Update 24 November 2021:

The Chief Veterinary Officers for England, Scotland, Wales and Northern Ireland have agreed to bring in new measures to help protect poultry and captive birds. The new housing measures will come into force across the UK from 00:01 on Monday 29 November 2021 to protect poultry and captive birds from avian influenza following a number of confirmed cases across Great Britain in recent weeks. See the AIPZ section.

https://www.gov.uk/government/news/bird-flu-latest-situation-avian-influenza-prevention-zone-declared-across-great-britain