Funding for this research was provided by:
The article processing charge was funded by the German Research Foundation (DFG) and the Albert Ludwigs University Freiburg in the funding programme Open Access Publishing.
Received: 17 April 2019
Accepted: 26 June 2019
First Online: 1 July 2019
Ethics approval and consent to participate
: All animal experiments were approved by the Regierungspräsidium Freiburg, Germany, Section: Landwirtschaft, Ländlicher Raum, Veterinär- und Lebensmittelwesen. Application No. G17/55 and X-16/04.
: Not applicable.
: The authors declare that they have no competing interests.