there are various reasons 1.according to research a human being has two st of tooth ,one is flat(present in goat cows) which are suited for eating grass,vegetables etc and other is sharp(present in tiger,hyena,cats lion)which are suited for eating meat.since both the types are present in human being the nature(god) wants a humans to have both 2.just imagine how many sheeps are slaughtered in india every day suppose the govt of india bans the slaughtering then where will the govt accomodate these animals which increase rapidly,can anyone answer