Substituição do milho pela polpa de citros em dietas com alta proporção de concentrado sobre a degradabilidade e cinética ruminal

Four Nellore steers, with 400 ± 12 kg weigh and rumen cannulae, were utilized to evaluate the effect of replacement levels of corn by citrus pulp on diet degradability and rumen kinetics. The experimental treatments were the substitution levels of corn by citrus pulp: 0, 40, 60 and 80%. The study evaluated DM, NDF and CP degradability of the diets, the DM and NDF of corn and citrus pulp, as well as rumen volume, liquid and solid passage and liquid per kg of DM intake per hour ( turnover ). The degradability was performed in the 14th experimental day; the incubation was at 0, 3, 6, 9, 12, 24 and 48 hours. The addition of citrus pulp in replacement of corn, increased the DM degradation up to the 60% level (p < 0.05). The CP and NDF degradation increase with the high substitution of corn to pulp (p < 0.05). The liquid flow per day and the liquid flow for DM intake per day, showed linear effect (p = 0.0177 and p = 0.0286), being highest to the 80% treatment. The substitution was favorable to diet degradation and rumen kinetics to level 60%. Corn substitution by citrus pulp at levels up to 60% negatively affects the degradation of diets with high concentrate