the world > animals > animal body > general parts > sexual organs and reproduction > [adjective] > relating to mating > that mates (3)
attributive with sense ‘breeding’; as in brood class; brood hen, brood mare, brood sow, and the like, where however the words are often hyphenated…
That pairs (in various senses of pair, v.2)
That mates or joins with a suitable partner; (esp. of a bird or pair of birds) that engages in mating.