The Ins and Outs of Feeding the OTTB

Understand how he was fed while on the track, and how needs differ off the track.

Off-the-track Thoroughbreds (OTTBs) are popular mounts for riders of many disciplines. But when feeding an OTTB, it's important to understand how he was fed during his time on the track, and how his nutritional needs differ once he begins his new life.

Feeding Racehorses

The idea body condition score for a racehorse is about 4 to 5 out of 9, which is slightly lower than that of a pleasure or low-level performance horse.

Racehorses exercise at a high intensity level and, thus, have some increased nutritional needs as compared to a pasture or pleasure horse:

  • Energy: This is the most important nutrient in the race horse's diet and is typically provided by carbohydrates (sugars/starches) and fats;
  • Minerals: When racehorses sweat, they lose sodium, chloride, and potassium; thus, they require added minerals to keep electrolyte levels balanced;
  • Vitamins: Racehorses have increased vitamin need in proportion to increased energy need, especially Vitamin E; and
  • Water: Water must be free choice to replenish losses during sweating.

In many cases, grain consists of more than 50% of the racehorse's diet. Grain totals are between 15-18 pounds per day, divided up into several small feedings. Grains are high in sugar and starches (usually 30-35% nonstructural carbohydrates [NSC]) to replace energy lost during exercise as glycogen. Glycogen provides approximately 80% of the energy for exercise. Fat is an acceptable energy source and contain 2.5 times more energy than carbohydrates, so racehorses' diets often consist of about 8% fat.

Hay needs to be high quality, regardless of type used, to ensure the horse receives appropriate nutrition from his forage.

Gastric ulcers and upset are the most common dietary concerns when feeding racehorses. Diets high in carbohydrates (35% or greater NSC), and large amounts of sugar and starch during one feeding can be sources of gastric ulcers. To combat ulcers and digestive upset, many managers provide omeprazole and pre- and probiotics to racehorses in an attempt to keep their digestive tracts healthy and functioning properly. Additionally, some managers provide alternate fiber sources, such as beet pulp, to keep their charges' hindgut healthy.

Feeding OTTBs

Once a racehorse leaves the track for his new career, his exercise intensity level typically drops drastically to low or moderate; thus, his nutritional needs change as well. He will still require dietary energy, vitamins, and minerals, but generally in lesser quantities to accommodate his new nutritional requirements.

In many cases, OTTBs will need their body condition score increased and their topline refined. Consider adding fat to the diet (via a commercial supplement or topdressed oil), which will increase body condition without adverse effects on attitude (more on that in a moment). Additionally, these horses can benefit from additional protein in the diet, which will provide amino acids for muscle development.

Unlike feeding practices on the racetrack, forages should provide the main source of nutrients in the horse's diet, which will help keep his hindgut healthy. Grain should supplement horse's forage to meet nutritional needs missing or deficient from hay or pasture. Based on each individual horse's individual needs, consider using:

  • Ration balancer pellets (low calorie protein, vitamin, mineral supplements to balance forage diet);
  • Complete feeds (high fiber grain products); or
  • Premixed commercial performance products (which provide nutrients, including calories, in various amounts to balance forage portion in the diet).

Grain should be fed in small amounts per meal to prevent digestive upset.

As a result of their former lives, some OTTBs can be hot tempered or nervous. To combat this via nutrition, utilize fat as energy source (between 10-15% in their grain portion) as described above, and reduce NSC level to less than 30% in their grain portion. Over time, these changes could help hot or nervous OTTBs settle.

Take-Home Message

Careful dietary consideration can help make OTTBs' transition from racehorses to pleasure or low-level performance horses easier on their digestive system. If questions arise, consult an equine nutritionist or veterinarian to design a feeding program tailored to each individual horse.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.