Off-the-track Thoroughbreds (OTTB) can be wonderful companions and athletes, but they do come with their share of breed-specific challenges.

After retiring from the racing industry, these horses often require specific care and training to adapt to new disciplines or leisure riding. Your OTTB also needs thoughtful feeding and management to transition from their high-performance diet to one that matches their new activity level.

Racehorses typically consume large amounts of high-energy feeds to support their intense exercise regime. Transitioning to a forage-based diet suitable for your OTTB’s new lifestyle is important, but must be done gradually to avoid weight loss or digestive upset.

Many OTTBs retire with injuries or health conditions that may require attention. These horses may also exhibit behaviors such as cribbing, weaving, or stall walking owing to their previous environment. Providing ample turnout, socialization with other horses, and quality veterinary care can help mitigate health concerns.

Understanding their background, needs, and potential is key to successfully managing these spirited and athletic animals. Continue reading to learn more about caring for a feeding your Off-the-track Thoroughbred.

Managing Off-the-track Thoroughbreds

Thoroughbreds are bred for speed and performance. On the track, their lives are highly regimented with structured routines, which can include intense training and limited turnout.

This lifestyle shapes their behavior, expectations and responses. These horses are accustomed to busy stable environments, frequent interactions with trainers and handlers, and short, intense bursts of exercises.

When you first bring your new OTTB home, it’s important to be patient and empathetic, recognizing that your horse is adjusting to an entirely new way of life. They must be gradually acclimated to their new surroundings.

This means introducing changes slowly, whether it’s a new feeding regimen, different types of exercise, or even the amount of time they spend in a pasture. What might seem normal to other horses may initially be unfamiliar and stressful for an OTTB.

Consistent, gentle handling and a predictable routine can help these horses feel secure as they learn to understand and trust their new environment and handlers. Positive reinforcement also plays a key role in helping them adapt.

Health Concerns of OTTBs

Physically, the transition from racing to a new career can be demanding. Many OTTBs retire with some level of wear and tear on their musculoskeletal system, so a thorough veterinary evaluation is essential.

This evaluation should guide their exercise and rehabilitation program. Your veterinarian will assess your horse for joint disorders, tendon and ligament strains, or even fractures, which can be the result of repetitive high-speed workouts.

It’s also important to monitor your OTTB’s weight and body condition closely, as changes in diet and exercise can significantly affect their physical well-being.

Retired thoroughbred racehorses also frequently suffer from gastric ulcers due to stress and feeding practices associated with racing. Respiratory issues and hoof problems are also frequent in OTTBs.

Proactively addressing these health concerns with appropriate management is crucial for the overall health and well-being of your horse.

Gastric Ulcers

Digestive concerns are very common in Thoroughbreds, with studies showing that over 90% of racing thoroughbreds have gastric ulcers. [1][2][15] Ulcers are sores or lesions that develop in the lining of the stomach in horses.

Several factors contribute to the high risk of ulcers in racehorses including stress, high-grain diets with limited forage, and the demands of training or competition.

Symptoms of ulcers in horses can vary, but may include:

  • Abdominal discomfort that may present as “girthiness
  • Tooth grinding (bruxism)
  • Difficulty in maintaining weight
  • Poor coat quality
  • Lack of appetite for grain

If your off-the-track Thoroughbred is experiencing ulcer symptoms, consult with your veterinarian to develop a treatment plan appropriate for your horse. You should also work with an equine nutritionist to implement dietary and management strategies that can help support gastric health in horses.

Topline Muscles

Building and maintaining topline muscling is another common concern for Thoroughbreds. The topline muscles include the muscles along the horse’s neck, back, loin, and croup.

These muscles support the spine and play a key role in movement and posture. For Thoroughbreds transitioning from racing to other disciplines, developing a strong, healthy topline is essential for their new athletic endeavors and overall well-being.

A poor topline can result from various factors, such as inadequate nutrition and failure to engage topline muscles properly during exercise and normal movement.

To address topline issues, ensure your horse’s dietary protein and amino acid requirements are met and introduce exercises that specifically engage topline muscles.

