Coprophagy and Caecotrophy
Prologue:
Often it is reported that rodents eat their "poops" (faeces) and rodent owner wonder about this odd behaviour. However coprophagy plays an important ecological role for rodents and other small mammals and enables them better to deal with resources. Therefore this behaviour is widely spread among small mammals.
Definition of terms:
Caecotrophy and coprophagy often are used as synonyms, but there are differences:- Coprophagy (from greek kópros = dung, and phagein = feeding) is a general term for feeding faeces and it doesn't discriminate between own faeces or foreign faeces feeding.
- caecotrophy (from greek caecum = blind gut, and trophé food, diet) describes the ingestion of own caecum faeces (caecotrophe). This is a special faeces produced in the blind gut (caecum) rich in nutrients. In leporids (hares, rabbits etc.) it differs considerably from the normal hard faeces, because it is softer and coated with mucus layer. In contrast this both sorts of faeces aren't distinguishable in chinchillas and degus.
Coprophagy in rabbits and hares
Interesting insights about coprohagy in rabbits and hares are reported by Hirakawi (2001) in a review published in the British Journal "Mammal Review". One of the main issues is the feeding of hard faeces (not soft faeces as usually reported). In contrast to the soft faces they aren't swallowed at once without chewing and it isn't distinguishable from other foods in the gut. Hard faeces are fed by leporids when food is lacking, also during resting periods, when animals do not forage and ingest fibrous diets low in nutrients instead. Another vital issue is a so called colonic separation mechanism (CSM). It enables the proximate colon to discriminate between coarse food particles and small particles and it sorts out the former ones passing them through the gut and retain the latter ones by retrograde motion along the gut walls. This leads the energy rich, small particles to the blind gut where it is fermented by microbials and used for caecotrophe production.
Coprophagy in rodents
This issue isn't as detailed explained in the review, but it gives here a good overview and some interesting details as well.
For instance is caecotrophy more developed in herbivorous rodents than in close relatives relying mainly on granivorous or frugivorous diets.
Coprophagy in Chinchillas
I quote this part as there isn't much the review has to tell us about:
Quote:
The Chinchilla (Chinchilla lanigera) (body weight: 0.36-0.48 kg) feeds in the night and reingests during the daytime like leporids. About 50 % of the daily faeces are thus reingested. Daytime faeces contain significantly more nitrogen that night-time faeces (Björnhag & Sjöblom, 1977; Holtenius & Björnhag, 1985). However, they are not mutually distinguishable (Björnhag, 1981b). The separation mechanism is probably at the proximal colon because of its structural similarity to that the Guinea pig (Holtenius & Björnhag, 1985).
Corrections
This extensive review was supplemented by some additional remarks and corrections, published later in Hirakawa (2002).
References:
Hirakawa, H. (2001): Coprophagy in leporids and other mammalian herbivores. Mammal Review 31: 61-80.
Hirakawa, H. (2002): Supplement: coprophagy in leporids and other mammalian herbivores. Mammal Review 32: 150-152.
Penzlin, H. (1996): Lehrbuch der Tierphysiologie. Fischer Verlag, Jena.
The review is available online and can be found e.g. by searching it with google scholar:
http://scholar.google.com/scholar?q=hirakawa+coprophagy
This text is a translation from a shortened version of this text:
viewtopic.php?f=12&t=101&hilit=coprophagy
Abstract in German / Kurzübersetzung:
Dieser Text behandelt das Thema Kotfressen und ist im wesentlichen eine gekürzte und etwas aktualisierte Version von diesem Text hier:
viewtopic.php?f=12&t=101&hilit=coprophagy
Statistik: Verfasst von davX — 14.10.2012, 23:16
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