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The objective of this research was to evaluate in situ degradability and physicochemical composition of leucaena silage mixed with different levels of buriti fruit peel. We used a completely randomized design with five levels of buriti fruit peel (0, 50, 100, 200 and 400 g kg−1). The silos were opened after 28 days of storage. In situ degradability monitoring was conducted using a split‐plot design in which four animals represented the blocks and silage supplemented with five levels of buriti fruit peel represented the treatments. The use of the additive in leucaena silage increased dry matter (DM) (P < 0.0001), ether extract (P = 0.0068), acid detergent fiber and decreased crude protein (P < 0.0001). The pH (P = 0.0335), ammoniac nitrogen (P < 0.0001) and DM recovery (P = 0.0983) increased with level of buriti fruit peel added in the silage. Gas losses (P < 0.0001) decreased with the addition of buriti fruit peel in the ensilage. Effluent losses (P < 0.1093) were not influenced by buriti fruit peel addition. The inclusion of buriti fruit peel linearly reduced the ruminal degradability DM of soluble fraction (a) (P < 0.0001) and potentially degradable insoluble fraction (b) (P < 0.0001). Inclusion of buriti fruit peel up to 50 g kg−1 of leucaena forage provides favorable conditions for silage and contributes to pH reduction, despite reducing ruminal degradability. The degradability can be increased with the mixture of silage to a non‐protein nitrogen supplement and thus overcome this problem.

Reproductive technologies, such as ovum-pickup (OPU) and in vitro embryo production (IVEP) are important tools to accelerate genetic gain associated with reproductive efficiency. The antral follicular population (AFP) can directly affect the success of OPU and may be used as a characteristic to select the oocyte donor cows with greater reproductive potential that will be used in OPU-IVEP programs. Although highly repeatable within animal, the AFP appears to be extremely variable across individuals. Thus, the investigation of consistent endocrine markers that can trustable predict AFP in cattle has been targeted in several recent studies. In this context, the plasmatic levels of anti-Müllerian hormone (AMH) have been reported to be correlated with the size of AFP and it has the potential of being an endocrine marker to help the identification of donor cows with greater number of follicles available for OPU, greater superovulation response and, consequently, increased in vivo and in vitro embryo production in cattle. This review summarizes recent information regarding AFP and its relationship with AMH, and the possibility of using AMH as a marker for the selection of donor cows that will start reproductive programs to disseminate genetics and eventually to enhance fertility in cattle.

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...

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