Valor nutritivo e características fermentativas da silagem de capim-elefante com diferentes proporções de raízes de mandioca.

Abstract Elephant grass (Pennisetum purpureum Schum) has been used as an option for silage making, due to its high potential for biomass and nutrients production. The aim of the study was to evaluate the chemical composition and fermentative traits of elephant grass cv. BRS Capiaçu enriched with different levels of fresh sugary and starchy cassava roots. The experimental design was in complete randomized blocks with five replications. Elephant grass was ensiled with different proportions of fresh cassava roots: 100% elephant grass; 90% elephant grass + 10% sugary cassava roots; 80% elephant grass + 20% sugary cassava roots; 60% elephant grass + 40% sugary cassava roots; 90% elephant grass + 10% starchy cassava roots; 80% elephant grass + 20% starchy cassava roots and 60% elephant grass + 40% starchy cassava roots. The results showed that the inclusion of 20 and 40% of fresh sugary and starchy cassava roots increased the in vitro dry matter digestibility and decreased the lignin, and neutral and acid detergent fibers contents. The inclusion of fresh sugary and/or starchy cassava roots at levels greater than 20% of the ensiled mass improves the nutritional value and keeps an adequate fermentation pattern of elephant grass silage cv. BRS Capiaçu, harvested after 120 days of regrowth