添加稻草对大头菜青贮料发酵品质和瘤胃降解的效果

Fermentation characteristics and rumen degradation of turnip ensiled with rice straw:

试验以大头菜和稻草为原料混合青贮。共设４个处理：１００％大头菜青贮（对照组），９４％大头菜＋６％稻草青贮（Ｒ０６），８８％大头菜＋１２％稻草青贮（Ｒ１２），８２％大头菜＋１８％稻草青贮（Ｒ１８）。感官评定，各处理组青贮料质量均为优质。随着稻草添加比例的增加，各组青贮料的干物质、中性洗涤纤维和灰分的含量相应上升，粗蛋白含量逐渐降低。试验组青贮料的饲料回收率显著高于对照组（Ｐ＜０．０１），但各试验组间差异不显著。添加１２％和１８％稻草的大头菜青贮料，氨态氮量显著低于对照组（Ｐ＜０．０１）。添加１８％稻草的大头菜青贮料，ｐＨ值偏高。试验组的乳酸含量显著低于对照组（Ｐ＜０．０５），而试验组之间差异不显著；各组青贮料的乙酸含量差异不显著，添加１８％稻草的大头菜青贮料的丁酸含量显著高于其余各组（Ｐ＜０．０５）。与对照组相比，试验组的干物质４８小时降解率及最大降解率显著降低（Ｐ＜０．０１），但各试验组之间的差异不显著。因此，在大头菜青贮中加入１２～１８％的稻草，仍可得到优质青贮料。

This experiment was carried out to assess the effect of turnip silage added with rice straw(RS)on the fermentation characteristics and rumen digestibility.The RS was added at four levels(as is basis):0(the control),6%(R06),12%(R12)and 18%(R18),respectively.Based on the sensory evaluation,the four silages were well preserved.Contents of dry matter (DM),neutral detergent fibre and ash of the silages increased with the increasing of RS,but crude protein content decreased.The DM recovery rate was significantly higher for the treated silages than that of the control(P<0.01),and with little difference between the treated silages.The ammonia nitrogen concentration was significantly lower for silages in groups R12 and R18 than that of the control(P<0 05),and no significant difference between the treated silages.Acetic acid content did not show significant difference between the four silages,and the butyric acid content was significantly higher in group R18 than in other groups.The rumen degradation rate of dry matter at 48h incubation and the potential degradation rate were significantly lower for the treated silages than those for the control(P<0.01),but there existed no significant difference between three treated silages.In summary,the adding RS to turnip silage at 12-18%(as is basis)may obtain higher quality silage.