1. Shaanxi Key Laboratory of Molecular Biology for AgricultureCollege of Animal Science and TechnologyNorthwest A&F UniversityYanglingShaanxiP. R. China
2. College of Animal Science and Veterinary MedicineHenan Agricultural UniversityZhengzhouHenanP. R. China
3. Tianjin Academy of Agricultural SciencesTianjinP. R. China
4. Mammalian NutriPhysioGenomicsDepartment of Animal Sciences and Division of Nutritional SciencesUniversity of IllinoisUrbanaIllinois