添加乳酸菌对开窖后玉米青贮品质及有氧稳定性的影响

Corn Silage Quality as Influenced by Adding Lactic Acid Bacteria after Silos Opening

玉米青贮时,设计4个添加乳酸菌处理:CK处理(不加任何菌剂);T处理(同型发酵乳酸菌);Y处理(异型发酵乳酸菌);TY处理(同型+异型发酵乳酸菌)。以60d为发酵期,检测各处理开窖后第0、48、96、144、192、240h品质变化及有氧稳定性。结果表明Y处理水溶性碳水化合物含量始终显著高于其余处理(P<0.05),Y和TY处理的有氧稳定性显著高于CK和T处理(P<0.05),分别达到195.58h和196.21h,且乙酸含量始终显著高于CK和T处理(P<0.05)。T处理pH值始终显著低于其余处理(P<0.05),且乳酸含量始终显著高于CK和Y处理(P<0.05)。综合评价排序:Y处理>TY处理>T处理>CK处理。因此,玉米青贮时单一添加异型乳酸菌,在改善青贮品质、提高开窖后有氧稳定性方面均优于在玉米青贮中单一添加同型或复合添加乳酸菌。

The corn was ensiled at four different treatments: CK treatment (without any inoculants);the T group (homofermentative bacteria);the Y group (heterofermentative bacteria);and the T+Y group (all of these homo-and heterofermentative bacteria), and then fermented for 60 days. Silage samples were collected after 0, 48, 96, 144, 192, and 240h of the silos opening and then analyzed to chemical composition and the aerobic stability. The results showed that Y treatment had the highest water soluble carbohydrates concentrations among the treatments (P<0.05). Aerobic stability time in the Y and TY treatments were greater than in the CK and T treatments (195.58 and 196.21h in air respectively, P<0.05), and acetic acid concentrations were significantly higher than in the CK and T treatments (P<0.05). T treatment showed the lowest pH value among the treatments (P<0.05). Comprehensive evaluation ranking: Y > TY > T > CK. Therefore, corn silage with hetero-fermented bacteria was better than the single addition of homofermentative bacteria or mixed inoculant containing homo- and heterofermentative bacteria in enhancing silage fermentation quality and improving the aerobic stability during the aerobic exposure period.