乳酸菌添加剂对3个苜蓿品种青贮饲料发酵品质、蛋白组分及有氧稳定性的影响

Effects of Lactic Acid Bacteria Additives on Fermentation Quality,Protein Fractions,and Aerobic Stability of Three Kinds of Alfalfa Silage

为探究乳酸菌添加剂对新牧1号、新牧4号、新疆大叶3个苜蓿品种(Medicago sativa)青贮饲料发酵品质、蛋白组分及有氧稳定性的影响。试验以新牧1号、新牧4号、新疆大叶3个品种苜蓿为青贮原料,设置添加乳酸菌添加剂及未添加共6个青贮处理,在(25±5)℃避光无氧条件下青贮60 d后,测定青贮饲料的发酵品质、营养成分、蛋白组分及有氧稳定性。结果表明,乳酸菌添加剂降低了青贮饲料的pH值、氨态氮和酸性洗涤纤维含量,提高了苜蓿青贮饲料中的乳酸和粗蛋白含量及其有氧稳定性;同时降低了苜蓿青贮饲料中的非蛋白氮和结合蛋白含量,提高了快速降解蛋白和中速降解蛋白含量,起到了改善苜蓿青贮饲料品质的作用。使用乳酸菌添加剂的新牧4号苜蓿青贮饲料中非蛋白氮和结合蛋白含量分别为52.57%和8.98%,显著低于另2个品种(P<0.05),其有氧稳定时间为142 h,显著高于另2个品种(P<0.05)。使用乳酸菌添加剂后新牧4号苜蓿青贮饲料的蛋白组分结构效价和有氧稳定性最好,其次是新疆大叶苜蓿青贮饲料,新牧1号苜蓿青贮饲料的品质相对较差。

To investigate the effects of lactic acid bacteria additives on fermentation quality,protein fractions and aerobic stability in three alfalfa silage.Three kinds of alfalfa,Xinmu 1,Xinmu 4 and Xinjiang Daye were used as raw materials and treated with control and lactobacillus additives,respectively.The fermentation quality,nutrient composition,protein composition and aerobic stability of silage were determined after 60 days at(25±5)℃under dark oxygen free conditions.The results showed that:compared with the control group,the additives group could reduce the pH,ammonia nitrogen and acid detergent fiber of alfalfa silage feed,and increase the lactate and crude protein content,and aerobic stability of alfalfa silage.At the same time,it could reduce non-protein nitrogen and binding protein content,and improve the quality of alfalfa silage by increasing the fast degraded protein and medium degraded protein content.The non-protein nitrogen and binding protein of Xinmu 4 in the additive group were 52.57%and 8.98%,respectively,significantly lower than those of other varieties(P<0.05),and the aerobic stabilization time was 142 h,whichwas significantly higher than that of other varieties(P<0.05).The results show that,the structural titer and aerobic stability of protein components of Xinmu 4 silage feed were the best after adding additives.