Received: 3 November 2019
Accepted: 3 March 2020
First Online: 14 March 2020
Ethics approval and consent to participate
: All experimental procedures were approved by the Animal Experiment Committee of the Guangxi Veterinary Research Institute, Nanning, China. All applicable international, national, and institutional guidelines for the care and use of animals were strictly followed.
: Not applicable.
: The authors declare that they have no competing interests.