Effect of fermentation bed on bacterial growth in gastrointestinal tracts of weaned piglets | 发酵床养殖对仔猪胃肠道大肠杆菌和乳酸菌增殖的影响

chinois. 为阐明发酵床养殖对断奶仔猪消化道菌群的影响，对发酵床和水泥地养殖仔猪消化道大肠杆菌和乳酸菌的动态变化进行比较分析。试验期为42d。15头30日龄断奶仔猪分别在试验开始第1天（断奶当天）、第21天和第42天进行扑杀，每次每组扑杀3头，取胃、回肠、盲肠、结肠粘膜层及各段内容物进行2类细菌的分离计数，同时检测相同时问点发酵床表层与深层垫料中的细菌数量。结果发现：随着养殖时间的延长（1～42d），消化道大肠杆菌呈下降趋势，如发酵床仔猪结肠段大肠杆菌由开始的6．4×107降低到2．2×105，而乳酸菌先下降后上升，如发酵床仔猪回肠段内容物乳酸菌数量由4．6×109降到2．6×108后再增加到1．4×1010。发酵床养殖未改变仔猪胃肠道细菌变化规律，同时发酵床垫料中的乳酸菌数量不影响断奶仔猪消化道内的乳酸菌数量；此外，随着发酵床使用时间延长，发酵床垫料中致病菌的数量和种类增加，发酵床垫料底层大肠杆菌在试验开始未检测到，在试验42d时增加到6．1×107。

anglais. In order to elucidate the effect of fermentation bed on bacterial growth in gastrointestinal tracts of weaned piglets, the changes of Escherichia coli and lactic acid bacteria in weaned piglets raised in pens with fermentation bed and cement floors were analyzed kinetically. Three piglets in each treat- ment were slaughtered at 0 d,21 d and 42 d respectively. The mucous layer and the content of the stom- ach, ileum, cecum, and colon as well as the cushion of fermentation bed, were sampled at each time point for bacterial detection. As a result, the number of E. coli decreased gradually with time, for example, the number of E. coli collected from the colon of the piglets raised on the fermentation bed decreased from 107 at the beginning to l0s. However, the amount of lactic acid bacteria in gastrointestinal tracts de- creased at the early stage but increased at the later stage, such as, the number of lactic acid bacteria col- lected from the ileum of piglets raised on the fermentation bed was 109at the beginning, then decreased to 108 and increased 1010 at last. The fermentation bed did not alter the tendency of bacterial fluctuation. Meanwhile, the high number of lactic acid bacteria in the fermentation bed cushion did not contribute to the growth of these bacteria in gastrointestinal tracts of weaned piglets. In addition, the species and num- ber of potential pathogens in fermentation bed would increase with the lengthening of utilization time with no t7,. coli in the bottom of fermentation mattress material and 107 on day 42.