by Kentucky Equine Research Staff

Ohio has one of the largest horse populations in the United States, with close to a quarter million horses. A recent survey of Ohio horse owners and enthusiasts gathered data on current management practices, with the goal of identifying research and educational opportunities to enhance equine welfare. In this article, Kentucky Equine Research nutritionist Ashley Fowler, Ph.D., addresses some of the survey findings related to nutrition, offering practical insights to help horse owners improve the health and well-being of their animals.

General Information

A total of 1,422 Ohio residents responded to the 52-question survey, the majority of whom were horse owners. Respondents reported owning a wide variety of breeds, with Quarter Horses being the most common (29%), followed by Thoroughbreds (9%), Paints (8%), Warmbloods (7%), and Miniature Horses (7%). Most horses (21%) were between six and ten years of age.

In terms of housing, 32% were group-housed on pasture, 31% were stalled with unlimited turnout, and 13% were either stalled full-time or had limited turnout. Despite this, horses typically had access to grazeable pasture for only about six months of the year.

Additionally, 27% of horses were classified as “at maintenance,” receiving only voluntary exercise.

Feeding Hay and Concentrates

Most survey respondents (96%) reported offering concentrates that were fed either by weight or visual estimation. The primary reason owners fed concentrates was to “meet nutrition requirements not met by forage alone,” such as vitamin, mineral, and protein needs, as well as energy requirements.

“As the researchers discussed, a limitation of this question is that horse owners were not asked to specify what kind of concentrate they fed. Ration balancers, complete feeds, and other commercial concentrates are fed for different reasons,” explained Fowler.

The reasoning for feeding a concentrate is sound, according to her, as forage rarely provides all the required nutrients. Ration balancers provide important vitamins, minerals, and high-quality protein and are appropriate for horses that do not need additional calories, such as horses in light work or easy keepers. More energy-dense concentrates help provide additional calories beyond what forage can provide, in addition to filling gaps in minerals, vitamins, and amino acids.

Forage was primarily fed by flakes, bales, or “armfuls” rather than by weight.

Read more: Horse Management Survey Results: A Nutritionist’s Perspective

by Kentucky Equine Research Staff

Veterinary researchers recently conducted a comprehensive review of 22 studies using platelet-rich plasma (PRP) to treat tendon and ligament injuries in horses.* These soft-tissue injuries are major contributors to lameness and result in substantial economic losses for both owners and trainers. Despite growing interest, limited controlled clinical data support the efficacy of PRP.

PRP is a type of orthobiologic therapy derived from the horse’s own blood. The blood sample is processed, usually by centrifugation, to create a concentrated suspension of live platelets and white blood cells. This mixture is then injected directly into the horse’s injured soft tissue, guided by ultrasound.

“After the PRP is injected, it transforms into a platelet-rich ‘gel’ that releases growth factors and anti-inflammatory mediators,” explained Catherine Whitehouse, M.S., a nutrition advisor for Kentucky Equine Research.

Those molecules then attract nearby stem cells and promote regenerative mechanisms that ultimately help repair and heal damaged tissues.

During the researchers’ review of the studies, they asked six questions that may help owners better understand PRP.

1. Is PRP safe in horses?

Yes, across all 22 studies, no significant adverse effects were reported following PRP treatment.

2. What is the most common way of producing PRP?

Across the 22 studies, fresh whole blood volumes collected from horses ranged from 15 mL to 300 mL, with most researchers using between 50 and 81 mL. The standard method for producing PRP involved a double-centrifugation protocol; however, alternative approaches were used, including single-centrifugation semi-automated kits and gravitational filtration systems.

3. What is the optimal concentration of platelets?

This remains unknown. The platelet concentration in PRP in the studies ranged from 100 x 10³ to 1,370 x 10³ platelets/ìL. When reported (only nine of the 22 studies reported concentration), this value alternated between 1.3 to 8.7 times the concentration of platelets in whole blood.

