Suplementação com diferentes níveis e fontes de energia para recria de novilhos em pastagem de Panicum maximum Jacq cv Tanzânia

• Autor(a) principal: Santana, Márcia Cristina Araújo
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5713
• topic: Suplementação; Fontes de energia; Níveis de energia; Bovino de corte; Supplementation; Sources of energy; Levels of energy; Beef cattle; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

This experiment was undertaken to evaluate the utilization of supplements with different levels and sources of energy in contrast with mineral supplement, for weanling cattle, during the dry season, on Panicum maximum Jacq cv Tanzânia pasture. The evaluated variables were mass of dried material and morphophysiological components; nutritive value of the pasture; live weigh gain and intake. In order to evaluate performance, 48 crossbred steers were used, with an average age of 12 months and 267 kg of initial live weight in a completely randomized design in a 2x3 factorial arrangement, being two levels of nitrogen fertilization and three supplements, with four repetitions. The supplements were: mineral (SM), supplement with corn grain (GM) or soybean hulls (CS) as energy source. The mineral supplement was considered the level zero of energy being the untreated control treatment. The other supplements had the same amount of energy and protein, 75% total digestible nutrients (NDT) and 25% crude protein (PB), which were supplied at 0.8% of live weight (PV), during 85 days. There was no interaction among the factors for the variables of the forage appraised. The supplements didn't influence the morphologic composition, mass and the nutritional value of the forage significantly. However there were no effects regarding the period for these variables. The use of nitrogen fertilization influenced the contents of crude protein, digestibility and mass of total dry matter, that increased with the highest level of nitrogen. The tanzânia grass maintained its nutritional value during all the dry period having significant variation in itscomposition and production of forage mass, however adjusting to the grazing system adopted. Significant difference was verified for the animals submitted to the treatments with the supplements GM and CS regarding to the mineral supplement (SM). These superior averages presented a daily gain of 460 g and 500 g for the animals of the treatments with supplements GM and CS, respectively. The body weight was 39 and 44 kg greater than the control treatment (SM), that represented a total superiority of 52%. By the way, it was verified that mineral supplementation (SM) was not able to supply the nutritional demands, presenting a weight gain lower than it could be expressed by the animal. There was no interaction between average daily gain and the appraised factors. The driy matter consumption of the diet and of nutrients were not significantly influenced by the use of the supplements, except for crude protein that was bigger. Substitutive effects were not verified with the use of the supplements GM and CS. These supplements were superior to SM regarding alimentary conversion. The use of the mineral supplementation in Tanzania grass pastures was able to promote moderate gains, compared to the other treatments. Independent of the energy source of the supplements there were no differences on the average dairy gain. Then, it is possible to use supplements based on soybean hulls, an alternative and satisfactory alimentary source during the dry period of the year.