Why The Cow And Not Another Animal

“Everyone can understand that we drink the milk of cows and take the help of bulls in producing agricultural products. Therefore, since our real father gives us food grains and our mother gives us milk with which to live, the cow and bull are considered our father and mother. According to Vedic civilization, there are seven mothers, of which the cow is one.” (Shrila Prabhupada, Chaitanya Charitamrita, Adi 17.154, Purport)