crossbreeding vs mating

crossbreeding and mating both are nouns.

Word	Noun	Adjective	Verb	Adverb
crossbreeding	Yes	No	No	No
mating	Yes	No	No	No

As nouns, mating is a hypernym of crossbreeding; that is, mating is a word with a broader meaning than crossbreeding:

crossbreeding: (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids
mating: the act of pairing a male and female for reproductive purposes

Other hypernyms of crossbreeding include conjugation, coupling, pairing, sexual union, union.

crossbreeding (noun)	mating (noun)
(genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids	the act of pairing a male and female for reproductive purposes
reproduction by parents of different races (especially by white and non-white persons)