Last updated: June 25, 2026
The night before a big race, my Thoroughbred Ashton refused his feed. Watching a horse turn away from a meal he normally cleaned up reminded me of something every trainer eventually learns: racehorse nutrition isn’t just about formulas—it’s about understanding the individual horse. After more than 30 years managing Thoroughbreds, I’ve found that feeding mistakes often cost more races than training mistakes.
Feeding racehorses starts with forage and works outward. These core principles have held up over 30 years of training at Fair Grounds, Evangeline Downs, and Delta Downs:
- Forage first, always: High-quality hay should make up at least 50% of daily intake—roughly 1.5% to 2% of total body weight. Feed hay before grain at every meal to slow down digestion and protect the gut against ulcers.
- Limit grain, add fat: Restrict concentrates to no more than 0.5% of body weight per meal to manage starch loads. Substituting safe fat sources provides dense calories with far lower digestive risks.
- Scale for active training: Caloric demands shift rapidly with workload. Horses in intense training require significantly more digestible energy than at maintenance—adjust rations dynamically by monitoring body condition.
- Verify all supplements: Over-supplementing or ignoring ingredient labels can lead to selenium toxicity or positive drug tests under racing commission rules.
Sources behind this guide: 30+ years managing Thoroughbred racehorses in Louisiana, combined with data from University of Minnesota Extension, Oklahoma State University feeding management research, and PMC equine energy requirement studies. All supplement and prohibited substance guidance should be confirmed with your veterinarian and jurisdiction’s racing commission.
Table of Contents
Understanding Equine Digestion
Horses are hindgut fermenters. Their digestive system is built for continuous grazing on fibrous material — the foregut (stomach and small intestine) handles initial breakdown of starches, proteins, and fats, while the hindgut (cecum and large colon) uses microbial fermentation to break down fiber into volatile fatty acids, which serve as a primary energy source. That fermentation process is the key to everything in racehorse feeding, because disrupting the hindgut microbiome — through sudden diet changes, excessive starch, or stress — produces colic, ulcers, and performance decline.
The practical implications of this are consistent: feed frequently, prioritize fiber, limit starch per meal, and make any dietary change gradually over 7–10 days. A horse’s stomach is relatively small and produces acid continuously — which is why long gaps between feedings and insufficient forage both increase ulcer risk. Long-stem hay produces saliva that buffers stomach acid; a horse without regular forage access is a horse at elevated risk for gastric ulcers regardless of what else is in its diet.
Miles’s Take — the grain overload that cost me thousands: Early in my racing career I fed a Quarter Horse heavily on grain, assuming more energy meant better performance. He ran poorly and seemed lethargic — nothing like his personality at home. Then the colic started. Chronic, recurring episodes. The vet identified the cause: excessive starch was disrupting his hindgut microbiome and the digestive distress was showing up as poor performance. Once I switched to fat supplementation and quality forage as the base, the colic resolved, his energy stabilized, and his performance improved. The lesson was expensive — thousands in vet bills and nearly a good horse — but it solidified one principle I’ve never deviated from since: lower starch, better fat, more fiber equals better digestion and better racing.
Forage — Foundation of Every Racehorse Diet
Every racehorse’s diet should start with forage — at least 1.5–2% of body weight daily, with hay making up no less than 50% of total intake. I feed a mix of Timothy, Alicia Bermudagrass, and Alfalfa, adjusting the ratio based on each horse’s workload and body condition. Timothy provides balanced nutrition and is the daily staple. Alfalfa is rich in protein and calcium and goes to horses needing extra nutritional support during hard training. Alicia Bermudagrass suits horses that don’t need high protein and calcium loads. Orchard grass rounds out the mix as a palatable fiber source that picky horses tend to eat well.
Always feed hay before concentrates — this is the most important sequencing decision in a racehorse’s daily diet. Hay first slows feed passage, increases saliva production that buffers stomach acid, and significantly reduces ulcer risk. When long-stem hay isn’t available, hay pellets or cubes fill the gap but provide less chewing benefit. I test hay quality seasonally; if a horse’s condition or manure changes, hay quality is the first variable I revisit.
