Funding for this research was provided by:
National Natural Science Foundation of China (No. 3140130343)
Text and Data Mining valid from 2018-03-27
Received: 7 August 2017
Accepted: 2 February 2018
First Online: 27 March 2018
: The experiment was approved by the China Agricultural University Animal Care and Use Committee.
: The authors declare that they have no competing interests.