Keep in mind that feeding more protein and amino acids than what your horse requires will not stimulate topline muscle growth. Instead, focus on providing a well-balanced diet that:

  • Meets protein requirements
  • Contains a good supply of limiting amino acids
  • Supports digestive health to enhance feed digestion and absorption

Hoof Issues

As a breed, Thoroughbreds also appear be more prone to hoof issues, which can affect their overall soundness and performance. [3]

Common hoof problems in OTTBs include:

Thoroughbreds can often have a long toe / low heel hoof conformation which strains the deep digital flexor tendon, fetlock, suspensory ligaments and the navicular area.

Ensure that your OTTB gets frequent farrier visits for proper hoof care and trimming. Consult with your veterinarian if you are concerned about persistent hoof health issues.

A well-balanced diet with adequate amounts of essential vitamins and minerals is crucial for supporting hoof health and promoting optimal hoof growth.

Respiratory Issues

Thoroughbred horses are prone to various respiratory issues, often stemming from the environment and athletic demands of their past life on the racetrack. Common respiratory problems in Thoroughbreds include:

  • Exercise-Induced Pulmonary Hemorrhage (EIPH), a condition where small blood vessels in the lungs burst during intense exercise. While common in racing, it’s typically less of a concern for Thoroughbreds no longer in racing.
  • Heaves, a type of equine asthma, is a chronic respiratory issue often triggered by allergens like dust, mold, or pollen. Symptoms include coughing, breathing difficulties, and mucus production. Heaves is more prevalent in stable-bound Thoroughbreds due to poorer air quality and limited airflow.
  • Inflammatory Airway Disease, a form of equine asthma, affects the lower airways, often due to environmental irritants. It can cause coughing, nasal discharge, and reduced exercise capacity.
  • Roaring / laryngeal hemiplegia is an abnormal respiratory noise during exercise that resembles a roar. It is caused by degeneration of the long nerves that innervate the muscles of the larynx and may require surgery.

The best way to prevent and manage respiratory issues in your OTTB is to provide a clean and dust-free environment, and maintain good air quality in your stable.

In some cases, veterinary treatment including medications or targeted management interventions, may be necessary to alleviate these conditions. As with any horse, regular veterinary check-ups are essential for addressing and preventing respiratory problems in OTTBs.

Mad About Horses
Join Dr. Chris Mortensen, PhD on an exciting adventure into the story of the horse and learn how we can make the world a better place for all equines.
Apple Podcasts Spotify Youtube
Mad Barn - Equine Nutrition Consultants | Mad Barn USA

How to Feed your Off-the-Track Thoroughbred

Off-the-Track Thoroughbred benefit from an individualized feeding program that take into account their current health status, body condition, and level of exercise.

Transitioning your OTTB to a new exercise program requires careful consideration of their nutritional needs. After retiring from the racetrack, most Thoroughbreds engage in much lower intensity exercise, leading to a significant decrease in their energy and protein requirements.

Your OTTB’s diet needs to be rebalanced to support their new workload and address any existing health concerns. This process involves more than just reducing the quantity of feed; it also requires adjusting the type of feed they receive.

Consulting with an equine nutritionist is recommended to formulate diet that optimally meets your horse’s nutritional needs and supports their performance goals in their new career. This professional guidance ensures that your OTTB gets started on the right feeding program to ensure a successful transition.

1) Evaluate their Current Diet

The first step in formulating a new diet for your OTTB is to evaluate their current feeding plan. When acquiring a new horse, it’s common to perform a pre-purchase veterinary exam to check for routine health concerns. However, evaluation of the horse’s current diet is frequently overlooked.

Understanding the current diet of your new Thoroughbred can help you prevent issues such as significant weight loss or poor acceptance of your planned diet during the transition.

This step is especially important for Thoroughbreds recently retired from racing, as their diets are typically high in energy and protein. If your Thoroughbred is coming directly from race training, their diet may include a substantial proportion of grain.

On the other hand, if your Thoroughbred has been out of race training for a while, they might have already transitioned to a lower-calorie diet more suitable for a less active lifestyle.

