Hare Krisna to everybody. Please, accept my obeisances. All glories to Srila Prabhupada! Jaya Sri Guru and Sri Gauranga!
There is a very important quote by Srila Prabhupada about milk right in Srimad Bhagavatam! It is a good answer to vegans and other people, who avoid drinking milk.
“As one can derive fire from wood, milk from the milk bag of the cow, food grains and water from the land… “ (Srimad Bhagavatam, Canto 8, Chapter 6, Text 12)
…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.
The end of the purport by Srila Prabhupada.
Navadwipa Chandra Das