采食行为与瘤胃上皮功能对湖羊SARA变异性的影响及机制研究

Sub acute ruminal acidosis (SARA) is a prevalent nutritional metabolic disorder found in meat sheep production. Previous studies indicated that huge varations exist in the extent and risk of SARA among sheep fed identical diets. However, the possible mechanisms contributed to these variations have not been studied. In the present sutdy, we foucus on the SARA susceptibility in hu sheep, and hypothesis that both feeding behaviors and ruminal epithelium transportation or metabolism activities for volatile fatty acids (VFA) are contribute to the different SARA susceptibility in sheep. Firstly, we indend to evaluate the risk of SARA and its susceptibility in sheep herd. And the sheep with highest and lowest ruminal pH will be classified as tolerant and susceptible to SARA, respectively. The feeding behavior and mRNA expresstion relate to VFA absorption and metabolism are determined, which to demostrate the cause of different SARA susceptibility in sheep. Finally, we use multi-platform metagenomic analyses and Real time PCR technologies to establish the relaitonship of ruminal bacteria and SARA susceptibility of sheep. All these experiments will provide new insight into the mechanism of SARA as well as scientific basis for the improvement of rumen health and efficiency in sheep prodution.

亚急性瘤胃酸中毒（SARA）是肉羊生产过程中常见的营养代谢疾病，研究发现，采食相同日粮的反刍动物，个体间SARA发生风险及严重程度存在明显的差异，但导致这种差异的机制并不清楚。因此，本项目以绵羊个体SARA耐受性差异的角度为切入点，假设“绵羊采食反刍行为与瘤胃上皮功能的差异是导致个体间SARA耐受性变异的主要因素”。项目以湖羊为研究对象，首先，系统评估其育肥阶段SARA风险与群体变异性；根据群体瘤胃pH筛选SARA耐受和易感个体，通过检测其采食反刍行为与瘤胃上皮挥发性脂肪酸转运与代谢相关基因表达情况，揭示引起绵羊SARA耐受性差异的机制；最后，借助宏基因组测序技术及荧光定量PCR等手段，阐明湖羊SARA易感性与瘤胃微生物多样性之间的内在关联机制。上述研究为揭示SARA发生机制提供新的视野，并为改善绵羊瘤胃健康提供理论依据。