As a horse’s work level increases, the greatest change in dietary requirement is for calories. | Photo: iStock

Q: I kept my horse in light work all winter, feeding him hay and a ration balancer. Now that it’s spring, our competition season is getting in to full swing, and his work level has gone up considerably. How should I adapt his diet?

A: As a horse’s work level increases, the greatest change in dietary requirement is for calories. Not all horses need a change of diet as their work level increases. Easier keepers might maintain their body weight on a forage diet with a ration balancer even as work intensity increases. Monitoring body condition is important to identify whether your horse needs more calories. If condition starts to drop below an overall score of 5 that’s a sign your horse needs more calories. For most working horses a 5 is considered ideal. However, depending on your discipline, a body condition score of 4 might be acceptable (think racehorses and eventers).

Some owners are motivated to change the diet when their horses start working harder not just for body condition but also to help the horse perform better. Riders sometimes tell me they feel their horses are missing something, lack stamina or spark, or that the riders don’t have “enough horse in front of their leg.” Several things could cause this issue (such as lameness or gastric ulcers), but sometimes it can be fixed by simply adding or changing to a more calorie-dense concentrate feed. Sometimes rather than feeding more calories, keeping calorie intake the same but substituting some amount of forage for concentrate feed is necessary