milk cow vs milcher

milk cow and milcher both are nouns.

Word	Noun	Adjective	Verb	Adverb
milk cow	Yes	No	No	No
milcher	Yes	No	No	No

As nouns, milk cow and milcher are synonyms defined as:

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

milk cow (noun)	milcher (noun)
cattle that are reared for their milk	cattle that are reared for their milk