外源生物制剂对玉米秸秆青贮质量及肉羊瘤胃降解率的影响

Effects of exogenous biological agents on silage quality and ruminal degradability of corn stalk

为研究外源生物制剂对玉米秸秆青贮发酵品质、营养价值及肉羊养分瘤胃降解率的影响,筛选高效青贮生物添加剂,探索实用的玉米秸秆饲料转化方法。以粮饲兼用型玉米品种中原单32秸秆为试验材料,生物制剂分别采用酶制剂、菌制剂及酶菌复合制剂,完全随机试验设计,共15个处理。玉米秸秆切短,装入聚乙烯袋,抽真空青贮60d后,采用实验室化学分析法及半体内试验测定发酵品质、营养成分和瘤胃降解率。结果表明,玉米秸秆青贮饲料各处理及对照感官评定均达到了优级;酶菌复合处理玉米秸秆发酵品质优于酶制剂、菌制剂处理,玉米秸秆添加木聚糖酶1g/3kg、果胶酶1g/3kg、β-葡聚糖酶1g/3kg、乳杆菌3g/3kg、纤维素酶1g/3kg(MCL_(2))处理和添加木聚糖酶1g/3kg、果胶酶1g/3kg、β-葡聚糖酶1g/3kg、乳杆菌3g/3kg、漆酶1g/3kg(MCL_(4))处理乳酸含量最高,分别为4.03%DM和3.95%DM(P<0.05);外源生物制剂处理玉米秸秆青贮饲料,干物质含量差异不显著(P>0.05);粗蛋白含量显著低于对照(P<0.05),玉米秸秆经酶制剂和酶菌复合处理青贮后,青贮饲料NDF、ADF及纤维素含量显著降低(P<0.05),其中MCL_(2)处理最低,分别为52.17%DM、31.94%DM和22.86%DM(P<0.05);纤维素酶添加量1g/3kg处理组(CE_(1)、MCL_(2)、MCL_(6)和MCL_(7))纤维素72h瘤胃降解率高于其他处理,但是差异不显著(P>0.05),其中ML_(2)纤维素降解率最高,为37.38%(P<0.05)。综上,外源生物制剂促进玉米秸秆发酵,增加青贮饲料营养价值,提高肉羊营养物质瘤胃降解效率,综合玉米秸秆发酵品质、营养成分及养分瘤胃降解率,酶菌复合处理>酶处理>菌处理,其中MCL_(2)处理效果最佳;纤维素酶降低玉米秸秆青贮饲料纤维素、酸性洗涤纤维、中性洗涤纤维含量,最适纤维素酶添加量为1g/3kg。

The object of this study was to research the effects of exogenous biological agents on fermentation quality,nutritive value and in situruminal degradability of corn stalk silage.The high efficiency biological agents were screened and the efficient and practical conversion methods of corn stalk were explored.There were 15exogenous biological agents treatments by randomined complete experimental design.Corn stalk was chopped and then packed in polyethylene bags.Fermentation quality,nutritive value and in situ ruminal degradability were analyzed using laboratory chemical methods and in situ technology of corn stalk silage after 60days of fermentation.The results showed that all of the treatments sensory evaluation were superior grade.The content of lactic acid of MCL_(2) treatment(xylanase 1g/3kg,β-glucanase1g/3kg,pectinase 1g/3kg,lactobacillus 3g/3kg,cellulase 1g/3kg)and MCL_(4) treatment(xylanase 1g/3kg,β-glucanase 1g/3kg,pectinase 1g/3kg,lactobacillus 3g/3kg,laccase 1g/3kg)were the highest,which were 4.03%DM and 3.95%DM respectively(P<0.05).There were no significant differences in dry matter content of exogenous biological agents treatments(P>0.05),and the crude protein content were lower than the control(P<0.05);Neutral detergent fiber(NDF),acid detergent fiber(ADF)and cellulose content of enzyme preparation treatments and enzyme mixed fungus preparation treatments had decreased,among which the MCL_(2) treatment were the lowest.They were 52.17%DM,31.94%DM and 22.86%DM,respectively(P<0.05).Ruminal degradability of 72hof MCL_(2) treatment was the highest,which was 37.38%(P<0.05).The exogenous biological agents promoted fermentation and increased the nutrients storage of corn stalk silage,and also improved the in situruminal degradability for ruminant.The effects of exogenous biological agents from great to small were enzyme mixed fungus>enzyme>fungus treatments.The MCL_(2) treatments had the best effects in this regard.And 1g/3kg was the best cellulase addition amount.