Funding for this research was provided by:
Beijing Municipal Natural Science Foundation (S170001)
National Natural Science Foundation of China (31630074,31272449 and 31902170)
Higher Education Discipline Innovation Project (B16044)
the National Key Research and Development Program of China (2016YFD0500506 and 2018YDF0501002)
the Jinxinnong Animal Science Developmental Foundation.
Text and Data Mining valid from 2019-11-11
Received: 25 February 2019
Accepted: 10 October 2019
First Online: 11 November 2019
Ethics approval and consent to participate
: Not applicable.
: All authors read and approved the final manuscript.
: The authors declare that they have no competing interests.