Brahmanas are the symbol of spiritual education, and cows are the symbol of the most valuable food (milk production & Butter); they must be given all protection.. that is real advancement of civilization.
A snake can be charmed by sound vibration 'mantra'or herbs, but the man, most envious, is more dangerous than the snake.
One should act according to the order of Krishna. This is very important point. That order of Krishna comes through disciplic succession from the bonafide spiritual master. Therefore, the spiritual master's order should be taken as the prime duty of life. If one gets a bonafide spiritual master and acts according to his direction, then one's perfection of life in Krishna consciousness is guaranteed. — Bhagavad Gita As It Is. 18.57.