Effect of Ensiling on Degradability of Dry Matter and Starch in Rumen about Potato Residues and Sweet Potato Residues

Four Holstein cows fitted with rumen cannulas were used for measuring degradability of dry matter and starch in potato residues samples,sweat potato residues samples and their silage samples by nylon bag technique.The results showed that the effective degradability and 72hdisappearance rate of dry matter and starch in rumen about potato residues and sweat potato residues were reduced significantly after ensiling(P 0.05),but the effective degradability of starch about potato residue silage was significantly higher than that about sweat potato residue silage(P<0.05).The amount of rumen bypass starch in potato residues silage and sweet potato residues silage were increased 57.43%(42.94g/kg)and 151.37%(122.52g/kg),respectively.The amount of rumen bypass starch in potato residues silage was extremely significantly lower than that in sweet potato residues silage(P<0.01).Therefore,the effective degradability of dry matter and starch about the tow kinds of potato residues were reduced effectively and the amount of rumen bypass starch were increased by ensiling.The amount of rumen bypass starch in sweat potato residues were obviously higher than that in potato residues.