He who offers up his evil desires will see the uselessness of slaughtering animals at the altar.
I believe this is a practice that hasn;t been done in centuries and out of the Old Testament, at least with most religions. However it wasn't but a few years ago an image sticks out in my mind of a Fundementalist Muslim man slitting the throats of several lambs in the street, on one of their holy days. Along with that idea is the centurys old way of their oppression of woman and children, and the teaching of hate twards others.
We arn't living in the 5th century BC, we live in the 21st century AD, where we are supose to be civilized. That poor lamb isn;t even aware of time, so why make an animal die a horrible death for something he doesn't have a thing to do with?