4. What “dose” of PRP should be injected and how often?

Veterinarians injected platelet-rich plasma directly into the lesions in all studies. The volumes varied dramatically, from 1 mL to 12 mL. Most studies used between 2 mL and 5 mL, and most adjusted based on the size of the lesion on ultrasound. Most studies used a single injection, but one study performed three injections into the same lesions at two-week intervals.

“Considering that the concentration of platelets varied markedly in each PRP preparation, the difference in injected volume further complicates the issue of decoding the optimal dose,” explained Whitehouse.

5. What were the clinical outcomes?

Platelet-rich plasma yielded positive results in 18 of the 22 studies (86%), with researchers citing improvements in lameness, ultrasound appearance, and recovery times. However, researchers only reported positive results in two of the four randomized clinical trials when PRP was used as the only treatment. In the two randomized clinical trials with positive results, lameness scores decreased by 30% to 60% compared to 10% to 25% in the control groups.

The reviewers added, however, “PRP appears to be effective at promoting short- and medium-term recovery, but its long-term efficacy may depend on factors such as injury severity and concurrent therapies.”

6. Can PRP be combined with other therapies?

Yes. All case series and clinical trials included in the review combined PRP with controlled exercise programs to enhance healing.

In some studies, PRP was also paired with mesenchymal stem cells or bone marrow aspirate concentrate. However, current data are insufficient to determine whether these combinations offer added benefit. Further research on combining PRP with other regenerative therapies, such as extracellular vesicles or gene therapy, is needed.

“Standardized reporting and methodological rigor of PRP studies should be improved to ensure reproducibility and facilitate evidence-based veterinary practice,” concluded the researchers.

“To support the horse’s musculoskeletal system, including soft-tissue structures and joints, offer oral joint health supplements,” recommended Whitehouse.

^*Carmona, J.U., and C. López. 2025. Efficacy of platelet-rich plasma in the treatment of equine tendon and ligament injuries: A systematic review of clinical and experimental studies. Veterinary Science 12(4):382.

Reprinted courtesy of Kentucky Equine Research. Kentucky Equine Research is an international equine nutrition, research, and consultation company serving horse owners and the feed industry. Our goals are to advance the industry's knowledge of equine nutrition and exercise physiology, apply that knowledge to produce healthier, more athletic horses, and support the nutritional care of all horses throughout their lives. Learn more at Kentucky Equine Research.

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Editor's Note: This is an important topic for us. We had a horse die from Potomac Horse Fever in New York State even though he was vaccinated, but it is still important to vaccinate your horses and watch for signs of this potentially deadly disease. 

As summer heats up, so does concern over a serious equine illness: Potomac Horse Fever (PHF). Once considered rare in Canada, PHF is now appearing more frequently prompting veterinarians and horse owners to stay alert.

What Is Potomac Horse Fever?

Potomac Horse Fever (PHF), also known as equine neorickettsiosis or equine monocytic ehrlichiosis, is a serious intestinal disease that affects horses, especially during the warmer months. It was first identified in 1979 near the Potomac River in Maryland, but cases have since been reported across North and South America— including a growing number in Canada. PHF is caused by a type of bacteria called Neorickettsia. For many years, the only known culprit was Neorickettsia risticii. However, researchers in Canada and USA have recently discovered a new species, Neorickettsia findlayensis, in horses showing signs of PHF.

These bacteria live inside tiny parasitic flatworms (called trematodes) that infect aquatic insects like mayflies, caddisflies, and dragonflies. Horses can become infected when they accidentally eat these insects—often while grazing or drinking from contaminated water sources. Once inside the horse’s digestive system, the bacteria are released and begin to invade the lining of the colon and cecum. From there, they can enter the bloodstream and infect immune cells, leading to symptoms like fever, diarrhea, and in severe cases, laminitis.

PHF is typically a seasonal disease because the insects that carry the bacteria are most active in summer and early fall.

