Funding for this research was provided by:
National Natural Science Foundation of China (3187130113, 31572414)
National Key R & D Program of China (2018YFD0500404)
Text and Data Mining valid from 2019-05-10
Received: 21 November 2018
Accepted: 30 April 2019
First Online: 10 May 2019
Ethics approval and consent to participate
: The experimental protocols for the care and treatment of the pigs were approved and conducted under the supervision of the Animal Care and Use Committee of Nanjing Agricultural University (Nanjing, Jiangsu province, China) and followed Use Guidelines of China.
: All authors gave their consent for publication.
: Authors in Nanjing Agricultural University declare that they have no conflict of interest. Author in Shanghai Academy of Agricultural Sciences declares that she has no conflict of interest.