热应激奶牛瘤胃液中嗜淀粉杆菌的含量

Quantities of ruminal cellulytic bacteria in heat stress dairy cattle

为探讨不同生理状态热应激奶牛嗜淀粉瘤胃杆菌(Ruminobacter amylophilus)的含量差异,选择48头产奶母牛,按照因子试验设计分为泌乳中期和后期牛、高产和中产牛、初产和经产牛。奶牛经历1周热应激后,采集瘤胃液,利用RT-PCR定量分析方法,测定瘤胃液中嗜淀粉杆菌的含量。结果显示,微生物的数量经lg转化后,泌乳中期奶牛嗜淀粉瘤胃杆菌为7.70,泌乳后期为7.95,差异不显著(P>0.05);高产牛嗜淀粉瘤胃杆菌为7.46,中产牛为8.20,差异不显著(P>0.05);初产牛嗜淀粉瘤胃杆菌为7.97,经产牛为7.68,差异不显著(P>0.05)。综上所述,在奶牛遭受热应激时,嗜淀粉瘤胃杆菌含量与奶牛的耐受热应激能力无明显关系。

The objective of this study was to investigate the quantities of Ruminobacter amylophilus in lactating dairy cows under heat stress.Forty eight cows were assigned to mid-stage or late-stage,high producing or medium producing,primiparous or multiparous groups with a factorial design.Rumen fluid was sampled 5 h in the morning post-feeding via oral cavity with stomach-tube when the animals had suffered heat stress for one week.The real-time PCR was employed with the specific primers targeting 16s rDNA genes to test the abundance of Ruminobacter amylophilus.The quantities expressed as a log-transformed of Ruminobacter amylophilus was 7.70 and 7.95 in mid-stage and late-stage dairy cows（P〉0.05）,7.46 and 8.20 in high and medium producing cows（P〉0.05）,7.97 and 7.68 in primiparous and multiparous,respectively.In summary,the quantities of Ruminobacter amylophilus has no relationship with heat resistence of cow.