I know this is an old post, but I don't believe it's reasonable to accuse the bible of error because it does not adhere to a modern man-made classification system.
Consider what rabbits do. Rabbits normally produce two kinds of feces, the more common hard feces as well as softer fecal pellets called cecotropes. Cecotropes are small pellets of partially digested food that are passed through the animal but are then reingested. As part of the normal digestive process, some partially digested food is concentrated in the cecum where it undergoes a degree of fermentation to form these cecotropes. They are then covered in mucin and passed through the anus. The rabbit ingests the cecotropes, which serve as a very important source of nutrition for the animal.
Cud-chewing completes the digestion of partially digested food. Why would it be strange to think that centuries ago, the idea of “cud” had a somewhat broader meaning than a modern definition.
But does the rabbit actually chew the cud? The Hebrew word translated “chew” is the word‘alah. With any attempt to translate one language to another, it is understood that there is often more than one meaning for a given word. A cursory glace at any Hebrew lexicon reveals that‘alah can mean go up, ascend, climb, go up into, out of a place, depart, rise up, cause to ascend, bring up from, among others. Here it carries the implication of moving something from one place to another. So the phrase translated to English as “chew the cud” literally means something on the order of “eats that which is brought forth again.”
Just figured I'd throw that out there.