I briefly touched this but I should go into a little more detail. Basically, when the animal is killed, it's throat is cut to "release the spirit" with a prayer. When my husband's grandfather would slaughter a sheep, he would cut its throat and begin by saying that it's spirit released and then sing a prayer in Navajo that says something like thank you for giving your life to nourish us, that the animal and its spirit is beautiful and strong, may this strength be passed on to those who partake of its body and for the spirit to go in peace. This is done with great reverence. It's not just slash the neck and sing the prayer to "get it done with". The belief of the animal having a spirit and communing with this spirit to say thank you and etc is very strong. The spirit of the animal must be at rest and honoured. An unrestful spirit may cause illness and that wouldn't be very good.

Stephanie

In every man there is something wherein I may learn of him, and in that I am his pupil.--Ralph Waldo Emerson