Animal sacrifice is as old an mankind itself. right from Adam's son Abel who, out of jealousy, was killed by his own brother. then Abraham was told to sacrifice his son. that sacrifice never took place, instead a ram was substitued and it is being observed to this day both in Jewish and Islamic religions.
it will be recalled what Jehova told the children of Isreal while the later were in slavery in Egypt. and Jehova said "this night i am passing through Egypt. slaughter a ram and splash the blood on your doors. when i see the blood, i will pass over you" what happened next is history. you can now see how important animal and blood sacrifice appeal to the gods in carrying out our wishes
Animal sacrifice is the ritual killing of an animal as part of a religion. It is practised by many religion s as a means of appeasing a god or gods or changing the course of nature. Animal sacrifice has turned up in almost all cultures, from the Hebrews to the Greeks and Romans, Israelites, Christianity, Islam, Judaism and from the Aztecs.
Remnants of ancient rituals of animal sacrifice are apparent in many cultures, for example the Spanish bullfights, or kapparos in Judaism, or ritual slaughter procedures like shechita or ḏabīḥah in Judaism and Islam, respectively. But to the practitioner within those religious belief systems, the religious and spiritual practice remains valid and necessary as "the sacrificial ceremony acts as a medium, a means of communication with the sacred, which enables him to create a link, a communion between him and the invisible powers".