No not very common at all. I do it because I pay extra at a small USDA processor who also handles custom slaughter of whole animals. So they already had the infrastructure to keep each individual carcass separate and tagged with the owner. It wasn’t that much harder for them to add their kill sheet batch number and the ear tag number to the box label. By law each batch of meat that is labeled for retail sale must hav a batch code on it. In my case I get a batch code for every individual. I then cross reference the batch code with the animal. I keep a running list of which animal corresponds to which code. I can’t do that for the sausages or the ground, both made with a mix of animals but I can say for certain which group of animals go into each batch of sausage or ground.
Contrast that with a huge commercial commodity processor where in any given package of ground meat you can have parts from as many as 100 or more different animals and there is absolutely no way to trace the chops or roast back to an individual animal.
It does make my meats more expensive than commodity meats. I have customers willing to pay for the knowledge. Some farmers do not have that as an option.