Questions to Ask

Important questions to ask regarding your Thoroughbred’s current diet include:

  • What specific type of hay is being fed, and is there a forage analysis available?
  • What is the daily quantity of hay provided, and does the horse consistently consume all of it?
  • Is the horse currently being fed a concentrate feed or a ration balancer? If so, which product is being provided and what is the exact amount being fed?
  • Does the horse consume the entire portion of concentrate or ration balancer provided?
  • What additional supplements, if any, are included in the horse’s current feeding regimen?
  • Are there specific feeds that the horse tends to avoid or not eat?

Knowing the answers to these questions will help you better transition your OTTB horse to their new diet.

Transition Schedule

To minimize digestive upsets and avoid palatability issues, it is recommended to make feeding changes gradually over 10 – 14 days. Consider the following transition schedule when introducing a new diet to your OTTB:

  • Days 1 – 3: Feed 75% current diet; 25% new diet
  • Days 4 – 6: Feed 50% current diet; 50% new diet
  • Days 7 – 9: Feed 25% current diet; 75% new diet
  • Day 10: Feed 100% new diet


2) Determine their Body Condition

Racehorses are often kept in lean condition to optimize their performance on the track. [4][5] Thoroughbreds are also famous for being hard keepers with a high metabolism, which means they typically require more calories than other horse breeds to maintain their weight.

Furthermore, OTTBs frequently experience weight loss as they transition to their new diet. However, being too lean can have negative health implications.

When designing a feeding plan for your new OTTB, it is important to first determine their current and ideal body condition. This assessment helps you understand their energy requirements so you can provide them with a balanced diet.

In horses, body condition score is assessed on a scale from 1 (poor) to 9 (extremely obese), as described by Henneke and colleagues. [6] This scale gauges fat deposition on different areas of the body to determine an overall body condition score.

  • Ideal Weight Horses (Score of 5 – 6): If your horse’s body condition score is a 5 or a 6, your goal is to provide a diet that maintains their current weight.
  • Underweight Horses (Score Below 5): If your horse’s body condition score is less than 5, their diet should be adjusted to provide more energy. This scenario is common for horses just retiring from race training, as they are often in a leaner state.
  • Overweight Horses (Score Above 6): Conversely, if your horse’s body condition score is above 6, you need to reduce the caloric density of their diet to support healthy weight loss. This may be the case for Thoroughbreds that have been turned out to pasture for some time after retiring from their racing career.

3) Determine their Nutritional Requirements

Providing a diet that meets your OTTB’s nutrition requirements is key to supporting their health, longevity, and performance.

Dietary requirements for horses are established by the National Research Council (NRC) and are based on a number of factors, including body weight and exercise level. The NRC’s Nutrient Requirements of Horses sets out required intake levels for protein, energy, and certain vitamins and minerals.

To calculate your horse’s nutritional requirements, you will need to know their body weight, as well as their current and planned activity level.

Body Weight

Many horse owners don’t know their horse’s exact body weight. But this information is important for determining the appropriate type and quantity of feed for your horse.

The typical weight for an Off-the-Track Thoroughbred can vary based on their height, build, and overall condition. However, most adult Thoroughbreds generally weigh between 1,000 to 1,200 pounds (about 450 to 550 kilograms).

You can estimate your horse’s body weight using a weigh tape to measure their heart girth. For a more precise estimate, also measure their body length and input both measurements into an equine body weight calculator.

Exercise Level

Use the following scale to determine your horse’s exercise level: [4]

  • Maintenance: No forced exercise, turnout out on pasture
  • Light: Recreational riding, occasional showing
  • Moderate: Recreational riding, frequent showing
  • Heavy: Race training
  • Very heavy: Racing competitions

Most racing Thoroughbreds are considered to be at a heavy or very heavy exercise level. However, most OTTBs are in light to moderate workloads.

Maintenance Requirements

Although not factored into NRC requirements, a horse’s temperament can significantly influence its maintenance needs. Thoroughbreds that exhibit “hot” behaviour expend more energy throughout the day and have a higher calorie requirement. [4][7]

To maintain their optimal condition, it may be necessary to increase energy and protein content in OTTBs with anxious or energetic temperaments.

