noun
broodmare
Technical term in horse breeding for a female horse kept for breeding purposes.
この牧場では数頭の繁殖牝馬を飼育している。
This farm keeps several broodmares.
種牡馬 is a stallion used for breeding, while 繁殖牝馬 is a broodmare.
Compound of 繁殖 (breeding) + 牝馬 (mare).