Feeding Tip: Be Careful of Change

The Horse's Digestive System

Building Blocks to Good Nutrition

Feeding Tip: When to Feed

Choosing a Ration

Tip: One Cause of Colic

Horses evolved as grazing animals, with digestive systems designed to slowly ingest a daily ration of 100% grass over a 24-hour period. It is important to understand that grazing is linked with almost continuous exercise, and that grass is about 60% water. In today's world, the domesticated horse may stand in a stall for 20 or more hours and only eat two meals of dry feed. For example, hay cubes have only about 10% water.

• At least half of a horse's diet should be forage, such as hay or pasture grass.
• Sudden changes in diet can put a horse at risk of colic. When changing from winter feed to summer feed, or changing to different feeds, do so gradually over a week to ten days.

Horses are "post-gastric fermenters." This means a large portion of the horse's digestion comes from the fermentation of fiber within the latter portions of the digestive system.

Illustration by Karen Kuchar KarenKuchar.com

• Fiber

  An important ingredient in your horse's diet is fiber. Horses use fiber as fuel. Fiber can provide all the energy needs for everyday metabolic functions like breathing, walking, grazing and sleeping. In addition, fiber helps to fulfill a horse's fundamental urge to chew, thus preventing vices like cribbing and wood chewing. Remember, "Horses are not 'grainivores', but herbivores." Dr. Clyde Johnson, VMD

  Without adequate fiber, your horse's digestive system will not function properly. Horses require fiber to move food particles efficiently through their digestive system. Insufficient fiber hinders the animals's ability to conserve water and electrolytes. In addition, without fiber in the system, high carbohydrate feeds may form into a compact mass in the digestive track. This could put the horse at risk for dehydration, impaction colic, and laminitis.

  Fiber should make up at least 50%, by weight, of a horse's daily diet. For a majority of horses, the percentage can be considerably higher. Pasture grass and hay are the most common sources of fiber. Sugar beet pulp is also a good source of fiber.

  Fiber content in pastures can fluctuate with climate, time of year, and soil quality. To find the fiber content of your hay, send samples to a lab for a nutrient evaluation. Your county extension agent can help you find a lab to provide the analysis for you.

• Protein

  Protein is probably the most misunderstood component of a horse's diet. It was long assumed that protein was an energy source for the body, however research has indicated that protein is a poor energy source, but essential to the growth and repair of body tissues.

  When a horse ingests protein, it is broken up in the digestive tract into individual amino acids which can then be absorbed through the wall of the small intestine into the bloodstream. From there, they travel to the sites where they are most needed for growth or repair of tissues.

  Young horses who do not receive adequate amounts of protein can suffer a number of ill effects, including decreased growth and muscle development, reduced appetite, body tissue loss, slow hoof growth, and poor hair coat. However, for adult horses, true protein deficiencies are quite rare and usually occur only when a horse is on very poor pasture or hay with no other supplemental feed for a prolonged period of time. With a corrected diet, most of the signs of protein deficiency in adult horses can be turned around in a short time. The damage done to a young, growing horse, however, can be more serious. Once the muscles have developed, a lack of protein can cause the muscles to decrease in size. This is caused by a loss of cell content even if the cell remains intact. Thus, in the developed horse, the cell content can be replaced by a good feeding program. In the young horse a lack of sufficient protein will inhibit the development of cells. If these cells have not developed, they can never be repaired. The result of protein deficiency in a young horse is not reversible.

  The amount of crude protein required in a diet depends on the needs of the individual horse. Remember, a growing horse requires more protein in their diet. Among the protein supplements, wheat bran is best because of its bulky nature and laxative effect. If you think you may need to add proteins to your horse's diet, talk with your equine veterinarian about your horse's needs and sources of high-quality protein supplements. Not checking with your veterinarian can be a costly mistake. Prairie hay is a very good source of protein as is alfalfa, but alfalfa is also high in calcium. This must be balanced in the horse's diet.

  The protein content of western grasses and eastern grasses are very different. There is empirical evidence that in some species, western grasses have more protein than similar appearing grasses grown in the east.

• Carbohydrates

  Carbohydrates and starches help provide extra energy, so that the horse can do the work you ask.

  Grains are the most convenient source of carbohydrates and starches. Simple (soluble) carbohydrates are glucose and other sugars which include the inner parts of the seeds or kernels. Complex (insoluble) carbohydrates are starches, fiber, and the less soluble portions of grains which are the outer parts of the seeds and the remainder of the plant.

