Correspondence: De Wu, Key Laboratory for Animal
Disease-Resistance Nutrition of the Ministry of Agriculture of
China, Institute of Animal Nutrition, Sichuan Agricultural
University, Ya′an 625014, China. (Email: pig2pig@sina.com)
*Jun Wang and Mei Yang contributed equally to this work.
Disclosure summary: The authors have nothing to disclose.
Received 29 July 2013; accepted for publication 20 December
2013.