stockman vs breeder

stockman and breeder both are nouns.

Word	Noun	Adjective	Verb	Adverb
stockman	Yes	No	No	No
breeder	Yes	No	No	No

As nouns, breeder is a hyponym of stockman; that is, breeder is a word with a more specific, narrower meaning than stockman:

Other hyponyms of stockman include stock breeder, beef man, cattleman, cow man, sheepman.

stockman (noun)	breeder (noun)
farmer who breed or raises livestock	a person who breeds animals