Louisiana hay storage note: Our humidity creates a hay storage challenge that owners in drier climates don’t face the same way. Store hay elevated and well-ventilated — mold develops quickly in Louisiana’s climate and can cause serious respiratory and digestive problems. I also monitor spring Bermuda grass pasture carefully: NSC levels spike in early spring growth, and metabolically sensitive horses turned out on fresh spring pasture without a grazing muzzle are at elevated laminitis risk. Spring pasture management is as important as any supplement decision.
What Do Racehorses Eat in a Typical Day?
The most common question new owners ask is what actually goes into a racehorse’s feed tub each day. The answer varies by horse, track, and trainer, but the framework is consistent: forage dominates, concentrates supplement it, and everything else is targeted to the individual. The amounts below reflect a typical 1,100 lb Thoroughbred in active training — easy keepers eat less grain, hard keepers more fat.
| Feed | Approximate daily amount | Primary role |
|---|---|---|
| Timothy hay | 10–15 lbs | Foundation fiber, gut health, saliva production |
| Alfalfa hay | 4–8 lbs | Protein and calcium for horses in hard training |
| Concentrate feed (e.g., Omolene 14%) | 4–8 lbs (split across 2–3 meals) | Concentrated energy; keep each meal under 0.5% BW |
| Beet pulp (soaked) | 1–2 lbs post-exercise | Hydration support and gentle recovery carbohydrate |
| Fat supplement (oil or rice bran) | As needed (start 1/4 cup, build gradually) | Concentrated calories without starch risk |
| Electrolytes | After hard work or on race days | Replace minerals lost through sweat |
| Water | Unlimited — typically 8–12 gallons/day in training | Non-negotiable; performance declines with even mild dehydration |
For a more specific example, here is the daily ration I use as a starting point for a 1,100 lb Thoroughbred in active training. Every horse is adjusted from this baseline based on body condition and workload response.
| Feed | Daily amount | When / how |
|---|---|---|
| Timothy hay | 10–12 lbs | Available continuously; always fed before grain at each meal |
| Alfalfa hay | 4–6 lbs | Mixed into hay ration; adjusted up for horses in hard training |
| Omolene 14% concentrate | 5–7 lbs split across 3 meals | Never more than 0.5% BW (≈5.5 lbs) per meal; fed after hay |
| Rice bran or vegetable oil | 1 lb rice bran or 1/4–1 cup oil | Mixed into grain; increases gradually over 2–3 weeks |
| Electrolytes | Per label — after hard workouts and race days | In water or top-dressed on feed; not daily for standard training |
| Beet pulp (soaked) | 1–2 lbs post-exercise | Soaked; given 15–30 min after cool-down |
| Water | Unlimited — 8–12 gallons typical | Always fresh; sipped slowly post-race not gulped |
| Feed type | Benefits | Watch out for |
|---|---|---|
| Timothy hay | Balanced fiber, gut-healthy, versatile for all horses | Lower calorie density than alfalfa — may need supplementing for hard workers |
| Alfalfa hay | High protein and calcium; excellent for horses in hard training | Too rich for easy keepers; can contribute to metabolic issues if overfed |
| Oats | Traditional racehorse grain; highly palatable and digestible | Starch content varies; soak or process to improve small intestine absorption |
| Commercial concentrate (14%) | Balanced nutrient profile; consistent between batches | Easy to overfeed; stick to 0.5% BW per meal limit regardless of product |
| Beet pulp (soaked) | Digestible fiber; excellent hydration support; easy on gut post-exercise | I prefer soaking — improves hydration and reduces choke risk in fast eaters |
| Rice bran / vegetable oil | High-fat calories without starch; supports calmer energy | Rice bran has high phosphorus — balance with calcium; introduce oil gradually |
Meeting Energy Demands Safely
Racehorses in training need substantially more energy than maintenance horses, but the exact increase depends on workload, fitness level, body condition, and individual metabolism. Research on performance horse energy requirements provides useful reference points — a 1,000-pound horse might need around 53 MJ/day at baseline plus 8 MJ for exercise, but in practice I adjust calories based on body condition score and performance rather than a fixed percentage. The research gives you a starting framework; the horse in front of you tells you whether it is working.
