Funding for this research was provided by:
New Technology for Prevention and Control of Important Diseases of Pigs (2017YFD0500602)
Received: 1 May 2019
Accepted: 16 October 2019
First Online: 5 November 2019
Ethics approval and consent to participate
: The experimental procedures used in this study were approved by the Animal Ethics Committee of the Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences (Heilongjiang-SYXK-2017-009) and were performed in accordance with the relevant animal ethics principles.
: Not applicable.
: The authors declare that they have no competing interests.