noun which may take the genitive case particle 'no'
for breeding; breeding stock; brood; stud
Used as a no-adjective to describe animals, plants, or facilities intended for breeding purposes. Often appears in compounds like 繁殖用の雌馬 (broodmare) or 繁殖用の池 (breeding pond).
This farm raises cattle for breeding.
Select killifish for breeding.
Compound of 繁殖 (breeding) + 用 (for use). The meaning is transparent from its components.