If the meat-packing industry is still operative, the pharmaceutical industry will be too. If the meat-packing industry is not operative, there isn't going to be any meat but what people raise themselves, and mostly that isn't going to be either pigs or cattle, because they're a lot of trouble. I found the recipe for insulin from ground-up pancreas - and if someone was going to follow that recipe, they'd need a lot more lab expertise than they got in Chem 101 - but how many pancreases would one person need? One can't just slaughter a sheep every week. The yeast method might be more do-able; I don't find a recipe for that, though.