青贮对薯渣干物质和淀粉瘤胃降解规律的影响

选择4头装有永久性瘤胃瘘管的荷斯坦奶牛作为试验动物，利用尼龙袋法研究了马铃薯渣和红薯渣青贮前后干物质和淀粉瘤胃降解规律。结果表明，青贮后马铃薯渣和红薯渣的干物质和淀粉的瘤胃72 h消失率及有效降解率均极显著降低（P＜0.01），马铃薯渣干物质和淀粉消失率由青贮前的95.72%和99.60%下降为53.43%和86.51%，红薯渣则由97.65%和99.81%下降为66.72%和84.69%，马铃薯渣干物质和淀粉的有效降解率降低了47.34%和35.98%，红薯渣则下降了51.48%和57.39%；马铃薯渣青贮和红薯渣青贮干物质的有效降解率差异不显著（P＞0.05），淀粉差异显著（P＜0.05）；马铃薯渣和红薯渣青贮后过瘤胃淀粉分别增加了57.43%（42.94 g/kg）和151.37%（122.52 g/kg），且红薯渣极显著高于马铃薯渣（P＜0.01）。因此，青贮处理有效降低了2种薯渣干物质和淀粉的瘤胃降解率，并提高了其过瘤胃淀粉量，红薯渣的过瘤胃淀粉量明显高于马铃薯渣。

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 72 h disappearance rate of dry matter and starch in rumen about potato residues and sweat potato residues were reduced significantly after ensiling （P＜0.01）.The disappearance rate of dry matter and starch in rumen about potato residues were reduced from 95.72% and 99.60% to 53.43% and 86.51% after ensiling.The disappearance rate of dry matter and starch in rumen about sweet potato residues were reduced from 97.65% and 99.81% to 66.72% and 84.69% after ensiling.The effective degradability of dry matter and starch about potato residues silage were reduced 47.34% and 35.98%, respectively, and sweat potato residues silage were reduced 51.48% and 57.39%, respectively. The effective degradability of dry matter about potato residues silage and sweat potato residues silage had no significant difference （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%（42.94 g/kg） and 151.37% （122.52 g/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.