优质本土乳酸菌对紫花苜蓿青贮饲料微生物数量及发酵品质的影响

Effect of high quality native lactic acid bacteria on microbial quantity and fermentation quality of alfalfa silage

试验旨在乳酸菌对紫花苜蓿青贮饲料微生物数量及发酵品质的影响。选取课题组前期筛选出的3种优质乳酸菌(植物乳杆菌、戊糖片球菌和短乳杆菌)菌液为材料,试验设6个处理,分别为自然发酵组(CK组,对照组)、5 mL/kg植物乳杆菌组(Z组)、5 mL/kg戊糖片球菌组(W组)、5 mL/kg短乳杆菌组(D组)、植物乳杆菌与短乳杆菌按1∶1配合添加组(Z1D1组)、戊糖片球菌和短乳杆菌按1∶1配合添加组(W1D1组),每个处理3个重复。自然发酵60 d,测定青贮饲料的感官评定并测定微生物数量、发酵品质及营养品质。结果显示,与CK组相比,添加乳酸菌可明显提高紫花苜蓿青贮样品的乳酸菌数量,降低好氧细菌和霉菌的数量,提高青贮样品乳酸和乙酸含量,有效抑制有害菌对饲料原料中蛋白质和氨基酸的分解,有效保存青贮饲料的营养物质。各组紫花苜蓿青贮饲料综合品质以单独添加短乳杆菌、戊糖片球菌、植物乳杆菌和短乳杆菌按1∶1配合添加评分最高。研究表明,添加优质本土乳酸菌可有效提升紫花苜蓿青贮饲料的发酵品质和营养品质。

The experiment was to develop lactic acid bacteria preparation suitable for silage in Kunming. Three kinds of high quality lactic acid bacteria(Lactobacillus plantarum, Pediococcus pentosus and Lactobacillus brevis) were selected asmaterial, and six treatments were set up in experiment, which were natural fermentation(CK group, control group),5 mL/kg Lactobacillus plantarum alone(group Z), 5 mL/kg Gastrococcus pentose alone(group W), 5 mL/kg Lactobacillus brevis alone(group D), Lactobacillus plantarum and Lactobacillus brevis were added 1∶1(group Z1D1), and Bacillus pentosus and Lactobacillus brevis were added 1∶ 1(group W1D1) for alfalfa silage, with three replicates in each treatment. The silage was naturally fermented for 60 d, and the sensory evaluation, microbial quantity, fermentation quality and nutritional quality were determined. The results showed that compared with CK group, adding lactic acid bacteria could significantly increase the number of lactic acid bacteria in alfalfa silage samples, reduce the number of aerobic bacteria and mold, increase the content of lactic acid and acetic acid in silage samples, effectively inhibit the decomposition of protein and amino acid in feed materials by harmful bacteria, and effectively preserve the nutrients in silage. The score of comprehensive quality of alfalfa silage in each group was the highest with Lactobacillus brevis alone,Pediococcus pentosus alone, and Lactobacillus plantarum and Lactobacillus brevis 1∶1. The experiment indicates that adding high quality local lactic acid bacteria can effectively improve the fermentation quality and nutritional quality of alfalfa silage.