The safest way to meet the energy gap is fat supplementation rather than grain escalation. University of Georgia Cooperative Extension notes that fat produces less heat during digestion and can contribute to a calmer demeanor — start with 1/4 cup of oil daily and increase gradually over several weeks. When grain is needed, stay under 0.5% of body weight per meal and under 2g of starch per kg body weight per feeding. Exceeding either limit risks undigested starch reaching the hindgut, where it disrupts microbial balance and triggers colic or laminitis. These limits are explained in detail in Oklahoma State’s Feeding Management Guide.
Grains and Processed Feeds
Oats are the traditional racehorse grain for good reason — they’re highly digestible and palatable, and horses generally accept them well. Their fiber content and energy value can vary considerably by processing, however. I prefer to heat-treat oats by soaking them in warm water before feeding; research on oat processing suggests this can improve starch digestion and nutrient absorption. For commercial feeds, I use Omolene with 14% protein as the base concentrate for my Thoroughbreds — it provides a balanced nutrient profile appropriate for horses in active training. Feed selection should be adjusted based on training intensity, individual metabolism, and age.
Processing grains — rolling, cracking, extruding — improves digestibility by breaking down hard seed coats and making starch more accessible for small intestine absorption. Unprocessed whole grains have seed coats that limit how much starch is available before it reaches the hindgut, which is exactly where you don’t want undigested starch to end up. Extruded feeds go further: heat and pressure during extrusion increase digestibility and encourage slower consumption, both beneficial for horses with digestive sensitivities or reduced chewing efficiency.
Miles’s Take — Corked and the extruded feed switch: My gelding Corked struggled with rolled oats for longer than I should have allowed. He wasn’t cleaning up his feed consistently, his weight was hard to maintain, and his manure told me his digestion was working harder than it should. When I transitioned him to an extruded commercial feed, the change was noticeable within a few weeks — he cleaned up his meals, his weight stabilized, and his manure normalized. The processing method was the difference. Not every horse responds to every grain format the same way, and if a horse is consistently leaving feed or losing condition despite adequate amounts, the grain’s digestibility is worth investigating before increasing the quantity.
Supplements — Benefits and Risks
Supplements are part of my feeding program, but I’m careful about what I use and in what amounts. For vitamins and minerals, I focus on Vitamin E, selenium, and B vitamins to support muscle function and overall health — our guide to equine vitamins and minerals covers each nutrient in detail. Vitamin E is a potent antioxidant supporting muscle health, immune function, and nerve integrity — horses in hard training on limited pasture access are often deficient. B vitamins support energy metabolism and are typically produced in the hindgut, but horses under high training loads or stress may benefit from supplementation.
Body builder supplements help maintain weight and muscle mass during periods of high workload or recovery, but I check ingredients carefully on every product before using it with a competition horse. Hoof and coat supplements support hoof integrity and coat quality, but some contain high mineral levels that can interfere with other nutrients if stacked carelessly — I use one targeted hoof supplement rather than multiple overlapping products.
Miles’s Warning — selenium and prohibited substances: Two supplement risks that come up repeatedly in racing barns. First: selenium toxicity. Too much selenium causes hair loss and hoof problems — it is one of the few minerals where the gap between beneficial and toxic amounts is small. UGA’s over-supplementation research is worth reading before adding any selenium-containing product. Second: prohibited substances. Body builders, joint supplements, and even some “natural” products contain compounds banned under racing commission rules. Verify every supplement against your jurisdiction’s prohibited substance list before the first dose. An inadvertent positive test is not a defense.
