses of pinto peanut were collected to analyse the crude protein, in vitro digestible organic matter and total digestible nutrients. The pinto peanut, high-density dry matter forage yield + elephant grass treatment was found to give the best results in terms of herbage yield, forage intake and stocking rate, as well as having higher crude protein contents for both elephant grass and the other grasses, followed by pinto peanut with low-density forage yield + elephant grass and finally elephant grass alone. Better results were found with the grass–legume system for pasture and animal responses.

The inoculation with Azospirillum brasilense has the potential to reduce the use of mineral fertilizers with efficient capacity to promote plant growth and yield. Most studies on the Azospirillum–plant association have been conducted on cereals and annual grasses. More studies are needed in perennial pastures, such as bermudagrass (Cynodon dactylon (L.) Pers.) that require substantial nitrogen (N) fertilization to maximize their production potential. Therefore, pastures based on Tifton 85 bermudagrass in association with annual ryegrass (Lolium multiflorum Lam.), which were inoculated with A. brasilense and fertilized with increasing amounts of N fertilizer and grazed by lactating Holstein cows were evaluated. Three grazing systems were evaluated: (i) Tifton 85, inoculated + 180 kg N/ha per year; (ii) Tifton 85 + 230 kg N/ha per year; and (iii) Tifton 85 + 280 kg N/ha per year. Forage samples were collected before and after grazing to evaluate the responses of the plants and animals. The forage yields of the systems were 21.0, 20.8 and 22.1 t DM/ha per year and the stocking rates were 3.9, 3.8 and 4.0 animal unit/ha per day, respectively. Crude protein, total digestible nutrients and neutral detergent fibre concentrations were 162, 560 and 667 g/kg, respectively. Inoculation in pastures planted with Tifton 85 bermudagrass in combination with ryegrass (plus 180 kg N/ha per year) had a positive effect, providing forage yield and nutritional value equivalent to those with fertilization with 230 kg N/ha per year.