Funding for this research was provided by:
National Natural Science Foundation of China (31772620)
System for Poultry Production Technology, Beijing Innovation Research Team of Modern Agriculture (BAIC 04-2018)
Text and Data Mining valid from 2019-04-05
Received: 9 November 2018
Accepted: 10 February 2019
First Online: 5 April 2019
Ethics approval and consent to participate
: All procedures complied with the Beijing Regulations of Laboratory Animals, and the study was approved by The Laboratory Animal Ethical Committee of China Agricultural University (permit number SYXK20130013).
: Not applicable.
: The authors confirm they have read Biomed Central’s guidelines on competing interests and declare no competing interests.