saying they were "chewing the cud" is just fine since the terminology back then was not based on modern science, but based on superficial appearances.
So in matters of science we shouldn't read the Bible word for word literally since it was aimed at people who didn't have the knowledge that we have now. It is, in other words, simplified for them and, while correct by the knowledge of the time, wrong based on our much better understanding of the world.
There is, of course, only the appearance of cud chewing. It is not cud chewing, it is not pseudo cud chewing, it isn't something a non ruminant can do.
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