Cinética de degradação das frações de proteína e carboidrato em forrageiras tropicais e simulação do desempenho de caprinos

• Ano de defesa: 2010
• Autor(a) principal: Silva, Simone Pedro da
• Orientador(a): Rodrigues, Marcelo Teixeira
• Banca de defesa: Borges, Iran , Fonseca, Carlos Elysio Moreira da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Caprinos; Fibra; Modelagem; CNCPS
• Palavras-chave em Inglês: Goats; Fiber; Modeling; CNCPS
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5668

The objective of this work was to determine the protein and carbohydrate fractions, kinetic parameters of fractions ruminal degradation in tifton 85 grass, leucaena and mulberry, as well as created performance simulations of growing goats consuming only such fodder. For obtain of the nitrogen fraction (A, B1, B2 and C) were determined the crude protein (CP), non-protein nitrogen (NPN), neutral and acid detergent insoluble nitrogen. The in vitro degradation profiles of the protein fractions were obtained by incubating the samples with Streptomyces griseus protease. In order to determine the carbohydrate fractions (A and B1) analyzed the sugars, starch, soluble fiber (neutral detergent FSDN). To obtain the fractions B2, C and the degradation rate of fraction B2 was used in vitro degradation profiles of the NDF. The degradation rates of fractions A and B1 were obtained by combining the techniques in vitro gravimetric and gas production. About protein fractions, the tifton 85 grass has a larger proportion of fractions B2, while the mulberry and leucaena higher proportions of fractions A and B1. The Leucaena showed lower degradation rates of fractions B1 and B2 protein (0.1005 and 0.0631 h-1). The carbohydrate fractions A, B1, B2, C ranged from 2.80 and 5.16, 17.87 and 66.19, 20.83 and 54.08, and 7.83 and 25.25 for the forages studied , and the tifton 85 grass has a larger proportion of fractions B2, while the mulberry and leucaena fraction B1. The degradation rates of carbohydrate fractions A, B1 and B2 were 0.78, 0.41 and 0.084 h-1 in tifton 85 grass, 0.35, 0.07 and 0.274 h-1 in mulberry respectively, where 0,1965 and 0.3846 h-1 for fractions A + B1 and B2 in leucaena. The fractions representing about 80% protein tifton 85 grass had problems of its use by animals. Protein in the mulberry has a higher availability than the protein of leucaena. The forages studied were low in starch, which does not justify the analysis of such a component, which may be obtained by the difference between NFC, FSDN and sugars. The mulberry and leucaena are feedstuffs that can provide good synchronization between carbohydrates and protein degradation. Aiming to simulate the performance and consumption in goats fed exclusively with forage tifton 85 grass, mulberry and leucaena to verify the nutrients that limit maximum performance. To the perform simulations we used the nutritional model similar to the "Cornell Net Carbohydrate and Protein System (CNCPS) with modifications the kinetic modeling of the attributes of digestion and passage of feedstuffs. The animal category chosen to simulations was the dairy goat in growth between weaning and mating (weight 20 kg and ADG 150 g). It was established that the animals are consuming forage alone. The dry matter intakes that caused maximum ruminoreticular capacity were 0.870 kg/day for tifton 85 grass; 3.200 kg/day for the mulberry tree and 2.150 kg /day for leucaena. The dry matter consumed by the animal that supplies the energy demand were 0.875, 0.744 and 0.732 kg/day for tifton 85 grass, mulberry and leucaena, respectively. The ammoniacal nitrogen balance in the rumen ranged from 8.5 and 11.0. The production of microbial mass arising from the carbohydrate total (TC) was 104.97 g/day for Tifton 85; 81.51 g/day for mulberry and 118.29 g/day for leucaena. The limiting factor in goats performance consuming tifton 85 grass or mulberry is the deficiency in metabolizable protein. The provision of only Leucaena supplies the demand in metabolizable protein to promote maximum performance. The forages do not have perfect synchronization between carbohydrates and protein, so that the rumen have excess nitrogen. Estimates of TDN nutritional model similar to CNCPS are different from the model proposed by Weiss.