The digestive system

00-10-foal

The horse is a single-stomached animal that shares with the ruminants (cattle, sheep and deer) the ability to digest fibrous plant materials. The stomach is small and is not the main site for digestion, whereas the large intestines situated within the hindgut comprise the majority of the digestive system. The hindgut digests through fermentation and thus the horse is classified as a hind gut fermenter. Some basic information on the physiology of the equine digestive system is given in the table below.

Length, volume and passage time through different parts of the digestive tract of a 500 kg horse

 

Length in meters

Maximal capacity in litres

Passage-time

Pharynyx

Up to 1.5

 

10 - 15 seconds

Stomach

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18*

1 - 5 hours

Small intestine

16 - 24

64

1.5 hours

Caecum

1

34

7 - 15 hours

Colon

6 - 8

96

8 - 16 hours

Rectum

0.2 - 0.3

---

1 - 2 hours

TOTAL

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20 - 30 hours

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*Normal volume about 1/3 of maximal capacity