Based on Japanese Archetypes the desert represents a hardship. Each of the animals represents an aspect of your life. The order in which you sacrifice the animals might be said to represent the importance of these things to you. The one that you sacrificed first is the least important, and the one that you kept is the most important.
1 You sacrificed the Lion. The Lion represents pride.
2 You sacrificed the Monkey. The Monkey represents your children.
3 You sacrificed the Cow. The Cow represents basic needs.
4 You sacrificed the Sheep. The Sheep represents friendship.
5 You kept the Horse. The Horse represents your passion.
No explanation required, I suppose.