Helping Animals and their people live healthier lives
REASONS NOT TO FEED STRAIGHT ALFALFA TO YOUR HORSE!
Alfalfa hay generally runs at least 18-20% protein, often higher. Not all of this protein is usable, as we will discuss later in this article. A mature working horse only requires about 12% protein. Dr. Michael Glades concluded after a study at the University of Maryland that horses with excess protein in their diets ran slower race times than horses receiving the NRC recommended amounts. He found that for each 1000 grams of protein that a horse ate above his basic needs, the racing times slowed 1 to 3 seconds.
Dr. Kerry Ridgway points to an all-alfalfa diet as the cause of higher body temperature in working horses, caused by the extra work required by the internal organs to convert the protein to usable energy. He feels this leads to excess sweating and electrolyte loss, which can in turn lead to dehydration, impaction and colic.
*Hypothyroldism, thumps, bad attitude.
According to Dr. Kerry Ridgeway, the excess calcium in an alfalfa diet interferes with parathyroid function and can lead to "thumps", muscle cramps and tying up.
Excess calcium interferes with absorption of iodine, a mineral necessary for proper thyroid function. Many horses on alfalfa become hypothyroid - the thyroid gets lazy. Symptoms can be a cresty neck, a horse that gets overweight very easily, develops dry and flaky skin, etc. Some breeds show hypothyroidism by becoming very "cinchy" and skin-sensitive, getting cranky when being groomed, or losing topline muscle and hair condition. Mares that are hypothyroid often become infertile.
Horses that are hypothyroid may be very plump and shiny, but are unhealthy. They are simply retaining water in the tissues, and this inhibits proper movement. Ask any woman with P.M.S. how she feels when she is retaining water! If your horse is cranky and belligerent, resists bending and flexing, is very lazy or reacts emotionally, it may be hypothyroid.
Researchers at Colorado State University and in Sweden reported on the effects of excess dietary protein on T4 thyroid hormone levels. Feeding protein above daily requirements decreases the T4 levels; optimum T4 levels are necessary for horses to metabolize glucose (blood sugar) properly. Glucose is the energy source used for work, and higher glucose levels are necessary during strenuous exercise. Higher glucose levels also delay the onset of lactic acid buildup in the muscles and blood. Lactic acid buildup causes the muscles to lose their ability to contract and relax properly, and to stay in a contracted (tied up) state.
The excess calcium in alfalfa suppresses the magnesium levels in the body. Magnesium is necessary for muscles to relax properly after the contraction phase. In the Colorado and Swedish studies, higher magnesium levels were found to increase the T4 thyroid hormone production. Mares and fillies are especially prone to tie up on alfalfa, since they become magnesium deficient when estrogen levels inrease during their heat cycles. Supplementing magnesium is often helpful.
*Kidney problems and scratches
If your horse's stall smells like ammonia, he is in trouble. Some of the protein in alfalfa hay is actually converted to non-protein nitrogen (urea) and/or nitrates, which are toxic to horses. In an effort to get rid of excess protein and these related substances, the body produces ammonia. This is very hard on the kidneys, and can also lead to respiratory problems from inhalation of the ammonia fumes. Healthy urine should be clear, not cloudy and foul-smelling.
The tiny tubes in your horse's kidneys will, over time, get clogged with the excess protein in alfalfa, and then the calcium will begin to form kidney stones. Alfalfa is particularly hard on aging horses - Karen E. Hayes, D.V.M., feels that no horse over age 15 should have any alfalfa at all.
Scratches, which are areas of open, oozing sores usually occuring on the pasterns and legs, seem to be related to increased photosensitivity. When the scratches are on white areas of the body, removing alfalfa from the diet usually clears them up.
