Polly,
Yes, all the grazing animals, (herbivores), have several stomachs - cows have 4, for example, so that they can even digest cellulose. Actually, they only regurgitate it once, but that practice allows them down a lot more grass, while they're foraging, and then later, when they're lying in the shade, relaxing, (if the weather is hot, and any shade is available), they regurgitate it, a wad at a time, and chew their "cud". Grass is relatively low-nutrient feed, so it takes a heck of a lot of it, to stoke the furnace of a 12 hundred pound cow. I find it very interesting that their digestive system is sophisticated enough that it knows to regurgitate fiber of a certain length, but it does not regurgitate anything below a certain size limit. When a cow chews her cud, a lot of saliva is added, which helps subsequent digestion, and before the "chime", (the name for partially digested food, as it leaves the stomach), is passed into the gut, particle size must be reduced to less than 1 millimeter.
Pigs, on the other hand, are monogastric, (they only have a single stomach, since they're not grazing animals), and their digestive system is very similar to ours, so that most of the parts would be interchangeable, in an emergency.
Love,
Tex