Silagem de capim-elefante cv. BRS Capiaçu com inclusão de diferentes proporções do algodão-de-seda

Abstract

The use of native species with forage potential for the production of grass silages conventionally used in the semiarid region can result in a significant increase in the dry matter production available for animal feed, improving the quality and nutritional value of diets. In search of results that demonstrate the most adequate inclusion proportion of these species to silages, the objective was to evaluate different inclusion proportions of silk cotton during the ensiling of elephant grass cv. BRS Capiaçu on the qualitative and nutritional aspects of silage. Five proportions (0, 15, 30, 45 and 60% based on natural matter) of inclusion of silk cotton (Calotropis procera) to elephant grass silage (Pennisetum purpureum Schum.) cv. BRS Capiaçu following a completely randomized design with four replications. The inclusion of silk cotton resulted in a linear reduction in dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and indigestible neutral detergent fiber (iNDF) contents at 0.06, 0.30, 0.23, 0.20 and 0.09 percentage points for each 1% of inclusion, respectively. There was an increasing linear effect on crude protein (CP) and total digestible nutrients (TDN), with an increase of 39.32 and 20.89% from the smallest to the largest proportion of inclusion of silk cotton to elephant grass cv. BRS Capiaçu silage. The hydrogen ion potential (pH), gas losses (GL), effluent losses (EL), dry matter recovery (DMR) and hemicellulose and lignin contents were not influenced by the evaluated inclusion levels, showing estimated means of 3.87, 1.42%, 11.55 kg t-1 of natural matter (NM), 97.36%, 19.30% and 7.20%, respectively. A linear increasing effect was observed for fraction a, c, effective degradability (ED) (2% and 5%) of dry matter, with an increment of 0.05, 0.0005, and 0.11 percentage points, respectively. There was a quadratic effect for fraction b, potential degradability (PD) and ED (2%) with minimum points of 23.72%, 50.52%, (at the 45% inclusion level) and 39.69%, (in the 15% inclusion level), respectively. The indigestible fraction (IF) had a quadratic effect with a maximum of 49.48% at the 45% inclusion level. The colonization time (CT) linearly reduced by 0.09 percentage points for each 1% inclusion of silk cotton. The inclusion of up to 60% silk cotton in elephant grass cv. BRS Capiaçu silage favors the nutritional aspects and nutritional value of silages.