Funding for this research was provided by:
Bundesanstalt für Landwirtschaft und Ernährung (2817701514)
Received: 17 October 2019
Accepted: 10 May 2020
First Online: 19 May 2020
Ethics approval and consent to participate
: The study was performed in accordance with the German Animal Protection Act and approved by the animal-welfare body of the state office for consumer protection in the German federal state Thuringia (registration number: 04–002/16).
: Not applicable.
: All authors declare that they have no competing interests.