When the body uses excess protein for energy, it snips off the nitrogen end of the protein strand before sending off the other amino acids for metabolic chores. In horses, this excess nitrogen forms urea (non-protein nitrogen) that is removed from the bloodstream via the kidneys and goes out in the urine, as was discussed above. To excrete the large amount of urea, the horse has to drink more water and urinate more frequently. Stalled horses will have soggy bedding which leads to hoof problems, thrush and discomfort (as well as more labor) and will be breathing ammonia fumes which lead to respiratory distress. There is also increased probability of dehydration during hot weather and endurance/performance events, because plasma ammonia is so toxic to the system that the need to urinate it out will outweigh the body's need to hold onto the water for hydration. These horses will also have thick, foamy sweat which does not cool them as effectively as the thin, watery sweat, so they sweat more which further dehydrates the body.
*Increased incidence of disease
Dr. T.W. Swerczek at the University of Kentucky feels that a diet high in protein and low in fiber can predispose stressed horses to become ill. Among the disorders he listed are Potomac horse fever, strangles, salmonella, ulcers, abortions, epiphysitis, etc. Stress factors can be weather, hauling, competing, even changing pasture companions.
Dr. Swerczek experimented with the diets on research horses that he infected with strangles. He divided them into two groups, and fed one group alfalfa and the other group grass hay. The horses fed alfalfa became so ill that even vaccines and antibiotics did no good. Yet, when he took away the alfalfa and high protein supplements, the disease disappeared on its own. The horses on grass hay experienced a very mild case of strangles that did not require any treatment.
He also feels that in the lactating mare, if the mare's kidneys are overloaded with high protein, the toxic metabolic wastes may be passed on in the milk and affect the health of her foal. Unhealthy foals with lowgrade colic or muscle aches from coughing can develop abnormal holding patterns in their bodies, which lead to faulty muscle development and crooked legs.
California and the west where straight alfalfa diets are common have the highest incidence of "stones" in the country. Intestinal stones are formed from ammonium magnesium phosphate. The ammonium comes from the excess protein in the alfalfa. Another contributing factor is the low fiber in alfalfa, which keeps the gut from functioning properly and allows the stones to form. Dr. Robert Bray at Cal Poly University recommends cutting back on the alfalfa portion of the ration as a means of helping to prevent stones. Research has shown that horses with a history of forming stones cannot tolerate any alfalfa without a recurrence.
*Developmental Bone Problems / Disease
Too much calcium, as found in straight alfalfa hay, interferes with the absorption of copper and zinc. These two trace minerals are important for healthy bones. Too much calcium can also lead to a calcium deficiency, strangely enough. When the circulating levels of calcium are too high in the blood, the body has an automatic mechanism which kicks out the calcium before it can be used to build strong bone. Because much of the calcium in alfalfa is unusable by the body, it can either lead to an actual calcium deficiency, or be deposited in inappropriate places as splints, spavins, etc. The safest form of calcium supplementation is a supplement of amino acid chelated (bio-available) calcium, combined with chelated trace minerals.
Researcher T. J. Hulland, a researcher at the University of Guelph-Ontario, feels that most "contracted tendons" in young horses are the result of contracted muscles in the forearm and gaskin. The tendons and ligaments themselves are not capable of shortening, but it is possible for a young horse that is getting too much calcium and protein to have the tight muscle, or borderline "tie up" condition described previously. If the problem is caught early on, dietary changes can often prevent permanent damage. By reducing the protein content of the ration (diluting alfalfa hay with mostly grass hay) and bringing the calcium/phosphorous ratio closer to the ideal 1: 1, and providing balanced minerals in a usable form, the foal is allowed to develop more normally. A magnesium deficiency, again caused by a calcium excess, can also cause the tight shoulder/gaskin muscles and cause the limb structure to become too upright.
Another bonus associated with a diet of primarily grass hay is the high levels of organic silica found in grass. This mineral is necessary for bone and connective tissue (collagen) to be properly formed. It is also essential for calcium absorption as bone is being formed. Current research is being done at Texas A & M University on the benefits of adding silica to the diets of growing horses. (An additional benefit of feeding grass hay - your horse's teeth may not need to be floated as often - the silica content of grass hay tends to keep the sharp edges worn down.) Bone is a living organ, constantly being formed and remodeled according to the mineral content of the body and the stresses placed upon it. Proper mineral balance is important!
