Levedura seca na alimentação de vacas lactantes

• Ano de defesa: 2011
• Autor(a) principal: Freitas, Denise Ribeiro de
• Orientador(a): Marcondes, Marcos Inácio
• Banca de defesa: Detmann, Edenio , Valadares, Rilene Ferreira Diniz
• 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: Coprodutos de cana-de-açúcar; Coprodutos do etanol; Produção de leite
• Palavras-chave em Inglês: By-products of sugar cane; By-products of ethanol; Milk production
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5775

The study evaluated the production and composition of milk, intake and apparent digestibility of dry matters and nutrients, efficiency on the use of nitrogenous compounds, yield and efficiency of microbial protein synthesis in dairy cows fed with different substitution of soybean meal proportions for integral yeast of sugar cane ethanol. It was used 16 Holstein cows, in which 8 were primiparous and 8 multiparous, distributed in four 4x4 Latin squares, organized according to days and order of lactation. The treatments consisted in a basal diet, in which the soybean meal was the main protein source, and three diets with 33,3; 66,6 and 100% levels of soybean meal substitution for the yeast, based on DM. The experiment lasted 68 days, subdivided in four experimental periods of 17 days. The levels of yeast inclusion did not influence the intake of DM, OM, EE, NDFi and TDN (P>0,05), however, the CP and NDFcp (P>0,05) intake decreased lineally and the NFC (P>0,05) intake raised lineally with the growing levels of yeast in animal diets. There was no treatment effect on the digestibility coefficient of DM, OM, CP, NDFcp and NCF (P>0,05), nevertheless, the EE digestibility coefficient lineally decreased with the yeast inclusion in the experimental diets (P<0,05). The milk yield, 4% fat-correct milk yield, fat content, crude protein, lactose, total solids and SCC did not differ between treatments (P>0,05). It was not verified the effects on the sum of allantoin excretions in the urine and milk, uric acid, total purine, microbial protein and microbial efficiency (P>0,05). It was observed a decreased lineal effect for the urea nitrogen concentrations in plasma and milk (P<0,05), however, it was not verified the difference for daily excretion of total and urea nitrogen in milk, total and urea nitrogen in urine, and nitrogen balance (P>0,05). It was concluded that the integral yeast can totally replace the soybean meal in the diet for dairy cows with a daily average milk yield of 25kg.