Horse Feeding

 

General

The most significant difference in feeding horses as compared to other domestic livestock is the purpose for which they are used. The working horse must be regarded as an athlete. Unfortunately, there is very limited experimental information on the nutritional needs of the horse.

 

Digestive System of the Horse

  1. The upper part of the GI tract is similar to the monogastric
  2. At the lower end of the GI tract is its large fermentation organ, cecum (much like the rumen)
  3. Both the rumen and cecum contain bacteria that break down cellulose; however,
    1. Ruminants ferment feed at the beginning of the GI tract
    2. Horses digest cellulose at the end of the GI tract
  4. Ruminants and horses eat at different rates
    1. Ruminants can eat rapidly and “store” in the rumen for leisurely rumination later
    2. Horses must eat more slowly to not force feed through the GI tract too rapidly (before digestion is complete)
  5. Forcing feed through the GI tract too rapidly can cause undigested feed to enter the cecum, and starch residues will be fermented rapidly, causing excessive gas production

 

Digestive Physiology

  1. The horse is a nonruminant herbivore that utilizes a significant amount of microbial fermentation in the hindgut (cecum).
    1. This hindgut fermentation is primarily for fibrous feeds.
    2. The principle microbial inhabitants of the equine gut are similar to the rumen of ruminant animals.
    3. Therefore fermentation results in the production of CO2, CH4, and VFA (acetate, propionate, and butyrate).
    4. Methane production in the hindgut is less than in the rumen, and is equivalent to less than 3% of the total energy intake.
  2. VFA’s are readily absorbed in the hindgut.
    1. 30% or more of the energy utilized by the horse can come from VFA’s.
    2. Propionate can also result in a significant amount of glucose production.
  3. Fiber is not utilized by the horse as efficiently as cattle because horses have a faster rate of passage.
    1. Therefore the microflora do not have as much time to digest the fiber.
  4. Bacteria in the hindgut also produce protein and water soluble vitamins, but the utilization of these products is not efficient.