Commission Implementing Regulation (EU) 2023/2628 of 27 November 2023 concerning the authorisation of guanidinoacetic acid and a preparation of guanidinoacetic acid as feed additives for chickens reared for breeding and chickens reared for laying in feed and in water for drinking, and chickens for fattening in water for drinking (holder of authorisation: Alzchem Trostberg GmbH), and correcting and amending Implementing Regulation (EU) 2016/1768