Nutrition Series Part 3
How to Safely Feed Concentrates
By Dr. Amanda Wilson
Since the domestication of the horse, humans have fed horses "grains" or concentrates. Historically they were fed as whole products: oats, barley, corn, etc. In the past century equine nutrition research has made leaps and bounds in learning about the requirements of horses and equine feed companies have formulated feeds to meet each horse's specific needs.
Concentrates are a good source for energy, protein, vitamins, and minerals. They are a good addition to a nutrition program for horses that have requirements that can't be met completely by forages. Some types of horses that require concentrates are: growing horses, working horses, broodmares, stallions during breeding season, and senior horses that can't chew hay well. Concentrates supplement the forage component of the diet in order to meet the horse's requirements.
When fed in appropriate amounts, concentrates are safe for horses. However, if horses are fed too much or before they have a chance to adapt to increased amounts, grain can cause serious digestive upset and other health issues. A good rule of thumb is that a horse should eat no more than 0.5% of his body weight in concentrates in one meal. For a 1,000 pound horse this means no more than 5 pounds of grain per meal. If the horse's daily requirements call for more than 5 pound of feed, this must be split over multiple meals throughout the day.
For this reason, equine nutritionists recommend keeping a scale in your barn to weigh feed. This helps ensure that your horse is getting consistent and correct amounts. It also accounts for different feeds having different weights. A scoop of sweet feed does not weigh the same as a scoop of Senior feed. This way, if you decide to change the type of grain you feed your horse you know the weight, rather than the "scoop."
What can happen if a horse is fed an excessive amount of grain at one time? The grain will pass quickly through the small intestine into the large intestine. In the large intestine, rapid fermentation will occur because of the bacterial population that lives there. This causes an increase in acid production, a change in the pH of the gut, and death of the "good" bacteria. When these bacteria die, they release toxins into the bloodstream. These toxins cause a condition known as "endotoxemia," which can lead to organ damage, colic, and laminitis. If your horse gets too much grain in a meal, call your veterinarian immediately to begin treatment aimed at reducing the effects of the toxins.
When used correctly, grains can be an important component of your horse's diet. The key is to select feed that is appropriate for your horse's life stage and level of work and feed it at the correct amount. As your horse's work level or life stage changes, consider gradually switching to a different feed. For further information on choosing an appropriate feed, contact your veterinarian or an equine nutritionist.