Funding for this research was provided by:
China Postdoctoral Science Foundation (2019M650126)
Basic Research Program of Jiangsu Province
Priority Academic Program Development of Jiangsu Higher Education Institutions
Received: 12 June 2019
Accepted: 23 July 2019
First Online: 27 August 2019
Ethics approval and consent to participate
: Protocols for the collection of samples in this study were reviewed and approved by the Institutional Animal Care and Use Committee of Yangzhou University College of Veterinary Medicine.
: Not applicable.
: The authors declare that they have no competing interests.