Funding for this research was provided by:
Ministry of Agriculture, Forestry and Fisheries of Japan
Received: 4 June 2019
Accepted: 24 October 2019
First Online: 9 November 2019
Ethics approval and consent to participate
: The blood samples used in this study were collected by the official veterinarians of the Livestock Hygiene Service Center and Meat Hygiene Inspection Center in each prefecture as part of normal veterinary investigations under the Act on Domestic Animal Infectious Diseases Control and the Slaughterhouse Act of Japan. Prior to the sample collection, we informed the aim and contents of the analysis of this study to each facility, and obtained the written consent from each facility. Therefore, the Institutional Animal Care and Use Committees of the National Institute of Animal Health, NARO judged that ethics approval was not required for this study. Animal handling and sample collection in farms was performed humanely by the official veterinarians of each prefecture with the consent of the owners. The blood of slaughtered cattle was collected from the axillary vein or heart when sampled in slaughterhouses by the official veterinarians of each prefecture.
: Not applicable.
: The authors declare that they have no competing interests.