From sales yearlings to seniors, halter horses to endurance racing, building and maintaining good muscle is a concern. While a number of nutritional supplements on the market claim they can help you do that, be sure you have the basics covered before you spend a penny.
The horse can’t build and maintain good muscle without the raw material to make, fuel and repair them. Those key “ingredients” are:
Water and salt: Like all soft tissues in the body, muscle cells are mostly water, and they’re bathed in body fluids that are mostly water and carry nutrients, hormones and other signals to the muscle cells. Dehydrated horses look, and are, smaller.
Rule #1, fresh water, at a comfortable drinking temperature, at all times and a minimum of 1 oz. of salt/day in the winter. Increase to 2 to 4 oz. per day in hot weather.
Calories/Fuel: Muscles obtain most of the fuel they need to function and build from energy in the form of carbohydrate (glycogen) and fat they store right inside the cells. These energy stores also contribute to the muscle’s size.
Muscles are the body’s major consumer of glucose. Glucose is taken up from the blood and either burned for energy or stored as glycogen.
Glucose metabolites are also key steps in the burning of fats. Muscles store more glycogen than fat, because they can’t obtain enough from the blood to keep functioning when exercising. If the muscle runs short of glucose metabolites during work, it will begin to break down the protein in muscle cells to convert it to glucose and glucose metabolites.
After exercising, the horse’s muscle is primed to readily take up glucose to replace glycogen stores that were used. This natural ramping up of the muscle’s “hunger” for glucose can be used to rapidly re-feed the muscles by the correct feeding meals and supplements.
Rule #2, Maintain sufficient calories and carbohydrate to maintain energy stores and prevent protein breakdown with work.
Protein: Everyone knows muscles are high-protein. To build and maintain muscle the horse needs adequate total protein in the diet and sufficient amounts of key amino acids (the building blocks of protein molecules). Amino acids of particular importance to muscle are the BCAAs, or branched chain amino acids, of leucine, isoleucine, valine, lysine, and in the case of horses in extremely hard work, possibly arginine.
Rule #3, Provide adequate protein from varied sources for a good mix of amino acids, and consider a BCAA or HMB (a BCAA) supplement if the horse is still having problems with muscle mass.
Antioxidants: Working muscles generate large amounts of potentially damaging oxygen byproducts (oxygen-free radicals) when burning their fuels. Maintaining adequate levels of key antioxidants to neutralize these free radicals is essential to protecting the muscle cells from damage. Vitamin E and selenium are two of the most important.
Rule #4, Provide 2000 IU/day of vitamin E to horses in light work, 5000+ IU/day for horses in moderate to heavy work, and a minimum of 2 mg/day of selenium. Blood selenium levels should be checked to determine the individual horse’s requirements because there is considerable individual variation.
Vitamins and minerals: This is too big a topic to cover in detail in this article, but adequate levels and balances of vitamins and minerals is critical to nerve functioning, protein metabolism, energy generation, muscular relaxation and contraction.
Rule #5, Adequate and balanced vitamins and minerals are essential for muscular development, repair and function.
Exercise: You can pump the horse full of all the calories and protein you like without improving muscle mass if the horse is not being exercised. “Use it or lose it” definitely applies to muscle tissue. Even the muscle wasting in older horses (unless related to disease) can be largely prevented and even reversed with regular exercise.
Rule #6, Regular exercise with proper nutritional support builds muscles.
Fat vs. muscle: Your horse has a layer of fat under his skin, which can vary tremendously in thickness. If you aren’t familiar with truly fit horses, and how well-developed muscles look and feel, you can be easily fooled into thinking that a fat horse has good muscle bulk. The body condition scoring systems, like the 9-point Heineke condition scale used in this country, or the 5-point system of Drs. Carroll and Huntington used in Australia, are geared to the amount of fat the horse has, not muscle. Many people commonly think indicate good muscling, like the back and neck line from withers to poll, are actually prone to depositing fat. It’s entirely possible for a horse to put on weight, even be fat, and have poor muscle development underneath it. Conversely, a horse with little fat covering over his ribs may have excellent muscular development.
For our trial of muscle-building products, we used a variety of horses, from yearlings to performance horses to seniors. We evaluated the products in a range of settings: sales prep, poor muscular development in both young and old horses, horses training and racing having trouble holding and building muscle or even having low-grade muscular problems.
To evaluate the effects, we chose to measure forearm circumference, as fat in this area is usually minimal. Muscular development along the muscular arch of the neck and muscle belly definition along the chest and shoulder were assessed. Horses were also body condition scored according to the 9-point Heineke scale to check for any changes that might actually be due to increased body fat. Special attention was paid to the amount and texture of fat along the chest wall and over the ribs, since there are no large muscles under the skin in that area.
Vitamins and Minerals: To see the difference vitamins and minerals could make we took at a look at three products: PalaMountains Equine, Oxy-Equine and Sport Horse. Both switching to a vitamin-mineral supplemented feed and use of Oxy-Equine resulted in improvements in both body-condition score and muscling, with no added advantage to adding the Oxy-Equine to a diet already containing a supplemented feed. Sport Horse significantly improved body condition and muscling in two yearlings that were already receiving good quality hay and a vitamin/mineral supplemented grain. Try this first if there’s any suspicion your vitamin and mineral bases may not be adequately covered.
Gamma Oryzanol-based: Gamma oryzanol is a plant steroid with a structure similar to animal steroid hormones, including sex hormones. Its anabolic (muscle building) effects have not been well researched in formal studies but gamma oryzanol derived from rice bran oil is one of the most common ingredients in equine muscle supplements. Some improvements in muscling were seen with several products, but the stand out in this category was Body Builder, with consistent improvements noted even in horses on well supplemented diets with adequate protein, calories and lysine levels. No improvements in performance were noted.
Creatine: Creatine is the darling of human body builders but doesn’t produce the same dramatic results in horses. We tried one creatine product and found no obvious changes in muscling. We’d skip the creatine.
Protein And Carbohydrate: Fat Cat was most effective in preventing muscle loss and maintaining body-condition score when fed immediately after work. A specific muscle-enhancing effect was not noted, though. Try this as a supplementary calorie source for a horse in work having trouble holding both weight and muscle bulk. The other product in this category, Cell Mass, is higher in protein and targets muscle-cell volume. Effects were seen when used in a diet where protein intake was likely borderline.
BCAAs And HMB: Our best results in terms of muscle bulk and exercise performance were seen with this category. We tried the products in horses receiving what should have been adequate diets in all respects but still having trouble holding and building muscle mass, even showing some soreness. Best results were obtained with Su-Per HMB and BCAA Complex, when given close to exercise.
The findings in our product trial also highlighted once again the importance of the base diet. Before trying a muscle-building product, get assistance in evaluating your basic feeding plan. Correcting any weaknesses there will also benefit the horse overall and may eliminate the need for a muscle supplement. The "Troubleshooting Action Plan" table will help you sort through this. Note: Any horse showing dramatic weight and/or muscle loss should be evaluated by a vet.
We recommend you troubleshoot and choose the product most closely matches your horse’s nutritional situation. If everything is ideal, we’d go with Body Builder for all ages of horses.