同/异质型乳酸菌添加对全株玉米青贮发酵特性、营养品质及有氧稳定性的影响

Effects of homo-and hetero-fermentative lactic acid bacteria on the fermentation characteristics,nutritional quality,and aerobic stability of whole corn silage

本试验旨在探讨同/异质型乳酸菌对全株青贮玉米发酵特征、营养品质及微生物的影响,为改善青贮玉米青贮的发酵特性,提高其营养品质和有氧稳定性开辟新途径。试验采用真空袋法调制全株青贮玉米,添加不同的乳酸菌菌剂发酵全株青贮玉米,处理分别为:不添加任何菌剂(CK);复合同质型乳酸菌菌剂植物乳杆菌+戊糖片球菌(T),添加量为1∶1,1×105 cfu/g;异质型乳酸菌菌剂布氏乳杆菌(Y),添加量为4×105 cfu/g和复合同、异质型乳酸菌(T+Y)。通过对4个处理发酵第60天发酵特性、营养品质、微生物含量以及开袋第5天有氧稳定性、微生物含量和CO2产气量的测定。结果表明,发酵第60天各指标按大小排序,pH为T+Y>T>CK>Y(P=0.001),乳酸含量为T+Y>Y>T>CK(P=0.095),氨态氮含量为T+Y>Y>T>CK(P=0.011),乙酸含量为Y>T+Y>CK>T(P=0.032),酵母菌数量为T+Y>T>Y>CK(P=0.023),霉菌数量为T+Y>T>Y>CK(P=0.028),干物质含量为T+Y>T>Y>CK(P=0.020),可溶性糖含量为CK>T+Y>Y>T(P=0.190),中性洗涤纤维含量为Y>CK>T+Y>T(P=0.001),酸性洗涤纤维含量为CK>T>Y>T+Y(P=0.730),粗灰分含量为T+Y>T>Y>CK(P=0.030),对于好氧细菌、乳酸菌数量、粗蛋白、酸性洗涤木质素、淀粉、粗脂肪含量均无显著影响(P>0.05)。开袋第5天各指标按大小排序pH为T+Y>T>CK>Y(P=0.001),CO2产气量为CK>T>Y>T+Y(P=0.007),霉菌数量为T+Y>Y>T>CK(P=0.001),有氧稳定性为Y>T+Y>CK>T(P=0.021),对于好氧细菌、乳酸菌和酵母菌数量无显著影响(P>0.05)。采用隶属函数法综合各项指标进行评价,各处理按优劣排序为Y(0.652)>T+Y(0.528)>CK(0.492)>T(0.441)。

The overall aim of our research was to improve the fermentation characteristics,nutritional quality,and aerobic stability of whole-corn silage.We investigated the effects of homo-and hetero-lactic acid bacteria on the fermentation characteristics,nutritional value,and microorganism content of whole-corn silage.Lactic acid bacteria were added to whole corn plants and sealed in a vacuum bag.The control(CK)had no added inoculant.The T group contained Lactobacillus plantarum+Pediococcus acidilactici at 1∶1,1×105 cfu/g;the Y group contained Lactobacillus buchneri at 4×105 cfu/g;and the T+Y group contained all of these homo-and heterofermentative lactic acid bacteria.The following indexes were analyzed to evaluate fermentation:nutritional quality,microbial content on the 60 th day of fermentation,microbial content,and CO2 gas production on the 5th day after opening the bag.The treatments were ranked as follows:pH,T+Y>T>CK>Y(P=0.001);lactic acid content,T+Y>Y>T>CK(P=0.095);ammonium nitrogen content,T+Y>Y>T>CK(P=0.011);number of yeasts,T+Y>T>Y>CK(P=0.023);number of molds,T+Y>T>Y>CK(P=0.028);dry matter content,T+Y>T>Y>CK(P=0.020);water soluble carbohydrates content,CK>T+Y>Y>T(P=0.190);neutral detergent fiber content,Y>CK>T+Y>T(P=0.001);acid detergent fiber content,CK>T>Y>T+Y(P=0.730);crude ash content,T+Y>T>Y>CK(P=0.030).There was no significant difference among treatments in crude protein content,acid detergent lignin content,starch content,crude fat content,and the number of aerobic bacteria and lactic acid bacteria(P>0.05).On the 5th day after opening the bag,the treatments were ranked as follows:pH,T+Y>T>CK>Y(P=0.001);CO2production,CK>T>Y>T+Y(P=0.007);mold count,T+Y>Y>T>CK(P=0.001);aerobic stability,Y>T+Y>CK>T(P=0.021).On the 5th day after opening the bag,there was no significant difference among the treatments in the number of aerobic bacteria,lactic acid bacteria,and yeasts(P>0.05).The comprehensive values of the four treatments,as calculated from the 16 indexes by a membership function analysis,were as follows:Y(0.652)>T+Y(0.528)>CK(0.492)>T(0.441).