Abstract:

To understand the effects of lactic acid bacteria (LAB) inoculation on the fermentation products, aerobic stability and microbial communities of silage, wilted Italian ryegrass and whole crop corn were stored in laboratory silos with and without inoculations of Lactobacillus rhamnosus and Lactobacillus buchneri. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Intensive alcoholic fermentation was found in untreated Italian ryegrass silage; the sum of ethanol and 2,3-butanediol contents at day 14 was about 7 times higher than that of lactic and volatile fatty acids. Alcoholic fermentation was suppressed by L. rhamnosus and L. buchneri inoculation, and lactic acid and acetic acid became the dominant fermentation products. Italian ryegrass silages were deteriorated in untreated and L. rhamnosus-inoculated silages, whereas spoilage was not found in L. buchneri-inoculated Italian ryegrass silage. In whole crop corn silage, L. rhamnosus did not affect the fermentation, while L. buchneri decreased the lactic acid content and increased the acetic acid content. Aerobic stability was enhanced in whole crop corn silage stored for a long period (120 days), with the increase of acetic acid content even without L. buchneri inoculation. A higher aerobic stability was achieved with a shorter ensiling period (56 days) in L. buchneri-inoculated whole crop corn silage.

Key words: Fermentation product, Aerobic deterioration, Lactic acid bacteria, Silage

摘要：

在青贮黑麦草(Lolium perenne)和青贮玉米(Zea mays)中添加鼠李糖乳杆菌和布氏乳杆菌,研究其对发酵产物与有氧稳定性的影响.青贮饲料贮藏时间为14,56和120 d.无添加青贮黑麦草发酵产物中乙醇含量较多,在14 d开封时,乙醇和2,3-丁二醇含量为乳酸和挥发性脂肪酸总和的7倍.添加鼠李糖乳杆菌与布氏乳杆菌可以抑制乙醇型发酵,使乳酸型与乙酸型发酵占主导.无添加青贮黑麦草与添加鼠李糖乳杆菌的黑麦草发生了有氧腐败,但是添加布氏乳杆菌的黑麦草保持了有氧稳定.在青贮玉米中,添加鼠李糖乳杆菌未影响发酵品质,但添加布氏乳杆菌增加了发酵产物中乙酸含量,降低了乳酸含量.添加布氏乳杆菌的青贮玉米从56 d开封开始保持了有氧稳定,其它组在120 d开封时保持了有氧稳定,所有组乙酸含量都增加.

关键词: 发酵产物, 有氧稳定性, 乳酸菌, 青贮