Silagem de soja associada a diferentes níveis de silagem de milho em dietas para bovinos de corte

• Ano de defesa: 2008
• Autor(a) principal: Souza, Wender Ferreira de
• Orientador(a): Pereira, Odilon Gomes
• Banca de defesa: Garcia, Rasmo , Chizzotti, Fernanda Helena Martins , Leão, Maria Ignez
• 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: Consumo; Digestibilidade; FDNi; NDT; PB
• Palavras-chave em Inglês: Intakes; Digestibility; iNDF; TDN; CP
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA
• Link de acesso: http://locus.ufv.br/handle/123456789/5626

The present study involved two experiments that aimed to evaluate nutrient intake and total digestibility, pH and ruminal ammonia concentration (first experiment) as well as the productive performance of beef cattle (second experiment) that were fed with diets containing soybean (SS) 0; 25; 50; 75; 100%. The rate forage:concentrate was 60:40, based on the dry matter. In the first experiment, five HxZ crossbred animals fistulated in the rumen and abomasum that had an initial weight of about 390kg were used. The animals were distributed in a 5x5 Latin square. Chromc oxide was used to estimate the fecal excretion. The intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), nonfiber carbohydrates (NFC), total carbohydrates (TC) and total digestible nutrients (TDN), expressed as kg.dia-1, showeda decreasing linear behavior while the intakes of EE and CP adjusted to the linear response plateau (LRP) model, thus estimating maximum values for the rates of 84 and 57% of corn silage in the forage, respectively. Diet effects were not detected (P>0.05) on the total apparent digestibility of DM, OG, CP, NDF and TC they revealed and average of 66.96; 69.49; 63.49; 57.60; 82.34 and 71.10%, respectively. On the other hand, EE aparent digestibility increased linearly following the corn silage rates. Quadratic effect of time collection for the ammonia concentration and the ruminal pH was observed where the maximum and minimal values 17.42 mg/dL and 6.23 mg/dL at 2,54and 4,27 hours were respectively estimated after feeding. In the second experiment, 35 anerolados and emasculated animals initially weighing 370 kg were used.The animals were distributed into a randomized block design with five treatments and seven repetitions. The experiment, which lasted 99 days long, was divided into a 15-day adaptation period and three 28-day periods. Five animals that were used as references were killed after the adaptation period in order to estimate the carcass gain. For estimating fecal excretion, ingestible neutral detergent fiber (iNDF) was used as an indicator, after the 240 hours "in situ" incubation. The intakes of NFC and CHO decreased linearly (P<0.05) according to the soybean silage rates in the diets, while the EE intake adjusted to a LRP model, with maximum value at the 89.55% rate of soybean silage in the forage. Lower intakes (P<0.05) of NCF and TC were observed for the diets that had higher rates of soybean silage than corn silage. Intakes for the other nutrients, expressed as kg/day, were not influenced by the diets. Weight and carcass gain, carcass yield and food conversion were not influenced by the diets either, they showed average values of 1.12 kg.day-1, 0.67 kg.day-1, 53.00% and 8.05, respectively. Soybean silage may be used as the single forage source in diets for anerolados cattle since it does not compromise the cattle productive performance or the ruminal fermentation patterns. However, its use may become and interesting alternative when associated to corn silage.