Funding for this research was provided by:
Stiftelsen svensk grisforskning (Dnr 201604)
Received: 21 January 2020
Accepted: 15 May 2020
First Online: 4 June 2020
Ethics approval and consent to participate
: No ethics approval was needed for this study. The collection of slaughter house material was approved by the Swedish Board of Agriculture (SE3801001912). The farmers participated on a voluntary basis.
: The authors declare that they have no competing interests.