Equine Digestive System Function To break down food

Equine Digestive System

Function • To break down food molecules into smaller molecules the body can absorb • Fuels the bodies activities;

How does digestion occur? • Mechanical Digestion- physical breaking and tearing of food (mastication) • Chemical Digestion- acidic breakdown of food

Where does it all start? 1. Horses Mouth! – Incisors and lips are used to grasp food and bring into the mouth – Pre-molars and molars are used for grinding the food Saliva starts chemical digestion

• 2. Down the esophagus the food goes! – Hollow, tube like structure ringed with muscles – Swallowing is a chain reaction of the muscles contracting to push the food into the stomach – 4 -5 feet long

3. Stomach • Horses have a stomach similar to humans • Muscular organ that contracts to squeeze food • Produces acids to chemically separate foods into their individual component Small, can’t contain a lot of food at one time (Mgmt) 8 - 17 QT capacity Food only stays here 15 min

4. Small Intestines • This is were nutrients are absorbed – Beginning of the SI continues to break down food into its basic nutrients (fats, carbs, proteins, vitamins, minerals, water) • as it progress through the length of the intestine, the nutrients are absorbed across the lining and into the blood stream. 70 ft. long, 48 QT capacity 30 -90 minutes

5. Cecum • Horses are considered to be modified monogastrics (1 stomach) – Modified because they have a cecum • An enlarged pouch-like structure located at the beginning of the large intestines • Contains microbes (bacteria and protozoa) that break down hay and grass 4 feet long, 28 -32 QTS several hours

Cecum, cont • An odd shaped organ, the entrance and exit are both located at the top – Can cause problems if the horse doesn’t drink enough water • Compaction= pain= colic

Large Intestines • 6. Large Colon – Absorbs the nutrients from the hay/grass – Contains microbes – 10 -12 feet long, 80 QTS

Large Intestine • 7. Small colon – 10 -12 ft long, but only 10 cm wide – Materials that are not digestible by the horse are left (everything else was digested) – Removes moisture from what is left » Feces

8. Rectum and Anus • Storage area for feces (1 ft) • Exterior opening to remove feces from body • Digestive process takes from 36 -72 hours to complete

Management Issues • Gastro-intestinal tract of the horse is very sensitive – Must change food slowly over 7 -14 days to give the microbes a chance to adjust – Colic is a major concern. Twist in the gut, impaction, blockage