Why the Sudden Rise?

According to Dr. Luis Arroyo from the Ontario Veterinary College, climate change and shifting insect populations may be contributing to the spread of PHF into new regions, including parts of Ontario where it wasn’t previously seen. Increased awareness and better diagnostic tools are also helping identify more cases.

Signs to Watch For

PHF can come on suddenly and progress quickly. Common symptoms include:

• High fever
• Lethargy
• Loss of appetite
• Diarrhea
• Colic-like symptoms

In severe cases, laminitis (a painful hoof condition) or even abortion in pregnant mares Early detection is critical. If your horse shows any of these signs, contact your vet immediately.

Diagnosis and Treatment

Diagnosis typically involves blood and fecal tests, including PCR testing. Treatment usually includes oxytetracycline, an antibiotic that can be effective if given early. Supportive care like IV fluids may also be needed.

Prevention Tips

Talk to your veterinarian to learn about available vaccines and how well they protect against different strains of PHF, including newer ones found in Canada.

Other preventive steps include:

• Turning off barn lights at night to avoid attracting insects
• Covering water troughs and feed bins
• Cleaning up dead insects around the barn
• Avoiding turnout near ponds, rivers or streams during peak insect season

PHF is a serious but manageable disease. With vigilance, early intervention, and preventive care, horse owners can help protect their herds.

Resource Links

Potomac Horse Fever (PHF) Webinar

Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects.
Arroyo LG, Moore A, Bedford S, Gomez DE, Teymournejad O, Xiong Q, Budachetri K, Bekebrede H, Rikihisa Y, Baird JD.
Can Vet J. 2021 Jun;62(6):622-628. PMID: 34219771; PMCID: PMC8118184.

This article originally appeared on Equine Guelph, The University of Guelph and is published here with permission.

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by Kentucky Equine Research Staff

As horse owners, we know well the importance of providing horses with water. Consider these six facts about water the next time you’re scrubbing buckets or waiting for the trough to fill.

1. Not surprisingly, water consumption depends on body weight. Expect a Belgian to outdrink a Haflinger any day of the week. Oddly enough, though, horses of similar body weight and breed may have completely different, though normal, intakes. What’s normal, you ask? Idle horses in a moderate climate will drink 5-15 gallons (20-55 liters) of water daily.

2. Just because your old mare drank two buckets of water yesterday and the day before that doesn’t mean she’ll drink two today. Variations in water intake for individual horses may occur from day to day. Keep track of water consumption as best as you can, and alert a veterinarian if your horse seems to drink little or no water.

3. Without question, diet affects water consumption. Horses grazing lush pasture grasses, which are high in moisture content, will drink less water than those faced with a pile of hay. In fact, horses that consume all-hay diets drink more water than those fed mixed hay-grain diets.

4. Drinking doesn’t take up a lot of your horse’s day. Researchers calculated that well-fed mature horses spend only five or six minutes a day drinking water, though this is achieved in several visits to the water source.

5. Do foals drink water, or do their dams provide adequate fluid until weaning? If you’re a breeder, you’ve seen foals hit the waterer as early as a week old. In one study, one-month-old foals drank nearly a gallon of water in addition to more than four gallons of milk daily.

6. Depending on environmental conditions and work intensity, exercising horses may require more water than their sedentary peers, especially if they sweat. Horses that sweat daily should be given electrolytes to help replace mineral losses in sweat. Research-proven supplements like Restore SR and Race Recovery provide the best electrolyte therapy.

Providing fresh, clean water to horses at all times remains a basic principle of horsemanship.

Reprinted courtesy of Kentucky Equine Research. Kentucky Equine Research is an international equine nutrition, research, and consultation company serving horse owners and the feed industry. Our goals are to advance the industry's knowledge of equine nutrition and exercise physiology, apply that knowledge to produce healthier, more athletic horses, and support the nutritional care of all horses throughout their lives. Learn more at Kentucky Equine Research.

