Good information tri. I've wondered the same thing as Rayne about the cows. Now, why are the cows considered sacred? How far back does this go and what circumstances surround this belief?
I'm not certain exactly how far back this belief dates. I am struggling to refrain from quoting Holy Scriptures, suffice to say that cows were considered sacred for at least as long as I can find in the recorded history I can access.
You can probably guess the surrounding circumstances. India has a very long history steeped in the vegetarian diet as as unquestioned way of life, supported by their Holy Scriptures. When the Muslims invaded, that changed more than a little. There is at least one Bollywood movie I've seen (Jodhaa Akbar?), that gives an example of what this may have been like. When the British invaded (well, it was much worse than an invasion!), the mentality for many became, "well, now we all just have eat meat to make us strong against the British". Then there arose a whole heap of problems that were not arguably related to meat consumption. Now, before these two periods of time, when the whole of India was strictly vegetarian, and by that I mean their diet did not include egg, the cow was held sacred because she produced milk for the people. My understanding is that because today's dairy products such as cheese, cream, ice-cream, etc were never a part of the people's diet, although ghee at some point was, there did not need to be a massive supply of milk for each person. The Indian people cared for every animal almost as they would their own children. Because cows only give milk when they are lactating, just as humans and other animals do, supply was limited and that alone increased its value. Forced pregnancies, like mass-agribusinesses engage in today, were never even contemplated and mass-breeding programs would have been unsustainable. A high population and land ownership situation ensured one family never controlled enough land to breed up cattle to provide for any more than their own family, at least for some part of the year. And so the people cared deeply for their cattle which at some point must have become intertwined with religion.
Just a couple of years ago, two independent studies in India concluded exactly how far back the vegetarian tradition went in India.