These Regulations are made in exercise of the powers conferred by the European Union (Withdrawal) Act 2018 (c. 16) (in particular under section 8(2)(a) to (c) of that Act) in order to address failures of retained EU law to operate effectively and other deficiencies arising from the withdrawal of the United Kingdom from the European Union.
Link: The Equine (Records, Identification and Movement) (Amendment) (EU Exit) Regulations 2019
Source: Legislation .gov.uk