Hydration and Electrolytes
Racehorses lose electrolytes through sweat at a rate that feed alone cannot replace during intense training. Fresh, clean water should be available at all times — this is not optional and not negotiable. I supplement with balanced electrolyte mixes after intense workouts rather than single-salt products; research on dehydration and electrolyte imbalances confirms that single-salt supplementation does not fully replace the mineral balance lost through sweat. When choosing electrolyte products, look for sodium chloride and potassium chloride as the first two ingredients. Avoid products where sugar leads the ingredient list — research has shown sugar does not improve electrolyte uptake and adds unnecessary carbohydrate load.
A salt block or loose salt should be available free-choice at all times. For idle horses, quality hay provides adequate potassium; for horses in active training, salt and targeted electrolyte supplementation are both necessary. I provide electrolytes after intense training sessions and around race days, not daily as a routine, unless the horse is in a particularly demanding training cycle or the weather demands it.
Louisiana summer heat protocol: Standard electrolyte approaches aren’t sufficient in our climate. When temperatures regularly hit 90°F+ with high humidity, I increase electrolyte frequency — even on light training days — and ensure cold water is always available. Horses drink significantly more cold water than warm in extreme heat. I’ve also observed that horses here sweat heavily before they’re truly working hard, which is climate, not conditioning. If a horse seems lethargic or is performing below expectation in July or August, heat stress is the first thing I evaluate before concluding there’s a training or feed problem. Adjust electrolyte supplementation for Louisiana summers earlier and more aggressively than you think you need to.
Daily Feeding Routine at the Barn
Consistency matters more than precision. Horses thrive on predictable schedules — irregular feeding times create stress and increase ulcer risk. The table below reflects my standard barn routine; amounts are approximate for a 1,100 lb Thoroughbred and should be adjusted by body condition and workload.
| Time | What | Amount / notes |
|---|---|---|
| 6:00 AM | Morning hay + grain + supplements | 4–5 lbs hay first; 2–3 lbs concentrates; daily supplements per individual needs. Keep grain under 0.5% BW and starch under 2g/kg BW per meal |
| 7:00 AM | Track work | ~1 hour post-feeding; hay keeps gut buffered without overloading before exercise |
| Between meals | Hay available continuously | Never let the hay rack empty; gaps in forage access increase ulcer risk |
| 12:00 PM | Midday hay + concentrates | 3–4 lbs hay; 1–2 lbs concentrates; water always available; salt block in stall |
| 1:00 PM | Turnout / paddock time | 30–60 min; grazing, movement, mental decompression; horses not on track daily still need outdoor time |
| 5:00 PM | Evening hay + grain + electrolytes if training day | 4–5 lbs hay first; 2–3 lbs concentrates; electrolytes in water or feed after hard work; monitor each horse’s consumption |
| Post-exercise | Beet pulp (soaked) | 1–2 lbs soaked beet pulp after 15–30 min cool-down; aids hydration and recovery; ensure water available throughout |
| Off days | Reduce concentrates; maintain forage | Full forage access; ~50% of usual concentrate amount; don’t swing dramatically — consistent transitions prevent digestive upset |
Monitoring Digestive Health
Small changes in behavior or manure are the earliest diagnostics. I check manure consistency at every feeding — too dry suggests insufficient water or fiber, too loose points to gut imbalance or a feed change. A horse leaving feed untouched, showing lethargy, or losing interest in its environment gets a closer look before any other explanation is assumed. I assess body condition monthly using the Henneke scale — a racehorse in active training should maintain BCS 5–6. If a horse drops below 5 despite adequate rations, I increase fat before grain and check for dental issues. Weight loss sometimes signals a health problem rather than a calorie shortfall.
Common Feeding Mistakes Racehorse Owners Make
These four mistakes show up in almost every barn at some point, including mine early on. Each is easy to avoid once you know what to look for.
