Alltech Feature Stories

Keeping racehorse feed "on track"

Precision nutrition fuels new generations of champions

What’s new in feeding today’s superstar racehorses and the champions of the future? In a sense, nothing and everything. While the basic nutritional needs of these elite equine athletes haven’t changed, attention to the form in which their daily ration is provided and the level of specific nutrients in their diets has become far more critical.

Keeping racehorse feed “on track”

What’s new in feeding today’s superstar racehorses and the champions of the future? In a sense, nothing and everything. While the basic nutritional needs of these elite equine athletes haven’t changed, attention to the form in which their daily ration is provided and the level of specific nutrients in their diets has become far more critical. As faster records are set on the racetrack and expectations for heightened performance increase, so do the demands on the horse’s system. More horses are sidelined by injuries caused by fatigue or a skeletal system that is not strong enough to perform its “job.”

The principle is the same as that for human athletes, said Dr. John Lew, equine nutritionist and manager of research and technical services at McCauley Bros., a horse feed company in Versailles, Kentucky.

“When split seconds count, every single nutrient has to be provided in the correct amount and ratio.”

Amy Gill, Ph.D., equine nutritionist and Thoroughbred racehorse breeder and owner

“Whether you’re talking about a horse or a person, if an athlete needs to run faster, jump higher or cover more distance—and remain healthy throughout an entire career—proper nutrition is key,” said Lew. “We know a lot more about feeding performance horses than we did in the past.”

Hay, oats and water, which were mainstays of the racing diet for decades (perhaps even centuries), simply don't cut it anymore. The racing industry has seen a move away from straight cereal grains in favor of commercial products designed specifically for racehorses. These newer feeds use alternative energy sources such as fat and soluble fiber to decrease the amount of energy from starches. When fed with a sufficient amount of forage (hay), they are formulated to supply the requisite nutritional needs of a racehorse.

A racing feed should limit calories from starches and sugars to less than 25 percent, with 6 to 10 percent of calories coming from fat. By comparison, a diet of straight oats and hay is deficient for a racehorse because it is very high in starches and does not provide enough lysine and minerals, which can compromise skeletal development.

“The racehorse diet has to be fully optimized in order for the horse to be properly fueled for the task of running races,” said equine nutritionist and Thoroughbred racehorse breeder and owner Dr. Amy Gill. “When split seconds count, every single nutrient has to be provided in the correct amount and ratio. On top of that, there are certain nutrients that should be provided at therapeutic levels to help keep the horse performing well.”


Based in the heart of Kentucky’s Bluegrass for 80 years, McCauley Bros. equine feeds have fueled some of the world’s greatest and most beloved horses.

Dr. Kristen Brennan, equine research project manager at Alltech's Center for Animal Nutrigenomics and Applied Animal Nutrition in Nicholasville, Kentucky, concurs. She has conducted ongoing extensive research on modern methods of maximizing the efficacy of performance horse diets. One of her studies is focused on the effects of nutrients on joint inflammation, a common health and fitness challenge for racehorses.

The potential of algae to reduce inflammation interests Gill, who has found it to be a beneficial source of omega-3 fatty acids, which are key to racehorse performance.

“Omega-3s from a cold-pressed vegetable source are preferable to those from fish,” she said. “They are a very potent and effective way to control whole-body inflammation, which is very common in racehorses because of the high levels of stress they experience.”

In particular, said Gill, vegetable-sourced omega-3s are effective in reducing inflammation in the lungs and gut, key areas where problems commonly develop in racehorses.

Lew has also conducted research on targeted nutritional therapies for horses (mainly Thoroughbreds and Standardbreds), which comprise the majority of McCauley’s clientele. The company is based in the Bluegrass region of Kentucky, the heart of Thoroughbred breeding in the United States. Six of the 20 starters and the first three finishers in the 2015 Kentucky Derby were McCauley feed customers.

It is a longstanding maxim that to excel at their job, racehorses need sufficient energy, protein, vitamins and minerals. In general, racehorses often require about twice as many calories as leisure horses do. Researchers in recent years have determined that certain nutrients may affect the fuel supply available in a horse’s muscles, as well as its ability to convert that fuel into a useful form that enables it to “go the distance.”

“We want to keep them healthy from weaning to winning.”

John Lew, Ph.D., equine nutritionist and manager of research and technical services at McCauley Bros.

Most of McCauley’s stock feeds were formulated for racehorse breeding farms, but Lew said the company will also custom-mix a formula on request.

“Whatever it takes for a barn of horses or for an individual horse to thrive, we want to keep them healthy from weaning to winning,” said Lew, who is also a former steeplechase jockey and an accomplished competitor in other high-performance disciplines, including three-day eventing and show jumping. He previously managed the University of Kentucky's horse farm.

Everything an operation provides as part of the horse’s daily sustenance—“how they feed, the type of hay and concentrate they use, even their water source”—should be evaluated by an equine nutrition expert, said Lew. McCauley nutritionists will visit farms on request, he added, because “if we don’t see the horses, we’re relying on second-hand information about their current condition and needs.”

“You have to give the horse the building blocks to fix a problem instead of putting a Band-Aid on it with pharmacological agents.”

Amy Gill, Ph.D., equine nutritionist and Thoroughbred racehorse breeder and owner

Gill said targeted nutritional therapies have shown major success; she sees them as the wave of the future for champion racehorses. She underscored the importance of gastrointestinal health for the horse, which is a hindgut fermenter. Today’s racehorses are under a lot of stress, said Gill, which makes them prone to ulcers and other gastric problems that can adversely impact their health and performance.

“You have to give the horse the building blocks to fix a problem instead of putting a Band-Aid on it with pharmacological agents,” she said.

Otherwise the issue is likely to resurface after treatment is stopped. While there are effective pharmaceuticals on the market to help heal ulcers, for example, the key is to determine during treatment what changes are needed in a racehorse’s diet to keep it from continuing to develop ulcers in the future.