Question
My nine-year-old Thoroughbred gelding needs more weight. He is hacked, schooled, or jumped six days a week, often competing on one of those days. Because he tends to stall-walk, he lives outside. He is fed 5.5 lb (2.5 kg) of a high-fiber, alfalfa-based (lucerne) product, 6.6 lb (3 kg) of a high-fat, high-fiber conditioning feed, 5.5 lb (2.5 kg) of grass pellets, 1 lb (500 g) of soybean meal, and about a cup (200 ml) of vegetable oil. I’d like to keep his diet as forage-dense as possible because he is prone to gastric ulcers. He will move to a lusher pasture soon, but for now he has free-choice haylage in addition to the aforementioned ration. He’s been dewormed recently and his teeth tended to. Any help would be appreciated.
Answer
Thoroughbreds tend to put on weight differently than other horses depending on what energy sources are provided to them. While your gelding is eating a fair bit now, the bulk of his diet is fiber, as you have alluded to. Unfortunately, some horses are not as efficient at digesting fiber as others and Thoroughbreds, in particular, are often managed on fairly high-starch diets because they are adept at utilizing starch as an energy source. Furthermore, too little starch in the diets of some horses, while contributing to a quiet disposition, can actually result in a larger belly and not enough fill over the topline and ribs.
With that potential limitation in mind, and using his current ration as a starting point, I recommend increasing the amount of conditioning feed offered. This feed includes some cereals, and these will supply more starch to his diet for rapidly available calories, increased muscle development, and elevated muscle glycogen stores. I would also replace a portion of the chaff and the grass pellets with more of the conditioning feed that will deliver further energy for weight gain as well as more nutrients to meet the requirements of a horse working at this level. Refer to the manufacturer’s recommendations on how much to feed and, if possible, divide the total amount into three meals a day. No single meal should be over about 5 lb (2.3 kg). If you choose to make these dietary changes, there is no reason to supplement soybean meal as he will be getting more than enough protein in the ration.
I also recommend a daily electrolyte supplement (Restore SR at 30-60 g/day, Restore in Australia) and a daily digestive-health supplement (RiteTrac at 120 g/day, available in the U.S. and other areas; Australian horse owners are encouraged to try these products). RiteTrac will serve to protect him from excess acid production in his stomach as well as from hindgut acidosis, which can reduce digestive efficiency, cause discomfort, reduce appetite, and even lead to laminitis when extreme.
If your gelding is already on a gastric-ulcer preventive, you can choose to feed EquiShure (120 g/day) instead of RiteTrac, as EquiShure targets only the hindgut with its buffering capacity. RiteTrac and EquiShure will be especially useful as the horse transitions to a lush pasture, because the gastrointestinal tract will require time to adjust to the new forage. Either of these products will help smooth that changeover by moderating the pH of the hindgut.
Alternatively, a different approach to feeding this gelding is possible. Instead of the conditioning feed, consider a high-calorie feed that has a mix of energy sources featuring cereals, beet pulp, and oil. Like the first ration, this feed would promote weight gain when fed according to the manufacturer’s instructions. You can continue using the supplemental vegetable oil, though the feed might already be thick with an oil and molasses mix, making even more oil difficult to add. Much of this will depend on your horse’s taste or distaste for oil, and how much he will tolerate.
Another possibility for additional calories is a stabilized rice bran, fed at 1-2 lb (0.5-1 kg), which will also help with condition. You can continue to feed some of the forage products, such as the haylage or the grass pellets, but they won’t figure as prominently as calorie sources. As with the first option, I would augment the diet with Restore SR and RiteTrac or EquiShure.
Finally, he should have at his disposal free-choice water and salt.
