Degradability Of Potato Residues And Sweet Potato Residues Silage In Rumen And Study On Their Assosiative Effect With Corn Silage

This study was composed of tow parts which were the degradability of potato residues silage and sweet potato residues silage in rumen and the assosiative effect of potato residues silage or sweet potato residues silage and whole corn silage or corn stalk silage in different association.Four Holstein cows fitted with rumen cannulas were used for measuring the degradability of various nutrients about potato residues samples, sweet potato residues samples and their silage samples by nylon bag technique. The results show that ensiling has significant effects on degradation characteristics of potato residues.①The effective degradability and72h disappearance rate of dry matter and starch in rumen about potato residues and sweet potato residues were reduced significantly (P<0.01) after ensiling. The disappearance rate of dry matter and starch in rumen about potato residues were reduced from95.72%and99.60%to53.43%and86.51%after ensiling. The disappearance rate of dry matter and starch in rumen about sweet potato residues were reduced from97.65%and99.81%to66.72%and84,69%after ensiling. The effective degradability of dry matter and starch about potato residues silage were reduced47.34%,34.98%and sweet potato residues silage were reduced51.48%,57.39%.The effective degradability of dry matter about potato residues silage and sweet potato residues silage had no significant difference (P>0.05), but the effective degradability of starch about potato residue silage was higher than sweet potato residue silage (P<0.05). The amount of rumen bypass starch in potato residues silage and sweet potato residues silage were increased57.43%(42.94g/kg) and151.37%(122.52g/kg) respectively. The amount of rumen bypass starch in potato residues silage was lower than in sweet potato residues silage (P<0.01).②Compared with original potato residues, the effective degradability and72h disappearance rate of crud protein in rumen about potato residues silage and sweet potato residues silage were reduced significantly (P<0.01). The disappearance rate of crud protein in rumen about potato residues and sweet potato residues were reduced from80.47%and73.20%to37.96%and47.66%after ensiling. The effective degradability of crud protein about potato residues silage and sweet potato residues silage which had no significant difference (P>0.05) compare with their original matter were reduced52.42%and43.52%respectively (P<0.05) after ensiling. The order of RDP about each sample was potato residues silage (6.59%), potato residues (5.68%), sweet potato residues silage (2.99%) and sweet potato residues (0.47%). The RDP of potato residues and sweet potato residues were increased16.02%and536.17%respectively. The RUP of potato residues was significantly lower than sweet potato residues (P<0.01). The potato residues siglage and sweet potato residues silage had no significant difference (P>0.05) compare with their original matter.③Ensling treatment significantly changed the degradation characteristics of Ash, P and Ca in rumen about potato residues. The effective degradability of Ash in rumen about potato residues and sweet potato residues were reduced43.43%and43.35%. Meanwhile, the effective degradability of P in rumen about potato residues and sweet potato residues were reduced from54.69%and32.43%to42.44%and20.02%after ensling, which potato residues silage was higher than sweet potato residues silage.④There was no degradation about NDF and ADF of potato residues silage and sweet potato residues silage in rumen.Therefore, the effective degradability of dry matter, starch, crude protein, and Ash, P and Ca about potato residues and sweet potato residues were reduced effectively, the amount of rumen bypass starch and RDP were increased by ensiling.Ankom Gas Presure Monitor was used for studying assosiative effects of potato residues silage and sweet potato residues silage combineing the whole corn silage or corn stalk silage in different association that was0:100,25:75,50:50,75:25and100:0. The result showed that when potato residues silage and sweet potato residues silage combining the whole corn silage or corn stalk silage in different association, the gas procution increased with fermentation time increasing. The different assocate proportion had obvious influences on the gas parameters. The association’s AA, PA, BA and MCP of sweet potato residues silage and whole corn silage had significant difference (P<0.05), and the association’s NH3-N of sweet potato residues silage and whole corn silage at75:25was lower than which at0:100(P<0.05), there was no significant influence on the ruminal fermentation indexs of other associations (P>0.05). When potato residues silage and sweet potato residues silage combined the whole corn silage in different association, their assosiative effects showed minus. When potato residues silage and sweet potato residues silage combined the corn stalk silage in different association, the assosiative effects that were0.159and0.791respectively reached maximum in the association25:75.When feeding animals, it is more suitable for potato residues silage or sweet potato residues silage to be combined corn stalk silage in the association25:75. And the associative effect of potato residues silage was better than that of sweet potato residues silage.