There are so many facilities afforded by cow protection, but people have forgotten these arts. The importance of protecting cows is therefore stressed by Krsna in Bhagavad-gita (krsi-go-raksya-vanijyam vaisya-karma svabhavajam [Bg. 18.44]). Even now in the Indian villages surrounding Vrndavana, the villagers live happily simply by giving protection to the cow. They keep cow dung very carefully and dry it to use as fuel. They keep a sufficient stock of grains, and because of giving protection to the cows, they have sufficient milk and milk products to solve all economic problems. Simply by giving protection to the cow, the villagers live so peacefully. Even the urine and stool of cows have medicinal value. SB 10.6.19 Purport
Jamadagni was more powerful than Kartaviryarjuna because of performing the agnihotra-yajna with clarified butter received from the kamadhenu. Not everyone can be expected to possess such a cow. Nonetheless, an ordinary man may possess an ordinary cow, give protection to this animal, take sufficient milk from it, and engage the milk to produce butter and clarified ghee, especially for performing the agnihotra-yajna. This is possible for everyone. Thus we find that in Bhagavad-gita Lord Krsna advises go-raksya, the protection of cows. This is essential because if cows are cared for properly they will surely supply sufficient milk. We have practical experience in America that in our various ISKCON farms we are giving proper protection to the cows and receiving more than enough milk. In other farms the cows do not deliver as much milk as in our farms; because our cows know very well that we are not going to kill them, they are happy, and they give ample milk. Therefore this instruction given by Lord Krsna -- go-raksya -- is extremely meaningful. The whole world must learn from Krsna how to live happily without scarcity simply by producing food grains (annad bhavanti bhutani [Bg. 3.14]) and giving protection to the cows (go-raksya). Krsi-go-raksya-vanijyam vaisya-karma svabhavajam [Bg. 18.44]. Those who belong to the third level of human society, namely the mercantile people, must keep land for producing food grains and giving protection to cows. This is the injunction of Bhagavad-gita. In the matter of protecting the cows, the meat-eaters will protest, but in answer to them we may say that since Krsna gives stress to cow protection, those who are inclined to eat meat may eat the flesh of unimportant animals like hogs, dogs, goats and sheep, but they should not touch the life of the cows, for this is destructive to the spiritual advancement of human society. SB 9.15.25 Purport
Although in this age men can live up to one hundred years, their duration of life is reduced because they do not drink large quantities of milk. This is a sign of Kali-yuga. In Kali-yuga, instead of drinking milk, people prefer to slaughter an animal and eat its flesh. The Supreme Personality of Godhead, in His instructions of Bhagavad-gita, advises go-raksya, which means cow protection. The cow should be protected, milk should be drawn from the cows, and this milk should be prepared in various ways. One should take ample milk, and thus one can prolong one's life, develop his brain, execute devotional service, and ultimately attain the favor of the Supreme Personality of Godhead. As it is essential to get food grains and water by digging the earth, it is also essential to give protection to the cows and take nectarine milk from their milk bags. SB 8.6.12 Purport
Protection and grazing ground for the cows are among the essential needs for society and the welfare of people in general. The animal fat required for the human body can be well derived from cow's milk. Cow's milk is very important for human energy, and the economic development of society depends on sufficient food grains, sufficient milk, and sufficient transportation and distribution of these products. Lord Sri Krsna, by His personal example, taught us the importance of cow protection, which is meant not only for the Indian climate but for all human beings all over the universe.
Less intelligent people underestimate the value of cow's milk. Cow's milk is also called gorasa, or the juice from the body of the cow. Milk is the most valuable form of gorasa, and from milk we can prepare many important and valuable foodstuffs for the upkeep of the human body. The killing of cows by human society is one of the grossest suicidal policies, and those who are anxious to cultivate the human spirit must turn their attention first toward the question of cow protection.
Light of the Bhagavata Text 27
Thereafter, mother Yashoda and Rohini, along with the other elderly gopis, waved about the switch of a Cow to give full protection to the child Sri
PURPORT: When Krishna was saved from such a great danger, mother Yashoda and Rohini were principally concerned, and the other elderly gopis, who were almost equally concerned, followed the activities of mother Yashoda and Rohini. Here we find that in household affairs, ladies could take charge of protecting a child simply by taking help from the Cow. As described here, they knew how to wave about the switch of a Cow so as to protect the child from all types of danger. There are so many facilities afforded by Cow protection, but people have forgotten these arts. The importance of protecting Cows is therefore stressed by Krishna in Bhagavad-gita (krisi-go-raksha-vanijyamvaisya-karma svabhavajam [Bg. 18.44]). Even now in the Indian villages surrounding Vrindavana, the villagers live happily simply by giving protection to the Cow. They keep Cow dung very carefully and dry it to use as fuel. They keep a sufficient stock of grains, and because of giving protection to the Cows, they have sufficient milk and milk products to solve all economic problems. Simply by giving protection to the Cow, the villagers live so peacefully. Even the urine and stool of Cows have medicinal value.