Total and partial digestion of nutrients in bovines fed diets with dry yeast, urea or cottonseed meal

[摘要] - Ten bovines with abomasal cannulas were used to evaluate the coefficients of digestibility of diets prepared with different protein sources (dry yeast, urea and cottonseed meal). The coefficients of digestibility were obtained by the total feces collection technique and using the chromic oxide as an internal marker. In the diet with urea, an increase of digestibility coefficients for the most nutrients, when the chromic oxide technique was used, was obtaneid. The ethereal extract fraction did not show differences among the used techniques. The analysis of the coefficients of digestibility among diets showed similarity, independently of the technique. The diet composed by urea provided higher digestibility of crude protein, independently of the evaluation technique, while the diet composed by cottonseed meal was higher on the gross energy digestibility, through the marker technique. There were no differences among diets for the individual digestibility of nutrients in guts, the same was observed in the N balance.

[学科分类] 兽医学

[关键词] cottonseed meal;dry yeast;nitrogen balance;nutrients digestibility;urea     IntroduçãoOs animais ruminantes têm a capacidade peculiar de coletar;armazenar;processar e aproveitar alimentos fibrosos;inadequados ao consumo humano;convertendo-os em substâncias nutritivas que;posteriormente;são aproveitadas para produção de carne;leite;lã e trabalho