Because alfalfa is very rich, it is not feasible to allow horses free access without them becoming much too heavy. Problem is, alfalfa is also quite low in fiber. Horses need adequate fiber in order for their digestive system to function properly - they are designed to be nibbling constantly and to have some fiber in the tract at all times. When they eat alfalfa, they usually are done in a hour or so, and then nothing is entering the tract until the next feeding, usually many hours later. This scenario predisposes a horse to colic. With quality grass hay, the horse is able to "graze" on it all day, and does not become ravenous and gobble feed. If proper digestive aids (probiotics, yeast cultures) are included in the ration, the animal is satisfied with less feed and does not develop a "hay belly".
A by-product of protein digestion is acid. A horse that is on a high alfalfa diet produces excess acid. Equine bodies, like ours, need to be on the alkaline side in order to survive; a high protein diet triggers some emergency responses in the system. Since minerals are mostly alkaline, the body will pull minerals from the tissues and bones in order to buffer the acids in the bloodstream so that the heart can keep functioning. To the body, the heart has a higher priority than strength of bones and ligaments. As the tissues and bones become demineralized, ligaments become slack. You may hear clicking in the joints, and the horse will maybe develop a sore back because the muscles are having to do the work that the ligaments should be doing. As time goes on, the body will try to stabilize the joints by building up calcium deposits, and you will see osselets, spavins, navicular, etc. The stage is set, and the horse becomes more and more unsound. A lower protein diet (grass hay and plain grain) with proper mineral support can help prevent this scenario, and perhaps even reverse some of the damage.
We need to reevaluate our ideas of what a fit, healthy horse looks like. Much of the technology being used in horse feeds is from the cattle and livestock industry, where high protein rations, sugar and thyroid inhibitors such as alfalfa, molasses and linseed meal are used to fatten animals for slaughter or to increase milk production. Problem is, a fat steer is not expected to remain sound for 20+ years, to bend and flex and travel freely, and have a trainable attitude! Many halter and pleasure horses, especially young futurity horses, are pushed beyond their genetic and nutritional capacity and end up being unsound at a very early age. Many horses that are considered "untrainable" or high strung are simply physically and emotionally out of control due to thyroid or other metabolic nutritionally-induced imbalance.
Dr.KarenHayes,D.V.M.,states, "Under no circumstances should the amount of alfalfa in yourhorse's diet ever exceed 40% (by weight). Any more than that and you are risking the perils ofexcess protein and excess calcium, both of which can do some unbelievable damage. If yourhorse's ration consists of 100% alfalfa, he may look healthy, but that does not mean it isn'ttaxing his system. "
We recommend top quality grass hay with perhaps a little alfalfa (maybe up to 20%) added for lactation and in some cases for growth. Feed plain (without molasses) grains such as oats, corn and barley mixed. Combined with balanced minerals in a bioavailable (chelated) form, and the proper use of digestive aids to maximize feed utilization, this diet will produce healthy athletes that are sound in body and mind. Your horses will thank you!
We can advise you about the supplements available to balance your ration for your particular needs. We have over 20 horse products available for maintenance, training, breeding and growth, and high performance. We look forward to working with you!
Bray, Dr. Robert E. "Enteroliths: A Potential Problem With Horses". Article prepared for EquiTech Conference, Los Angeles, CA. Nov. 1993.
Susan Garlinghouse, MS "Alfalfa for Distance Horses", Endurance News , Nov 2000
Hayes, Karen E. N., D.V.M. "Don't Let DOD Derail Your Foal", Modern Horse Breeding, May 1992.
Hayes, Karen E. N., D.V.M. "The Great Hay Debate", Horse and Rider
Hudson, Mary "Subtle Signs Of Lameness In Foals And Weanlings", Modern Horse Breeding
Smith, Carin A., D.V.M. "is Your Horse Hypothyroid?" Horse Illustrated January 1994
Stewart-Spears, Genie "Disease Linked To Nutrition", The Chronicle of the Horse, January 1992
Thompson, Diana "Too Much Of A Good Thing", AERC Endurance News, October 1992
Vandergrift, Bill, PhD. "Helping Horses That Tie Up", Modern Horse Breeding, September 1994
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