dog food: actually , once the blood congeals the dog food guys don’t even want them. It’s too hard to separate the meat from the offal. For a few days the hide is salvageable. The Mexicans will take it for leather but you’d need to have a Mexican handy to skin it out, scrape it dry, and haul it to Mexico.
On a slightly related side note back in the 70’s I got a letter from George Lawrence, the guy who used to make gun leather. He wanted me to write my congersperson to complain about so many cow hides going to Mexico and Japan. He was having trouble buying hides since they were taking them all from the hot dog factories.
Getting an already-dead cow to someone who can use it is a problem all by itself. The field dressing guys just ain’t interested.