Four mistakes I’ve stopped making:
- Feeding by volume instead of weight. Scoops and flakes look consistent but aren’t — feeds vary in density. I weigh both hay and concentrates; a scale is one of the most useful tools in a barn
- Adding grain when a horse needs calories. The instinct when a horse loses weight is to add grain. The better move is fat and forage first. Grain overload creates more problems than it solves
- Long gaps between meals. A horse without hay for four or more hours has acid building in its stomach with nothing to buffer it. Continuous hay access reduced my barn’s ulcer rate more than anything else
- Abrupt feed changes. The hindgut microbiome needs 7–10 days to adapt to any significant dietary change. Switching hay or concentrate type without transition invites digestive upset
That daily attention pays off most in the 24 hours around a race, when every feeding decision is amplified.
Race Day Feeding Strategy
Ashton was one of the horses who taught me that race-day appetite changes are information, not inconveniences — when a horse behaves differently around feeding on race day, I pay attention before assuming it’s nerves. Race day feeding starts with the evening before: I keep the horse on its normal routine and avoid any feed changes. The morning of the race, I feed the regular morning meal at the barn before we leave for the track — a normal meal, nothing extra, nothing different. Changing the feeding routine on race day adds unnecessary digestive stress at exactly the wrong time.
At the receiving barn, I provide hay and water with added electrolytes until approximately three hours before the race. Small amounts of forage throughout the day maintain gut function without adding unnecessary weight. When the track veterinarian administers furosemide (Lasix) — typically four hours before race time — I withhold both feed and water until after the race. Lasix induces diuresis and significant fluid loss; feeding or watering after administration and before racing can create complications.
Post-race: offer water in small amounts immediately — a few sips, then walking, repeat. I’ve had horses get loose post-race from drinking too fast; now I’m strict about it regardless of how thirsty they seem. Drinking large volumes quickly while still hot is a colic risk, especially in a dehydrated horse. In my barn I typically wait about two hours before offering a full meal once the horse is cooled and relaxed — forage and concentrates to begin recovery. One to two pounds of soaked beet pulp at that point aids hydration and sits gently on the digestive system.
How Much Does It Cost to Feed a Racehorse?
Feeding a racehorse in active training typically costs $8–$20 per day for hay and concentrates alone, before supplements. At Louisiana regional tracks I budget $10–$14 per day per horse for feed — hay at $6–$8 and concentrates at $3–$6 depending on feed used. Supplements add $1–$5 per day per horse. Hay prices vary considerably by region, season, and quality, and a drought year can push monthly feed costs 20–30% higher than normal.
Feed cost reality check — Louisiana rates (2025–2026):
- Quality Timothy or mixed grass hay: $8–$12 per bale; a horse in training consumes roughly 1–1.5 bales per week
- Alfalfa hay: $15–$20 per bale in Louisiana; more expensive but you use less of it per horse
- Omolene or comparable 14% concentrate: approximately $25–$35 per 50 lb bag; a horse in training goes through roughly 1 bag every 7–10 days
- Monthly feed cost estimate (hay + grain, no supplements): $300–$500 per horse depending on workload and individual needs
- Full feeding program including supplements and electrolytes: $400–$700 per month per horse
Key Takeaways — Feeding Racehorses for Peak Performance
- Forage is the foundation. At least 1.5–2% of body weight daily, hay before grain at every meal — these habits prevent more digestive problems than any supplement program
- Add fat before adding grain. Fat provides concentrated calories without the starch risk. Hard limits: 0.5% BW in concentrates per meal, 2g starch per kg BW per feeding. Exceeding either invites colic and laminitis
- Process your grains and watch the format. Extruded or rolled feeds are more digestible than whole grains. If a horse won’t clean up feed or can’t maintain weight on adequate rations, grain format is often the overlooked variable
- Verify every supplement before using it with a competition horse. Prohibited substance violations often come from products that seem benign. Selenium toxicity comes from stacking products that each contain selenium individually
- Race day feeding starts the night before. Keep the routine normal. Feed the morning meal at the barn. Hay and electrolytes at the track until three hours pre-race. Withhold after Lasix. Sip water gradually post-race. Wait two hours before a full meal
- Manure and behavior are your earliest diagnostics. Changes in manure consistency, appetite, or demeanor often signal a digestive problem days before it becomes visible in body condition. Daily observation is the most valuable monitoring tool
- The horse in front of you is the final authority. Ashton refusing his feed the night before a race told me something no feeding schedule could — that something was off with that individual horse on that particular night. Principles and schedules are starting points. Paying attention to what your horse actually does every day is what turns feeding knowledge into racing results
Frequently Asked Questions
How much forage should a racehorse eat daily?
