日粮中添加维基尼亚霉素对肉牛瘤胃微生物数量的影响

Influence of adding virginiamycin to diets of steers on ruminal microbial populations

选用4头体重为559.4±30.1kg,健康且装有瘤胃瘘管的4岁龄杂交肉牛,进行重复交叉试验设计,处理组添加维吉尼亚霉素,旨在观察日粮中添加维基尼亚霉素对瘤胃微生物数量的影响。在每个正试验期第28天的饲喂前8:00和饲喂后12:00、16:00采集瘤胃液进行亨氏滚管法培养计数。试验发现日粮中添加维基尼亚霉素能有效抑制调节瘤胃微生物中淀粉降解菌数量和蛋白降解菌数量(P<0.01),但对纤维降解菌、总细菌和原虫的数量影响不显著。维吉尼亚霉素在不同采样时间点抑制调节瘤胃微生物数量的统计结果显示,维吉尼亚霉素在8:00时,能有效抑制调节淀粉降解菌数量(P<0.05),在12:00时,能有效抑制淀粉降解菌数量和蛋白降解菌数量(P<0.05)。维吉尼亚霉素在不同时间点对纤维降解菌、总细菌和原虫的数量影响不显著。但对照组和处理组中,原虫数量和总细菌数量随时间均呈现出"高-低-高"的趋势。结果表明,向日粮中添加维吉尼亚霉素能有效调节高精料条件下占主导地位的淀粉降解菌和蛋白降解菌的数量,从而缓解瘤胃酸中毒。

This experiment was conducted to investigate the influence of adding virginiamycin to diets of steers on ruminal microbial populations. Four ruminally cannulated steers （559.4± 30.1 kg） were utilized in a repeat crossover design. Treatment group added virginiamycin. Ruminal fluid was collected on 28 d of experimental period, starting at 8：00 prefeeding and at 12：00 and 16：00 post-feeding from the anterior, dorsal, and mid-ventral region of the rumen. The Amount of microbial was counted after culturing using roll-tube technique. We detected that adding virginiamycin to diets of steers could active suppression and regulate amylolytic bacteria populations and proteolytic bacteria populations （P〈0.01）. But the populations of cellulolytic bacteria, total viable bacteria and protozoon were no difference between control group and treatment group. Statistics result of virginiamycin regulated that the different sampling time showed： viginiamycin could inhibite and regulate amylolytic bacteria populations when the sampling time was at 8：00 （P〈0.05）. Viginiamycin could inhibite and regulate amylolytic bacteria populations and proteolytic bacteria populations when the sampling time was at 12： 00（P〈0.05）. But the populations of cellulolytic bacteria, total viable bacteria and protozoon were no difference between control group and treatment group at the different sampling time. But the populations of total viable bacteria and protozoon to showed a tendency that ＂high-low-high＂ with time changed between control group and treatment group. The results showed that virginiamycin could active suppression and regulate amylolytic bacteria populations and proteolytic bacteria populations on high concentration. Therefore, virginiamycin potentially could prevent ruminal acidosis.