We Americans have become very picky eaters, sometimes with good reasoning, but some of it is merely due to the learned 'squeamish' factor. We really don't even want to know where those sanitized packaged chops, steaks and skinless/boneless breasts we do eat come from...
Many folks who read this blog are dedicated in some form to sustainability, and some even raise their own hog or steer to butcher for the family meat supply. After grazing an animal until it reaches butchering size, they are usually trucked off to the butchering facility. Folks get their animal back in neat little frozen packages, total weight well under what they took in.
In the US Meat Industry, statistically only about ⅔ of every beef or hog reaches our domestic grocery stores. Much of the rest is not only very edible, but some of it is far superior nutritionally to the muscle cuts which show up in the meat departments of our stores. The percentage of what reaches our stores now used to be higher, but we have learned to shun many nutritious edible parts over the last 50+ years. Personally, I have shunned those parts with good reason: the CAFO animal offal (for example, liver is offal and a large filter) contains higher amounts of toxins, whether from pesticides and herbicides in their feed or in antibiotics given to the animals.
Most of those edible parts we shun are sold cheaply to other cultures who favor parts like beef tongue, liver, brains, tripe, testicles, intestines and tails (parts considered offal), although some does come to us in the form of hot dogs and sausages. The inedible parts like hide and bones are also profitable to the industry; they are sold to processors for various uses including animal food. Nothing goes to waste, everything makes a profit for them.
Home-raised meat is not very different in what percentage of it we eat, and many small meat processors do not have a market for the portion they don't butcher and package. Much what we discard is not only edible, but some of it is far superior nutritionally to the muscle cuts. How sustainable is it to discard ⅓ of an animal when much of it is edible and all of it is useable?
I am now buying all my meat locally; it is strictly from small, family-farm pastured animals that are chemical, hormone and antibiotic free. Like most people, I could say I don't eat offal. Truthfully all I can say I is that I haven't eaten offal in many years, but now that I have access to pastured meat, that is changing. Why should I spend $6-8/pound for some cuts of meat when the $2/pound will give me more nutrients?
The organs of pastured animals contain much more nutrition that the muscle parts. According to Sally Fallon (Nourishing Traditions), organ meats contain 10 to 100 times the nutrients of muscle meats. In the wild, the organs are always the first things eaten by a predator because of the higher nutrients they contain. Same was true of the Native Americans... they ate the buffalo or other animal organs first, and cured the muscle parts for later when food wasn't plentiful... But when I ask the local farmers for leaf fat, heart, tongue, sweetbreads, oxtail or other offal parts, the usual answer I get is that they don't sell them because there is no demand.
I had to beg the fellow who raises lamb to have his butcher save the sweetbreads for me when I ordered the cheap but very meaty neck bones for stock. He gave me the sweetbreads free because they normally don't keep them. For under $10 I got enough neck meat for at least 8 meals, not counting the delicious and nutritious stock I canned.
Beef liver is a nutritious organ meat that contains several vitamins and minerals important to the human body. One slice of liver (about 3 ozs.) contains 423% of the daily requirement of vitamin A; 163% for riboflavin/B2; 1,122% for vitamin B12 and 28% for iron on a 2,000-calorie per day diet as recommended by the USDA. By contrast, the same amount of a chuck roast supplies 0% vitamin A, 12% B2, 36% B12 and 15% iron.
The average beef liver weighs 10-12 pounds, and I can buy a whole grass-fed beef liver for around $10. (The liver in Grass-fed/Pastured beef is a still a filter, but it isn't filtering any toxins if there aren't any.) I don't like the stronger taste of mature beef liver as much as the more delicate taste of calf's liver, but soaking a slice in buttermilk for an hour or so removes the strong taste! Another tip for liver is to partially freeze it, then slice it very thin, and sauté quickly. Cooking with some bacon or in bacon fat adds flavor, and I prefer cooking liver with shallots rather than onions... plus I add a splash of sherry just before removing it from the pan.