National Basic Research Program of ChinaNational Basic Research Program of China [2012CB126305]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [31372319]; Hubei Provincial Research and Development Program [2010BB023]; Natural Science Foundation of Hubei ProvinceNatural Science Foundation of Hubei Province [2013CFA097, 2013CFB325, 2012FFB04805, 2011CDA131]; National Research Initiative Competitive Grants from the Animal Growth and Nutrient Utilization Program of the USDA National Institute of Food and Agriculture and Texas AgriLife Research [H-82000]