添加乳酸菌和纤维素酶对紫花苜蓿青贮品质的影响

Effects of Adding Lactic Acid Bacteria and Cellulase on Silage Quality of Medicago sativa

以第二茬盛花期紫花苜蓿为青贮原料,分别添加0.005g/kg乳酸菌、0.005g/kg纤维素酶以及0.005g/kg乳酸菌+0.005g/kg纤维素酶,以无添加为对照,青贮60d后取样分析发酵品质和营养成分,并对苜蓿青贮品质进行评定。结果显示:添加乳酸菌和纤维素酶可显著降低青贮pH值和乙酸含量,显著提高乳酸含量(P<0.05)。乳酸菌+纤维素酶处理pH值(4.10)和乙酸含量(1.11%FW)显著低于其他处理(P<0.05),而乳酸含量(2.84%FW)显著高于其他处理(P<0.05),弗氏评分最高(88分,优级)。纤维素酶处理中性洗涤纤维含量(52.11%DM)、乳酸菌+纤维素酶处理中性洗涤纤维(51.30%DM)和酸性洗涤纤维含量(31.02%DM)显著低于乳酸菌处理和对照(P<0.05)。综上表明,添加乳酸菌和纤维素酶可改善苜蓿青贮饲料发酵品质,乳酸菌+纤维素酶组合改善效果最佳;使用纤维素酶可提高苜蓿青贮饲料的营养价值。

The second cut alfalfa as silage material was harvested at flowering stage.There were 4 treatments:Control group(no additives added),lactic acid bacteria(0.005 g/kg FW),cellulase(0.005 g/kg FW)and lactic acid bacteria+cellulase(0.005 g/kg+0.005 g/kg FW).After 60 days,the fermentation characteristic and nutrient composition were analyzed,and the fermentation quality of alfalfa silage was evaluated.The results showed that the addition of lactic acid bacteria or cellulase significantly reduced the pH and acetic acid content,and increased lactic acid content(P<0.05).There were lower pH(4.10),acetic acid content(1.11%,FW),and higher lactic acid content(2.84%,FW)in lactic acid bacteria+cellulase treatment than other treatments(P<0.05),the Flieg score of lactic acid bacteria+cellulase treatment was the highest among all treatments(88 points,excellent).The neutral detergent fiber(NDF)(52.11%DM)treated with cellulase,NDF(51.30%DM)and acid detergent fiber(ADF)(31.02%DM)treated with lactic acid bacteria+cellulase were significantly lower(P<0.05)than those treated with lactic acid bacteria and control treatment.Overall,adding lactic acid bacteria or cellulase could improve the fermentation quality of alfalfa silage,the combination of lactobacillus and cellulase had the best effect.The nutritive value of alfalfa silage could be improved by adding cellulase.