Srila Prabhupada on Cow Protection.
In this verse, the cultivation of bhakti-yoga is compared to many material activities. By friction one can get fire from wood, by digging the earth one can get food grains and water, and by agitating the milk bag of the cow one can get nectarean milk. Milk is compared to nectar, which one can drink to become immortal. Of course, simply drinking milk will not make one immortal, but it can increase the duration of one’s life. In modern civilization, men do not think milk to be important, and therefore they do not live very long. 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 nectarean milk from their milk bags.
The people of this age are inclined toward industrial enterprises for comfortable living, but they refuse to endeavor to execute devotional service, by which they can achieve the ultimate goal of life by returning home, back to Godhead. Unfortunately, as it is said, na te viduh svartha-gatim hi visnum durasaya ye bahir-artha-maninah. People without spiritual education do not know that the ultimate goal of life is to go back home, back to Godhead. Forgetting this aim of life, they are working very hard in disappointment and frustration (moghasa mogha-karmano mogha jnana vicetasah). The so-called vaisyas–the industrialists or businessmen–are involved in big, big industrial enterprises, but they are not interested in food grains and milk. However, as indicated here, by digging for water, even in the desert, we can produce food grains; when we produce food grains and vegetables, we can give protection to the cows; while giving protection to the cows, we can draw from them abundant quantities of milk; and by getting enough milk and combining it with food grains and vegetables, we can prepare hundreds of nectarean foods. We can happily eat this food and thus avoid industrial enterprises and joblessness.
Agriculture and cow protection are the way to become sinless and thus be attracted to devotional service. Those who are sinful cannot be attracted by devotional service.