Silagem de capim-Mombaça em diferentes proporções na dieta de bovinos de corte

• Ano de defesa: 2007
• Autor(a) principal: Vieira, Bruno Ramalho
• Orientador(a): Obeid, Jose Antonio
• Banca de defesa: Garcia, Rasmo , Veloso, Cristina Mattos
• 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: Concentrado; Digestibilidade; Consumo; Desempenho
• Palavras-chave em Inglês: Concentrate; Digestibility; Consumption; Performance
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5558

The work was constituted of two experiments, realized at Experiment Research and Extension Center of Triângulo Mineiro (CEPET) UFV, Brazil, from May to August of 2006. At the first one, the objective was to evaluate intake, total and partial digestibility of nutrients, pH, and ruminal ammonia in beef cattle fed with Mombaça silage and concentrate at the following proportions: 80:20, 65:35, 50:50 and 35:65, in the dry matter basis. They were used four Holstein x Zebu steers, with average live weight of 229 kg, fistulated in the rumen and abomasum. The animals were allotted in 4x4 Latin Square Design, with four experimental periods of 21 days each. Chromic oxide was used to estimate the digesta flow and fecal production. The intakes of DM, OM, CP, EE and total carbohydrates (Kg/day), and the partials digestibilities of NFC increased linearly with plateau at the concentrate levels of 54.11; 54.83; 52.90; 62.25 and 55.15, 52.70%. However, the intakes of others nutrients, except NFD, and the total apparent digestibilities of DM, OM and NFC and the partials of OM increased linearly as the concentrate levels in the diets increase. No differences were found on the intake and the total and partial apparent digestibilities of NDF, presenting mean intake values of 2.16 Kg/day, and 0.91% LW and, to total, ruminal and intestinal apparent digestibilities of 56.32; 85.97; and 14.03%, respectively. The total and partial apparent digestibilities of EE and CP were not influenced by the concentrate increment. The ruminal pH and ammonia concentration presented a quadratic behavior in relation to the time of sample, with maximum register at 2.8 and 3.5 hours after feed, respectively, replying to pH 6.53 and 24.76 mg/dL of ammonia. The second experiment was designed to evaluate the intake, and the total apparent degestibilities of the nutrients, the weight gain, the feed conversion, the carcass gain and yield in beef cattle fed Mombaça grass silage and concentrate at the following proportions:80:20, 65:35, 50:50 and 35:65, in the dry matter basis. They were used twenty-four Holstein x Zebu animals, non castrated, averaging live weight of 401 kg, allotted in randomized blocks. The fecal production was estimated using acid detergent fiber as indicator. The experiment lasted 84 days, divided in three periods of 28 days, after 15 days of adaptation in which four reference animals were slaughtered to estimate carcass gain. The intakes of DM, OM, EE, CP, NFC, total carbohydrates and TDN, independent of the expression, increased linearly with the concentrate increment on the diets, while the NDF intake had a quadratic behavior. The carcass yield wasn t influenced by the diets. The live weight daily gain and the carcass gain increased linearly with plateau at the levels 57.52 and 55.34% of concentrate, respectively, otherwise, the feed conversion presented a quadratic behavior as the concentrate levels in the diets increase. The total apparent digestibilities of DM, OM, and total carbohydrate increased linearly with plateau at the concentrate levels of 63.16, 61.95 and 60.67%, on the other hand, the digestibilities of EE, CP, NDF and NFC present linear behavior. Considering ruminal variables and animal performance of beef cattle receiving diets with Mombaça grass silage, it is recommended levels of concentrate of 53 to 63%.