Silagens de milheto e de sorgo biomassa em dietas para novilhas mestiças holandês/zebu criadas no semiárido

Abstract

The regions with a semi-arid climate suffer from prolonged periods of drought, which directly reflects in the production of cattle herds. In this way, implementing strategies to mitigate the impacts caused by the reduction of pasture production are necessary. Both millet and sorghum biomass are alternatives for the production of roughage in semi-arid regions, as they have tolerance to water deficit, considerable nutritional value and large production of dry matter per unit area. Based on the above, the objective was to compare different proportions of millet and sorghum silages biomass BRS 716 in the diet of crossbred Holstein / Zebu heifers on nutrient intake and digestibility, microbial protein synthesis, nitrogen balance, ingestive behavior and body performance. The experimental design was in two Latin squares 5 x 5, simultaneous, composed, each, by five animals, five treatments and five experimental periods. Five experimental diets with different proportions of millet and sorghum silage biomass (0, 25/75, 50/50, 75/25 and 100% of biomass sorghum silage in relation to millet silage) were evaluated. The diets were evaluated in ten heifers with an initial body weight of 264.95 ± 19.4 kg (± EPM). The roughage: concentrate ratio in the diets was approximately 75:25 on the basis of matter. Millet and sorghum silage biomass BRS 716, associated or not in different proportions, in the diet of crossbred Holstein / Zebu heifers does not alter the consumption of dry matter and nutrients, digestibility, microbial protein synthesis, nitrogen balance, feeding behavior and performance body.