Cud chewers are generally classified as belonging to the order of ruminants- (a sub order of artiodactyls) - and are defined as an "even-toed animal that regurgitates and masticates its food after swallowing. " This means that a cow, for example, will eat vegetation and swallow it. The cow's stomach is divided into four chambers where some of more easily digestible nutrients are absorbed by the body while other more fibrous material is stored in the stomach and then regurgitated. The cow will re-chew this material and re-swallow it so that it can digest it as well.
Rabbits and hares, however, do not have a chambered stomach such as the cow. They also do not regurgitate their food. What they do perform is a function named cecotropy. I will quote the process as cited at http://www.mhhe.com/biosci/genbio/rjbiology/ELOs/ELO45.html
Read more: http://www.comereason.org/bibl_cntr/con055.asp#ixzz1dEJMjX9M
Bacterial Digestion of Cellulose Within Animals - Vertebrates lack enzymes to digest plant material. Some bacteria can do so and are harbored by animals... Rats and rabbits redigest cellulose another way. [They] eat feces and literally redigest them a second time. Efficiency approaches that of ruminants.
In a more detailed version, Margert "Casey" Kilcullen-Steiner, (M.S., L.A.Tg) writes:
http://microvet.arizona.edu/Courses/MIC443/notes/rabbits.htm
Rabbits are sometimes called "pseudo-ruminants"... The rhythmic cycle of coprophagy of pure cecal contents practiced by all rabbits allows utilization of microbial protein and fermentation products, as well as recycling of certain minerals. Whereas the feces commonly seen excreted by rabbits are fairly large, dry and ovoid, excreted singly, and consist of fibrous plant material, cecotrophs are about half that size, occur in moist bundles stuck together with mucus, and are very fine textured and odiferous. They are seldom seen, as the rabbit plucks them directly from the anus as they are passed and swallows them whole. Normal rabbits do not allow cecotrophs to drop to the floor or ground, and their presence there indicates a mechanical problem or illness in the rabbit.
And Janet Tast, D.V.M. notes:
http://www.ultranet.com/~hrs/artcl03.htm
"One may not give much thought to the lazy chewing of the cud that we observe cows doing all the time, but this behavior is analogous to coprophagy. The only difference between cud chewing and coprophagy is the point in the digestive tract at which nutrients are expelled and then placed back into the mouth."
Rabbits and hares, however, do not have a chambered stomach such as the cow. They also do not regurgitate their food. What they do perform is a function named cecotropy. I will quote the process as cited at http://www.mhhe.com/biosci/genbio/rjbiology/ELOs/ELO45.html
Read more: http://www.comereason.org/bibl_cntr/con055.asp#ixzz1dEJMjX9M
Bacterial Digestion of Cellulose Within Animals - Vertebrates lack enzymes to digest plant material. Some bacteria can do so and are harbored by animals... Rats and rabbits redigest cellulose another way. [They] eat feces and literally redigest them a second time. Efficiency approaches that of ruminants.
In a more detailed version, Margert "Casey" Kilcullen-Steiner, (M.S., L.A.Tg) writes:
http://microvet.arizona.edu/Courses/MIC443/notes/rabbits.htm
Rabbits are sometimes called "pseudo-ruminants"... The rhythmic cycle of coprophagy of pure cecal contents practiced by all rabbits allows utilization of microbial protein and fermentation products, as well as recycling of certain minerals. Whereas the feces commonly seen excreted by rabbits are fairly large, dry and ovoid, excreted singly, and consist of fibrous plant material, cecotrophs are about half that size, occur in moist bundles stuck together with mucus, and are very fine textured and odiferous. They are seldom seen, as the rabbit plucks them directly from the anus as they are passed and swallows them whole. Normal rabbits do not allow cecotrophs to drop to the floor or ground, and their presence there indicates a mechanical problem or illness in the rabbit.
And Janet Tast, D.V.M. notes:
http://www.ultranet.com/~hrs/artcl03.htm
"One may not give much thought to the lazy chewing of the cud that we observe cows doing all the time, but this behavior is analogous to coprophagy. The only difference between cud chewing and coprophagy is the point in the digestive tract at which nutrients are expelled and then placed back into the mouth."
