Funding for this research was provided by:
the Ministry of Agriculture for Swine Disease Control (CARS-35)
the National Key Program of Research and Development of China (2018YFD0500803)
the Priority Academic Program Development of Jiangsu Higher Education Institutions
Received: 29 August 2020
Accepted: 26 October 2020
First Online: 11 November 2020
Ethics approval and consent to participate
: All animals were housed in the animal facility of Nanjing Agricultural University (NAU), Nanjing, Jiangsu, China. All experimental protocols for animals were conducted following the National Guidelines for Housing and Care of Laboratory Animals (China) and performed in accordance with NAU institutional regulations after approval by the Institutional Animal Care and Ethics Committee of NAU (SYXK(SU)2017-0007).
: Not applicable.
: None of the authors have any possible conflicts of interest.