Nutrient Requirements

The following table shows daily nutrition requirements for a 500 kg (1100 lb) Thoroughbred horse at maintenance, in light exercise, or in moderate exercise.

Nutrient Maintenance Light
Energy 16.7 Mcal 20 Mcal 23.3 Mcal
Protein 630 g 699 g 768 g
Lysine 27.1 g 30.1 g 33 g
Sodium 10 g 13.9 g 17.8 g
Zinc 400 mg 400 mg 450 mg
Copper 100 mg 100 mg 112.5 mg
Selenium 1 mg 1 mg 1.125 mg
Vitamin E 500 IU 800 IU 900 IU


For help determining your horse’s individual nutritional requirements, you can use our online nutrition calculator and input their information.

4) Feed a Forage-First Diet

Horses evolved to eat a forage-based diet consisting of grasses and other plants found in their natural environments. In the wild, horses spend approximately 40 – 70% of their time consuming forage and expressing grazing behaviors. [8]

The goal of providing a forage-first diet is to feed as much forage as possible to mimic your horse’s natural grazing behavior and support their digestive health.


Pasture is an excellent option for many Thoroughbreds, offering not only a natural source of forage but also opportunity for physical activity and mental stimulation. [8]

If your horse has recently retired from racing, they may need to be gradually transitioned to pasture turnout to allow their digestive system time to adapt.


In cases where pasture access is limited, providing free-choice hay is crucial to maintain gut health and prevent long periods without forage. The abest hay to provide your off-the-track Thoroughbred depends on their activity level and whether they need to gain or lose condition.

For horses in heavy work or those that need to gain weight, nutrient-dense forages such as mixed alfalfa-grass hay can supply extra calories. Mixed hay that is soft and leafy is more palatable and encourages increased intake.

If your Thoroughbred is an easy keeper or overweight, lower-calorie hay is best to maximize forage intake without providing excess calories. Choose a mature grass hay or use a slow feeder to enable free-choice intake.

Forage Quality

Although the feel, smell and appearance of hay can give you some indication of quality, the only way to accurately assess forage quality is by submitting a hay sample for analysis.

Your forage analysis report will detail the energy, protein, fiber, starch, sugar and mineral composition of your hay. An equine nutritionist can help you interpret these results and balance your OTTB’s diet accordingly.

Hay Analysis
Know exactly what nutrients your horse is getting in their diet with our comprehensive equine forage testing.
Order Now

5) Meet Vitamin and Mineral Requirements

Vitamins and minerals are important nutrients that are involved in various bodily functions and in maintaining the overall health of your horse.

While forage provides some of the vitamins and minerals your horse needs, forage alone typically will not meet all of your horse’s vitamin and mineral requirements. [9][10] Deficiencies in these essential nutrients may lead to health concerns such as:

  • Reduced immune function
  • Weak hooves
  • Poor skin and coat quality
  • Metabolic disfunction
  • Poor exercise performance
  • Reproductive issues

To prevent nutritional deficiencies, provide your horse with a balanced vitamin and mineral supplement. Choose concentrated supplements with a low feeding rate and avoid grain-based complete feeds, which provide excess sugar and starch and can contribute to gut health issues.

Mad Barn’s Omneity is a concentrated vitamin and mineral supplement formulated to balance the majority of forages-based diets.

Omneity supplies essential vitamins, minerals and amino acids to support hoof growth, coat quality, performance and metabolic health. It also contains digestive enzymes and yeast to support gut health and the immune system.

Omneity – Premix

5 stars
4 stars
3 stars
2 stars
1 star

Learn More

  • 100% organic trace minerals
  • Complete B-vitamin fortification
  • Optimal nutrition balance
  • Our best-selling equine vitamin

6) Add Calories As Needed

If your horse needs additional energy beyond what is supplied by their forage, you may need to supplement their diet with safe calorie sources to achieve an ideal body condition.

Racehorses are often fed energy-dense grains like oats and corn to meet their higher calorie requirements. But these feeds contain high levels of sugar and starch, which can increase the risk of gastric ulcers, colic and other digestive issues. [11]

If you are feeding grain-based concentrates, make sure to split your OTTB’s daily ration into multiple small meals to reduce the risk of digestive upset.

