Funding for this research was provided by:
EIP-Agri (not applicable)
Received: 19 December 2019
Accepted: 8 April 2020
First Online: 5 June 2020
Ethics approval and consent to participate
: The experiments were carried out in accordance with German regulations (Animal Protection Act). No direct interventions were carried out on animals which could be associated with pain, suffering or damage to these animals. The examinations required no announcement or permission with regard to the Animal Protection Law (§7, paragraph 2) since no measures inflicting pain, suffering or injury to these animals were carried out.
: Not applicable.
: The authors declare that they have no competing interests.