Silagem de soja na alimentação de bovinos de corte

• Autor(a) principal: Rigueira, João Paulo Sampaio
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5572
• topic: Consumo; Digestibilidade; Ganho de peso; Consumption; Digestibility; Weight gain; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA

Two experiments were carried out to evaluate the intake, total and partial nutrient digestibilities, pH and ruminal ammonia concentration (Experiment1), as well as the productive performance in beef cattle (Experiment 2) fed diets containing only soybean silage (SS) (control), soybean silage with microbial inoculant (SSI), soybean silage with inoculant and molasses (SSIM) and soybean silage with molasses (SSM). The inoculant used in the experiment was Sil All C4 (Alttech, Brazil). Molasses powder was used in the proportion of 2.5% in natural matter. The isonitrogen diets had 13% of crude protein. The roughage:concentrate ration was 70:30 on dry matter basis, with 40% of soybean silage and 30% of corn silage. In the first trial, four crossbred Holstein x Zebu rumen and abomasum fistulated animals, 230-kg average initial weight, were assigned to a 4 × 4 Latin square. Chromic oxide was used as marker to estimate digesta flow and fecal excretion. Nutrient intakes, expressed as kg/day, as well as its respective total, ruminal and intestinal apparent digestibilities were not influenced (P>0.05) by the diets. However, DM consumption, in percentage of live weight and g/kg0.75, was influenced (P<0.05) by the diets. No effect (P>0.05) of diet and collection time, or the interaction of these factors on ammonia and pH was found, with mean values of 11.91 and 6.45 mg/100 mL respectively. The passage rate was also not influenced by diets, with mean estimated value of 5.48% hour-1. In the Experiment 2, 32 non-castrated HxZ animals, 355-kg initial weight, were used in a randomized block design, with four treatments and seven repetitions. The experimental period was 99 days, divided into 3 shorter periods, after 15 days of adaptation. Four reference animals were sacrificed after the adaptation period in order to estimate carcass gain. Fecal excretion was estimated using indigestible acid detergent fiber (ADGi) as indicator, after in situ incubation for 240 hours. Lower nutrient intake (P<0.05) was found for the diet containing soybean silage without additive (control) compared to diets with inoculant and molasses. For the same diet, it was recorded higher (P <0.05) apparent digestibilities of DM, OM, CP, NDF, ADF and total carbohydrates (CHO). Ether extract digestibility was not affected (P>0.05) by the diets. Food conversion, weight gain and carcass gain were not influenced by the diets, with mean values of 5.9; 1.49, and 0.91Kg/day respectively. It was concluded that the addition of molasses powder, with or without bacterial inoculant, to soybean at the time of ensilage does not affect the performance and the fermentation pattern in beef cattle, although it favors nutrient intake.