milcher vs milk cow

milcher and milk cow both are nouns.

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

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

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

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