If a farm accumulates animal carcasses and sends the carcasses to a rendering plant to be added to animal food, is the farm required to register?

No. A farm may hold RACs and remain within the “farm” definition. Unprocessed animal
carcasses destined for rendering into animal food are a RAC. The definition of “farm” in 21 CFR
1.227 allows holding of one’s own RACs and others’ RACs. Therefore, even if a farm is
accumulating carcasses from other farms, that fact would not require it to register.