Rising animals is way too expensive to throw away anything: depending on the quality of the cuts, they will undergo different processes and used in different ways. The best of the best is sold to restaurants and butchers, then to supermarkets and discount markets. Lesser cuts get processed in canned meat, minced, stuffed in sausages, hamburger, hotdog and frankfurter. The rest goes in the production of meat extract and bouillon, while the fat is rendered and cartilages are used for collagen and gelatin. Whatever is not used for human consumption, is used for pet food, cattle food, fish food or fertilizers. Unless there are some serious health concerns, nothing is just "thrown away". Sometimes not even in that case (see: BSE or Mad Cow Disease)