养猪生产中，60%～80%的生产成本来自于饲料，提高猪饲料转化率对降低饲养成本极为重要。饲料转化率受遗传、环境条件和猪群健康状况等很多因素影响，在人类中已有研究表明，肠道微生物影响食物消化吸收，和许多代谢疾病密切相关。因此本研究将利用纯种杜洛克为研究材料，采用电子自动喂料器测定实验猪群的饲料转化率，对160个个体进行16S rRNA测序，初步分离与饲料转化率相关的肠道微生物种类，在此基础上选择饲料转化率和肠道菌群都差异极端的个体20头进行肠道微生物宏基因组测序，通过宏基因组基础上的关联性分析分离与饲料转化率显著相关的宏基因组标记，并分析这些宏基组基因标记在猪肠道中的表达情况，阐明宏基因组影响猪饲料转化率的分子机制。据此探讨利用宏基因组预测( Metagenomic prediction)来进行提高饲料转化率的种猪选择的准确性。本项目研究为通过肠道微生物调控提高猪饲料转化率奠定理论基础。

Feed consumption occupies about 60%-80% of pig production cost.So it is extremely important to improve the feed conversion ratio for reducing the production cost.Many factors can affect the feed conversion ratio,including genetics, enviroment and health status of pig population. There have been some studies in humans confirming that gut microbiota affect the metabolism of food and absorbing of nutrition,and related to many metabolic diseases. In this project, we will use Duroc as the experimental material.The feed conversion ratio for all experimental pigs will be measured by electronic automatic feeder. And then, we will initially isolate the gut microbiota that are significantly associated with feed conversion ratio in 160 experimental pigs by 16S rRNA sequencing.After that, total 20 individuals which showed extreme difference in feed conversion ratio and structure of gut microbiota will be chosen to perform the metagenome sequencing analysis.Based on the metagenomic sequencing analysis, we will perform a metagenome-wide association study of gut microbiota in feed conversion ratio to identify metagenomic markers associated with feed conversion ratio.The expression profiles of these associated metagenomic gene markers will be tested in porcine gut. And the molecular mechanisms about effects of metagenome in feed conversion ration will be illustrated by using these data. Based on above results, we will explore whether metagenomic predictions can be used to predict the feed conversion ratio of breeding herds. The studies of this project will provide the important guides on improving the feed conversion ratio through artificially adjusting the gut microbiota.