Efeito dos níveis de fibra em detergente neutro oriunda da forragem sobre a eficiência microbiana e os parâmetros digestivos em cabras leiteiras

The objective of this study was to evaluate the effect of diets with different neutral detergent fiber levels derived from the forage (NDFf), on ruminal parameters (pH and ammonia) in dairy goats. Five non-lactating goats were used, with fistulae in the rumen. The animals were arranged in a 5 × 5 Latin square using the NDFf levels (19, 27, 35, 42 and 18%), as independent variables. The increase in the NDFf levels of the rations reduced linearly the coefficients of apparent digestibility of DM, OM, EE and NSC and affected the NDF digestibility coefficient quadratically. The coefficients of ruminal digestibility of DM, OM and NDF increased linearly with the variation in the NDFf levels. However, reduction was observed in the coefficient of intestinal digestibility of DM, OM, CP and NDF. The increase in the NDFf contents and the collection times influenced the ruminal pH, but the ruminal ammonia only affected by the collection times. The efficiency of microbial protein synthesis, when expressed in g/kg TDN, was influenced by the increase in NDFf levels, was best at the 29.57% NDFf level.