In order to evaluate the kinetics of ruminal digestion by means of the in situ incubation tectonics of the dry matter (DM), crude protein (CP) and neuter detergent fiber (NDF) of isoenergetic and isoprotein rations with 16% of crude protein with different levels (0, 10, 20, 30 and 40%) of replacement of ground corn with straw and cob (GCSC) for coffee hull, an experiment was conducted at the Department of Animal Science of the Universidade Federal de Lavras - UFLA - Lavras - MG, Brazil, with three non-lactating cows of the holstein breed, fitted with ruminal cannulas into which samples of forage, coffee hull, CGSC and experimental rations for 0, 6, 12, 24, 48, 72 and 96 hours were incubated. The data obtained about the degradability were fit for a non-linear regression by Gauss-Newton's method. The data obtained allowed to evaluate that with increasing levels of coffee hull, the effective degradability of the dry matter of the rations proved similar to that of the ration without that residue, a trend of increased effectively degraded protein being also observed. But with neuter detergent fiber the effect was the reduction of effective degradability. Based upon this experiment, it follows that the replacement of GCSC for coffee hull up to the level of 40% did not affect the effective degradability of both the dry matter and crude protein of concentrates. Nevertheless, it reduced the effective degradability of neuter detergent fiber.
Coffee hulls; ruminal digestibility; supplement
