These Regulations are made in exercise of powers in the European Union (Withdrawal) Act 2018 (c.16) in order to address failures of domestic legislation to operate effectively and other deficiencies (in particular, under paragraphs (a), (d) and (g) of section 8(2) of the Act) arising from the withdrawal of the United Kingdom from the European Union.
Link: The Animal Health and Welfare (Amendment) (Northern Ireland) (EU Exit) Regulations 2019
Source: Legislation .gov.uk