milker vs dairy cattle

milker and dairy cattle both are nouns.

Word	Noun	Adjective	Verb	Adverb
milker	Yes	No	No	No
dairy cattle	Yes	No	No	No

As nouns, milker and dairy cattle are synonyms defined as:

Other synonyms of milker include dairy cow, milch cow, milcher, milk cow.

milker (noun)	dairy cattle (noun)
cattle that are reared for their milk	cattle that are reared for their milk