A horse's digestive system is such that it has adapted over thousands of years to deal with huge amounts of long stemmed cellular roughage through microbial fermentation in the hindgut (caecum or large intestine). It is not particularly designed in a fashion that allows for the digestion of starches in the small intestine, as the level of enzymes in that particular area of the intestines is low, and it has leveled at some protein and fat absorption in that area.

Therefore, when we do feed them high levels of raw grain in the ration, a largely undigested proportion (containing high levels of starch) finds its way back into the large intestine and creates and increase of the acid levels in this area, which is the causative effect of a condition known as 'hindgut acidosis', or a rapid build up of gasses in the colon due to fermentation of starch in this region.

When absorbed into the blood excess starch acids also increases the risk of 'behavioral disorders'- horses suddenly shying, rearing, bucking, seeing pixies on the fence posts and any amount of fixated problems a horse seems intent on displaying at a moments notice for any equal amount of unexplainable reasons.

On the serious side of the coin however, it may also lead to a low-grade laminitis or founder. Horses on large amounts of raw grain and in training (exceeding 5kg daily), are also quite likely to develop symptoms of sore feet, white line separation and a shortened or 'choppy' stride due to a low-grade laminitis. As well, young horses are more prone to ‘tying-up’ when fed raw grain rather than extruded.

Extrusion, (unlike micronisation a completely different 'cooking' process) is a controlled moisture and pressure (pressure cooking) method combines to rapidly heat and cook the starch and protein content of cereal grain and oil seeds. The cooking temperature is strictly controlled to avoid any over processing or burning the protein and fat content in the grain. Then the cooked grain is quickly cooled to remove any retained heat so it does not continue to 'cook', and to also minimize damage to the vitamin content of the grain.

The extrusion process expands the starch particles, and opens the way for a more direct and therefore efficient digestive enzyme attack on the gram starch and proteins as the food mass passes through the small intestine.

Any number of grains are nowadays extruded, and Barley grain appears to be the primary candidate for the process. By doing so the increase of starch digestibility is increased from around 23% for raw grain, to above 65% for extruded. Boiling barley also has a marked benefit over raw grain in that the digestibility factor rises double (to about 50%) that of the raw unprocessed gram. However, the boiling process is not controlled in our own kitchens, and lot of the natural vitamin content is damaged or ‘cooked out’, and is then not available for uptake, plus, it is a time consuming job, although personally I do not find it a problem.

• Some of the benefits for using extruded grains in our horse's rations are -
  
  More efficient digestion and utilisation of the grain, and therefore the ration.

• 
  They provide a cool energy source with less behavioral disturbances. Improves the safety of grain feeding as cooking kills harmful bacteria and eliminates any anti-nutritional factors present in the grain, especially protein grains such as soybeans and peas.

• 
  Extruded feeds also reduce wearing on the teeth; and aged horses find it a convenient source of ‘easy pickings’, compared to those that have to chew and grind levels of hard or raw grains such as corn, sorghum or raw barley.

• 
  By feeding extruded grain it leads to a reduction in heat production through limiting excess starch being fermented and releasing heat in the hindgut. This in turn also results in the horse sweating less under hot conditions, better digestion, a reduction in the amount needed to be fed, saves money, improves palatability and reduces wastage.

• 
  Extruded feeds are suitable for all classes and ages, including foals and especially in aged horses where digestive function is often less efficient.
   

home

Mail: horseproblems@horseproblems.com.au