Funding for this research was provided by:
National Natural Science Foundation of China (31430082)
National Key Basic Research Program of China, 973 Program (2013CB127300)
Text and Data Mining valid from 2018-07-02
Received: 26 September 2017
Accepted: 17 May 2018
First Online: 2 July 2018
Ethics approval and consent to participate
: The experimental proposals and procedures for the care and treatment of the pigs were approved by the Animal Care and Use Committee of Nanjing Agricultural University and followed Chinese guidelines for animal welfare.
: The authors declare that they have no competing interests.