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Sentinel Horse Nutrition offers expert guidance in their eBook "Helping All Horses Live Healthier Lives". Read the excerpt below and be sure to get your free copy of the entire eBook!

Protein and Muscle Recovery for Performance Horses

Protein is a vital part of a horse’s diet. This is particularly true of performance horses as protein aids in muscle development, repair and overall health. Understanding the importance of specific amino acids will give your clients’ horses the best chance of top performance and recovery.

Amino acids: the building blocks of muscle.

Amino acids are the building blocks of protein, but not all amino acids are equally present in an equine diet. Limiting amino acids, such as lysine, methionine and threonine, cannot be synthesized by the horse and must be provided through feed. When these essential amino acids are in short supply, the horse’s ability to utilize other amino acids is restricted, which can negatively impact muscle development, repair and overall performance.

Competitive horses with an amino acid deficiency may exhibit signs such as poor topline development, muscle loss despite adequate caloric intake, delayed recovery after exercise and lack of stamina. Behavioral indicators may include reluctance to engage in strenuous activity, difficulty building or maintaining muscle mass and a dull coat, as protein also plays a role in skin and hair health. Ensuring a balanced intake of essential amino acids is critical in supporting peak athletic performance, strength and recovery. 

In equine nutrition, the primary limiting amino acids are:

Often the first limiting amino acid in equine diets, lysine is essential for growth and muscle development. Ensuring adequate lysine intake supports optimal protein synthesis.

This sulfur-containing amino acid plays a role in the synthesis of other proteins and supports hoof and hair health.

This amino acid is important for immune function and gut health and contributes to muscle protein synthesis.

Protein quality and digestibility.

Incorporating high-quality protein sources like soybean meal or alfalfa ensures the availability of essential amino acids necessary for muscle maintenance and repair. Performance horses experience significant muscle stress during training and competition, and intense exercise can cause microdamage to muscle fibers, requiring proper protein intake for recovery and adaptation.

Without adequate amino acids, muscle recovery slows, leading to fatigue, loss of topline and diminished performance. Ensuring a diet rich in essential amino acids supports strength, endurance and the ability to perform over time.

“Protein plays a vital role in muscle development, tissue repair and the horse’s overall health, but it works best as part of a wellrounded diet,” Sturken says. “It's important to balance protein with other energy sources to meet the horse's overall nutritional needs without overloading.”

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by Kentucky Equine Research Staff

Back pain occurs frequently in horses and, depending on the degree of discomfort, can limit performance. To better understand back pain in athletic horses, veterinarians examined 75 horses with histories suggestive of back problems using equipment and techniques available to most practitioners.^*

Horses were first examined at rest, noting conformation idiosyncrasies and muscle atrophy, as well as skin lesions from saddle marks. Responses to digital manipulation along the spine were also recorded. Rectal examinations performed on all horses revealed any abnormalities or pain in the pelvis (e.g., myositis, sacroiliitis, pelvic fracture, spondylosis, other sources of pain). Horses were then evaluated while hand-walking, longeing, and under saddle when ridden and jumping. Stretching exercises were also performed, enticing horses to take part by using treats placed by the horses’ elbows or between the forelimbs.

“At the walk, many horses had restricted hind limb movement and mobility, often raising the head and arching the back,” described Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research.

Further, tail-swishing when transitioning from trot to canter, stiffness, and poor hind limb impulsion were frequently noted. When horses were jumping, mistakes and refusals, including sliding stops, were noted.

Lateral radiographs of the thoracic dorsal spinous process and ultrasound examinations of the supraspinous and sacroiliac ligaments were performed. When indicated, mepivacaine blocks were performed in the interspinal space between painful spinous processes or the sacroiliac joint.

In that population of 75 horses, 18 horses were diagnosed with muscular strains, 30 cases of sacroiliac pain, and 16 cases of vertebral lesions such as crowding or spondylosis.

