YOU SAID:

I went to eat and came back to feed my cow

INTO JAPANESE

私は食べに行き、牛を養うために戻ってきました

BACK INTO ENGLISH

I went to eat and came back to feed the cows

INTO JAPANESE

私は食べに行き、牛に餌をやるために戻ってきました

BACK INTO ENGLISH

I went to eat and came back to feed the cows