Racehorses should consume at least 1.5–2% of their body weight in forage daily, with hay making up at least 50% of total diet. High-quality forage provides essential fiber, vitamins, and minerals, and continuous hay access between meals significantly reduces ulcer risk by keeping stomach acid buffered.
Should I feed hay before or after grain?
Always feed hay before grain. Feeding hay first slows feed passage through the digestive system, promotes better digestion, increases saliva production that buffers stomach acid, and significantly reduces the risk of gastric ulcers. This sequencing applies at every meal, not just morning feeding.
How do I know if my horse’s grain ration is too high?
Two limits apply: no more than 0.5% of body weight per meal in concentrates, and no more than 2 grams of starch per kilogram of body weight per feeding. Excessive grain can lead to undigested starch reaching the hindgut, disrupting microbial balance and causing colic or laminitis. If a horse is getting adequate calories but showing digestive issues, grain reduction and fat increase is almost always the right direction.
What type of hay is best for racehorses?
Timothy hay provides balanced nutrition and is a reliable staple. Alfalfa hay is rich in protein and calcium and benefits horses needing extra nutritional support during hard training. Orchard grass is palatable and a good fiber source for horses that eat selectively. Alicia Bermudagrass works well for horses that don’t need high protein and calcium loads. I use a mix and adjust ratios by horse and workload rather than using one hay type across the barn.
Can I over-supplement my racehorse?
Yes, and it’s more common than most owners realize. Selenium toxicity — causing hair loss and hoof problems — can result from stacking multiple products that each contain selenium. Body builders and joint supplements sometimes contain prohibited substances. Always check ingredients against your racing jurisdiction’s banned substance list, and consult your veterinarian before adding anything new to a competition horse’s program.
How do I transition a racehorse to a new feed?
Over 7–10 days minimum. Start by mixing a small amount of the new feed with the current feed, increasing the ratio of new feed each day. The hindgut microbiome needs time to adapt to a changed diet — abrupt transitions disrupt microbial balance and can cause colic. This applies to both concentrate changes and hay type changes.
What are the best electrolytes for racehorses?
Choose products where sodium chloride and potassium chloride are the first two ingredients. Research has shown electrolytes containing sugar as a primary ingredient do not improve uptake and add unnecessary carbohydrate load. Balanced electrolyte mixes replace the full range of minerals lost through sweat better than single-salt products. Administer after intense workouts and on race days rather than as a daily routine for horses in standard training.
Should I feed differently on off days versus training days?
Yes. On heavy training days, horses need full rations and electrolyte supplementation. On off days, reduce concentrates to approximately 50% of the training day amount while maintaining full forage access. Don’t swing dramatically — gradual daily adjustments are easier on the digestive system than large swings between training and rest days. A horse’s body condition score will tell you over time whether the adjustment is calibrated correctly.
About Miles Henry
Racehorse Owner & Author | 30+ Years in Thoroughbred Racing
Miles Henry (legal name: William Bradley) is a professional horseman based in Folsom, Louisiana. He holds Louisiana Racing License #67012 and has spent over three decades managing Thoroughbreds at premier tracks including Fair Grounds, Delta Downs, and Evangeline Downs.
Expertise & Hands-On Experience: Beyond the track, Miles has decades of experience in specialized equine care, covering everything from hoof health and nutrition to training protocols for Quarter Horses, Friesians, and Paints. Every guide on Horse Racing Sense is rooted in this “boots-on-the-ground” perspective.
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