“Sacroiliac desmopathy was highly prevalent among the presented cases while interspinous desmopathy came next,” according to the examining veterinary team.

The team noted that back disorders may be attributable to ill-fitting tack, inadequate training, improper shoeing, and unequal distribution of rider weight.

Specific diagnoses may include lesions of the supraspinous, interspinous, and sacroiliac ligaments; strains of the longissimus muscle; impinging dorsal spinous processes or kissing spines; osteoarthritis; intervertebral disc disease; and vertebral fractures.

“In addition, the veterinarians cited poor management, including inadequate nutrition, as a potential contributing factor for back pain. Low-quality feeds and forages may not supply adequate nutrients important for strength and durability of the musculoskeletal system. Making sure your horse has a balanced diet with quality ingredients and proper amounts of vitamins and minerals is key to supporting healthy bone and muscle tissue,” advised Crandell.

Supporting optimal joint health can be achieved, at least in part, by supplementing horses with glucosamine, chondroitin sulfate, hyaluronic acid, and MSM found in quality supplements such as KER-Flex.

Horses included in this study were treated conservatively with rest for one to three months based on severity and nonsteroidal anti-inflammatory drugs (oral phenylbutazone or “bute”). In addition, horses that responded to the mepivacaine blocks were subsequently injected with the corticosteroid triamcinolone acetonide.

“Adequate rest and early treatment were prerequisites for recovery,” concluded the veterinarians.

^*Shokry, M., L.B. Ali, and M. El-Sharkawy. 2025. Relationship between back pain and poor performance in show jumping athletic horses. Open Veterinary Journal 15(3):1480-1487.

Reprinted courtesy of Kentucky Equine Research. Kentucky Equine Research is an international equine nutrition, research, and consultation company serving horse owners and the feed industry. Our goals are to advance the industry's knowledge of equine nutrition and exercise physiology, apply that knowledge to produce healthier, more athletic horses, and support the nutritional care of all horses throughout their lives. Learn more at Kentucky Equine Research.

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By Juliet M. Getty, Ph.D.

If you have pasture but hesitate to let your insulin-resistant horses graze, you may be pleasantly surprised. With the right approach, you can make use of your pasture, reduce your reliance on hay, and support your horse’s overall well-being. Consider this: insulin-resistant horses are under significant oxidative stress and inflammation. Restricting them to a dry lot with only hay can actually intensify that stress response. In contrast, allowing controlled access to pasture can offer natural enrichment and may be a valuable step toward healing.

Your hesitation may be well-founded, particularly if the pasture is high in sugar and starches. This concern is heightened when the grass is overly short, regularly fertilized, or consists of a single grass species without any edible weeds. Horses tend to consume copious amounts rapidly, which can cause a sharp increase in blood insulin levels — raising the risk of insulin resistance and potentially triggering laminitis.

Add in the cold nights of early spring and the cooling temperatures of fall, when grasses naturally hold onto higher levels of sugar and starch, and you have a potentially dangerous situation. When nighttime temperatures drop below 40°F, it becomes especially risky to allow pasture grazing the following morning — particularly for insulin-resistant horses — because the cold conditions cause grasses to store even more sugar and starches. These seasonal shifts make pasture-grazing management critical to protecting your horse’s metabolic health.

Summer has arrived for most of us, and with it comes greater stability in the sugar and starch levels of pasture grasses. So why assume your pasture is unsafe? Without testing, any concern is purely speculative. In fact, in many cases, pasture grasses have tested lower in sugar and starch than the hay being fed.

The only way to know for sure is to have your pasture analyzed. Testing for sugar and starch gives you a clear picture of how your pasture is behaving. Specifically, measuring ESC (ethanol soluble carbohydrates) will tell you the sugar content — the primary factor influencing insulin levels. Starch breaks down into glucose and can raise insulin as well. Knowing these numbers takes the guesswork out of pasture management, especially for horses with metabolic concerns.

