"In this world man is not meant to toil like hogs. He must be intelligent to realize the importance of human life and refuse to act like an ordinary animal. A human being should realize the aim of his life, and this direction is given in all Vedic literatures, and the essence is given in Bhagavad-gita. Vedic literature is meant for human beings, not for animals. Animals can kill other living animals, and there is no question of sin on their part, but if a man kills an animal for the satisfaction of his uncontrolled taste, he must be responsible for breaking the laws of nature. In the Bhagavad-gita it is clearly explained that there are three kinds of activities according to the different modes of nature: the activities of goodness, of passion and of ignorance. Similarly, there are three kinds of eatables also: eatables in goodness, passion and ignorance. All of this is clearly described, and if we properly utilize the instructions of Bhagavad-gita, then our whole life will become purified, and ultimately we will be able to reach the destination which is beyond this material sky. That destination is called the sanatana sky, the eternal spiritual sky." Bhagavad-Gita, Introduction

"By nature's law, or the arrangement of the Supreme Personality of Godhead, one kind of living entity is eatable by other living entities. As mentioned herein, dvi-padam ca catus-padah: the four-legged animals (catus-padah), as well as food grains, are eatables for human beings (dvi-padam). These four-legged animals are those such as deer and goats, not cows, which are meant to be protected. Generally the men of the higher classes of society--the brahmanas, ksatriyas and vaisyas--do not eat meat. Sometimes ksatriyas go to the forest to kill animals like deer because they have to learn the art of killing, and sometimes they eat the animals also. Sudras, too, eat animals such as goats. Cows, however, are never meant to be killed or eaten by human beings. In every sastra, cow killing is vehemently condemned. Indeed, one who kills a cow must suffer for as many years as there are hairs on the body of a cow. Manu-samhita says, pravrttir esa bhutanam nivrttis tu maha-phala: we have many tendencies in this material world, but in human life one is meant to learn how to curb those tendencies. Those who desire to eat meat may satisfy the demands of their tongues by eating lower animals, but they should never kill cows, who are actually accepted as the mothers of human society because they supply milk. The sastra especially recommends, krsi-go-raksya: the vaisya section of humanity should arrange for the food of the entire society through agricultural activities and should give full protection to the cows, which are the most useful animals because they supply milk to human society."

Srimad-Bhagavatam 6:4:9 Purport

"Now, with the help of my arrows, I shall cut you to pieces and with your flesh satisfy the hunger-stricken citizens, who are now crying for want of grains. Thus I shall satisfy the crying citizens of my kingdom.

Purport: Here we find some indication of how the government can arrange for the eating of cow flesh. It is here indicated that in a rare circumstance when there is no supply of grains, the government may sanction the eating of meat. However, when there is sufficient food, the government should not allow the eating of cow's flesh just to satisfy the fastidious tongue. In other words, in rare circumstances, when people are suffering for want of grains, meat-eating or flesh-eating can be allowed, but not otherwise. The maintenance of slaughterhouses for the satisfaction of the tongue and the killing of animals unnecessarily should never be sanctioned by a government. As described in a previous verse, cows and other animals should be given sufficient grass to eat. If despite a sufficient supply of grass a cow does not supply milk, and if there is an acute shortage of food, the dried-up cow may be utilized to feed the hungry masses of people. According to the law of necessity, first of all human society must try to produce food grains and vegetables, but if they fail in this, they can indulge in flesh-eating. Otherwise not. As human society is presently structured, there is sufficient production of grains all over the world. Therefore the opening of slaughterhouses cannot be supported. In some nations there is so much surplus grain that sometimes extra grain is thrown into the sea, and sometimes the government forbids further production of grain. The conclusion is that the earth produces sufficient grain to feed the entire population, but the distribution of this grain is restricted due to trade regulations and a desire for profit. Consequently in some places there is scarcity of grain and in others profuse production. If there were one government on the surface of the earth to handle the distribution of grain, there would be no question of scarcity, no necessity to open slaughterhouses, and no need to present false theories about over-population."

Srimad-Bhagavatam 4:17:25 Purport

"There are two kinds of meat-eaters--one who is born in a family of meat-eaters and one who has learned to associate with meat-eaters. From Srila Rupa and Sanatana Gosvamis (formerly Dabira Khasa and Sakara Mallika) we can learn how one attains the character of a meat-eater simply by associating with meat-eaters. At the present moment in India the presidential offices are occupied by many so-called brahmanas, but the state maintains slaughterhouses for killing cows and makes propaganda against Vedic civilization. The first principle of Vedic civilization is the avoidance of meat-eating and intoxication. Presently in India, intoxication and meat-eating are encouraged, and the so-called learned brahmanas presiding over this state of affairs have certainly become degraded according to the standard given herein by Srila Rupa Gosvami and Sanatana Gosvami. These so-called brahmanas give sanction to slaughterhouses for the sake of a fat salary, and they do not protest these abominable activities. By deprecating the principles of Vedic civilization and supporting cow-killing, they are immediately degraded to the platform of mlecchas and yavanas. A mleccha is a meat-eater, and a yavana is one who has deviated from Vedic culture. Unfortunately, such mlecchas and yavanas are in executive power. How, then, can there be peace and prosperity in the state? The king or the president must be the representative of the Supreme Personality of Godhead. When Maharaja Yudhisthira accepted the rule of Bharata-varsa (formerly this entire planet, including all the seas and land), he took sanction from authorities like Bhismadeva and Lord Krsna. He thus ruled the entire world according to religious principles. At the present moment, however, heads of state do not care for religious principles. If irreligious people vote on an issue, even though it be against the principles of the sastras, the bills will be passed. The president and heads of state become sinful by agreeing to such abominable activities. Sanatana and Rupa Gosvamis pleaded guilty to such activities; they therefore classified themselves among the mlecchas, although born in a brahmana family."

Caitanya-caritamrta, Madyam lila 1:197

"In Kali-yuga men all over the world are very expert in opening slaughterhouses for killing animals, which they eat. If the old ritualistic ceremonies were observed, people would be encouraged to kill more and more animals. In Calcutta there are many butcher shops which keep a deity of the goddess Kali, and animal-eaters think it proper to purchase animal flesh from such shops in hope that they are eating the remnants of food offered to goddess Kali. They do not know that goddess Kali never accepts nonvegetarian food because she is the chaste wife of Lord Siva. Lord Siva is also a great Vaisnava and never eats nonvegetarian food, and the goddess Kali accepts the remnants of food left by Lord Siva. Therefore there is no possibility of her eating flesh or fish. Such offerings are accepted by the associates of goddess Kali known as bhutas, pisacas and Raksasas, and those who take the prasada of goddess Kali in the shape of flesh or fish are not actually taking the prasada left by goddess Kali, but the food left by the bhutas and pisacas."

Srimad-Bhagavatam 4:19:36 Purport

Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.