In the 80s and 90s I worked on a lot of dairy farms and unless they were rearing lots of calves most went off to market or were shot at birth
So I used to take home loads of unsuitable for humans milk and mix it with barleymeal for raising my porkers..........along with fruit and veg from the grocers it used to form the perfect diet, high in protein, fat and essential vits which along with the carb in the barley and the fruit and veg made for cheap tasty pigs that grew like weeds!!!
I also kept a herd of goats and the surplus milk went the same way!
...............I occaisionally raised a veal calf on the cows milk and goats milk mixed plus hay and they were fab too!