In this movement, our one program is to respect the cows. We chant this mantra, namo brahmanya-devaya go-brahmana-hitaya ca. The brahminical culture and the cows… Why they have selected the cows? There are so many animals. Why cow protection is so important in Krsna consciousness? Why Krsna personally Himself became a cowherd boy and was taking the care of the cows and the calves? Oh, that is very essential.

From Srila Prabhupada's lecture on Srimad-Bhagavatam 1.16.19 — January 15, 1974, Honolulu