纤维素酶和糖蜜对天然牧草青贮品质和微生物组成的影响

Effects of Cellulase and Molasses on Quality and Microbial Composition of Natural Forage Silage

为研究纤维素酶和糖蜜对天然牧草青贮营养、发酵品质和微生物组成的影响,设置4组处理,分别为对照组(无添加剂)、单独添加纤维素酶组(0.2 g/kg)、单独添加糖蜜组(30 g/kg)、混合添加纤维素酶和糖蜜组(0.2 g/kg+30 g/kg),每组3个重复,取样时间为青贮7 d、15 d、30 d、60 d。结果显示,与对照组相比,单独或混合添加纤维素酶和糖蜜均能不同程度地改善天然牧草的青贮品质,纤维素酶组的中性洗涤纤维含量显著降低(P<0.05),乳酸和乙酸含量显著增加(P<0.05),pH和丁酸含量显著降低(P<0.05),糖蜜组的粗蛋白质含量显著增加(P<0.05),纤维素酶+糖蜜组的干物质和可溶性碳水化合物含量显著增加(P<0.05),添加剂组的氨态氮含量显著降低(P<0.05),乳酸菌和酵母菌数量均显著增加(P<0.05)。综上,单独添加纤维素酶的效果优于混合添加纤维素酶和糖蜜,混合添加纤维素酶和糖蜜的效果优于单独添加糖蜜组,表明单独添加纤维素酶对天然牧草青贮品质提升效果最好。

This study aimed to investigate the effect of cellulase and molasses on the nutritional quality,fermentation quality and microbial composition of natural forage silage.There were four groups in this study,including control(no additives),cellulase addition(0.2 g/kg),molasses addition(30 g/kg),and combination of cellulase and molasses(0.2 g/kg+30 g/kg),with three replicates per group.Sampling times were 7 d,15 d,30 d and 60 d for silage.The results showed that compared with the control group,the addition of cellulase and molasses alone or in combination improved the silage quality of natural forages.Cellulase treatment showed a significant decrease in pH value,neutral detergent fiber and butyric acid content(P<0.05)and a significant increase in lactic and acetic acid content(P<0.05).Crude protein content was significantly increased in the molasses treatment(P<0.05).The content of dry matter and soluble carbohydrates were significantly increased in the cellulase and molasses combination treatment(P<0.05).The ammonia nitrogen content was significantly lower in the additive groups(P<0.05),and the number of both lactic acid bacteria and yeast increased significantly(P<0.05).In conclusion,the addition of cellulase had the greatest effect on improving the quality of natural forage silage,followed by the combination of cellulase and molasses,then molasses alone.