While I am not a vegan, I also do not advocate the slaughter of animals for sport. My feelings are more like those of the Native Americans - kill only what you intend to consume and then eat what you kill and use the remains as much as possible. That would include tanning the hide for leather, using horn and bones for tools and the remainder for fertilizer for crops. If no animals died and decomposed, there would be significantly less vegetation. If there was less vegetation, we would have fewer animals.

In short, we need all other forms of life - animal and vegetable. Use them wisely and they will last forever. Waste them and they will be gone. This can be applied to all natural resources - water, coal, oil, trees, minerals etc. Recycle and re-use whenever possible.