It is said here that the cows used to moisten the pasturing land with milk because their milk bags were fatty and the animals were joyful. Do they not require, therefore, proper protection for a joyful life by being fed with a sufficient quantity of grass in the field? Why should men kill cows for their selfish purposes? Why should man not be satisfied with grains, fruits and milk, which, combined together, can produce hundreds and thousands of palatable dishes? Why are there slaughterhouses all over the world to kill innocent animals? Maharaja Pariksit, grandson of Maharaja Yudhisthira, while touring his vast kingdom, saw a black man attempting to kill a cow. The King at once arrested the butcher and chastised him sufficiently. Should not a king or executive head protect the lives of the poor animals who are unable to defend themselves? Is this humanity? Are not the animals of a country citizens also? Then why are they allowed to be butchered in organized slaughterhouses? Are these the signs of equality, fraternity and nonviolence?

From Srila Prabhupada's purport to SB 1.10.4