The crude glycerin reduces losses fermentative and improves the nutritional value of marandu grass silage in a semiarid region / A glicerina bruta reduz perdas fermentativas e melhora o valor nutricional da silagem de capim marandu em uma região semiárida

The ensiling of marandu grass at the recommended time of management results in low dry matter (DM) content and nutritional value, but the addition of crude glycerin can compensate for these deficits if used during ensiling. Thus, the aim of this study was to evaluate the best level of inclusion of crude glycerin that can improve fermentation and the nutritional value of silages prepared with Urochloa brizantha cv. Marandu. The treatments consisted of five levels of inclusion of crude glycerin (0, 7.5, 15, 22.5, 30% of fresh forage) during ensiling of marandu grass with eight replications following the completely randomized design. For the evaluation of ruminal kinetics, four crossbred steers were used, cannulated in the rumen, following a randomized block design in a split plot scheme. For the percentage unit of inclusion of glycerin, there was a linear reduction of 0.34% in gas losses and increase of 0.45% and 0.55% in the recovery of DM (P <0.01) and in the DM content (P <0.01), respectively. The inclusion of up to 22.5% of crude glycerin in the silage of marandu grass is recommended to reduce losses during fermentation and improve the recovery of dry matter and the nutritional value of silage