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

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)。

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

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+Pediococcusacidilactici at 1:1,1×10s 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 60th 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);CO2 production,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).