EQUINE DIGESTIVE TRACT
Takes about 3 days for food to move
from mouth to rectum. Exercise &
excitement can affect this time frame.
- Mouth (start
of digestion)
- Teeth: masceration = chewing
- Saliva:
contains water to soften food & enzymes (ie. Amylase breaks down
starch)
- Esophagus
- Musculomembranous
tube (muscular tube that is soft & pliable) to the stomach
- Food
only moves 1 way down this tube (horse cannot throw up)
- 50-60
inches long
- runs
along the left side of the trachea & passes thru the diaphragm to the
stomach
- Stomach:
in horses it is a large dilation (enlargement) of the alimentary tract
(digestive tract) between the esophagus & the small intestine
- Holds
only 2-4 gallons & works best about 2/3 full
- Digestion
in stomach is due to
- acid production
- the
enzyme, pepsin, that can work in the acid environment
- Small
intestine
- Immediately
after the stomach
- About
70 feet long, very looped & folded
- Lined
with villi which are little folds that increase the surface area of the
lining where nutrients are absorbed from the food being digested
- 3
parts in order: duodenum, jejunum, ileum
- nutrients
are broken down & absorbed into the bloodstream in the small
intestine, especially carbohydrate, protein, fat & mineral
- Enzymes
from pancreas & bile from liver enter small intestine
- enzymes
from pancreas: lipase (breaks down fat), amylase (breaks down starch),
lactase, sucrase, maltase & isomaltase (break down sugars), trypsin
(breaks down protein)
- Bile
produced in liver (in horses) emulsifies fat into globules so that
enzymes can act on them
- Large
intestine
- Is
NOT lined with villi but has folds
- About
25 feet long
- Where
bacteria degrade cellulose from diet & bacteria also produce certain
amino acids & vitamins
- Small
intestine leads into large intestine.
- The
parts of the large intestine in order are cecum, large colon, small colon
& rectum.
- Cecum
- About
4 feet long
- 6-7
gallon capacity
- plant
fiber broken down by bacteria
- Large
colon
- About
12 feet long
- Last
of nutrients are broken down here & absorbed
- Small
colon
- About
10 feet long
- Water
is absorbed
- Manure
balls are formed here
- Rectum
(anus) about 1 foot long