However, a better option is to provide additional calories from high-fiber feeds, which are more suited to a horse’s natural digestive system. Fiber-based feeds, such as beet pulp, alfalfa hay/pellets/cubes, and soy hulls, are readily fermented in the horse’s hindgut to provide a steady release of energy.

Alfalfa and beet pulp are very high in calcium which can be balanced by adding oats or wheat bran in an amount suggested by your nutritionist to match the rest of the diet.

Fat can also be added to your OTTB’s diet as a concentrated energy source that provides double the calories per gram compared to carbohydrates. Fats are typically added in the form of oils, which can be supplemented up to around 2 cups per day for the average 1100 lb (500 kg) horse.

w-3 Oil

5 stars
4 stars
3 stars
2 stars
1 star

Learn More

  • Promotes joint comfort
  • Helps to fight inflammation
  • Skin & coat condition
  • Palatable source of Omega-3's

7) Supplements to Support Health

When formulating a diet for your OTTB, the first priority is to provide a balanced feeding program with adequate energy, protein, vitamins and minerals. After balancing the diet, you may consider adding supplements to address individual needs or performance goals.

Gut Health

Stomach issues are highly prevalent in racing Thoroughbreds, and can persist for several months or years after they have retired from the racetrack. [2] You can support your horse’s gastric health with the following feeding strategies: [16]

  • Provide a forage-based diet and ensure constant access to forage
  • Limit grain consumption and split feed into multiple small meals per day
  • Provide constant access to fresh, clean water
  • Ensure your horse gets adequate salt to encourage hydration
  • Avoid exercising the horse on an empty stomach. Always feed at least a few pounds of hay before exercise.

You can further support your horse’s gastric and hindgut health by incorporating Mad Barn’s Visceral+, a comprehensive gut supplement.

Visceral+ is formulated with a blend of probiotics, prebiotics, yeast, amino acids, phospholipids, minerals, herbs, and other nutrients. These components work together to support the immune system and help maintain a healthy stomach lining, contributing to overall digestive well-being.


5 stars
4 stars
3 stars
2 stars
1 star

Learn More

  • Our best-selling supplement
  • Maintain stomach & hindgut health
  • Supports the immune system
  • 100% safe & natural


If your OTTB is experiencing topline issues, work with your veterinarian and trainer to identify any underlying problems affecting topline development. Ensure that your horse’s diet contains adequate protein and implement a conditioning program to strengthen the topline muscles.

Once you’ve covered these fundamentals, you may want to consider amino acid supplementation to enhance the protein quality of your horse’s diet. Amino acids are essential for muscle growth, acting as building blocks for protein synthesis.

Supplements that provide limiting amino acids such as lysine, threonine, and methionine are particularly beneficial. These are the amino acids most likely to be deficient in the equine diet.

Three Amigos

5 stars
4 stars
3 stars
2 stars
1 star

Learn More

  • Optimal protein synthesis
  • Hoof & coat quality
  • Topline development
  • Athletic performance


Several nutrients can support lung health and respiratory function in OTTB horses. Consider the following supplements:

  • Spirulina is a nutrient-dense blue-green algae that has antioxidant properties and helps to maintain homeostatic regulation of inflammation. [12]
  • Jiaogulan is a Chinese herb that has been shown to reduce coughing in horses with respiratory issues when fed in combination with spirulina. [13]
  • W-3 Oil is a fat supplement that is enriched with natural vitamin E and docosahexaenoic acid (DHA), an omega-3 fatty acid. Feeding DHA has been shown to support horses with inflammatory airway issues. [14]

Example Diets

Below are two sample diets for an average 1100 lb (500 kg) off-the-track Thoroughbred in light exercise. The maintenance diet supplies enough calories to meet energy requirements while the weight gain diet provide a calorie surplus.

