Notes

http://www.stephen-knapp.com/vegetarianism_recommended_in_Vedic_scripture.htm <-- what vedas aand bhagwad geeta and ramayana says

video by agniveer -- https://www.youtube.com/watch?v=ecCPLt5rE58

https://www.youtube.com/watch?v=b29RWM8JFME -- Why is the cow holy? [The Hindu Academy]

why cows according to hinduism?

To understand this we need to understand the importance of Cows in Hinduism. The following is an excerpt from the book, Aghora: At the left hand of God,

The cow is a perfect mother. She has four teats: one for her calf, one for guests including birds and animals, one for use in rituals and one for her master. The milk is automatically divided into four equal portions; everyone is provided for. And the cow is passionately devoted to her calf, just as a real mother must be to her child. Sometimes the mere sight of the calf makes milk flow from cow's udder; not drip -- flow...

and if the calf dies the cow refuses to give milk -- not like our water buffaloes who can be tricked with the head of a calf on stick. The buffalo is the symbol of Tamas, stupidity, dullness; the cow is pure Sattva, mental brightness...

Not just buffaloes, even your western cows will give milk whether or not the calf is still alive... What is so great about giving milk? All animals do it. The greatness of out Indian cows is that they give milk only out of an outpouring of love.That is the value of cow's milk. Won't a little of that love come through into the milk? It must.That emotion separates cows from other animals...

We are not worshipping the hide, hooves or the tail; we worship the essence...

Lord Krishna was called Gopala when he was a baby. Gopala literally means "protector of cows". There are many esoteric meaning to this word, but even the obvious meaning is beautiful. Gopala was such a lovable little baby that all the cows in the vicinity loved him more than they loved their own calves.

So, basically the answer to the significance of Cows to Krishna, in particular and Hinduism, in general is what is mentioned in the preceding excerpts.