Fat. Venison doesn’t have much. That causes one of the main challenges to cooking it. Go too far and it will just be dry and tough.
Many times, cooks (or processors) will add fat to venison. Has anyone ever told you about their amazing backstrap recipe, where they wrapped everything in bacon? Well, I would argue that is more of an amazing bacon recipe, and the steak was probably overcooked. Same thing for sausages and hot dogs. I’ve heard people tell me time and again how great venison hot dogs are. What I don’t think they know is that their “venison” dog is probably at least 50% ground pork. Same goes for any venison sausage.