Sample OTTB Diets

Feed Maintenance Diet Weight Gain Diet
Hay Free-choice
(~24 lbs / 11 kg)
(~24 lbs / 11 kg)
Beet Pulp 1 lb / 450 grams
(dry weight)
1 lb / 450 grams
(dry weight)
Salt 30 grams
(2 tablespoons)
30 grams
(2 tablespoons)
200 grams
(2 scoops)
200 grams
(2 scoops)
W-3 Oil 120 mL
(4 oz)
Nutrient Analysis*
Digestible Energy
(% of requirement)
100 105
Crude Protein
(% of requirement)
142 140
(ESC + starch; % of diet)
9 9

This nutrient analysis is based on an average forage sample from North America and the NRC (2007) requirements. For a better estimation, submit your forage for analysis and consult with an equine nutritionist.

Thankfully, thoroughbreds are not prone to metabolic syndrome and therefore the overall hydrolyzable carbohydrate (HC) content of a forage-based diet is not a concern.


Off-the-Track Thoroughbreds come with their share of concerns, especially if they have recently retired due to an injury or other health issue. However, with proper feeding and management, your OTTB can successfully transition to a new career and lifestyle.

Before deciding what to feed your horse, you should evaluate their current diet and assess their body condition. Once you have determined your OTTB’s nutrient requirements, you can formulate their diet by selecting quality forage and ensuring their vitamin and mineral requirements are met.

Additional feeds may be required to meet calorie requirements. Avoid grain-based concentrates, and instead opt for fiber-rich feeds or fat supplements to provide safe energy sources. Nutritional supplements may be added to provide targeted support for individual health needs and performance goals.

Have questions about what to feed your off-the-track Thoroughbred? Submit your horse’s information online for a free consultation with our equine nutritionists to ensure your horse’s nutritional needs are optimally met.

Is Your Horse's Diet Missing Anything?

Identify gaps in your horse's nutrition program to optimize their well-being.


  1. Vatistas, N.J. et al. Cross-sectional study of gastric ulcers of the squamous mucosa in Thoroughbred racehorses. Equine Vet Journal. 2010.View Summary
  2. Hammond, C.J. et al. Gastric ulceration in mature Thoroughbred horses. Equine Vet Journal. 1986. View Summary
  3. Reed, S.K. et al. Survey on Thoroughbred use, health and owner satisfaction following retirement from racing. Equine Vet Education. 2019.
  4. National Research Council Chapter 1: Energy and feed processing. Nutrient Requirements of Horses. 2007.
  5. Geor, R.J. et al. Chapter 13: Practical considerations for feeding racehorses. 2013.
  6. Henneke, D.R. et al. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Vet Journal. 1983. View Summary
  7. National Research Council Chapter 4: Protein and amino acids. Nutrient Requirements of Horses. 2007.
  8. Lewis, L.D. Chapter 5: Pasture for Horses. Equine Clinical Nutrition: Feeding and care. 1995.
  9. Lewis, L.D. Chapter 4: Harvested Feeds for Horses. Equine Clinical Nutrition: Feeding and care. 1995.
  10. National Research Council Chapter 8: Feeds and feed processing. Nutrient Requirements of Horses. 2007.
  11. Geor, R.J. and PA Harris. How to Minimize Gastrointestinal Disease Associated With Carbohydrate Nutrition in Horses. Proceedings of the Annual Convention of the AAEP. 2007.
  12. Wu, Q. et al. The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview. Archives of Toxicology. 2016.
  13. Kellon, E.M. Use of the Herb Gynostemma Pentaphyllum and the Blue-green Algae Spirulina Platensis in Horses. Proceedings of the 3rd European Equine Nutrition & Health Congress. 2006.
  14. Norgradi, N. et al. Omega-3 Fatty Acid Supplementation Provides an Additional Benefit to a Low-Dust Diet in the Management of Horses with Chronic Lower Airway Inflammatory Disease. Journal of Veterinary Internal Medicine. 2015.View Summary
  15. Murray, M.J. et al. Factors associated with gastric lesions in thoroughbred racehorses. Equine Vet J. 1996. View Summary
  16. Buchanan B.R. & Andrews F.M. Treatment and prevention of equine gastric ulcer syndrome. Vet Clin. 2003. View Summary