Back in the old days, when cars and giant robots were powered by clockworks and steam, budding young surgeons practiced their craft on cadavers or pigs. Although the technique has survived somewhat into this millennium, it doesn't really help out doctors' reputations too much. The alternative is working on synthetics, but most flesh equivalents that aren't made of tissue just don't provide the same experience.
Veterinarians at Colorado State University may have found a solution: they've developed a surgical analogue to living tissue that not only cuts like real tissue, it bleeds too. The fake flesh, just like the real thing, even has built-in blood vessels to help doctors practice their "whoops, I cut something bad, hand me the forceps" technique.
The Colorado State scientists built their artificial tissues based on real live, or in this case dead, samples of equine abdominal wall. They used multiple layers of silicone with differing textures to simulate the properties of real horseflesh. It's got skin, subcutaneous fat, muscle, and tougher fascia which sheathes the muscular tissue.
Budding vets love the new fake horse belly, and think it's a drastic improvement over carpet pads, which they used to practice on. In fact, Dr. Dean Henderson, the director of the school's veterinary teaching hospital, thinks that the technique may carry over to people surgery as well. That's less pigs on the operating table and more in my belly, so that's a win-win situation right there.