Potencial forrageiro da silagem de sorgo biomassa

Abstract

The biomass sorghum BRS 716 is a forage with high potential for mass productivity, being an important crop to be cultivated in the semiarid region of Brazil. However, aspects related to the management of planting, harvesting and silage are still deficient. Experiment 1: the objective was to evaluate the fermentative profile, aerobic stability and nutritional value of the biomass sorghum silage BRS 716 harvested at different cutting ages and managed in three planting spacing. The dry matter and total carbohydrate content of the silage showed an increasing linear effect (P <0.05), and crude protein and ash reduced linearly (P <0.05) with advancing cutting age. Considering the fermentative profile, ensilage losses and nutritional characteristics, it is recommended to ensilage the biomass sorghum BRS 716 160 days after planting with 90 cm spacing. Experiment 2: the objective was to evaluate the replacement of forage sorghum silage by biomass sorghum silage, in diets for 3⁄4 Holstein / Zebu heifers, on the consumption and digestibility of dry matter (DM) and nutrients, nitrogen balance, ingestive behavior and animal performance. The “b” fraction of the dry matter was higher with biomass sorghum silage. There was no difference (P> 0.05) for dry matter intake (P = 0.45) and TDN (P = 0.76). The digestibility of dry matter, crude protein, ether extract and neutral detergent fiber increased linearly with the inclusion of biomass sorghum silage. The animals showed an average daily weight gain of 1.30 ± 0.025kg. Therefore, biomass sorghum silage can replace up to 100% forage sorghum silage in the diets of 3⁄4 Holstein / Zebu heifers.