Well, I called my father, shlita. I will try to relay what he explained
to me:
1. The posting is accurate. The process with which a cow gets its
nutrients (chewing the cud) and how a rabbit gets its nutrients
(coprophagy) are basically the same. A cow (and other species which
"chew the cud") has an enzyme in its digestive tract in the first
chamber of the stomach (the rumen). This enzyme breaks down the food and
the animal proceeds to eat a kind of "bacteria soup" made up of the
nutrients broken down by the enzyme from the "first" eating. The rabbit
and other similar species, which does not have a rumen with the enzyme
to break down the food, accompishes the same process externally -
outside the body. After eating and excreting, the bacteria in the feces
contains the nutrients broken down from the food already digested by the
rabbit. By eating the feces, the rabbit again ingests the nutrients -
just like the cow.
2. A second explanation which my father, shlita, finds quite credible
is that "shafan" and "arneves" are from the camel and llama families
(which chew their cud). My father saw in a sefer from a rov in Germany
that the yiddish word for rabbit is "huz" which this rov traced to its
arabic origins to mean "little camel". How yiddish picked it up to use
for rabbit is probably complicated and needs a lecture on semitic
languages to understand. In any event, under this approach, "shafan" and
"arneves" have nothing to do with the rabbit or similar species. My
father brings a "siyua l'dvorov" of this rov from the Gemara in Chulin
59 which shows that "shalit b'olomo yodea" - that Hashem, as the Supreme
Ruler of His world knows His creations - from the fact that the Torah
testifies that a "shafan" is the only species that chews its cud but
does not have split feet. Well, what about the other species mentioned
in the same parsha, like "arneves"? The traditional answer is (I don't
have any seforim with me now, so I'm not sure where this is brought
down) that the Gemara, by saying "shafan", means all of the species
mentioned in the pesukim there along with "shafan". But according to
this rov, if all of those species are members of the "little camel'
families, it makes very good sense that the Gemara just mentioned
"shafan" or the arabic "huz" meaning "little camel", and of course all
other little camels are included.
Gemar Chasima Tova
Yosey