Ruminal degradation kinetics of elephant grass silage with different levels of jack fruit and cassava scrapingCinética de degradação ruminal de silagem de capim-elefante com diferentes níveis de jaca e raspa de mandioca

The objective of this study was to evaluate in situ ruminal degradation kinetics in two experiments, which different levels of dehydrated jackfruit (0, 5, 10 and 15% in natural matter) and cassavas scraping (0, 7, 15 and 30 % in natural matter) in the elephant grass silage, were used. The two experiments were carried out at the Department of Animal Science, Federal University of Viçosa, Brazil, in the same period and followed the same protocol. A mixed model was used, in which was considered random effect of experiment and fixed effects of experimental treatment and interaction among treatments with experiments. Samples of 3 g of each silage treatment were incubated in the rumen of three steers by periods of 0, 3, 6, 12, 24, 36, 48, 72, 96 and 120 hours. Then, the potentially degradable fraction(B), indigestible fraction (I), degradation rate of potentially degradable fraction (c), lag time, and effective degradability (ED) at 2, 5 and 8% per hour, were evaluated. No effect of addition of additives in ensiling of Napier grass for the effective degradability (P> 0.05) was observed, presenting an intercept at 47.7, 40.7 and 34.9% for the passage rates of 2, 5 and 8 %/h respectively. There were significant interaction among experiments with treatments (P