Yes, but don't forget that for a relatively small amount of a beef liver you need to kill a whole cow. And when you kill the animal you couldn't cherry-pick the parts of the meat you use, everything was used while it lasted. The parts that could be preserved would last for a while and things like a liver would be eaten right away or used to make sausages. In the middle age common folks didn't eat meat as often as we do today, it was a luxury. They primarily used a lot of buttermilk, cheese and eggs instead.