Funding for this research was provided by:
Japan Society for the Promotion of Science (17H04639)
Received: 28 February 2019
Accepted: 9 October 2019
First Online: 12 November 2019
Ethics approval and consent to participate
: In the present study, serum samples and farms information were collected from slaughterhouses by the permission of meat inspection office. These pigs were not culled and not aggressively operated on for sampling purpose in this study.
: Not applicable
: The authors declare that they have no competing interests.