Torta de girassol em suplementos múltiplos para bovinos em pastejo no período seco do ano: parâmetros nutricionais

The objective was to evaluate the effect of inclusion levels of sunflower cake as protein source to replace soybean meal in multiple supplements for cattle grazing during dry season on nutritional parameters. Five steers were used, Nellore, non-castrated, with age and average initial weights of 20 months and 354.7 kg, respectively, divided into five paddocks of 0.25 ha each, consisting of Brachiaria brizantha cv. Marandu. The experiment was divided into 5 x 5 Latin square, composed of five experimental periods of 15 days each and five animals. The strategy adopted was the inclusion of sunflower cake in increasing levels of zero, 270, 406, 540 g/kg supplement and mineral supplement composed only by the will provided in the trough (control). Supplements were formulated to be isonitrogenous (25% CP) and provided the amount of 1.5 kg / animal / day of natural material. The forage mass and the availability of dry matter digestible pontecialmente were 3,120 and 2,379 kg DM/ha respectively. Effect was observed (P <0.10) levels of inclusion of sunflower cake compared to the control of supplement DM intake and BP. The FDMI was numerically higher in the supplemented animals (8.05 kg DM / day) over the control animals (7.09 kg DM / day). There was no effect of the supplements on ruminal pH (P> 0.10). There was a significant difference in the concentrations of NH3-N between animals that received only mineral mixture (8.64 mg / dL) and cattle supplemented with 0 (12.61 mg / dL) and 27% (11.79 mg / dL) of adding TG in time 4 hours after supplementation. However, the concentration of NH3-N, between supplemented animalsindependent of the inclusion of TG was not significant (P> 0.10), but was numerically lower for animals supplemented with 40.6 (10.81 mg / dL) and 54% (10.50 mg / dL) inclusion of sunflower cake. We conclude that the inclusion of sunflower cake in the formulation of the supplements did not interfere with nutritional parameters can replace soybean meal in up to 100% without affect consumption of animals, this level of supplementation.