Funding for this research was provided by:
Miljø- og Fødevareministeriet (34009-14-0849)
Received: 11 March 2020
Accepted: 26 January 2021
First Online: 12 February 2021
Ethics approval and consent to participate
: An Animal Care and Use Committee approval was not obtained for this study because the data were collected in commercial or breeding herds following Danish national standards of management and welfare procedures.
: Not applicable.
: The authors declare that they have no competing interests.