I have never taken an animal to a processor.
In my personal experience I believe my final yield to be about right for a general rule I got from somewhere for large game.

Field dressed, you salvage 60% of live weight.
Processing for consumption you salvage 60% of field dressed weight.
Therefore you should normally get about 36% of live weight for consumption. That would mean that you salvaged all the meat using trimmings, rib, neck meat etc for things like burger or summer sausage plus your steaks, roasts, etc.

So, 500 pounds live should yield about 180 pounds of meat.
My experience with deer, speed goats and elk have approximated this less stuff lost to damage or just not saved by me.

"The significant problems we face cannot be solved at the same level of thinking we were at when we created them."
Albert Einstein

At Khe Sanh a sign read "For those who fight for it, life has a flavor the protected never knew".