Leviticus 11:3-4

Ruminant animals do not completely chew the grass or vegetation they eat; the partially chewed grass goes into the large rumen where it is stored and then broken down into cud. When the animal has eaten its fill, it will rest and chew its cud; the cud is then swallowed once again where it will pass into the next three compartments.

Sidebar here: a camel is a pseudo-ruminant because it has only three compartments in its stomach, not the principle room, but

Now, notice God always supplies at least two witnesses, like fins and scales, split hoofs and chews the cud. The clean-unclean dichotomy is not an arbitrary list. The clean and unclean laws tell that every ruminant except for the specific example mentioned are clean. The reason the meat is clean is that the food has been digested multiple times, cleansing out the impurity, providing yet another comparison for the meditation process.

Leviticus 11:1-8

So, swine is the term that is used here generally for all porcine creatures, anything that is like a pig, the pig-kind, they are specifically mentioned in verse 7 as unclean because despite having cloven hooves, they do not chew the cud. When we try to determine whether an animal is clean or unclean, it has got to do both of those things. It has to have the cloven hoof and it has to also chew the cud. If it lacks one or the other, then it is unclean. Very easy to figure out.