基于基因组选择和选配策略提高猪生长性状育种效率的研究

Pig growth traits are important economic traits that directly affect the economic benefits of pig-raising enterprises and also is one of the main target traits of pig genetic improvement. With the development of high-throughput genotyping and statistical models, genomic selection (GS) has been widely used in pig breeding. However, GS focuses on selection, that is, individuals with excellent performance can be accurately selected. Unfortunately, how to allocate the selected male and female genomic information to form the best mating combination to achieve the best performance of their offspring is still remains unsolved, and worth for further investigations. In addition, in hybrid populations, the dominant genetic effect plays an important role on the phenotypic value, but GS generally only capitalize additive genetic effect. Therefore, the aim of this study is to develop two mating allocation strategies (only additive genetic effect and additive plus dominant genetic effects) using growth traits (eg. average daily gain, residual feed intake) in pigs. Expected progeny values (EPVs) were computed based on the estimated genetic value and genotype probabilities of hypothetical progeny from the mating. Then, the index combining the economic value (EVs) of each trait will be used to evaluate the performance of different mating pairs. This study will provide new ideas and helpful references for the application of genome mating in pig production.

生长是猪的重要的经济性状，其直接影响着养猪企业的经济效益，也是猪遗传育种主要的目标性状之一。随着高通量基因分型技术和统计模型的快速发展，基因组选择已广泛应用于猪育种。而基因组选择重在选种，即能够准确选择出具有优良性能的个体，但如何从这些优秀个体中选择最佳交配组合以达到后代性能最优，仍是目前猪育种工作的难题,且没有一套详细的选配方案。此外，在杂交育种中，显性效应对表型值的影响起着重要作用，但基因组选择应用时一般只考虑加性遗传效应。因此，本研究拟利用猪的生长性状（如平均日增重、采食量等），通过两种选配策略（只有加性遗传效应以及包括加性和显性遗传效应），根据遗传值和亲本交配产生的基因型概率，预测不同亲本组合产生下一代的期望值，再综合每个性状的经济值，选择最大经济效益的组合，并为基因组选配在猪中应用提供参考。

生长性状是猪遗传育种主要的目标性状之一。良好的生长性状不仅反映出猪优异的生产性能，更意味着在更快的时间、用更低的成本使猪出栏。基因组选择技术已在猪育种中开展了深入研究，大大加快了猪生长性状的选种效率和遗传改良速度。但基因组选择重在选种，对于如何从这些优秀个体中利用它们的基因组信息选择最佳交配组合，以达到后代性能最优化，目前为止还没有一套完整的与基因组选择配套的基因组选配方案。因此，在本项目的资助下，完成了（1）显性效应对豫农黑猪生长体尺性状的影响；（2）通过全基因组关联分析鉴定了影响豫农黑猪生长、体尺、白鼻等性状的关键基因；（3）通过肠道微生物组成与背膘厚关联分析，发现了重要的影响豫农黑猪背膘厚的重要菌群；（4）通过比较多种基因组选择模型，完成了相应的遗传评估。本研究为猪的分子育种提供新思路和有益参考。项目共发表SCI论文5篇，中文核心期刊4篇。