Srila Prabhupada speaks about:

MOTHER COW, MOTHER EARTH

THE SEVEN MOTHERS

The original mother, the wife of the guru or spiritual master,
the wife of a brahmana [one who knows the soul],
the queen-the kings wife,
the cow, the nurse and the earth.
(Srimad-Bhagavatam [SB] 7.12.8)

(We learn from Srila Prabhupada and the Vedic literatures that these seven Mothers must be respected and protected)

COW IS YOUR MOTHER

According to Vedic civilization the cow is to be given special protection. Why it is recommended for the cow? It does not say of other animal. When animal killing is required according to Vedic civilization, those who are meat-eaters, they are allowed to kill some insignificant animal like deer, goat, pigs. It is for the animal eaters, not for all. But if one is bent upon... And there are persons, they want meat-eating. So for them these unimportant animals are recommended. But cow is very important animal. You get from its milk so many nutritious food. So apart from religious sentiment, from economic point of view, cow-killing is not good. And from moral point of view it is not good because you drink cows milk, so cow is your mother. According to Vedic civilization, there are seven mothers. (Garden Conversation, 6/24/75, Los Angeles)

KILLING THE COWS AND SPOILING THE LAND IS NOT CIVILIZATION

Killing the cows and spoiling the land will not solve the problem of food. This is not civilization. Uncivilized men living in the jungle and being unqualified to produce food by agriculture and cow protection may eat animals, but a perfect human society advanced in knowledge must learn how to produce first-class food simply by agriculture and protection of cows. (SB 10.7.13-15)