Question
Polly is my eight-year-old, 15-hand (152 cm) Quarter Horse mare. She weighs about 1,050 lb (475 kg) and is in moderate body condition (score of 5). She’s used as a barrel-racing mount. She spends most of her time on pasture (12-14 hours) and is kept in a large run the remainder of the time, where she is fed 2 lb (0.9 kg) of COB (corn, oats, and barley with molasses) top-dressed with a digestive supplement and 8 oz of flaxseed. She gets free-choice grass/alfalfa (lucerne) hay when she’s still in her run. While Polly looks healthy, I am unable to keep her sound for daily riding and weekend barrel-racing events due to muscle soreness. Because I have already spent a lot of money on diagnostics and various treatment modalities (chiropractic, osteopathic, massage), I wonder if nutrition could be causing muscle soreness. I would appreciate any insight.
Answer
Horses that suffer from muscle myopathies, such as recurrent exertional rhabdomyolysis (RER) and polysaccharide storage myopathy (PSSM), often benefit from a diet low in starch and sugar (cereal grains such as corn, oats, and barley) and high in fermentable fiber and fat. Studies have found that switching from a traditional sweet feed to a feed containing energy sources predominantly from fat and fiber (beet pulp, rice bran, vegetable oil, and alfalfa meal) resulted in less muscle damage after exercise and reduction in muscle pain and stiffness.
Many Quarter Horses suffer from PSSM, and diagnostic testing is available for those that have a certain form of the disease. A veterinarian can help you determine if PSSM is a problem with Polly. Appropriate feeding strategies can be put into place if she’s found to have PSSM.
Using the information I have at hand, I am interested in the small amount of grain Polly receives (2 lb or 0.9 kg per day). When competing and traveling, does she receive more grain? Because of the lack of fortification in the COB, Polly is receiving less than the recommended amount of minerals and vitamins.
There are a couple of ways to provide Polly with the additional vitamins and minerals needed for optimal health and performance: feeding a ration balancer pellet; adding a concentrated vitamin and mineral supplement to the current amount of feed, like Micro-Max (available from KER Targeted Nutrition in the U.S. and other areas; choose Gold Pellet from KER in Australia); or selecting a concentrate feed that has a higher micronutrient fortification level and feed at the recommended amount, often at least 4-5 lb (1.8-2.3 kg) each day.
Unrestricted forage diets fed at greater than 1.5% body weight (15 lb or 6.8 kg per day per 1000-lb or 450-kg horse) typically provide enough calcium, phosphorus, and magnesium to meet requirements for both sedentary horses and those participating in light and moderate work. However, the only way to know exactly what your forage is providing Polly is to have a nutritional analysis conducted.
Nutritional strategies that may offer relief from muscle stiffness and soreness include feeding a complete and balanced diet, provision of daily electrolytes, changes in dietary energy sources, and the supplementation of antioxidants and anti-inflammatory compounds.
Nano-E is natural-source vitamin E supplement that, through its antioxidant properties, assists in post-exercise muscle recovery and in the prevention or reduction of muscle soreness in performance horses. Nano-Q10 features the antioxidant coenzyme Q10, which is involved in the production of energy. Like vitamin E, coenzyme Q10 is a powerful antioxidant that protects cells from chemicals called free radicals that can damage cells and their DNA. Besides providing direct antioxidant protection, coenzyme Q10 improves the antioxidant potential of other antioxidants in the body, like vitamins E and C. Both Nano-E and Nano-Q10 feature nanodispersion technology, which makes them incredibly bioavailable. In Australia, also look for Preserve.
Supplementing with fish oil offers a concentrated source of the long-chain omega-3 fatty acids DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which have potent anti-inflammatory actions and have been shown to reduce inflammatory markers in the horse. As you are currently feeding flax, you are offering a source of omega-3s, known as alpha-linolenic acid (ALA); however, this short-chain omega-3 requires the conversion to DHA and EPA to be most beneficial, and the horse has a limited capacity to complete the conversion process. Based on your information, I feel it would be warranted to offer additional anti-inflammatory support. EO-3 is the preferred fish oil supplement for horses, and I would recommend feeding 30 to 60 g per day.
As I mentioned at the beginning of the response, there is a possibility that Polly might have PSSM. If this is confirmed through laboratory testing, her diet will have to be reworked, this time with an eye toward reducing starch and sugar content. Polly’s energy, vitamin, and mineral needs can be met through the use of Re-Leve, a research-proven feed for horses with low-starch needs.
