The bulls and cows are offered special protection by followers of the Vedas.

SB 1.16.20 P   How Pariksit Received the Age of Kali

   The meat-eaters are generally called mlecchas. But all meat-eaters are not mlecchas. Those who accept meat in terms of scriptural injunctions are not mlecchas, but those who accept meat without restriction are called mlecchas. Beef is forbidden in the scriptures, and the bulls and cows are offered special protection by followers of the Vedas. But in this age of Kali, people will exploit the body of the bull and the cow as they like, and thus they will invite sufferings of various types.
   The people of this age will not perform any sacrifice. The mleccha population will care very little for performances of sacrifices, although performance of sacrifice is essential for persons who are materially engaged in sense enjoyment. In the Bhagavad-gita performance of sacrifices is strongly recommended (Bg. 3.14-16).