Let me ask a different question. Given that he’s not our father, uncle, or even a distant cousin, why not kill a bull. It’s quite simple actually. For a farmer or a herder, it’s just dumb to kill a bull for it can do a lot of things. A bull can till your field, it can impregnate other bovine animals, it can pull heavy things, and it can also keep you company in your bouts of solitary farming. It’s a win-win.
It’s the same for cows. We preserve cows not because they are sacred. Well, there is that too. The primary reason, why people -not only Hindus- don’t kill them is that the cow is the source of livelihood for many families living in rural areas and tier III cities. And there are many believe me.
All the way from a joint family having a dozen cattle to a family of 4 or 5 with only one cow and one bull; farm animals are an essential commodity in the villages. People living there are entirely dependent on these animals for their food as well as earnings. You think one day they’ll wake up and think, “Wow you know what I would love to eat today? Beef.”
It doesn’t work like that. One day of beef would mean months of starvation for the family. Not to mention the social ostracizing for killing a divine animal.
Also, when an animal has been living with you for so long, it becomes a part of your family. And you don’t just eat your family, do you? On top of all this, according to Hindu religion, a cow is considered equivalent to mother in a country with an 80 percent Hindu population. Even after all this logic and faith, you can kill a cow and a bull and a goat too for that matter. But wouldn’t it be dumb to kill a cow just out of spite? What do you think?