Funding for this research was provided by:
Key Research and Development Project of Hainan Province (ZDYF2019073)
Hainan University Research Fund (hdkytg201702)
Received: 15 August 2019
Accepted: 15 November 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: The care and use of chickens in this study was approved by Hainan University Institutional Animal Care and Use Committee. Informed consent is not required.
: Not applicable.
: The authors declare that they have no competing interests.