  Grain products are called concentrates, and are composed of more soluble carbohydrates than roughage (hay, pasture). Most of the soluble carbohydrates are broken down and absorbed in the horse's small intestines. The insoluble carbohydrates pass on to the colon and cecum where they produce energy or are stored in various tissues as fat reserves for later energy production.

  If too much grain is ingested with too little hay, cecal acidosis can develop, causing diarrhea, colic, and laminitis.

  If feeding grain, feed small meals, allowing time for processing the carbohydrates before the system moves everything along to the cecum. The more carbohydrates that are digested in the small intestine, the less cecal acidosis results.

  Feeding Tip: "Chew Your Food Slowly"

  • If a horse eats extremely fast it may choke. A choke in a horse is a serious emergency problem. In a horse, a choke is when the esophagus is clogged and it can not swallow, unlike in humans, it is when the larynx is stuck and they can not breathe. Therefore when a horse is choking it is not as readily apparent but equally serious and requires the attention of your veterinarian.

  • If your horse tends to eat grain too rapidly, place several smooth stones that are 3-4 inches in diameter in the feed bunk. This slows your horse down and makes him chew the grain before seeking more.

• Fats

  Some research has shown that horses fed high-fat diets may have a performance advantage over horses on high-protein or high-carbohydrate diets. If you feel your horse's life style requires a high-level of performance or places unusual demands on your horse, talk with your veterinarian about a specialized diet. Be sure to also talk with your vet about re-adjusting your horse's diet when the demand for a high level of performance changes. It is important to work with an equine veterinarian to help you make necessary adjustments to get all the essential nutrition for your horse.

• Vitamins

  While horses require vitamins only in trace quantities, many factors can decrease the vitamin content of horse feed:

  • Vitamins E and A are sensitive to sunlight, heat, and oxidation
  • Hay stored for a year or longer, or that was rained on between cutting and baling, can have greatly decreased concentrations of these vitamins.
  • Pelleted feed products are processed using heat and pressure. If you are feeding pelletized hay, it is important to know if and how the natural vitamins were effected or supplemented.

• Minerals

  Use caution when supplementing minerals, the difference between the required amount and a toxic amount is small. Do not use multiple feed supplements. Be aware of exactly what a supplement contains and how much of it is already found in your horse's diet. "Most horses being fed quality food do not need supplements."

  Because the concentration of a particular mineral within a plant is proportional to the concentration in the soil, a soil analysis will help inform you of any supplementation your horse may need.

• Water, Electrolytes, Salt

  Water is the most important ingredient in your horse's diet. Two or three days without water can cause severe illness or death. The average 1,000 pound horse drinks over 18 liters (4.5 gallons) of water each day. A source of fresh, clean water should be available to your horse at all times.

  Electrolytes are usually present in adequate amounts in the horse's diet to take care of normal sweat losses. Unless your horse is sweating heavily, electrolyte supplementation is usually not necessary. As with all cases of a specialized diet, talk with your veterinarian first. If you and your vet decide to add an electrolyte supplement to your horse's water be sure to provide a source of water without the supplement. Some horses will not drink water with electrolytes added.

  White salt (sodium chloride) should be available at all times. In cold climates, be sure to prevent the water source from freezing in the winter. Offering room temperature water, when the ambient temperature is cold, will significantly increase a horse's daily water intake.

• When feeding a working horse, it is best to feed 25% of the required hay in the morning, 25% at noon, and 50% in the evening.

• Because forage in the horse's digestive system can decrease the amount of grain processed in the small intestine, it is best not to feed hay for an hour or more before feeding grain, or for three or more hours afterwards.

Most of the time your horse will tell you if he's receiving good nutrition. Factors include a shiny coat, good appetite, pleasant outlook, and good energy level. If you are feeding average to excellent quality forage and grain, you can be assured that your horse's diet will meet his daily nutrient requirements. If you feel that your horse is not getting the nutrients needed, ask your equine veterinarian to help you with the calculations to analyze what your horse might need in fiber, carbohydrates, fats, vitamins and minerals.

Your knowledge and observations are the key to your horse's good health care.

"The colic's that are not caused by parasites and come in the spring and fall often are caused by poisonous weeds".

Speaking Equine thanks Dr. Clyde Johnson, VMD and past president of AAEP for his tips to good horse care.

We strongly encourage horse owners to seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy. After all, it is your horse's life.