This has now been rectified within the UK Trade tariff; the update is as follows.

A recent change has been implemented into the Customs Declaration Service (CDS) tariff affecting imports of products of animal origin (POAO) and animal by-products (ABP) from the EU (not including the Republic of Ireland). 

Importers of these products should have been making pre-notifications on the Import of products, animals, food and feed system (IPAFFS) since January 2022 and including references from IPAFFS in the customs declarations for these goods. 

This is now required, and to ensure your movements are not disrupted, you should make these pre-notifications on IPAFFS and include the reference from your pre-notification in your customs declaration. For further information, visit customs declaration completion requirements or the online tariff. 

If you've already pre-lodged your declaration, you should amend it before the goods arrive in the UK to include the correct pre-notification reference from IPAFFS. 

If you've pre-lodged your declaration and your goods have already arrived in the UK, you need to re-submit your declaration with the correct pre-notification reference.