Question
I own a 30-year-old Thoroughbred mare that weighs about 1,100 lb (500 kg) with a body condition score of 4. Historically, she has been an easy keeper, but now she needs to gain weight. She is ridden three days a week, though the work is not intense. Her ration includes unlimited timothy hay (which appeals to her only slightly), 8 lb (3.6 kg) timothy hay pellets, 2 cups beet pulp, and 2 cups of stabilized rice bran. She has limited turnout. While she is bright and energetic, she has trouble maintaining her weight on this diet. I purchased some soybean meal to try to up the protein content of her ration, but I don’t know how much to safely add to her diet. At one point, I took her off of a senior feed I had been feeding because we thought it might be contributing to diarrhea that she was experiencing. Anything with wheat or alfalfa seems to cause hindgut upset, and alfalfa hay also makes her legs swell. What can I do to help this mare gain weight?
Answer
Soybean meal is an excellent source of protein and amino acids for horses. Feeding 0.5-1 lb (0.25-0.5 kg) per day should be sufficient to add quality amino acids to your mare’s timothy-based diet in order to promote muscle development. Supplying branched-chain amino acids can also enhance muscle accretion.
Some older horses tend to lose condition over the winter, despite increases in caloric intake, though these horse often pick up weight once they have access to fresh pasture. However, if your mare continues to lose weight and condition, consultation with your veterinarian is needed to rule out any underlying health conditions. Dental issues can cause weight-related problems in old horses, so if you haven’t already, have your mare’s teeth evaluated by a professional.
Bumping up digestible energy (calories) through the use of beet pulp and rice bran is great for promoting weight gain. Stabilized rice bran can be included in the diet at 1-3 lb (0.5-1.4 kg), and soaked beet pulp can be offered as a hay replacer or as supplemental calories. Another option for adding concentrated calories is top-dressing vegetable oil (soybean or canola oil) onto soaked beet pulp or timothy pellets.
If the mare does not consume a lot of timothy hay, then offering a timothy cube or just increasing the amount of timothy pellets offered can provide the necessary fiber and energy needed to maintain condition. Forage cubes offer a slightly longer fiber length than pellets, which can help satisfy the mare’s natural instinct to chew.
Some forage products are fortified to meet the horse’s dietary needs when fed as a large part of the diet. Based on your mare’s multiple food sensitivities, a commercial ration balancer may not be suitable due to the likely inclusion of alfalfa meal and wheat. Instead, you may consider adding a concentrated vitamin and mineral supplement to provide the essential nutrients in a small daily amount that contains limited ingredients. An appropriate product is Micro-Max, which provides all of the essential micronutrients in just 2-4 ounces a day. Micro-Max does contain alfalfa but adds minute levels to the diet based on the feeding rate, so it is unlikely to cause problems. Australian horse owner should look for Gold Pellet.
Additional products that I believe would benefit your mare include EO•3 and EquiShure. EO•3 is a high-quality fish oil containing the long-chain omega-3 fatty acids DHA and EPA, which foster a strong immune system and mediate allergic reactions. EO•3 is the preferred source of omega-3s compared to plant-based sources such as flax and chia that contain short-chain omega-3 fatty acids.
EquiShure is a unique digestive buffer that features a protective coating to ensure its delivery to the hindgut. EquiShure functions to neutralize excess acid in the hindgut as a result of rapid fermentation, thereby stabilizing the microbial population. EquiShure is recommended for horses experiencing digestive upset such as gassiness, loose manure, and poor feed digestion and utilization. Supplementation in older horses has been beneficial for weight gain.
