Funding for this research was provided by:
Biotechnology and Biological Sciences Research Council (BB/P013759/1, BB/P013732/1, BB/J004235/1, BB/J004243/1)
Received: 6 September 2019
Accepted: 25 October 2019
First Online: 21 November 2019
: Animals were housed in premises licensed under a UK Home Office Establishment License within the terms of the UK Home Office Animals (Scientific Procedures) Act 1986 (Study number PUN056: approved by the Roslin Institute named veterinary surgeon). Housing and husbandry complied with the Code of Practice for Housing and Care of Animals Bred, Supplied or Used for Scientific Purposes and were overseen by the Roslin Institute Animal Welfare and Ethical Review Board. Animals were culled by schedule one methods authorized by the Animals (Scientific Procedures) Act 1986. Birds were euthanized by cervical dislocation.
: Not applicable.
: The authors declare that they have no competing interests.