Understanding carbohydrate patterns in pasture grass

Grasses generate simple sugars (ESC) and starch through photosynthesis when exposed to sunlight. On bright, sunny days, ESC and starch levels peak in the late afternoon to early evening.

As evening sets in, the grass begins using these stored carbohydrates for its own metabolic needs. This process continues overnight, and by early morning, ESC and starch levels are at their lowest.

On cloudy or rainy days, photosynthesis is reduced, resulting in lower overall sugar and starch production.

But sugar and starch can increase when:

• Grasses are under stress—from drought, overgrazing, or frequent mowing—they tend to retain higher levels of ESC and starch as a survival mechanism. To prevent this, avoid mowing shorter than 4 inches.
• Grass is allowed to grow excessively tall, leading to the formation of seed heads, which are high in carbohydrates and can pose a risk to insulin-sensitive horses.

Best- and worst- case scenarios for pasture testing

Remember, your pasture is a living, dynamic system, and any test you perform is simply a snapshot of its current condition. For more accurate insight, it’s ideal to test two or three times on your chosen day and repeat testing every two weeks. Below are guidelines for selecting times to test when managing insulin-resistant (IR) horses:

• Best case scenario: Test early in the morning, just before sunrise, following a sunny day. This timing typically offers the lowest levels of sugar (ESC) and starch and gives you the best estimate of how safe the pasture is for early-morning grazing by an IR horse.
• Worst case scenario: Test in the late afternoon, between 5:00 and 6:00 p.m., after a full sunny day. This is when sugar and starch levels are at their highest, and it represents the riskiest time for an IR horse to graze.
• Midday testing (optional): Testing around 11:00 a.m. on a sunny day can help you determine a safe time to bring horses off pasture before carbohydrate levels begin to climb.

How to test your pasture

For accurate results tailored to horses, Equi-Analytical Labs is an excellent choice, as their analysis is geared toward equine needs rather than cattle. Testing instructions are straightforward and available on their website: https://equi-analytical.com/feed-and-forage-analysis/taking-a-sample/

Here’s a summary of the process:

• Randomly select about 15 locations throughout your pasture.
• Clip the forage at the height your horse typically grazes. For instance, if the grass is 10 inches tall and your horse grazes the top 4 inches, clip just those top 4 inches.
• Cut the samples into small pieces, mix thoroughly, and place them into the bag provided by the lab.
• Freeze the sample overnight, then mail it in according to their shipping instructions.

On the order form, choose:

• “Fast Track” for carbohydrate levels (including ESC and starch), or
• “Equi-Tech #601” if you'd also like a mineral analysis.

For international submissions, guidelines can be found here: https://equi-analytical.com/feed-and-forage-analysis/submitting-a-sample/international-sample-submission/

Understanding key terms in your analysis report

It is important to understand the terminology used in your pasture analysis report:

• Percent Moisture and Dry Matter – These two values always add up to 100%. Since pasture grass contains a large amount of water, the moisture percentage will be high.
• “As Sampled” column – Reflects the nutrient content of the grass with its natural moisture. This represents what your horse is consuming in the pasture.
• “Dry Matter” column – Shows the nutrient content of the forage without any moisture. These values are more concentrated and allow for more accurate comparisons, especially when evaluating hay or other dry feeds.
• Digestible energy (DE) – Indicates how energy-dense, or “fattening,” the forage is. Expressed in megacalories (Mcal) per pound or kilogram.
• Water soluble carbohydrates (WSC) – Includes simple sugars and fructans. Fructans are not a concern for insulin-resistant horses since they do not raise insulin levels.
• Ethanol soluble carbohydrates (ESC) – Represents only the simple sugars—the main contributors to an insulin response.
• Starch – Long chains of glucose that break down during digestion into individual glucose molecules, raising blood insulin levels.
• ESC + Starch – This is the most important calculation for insulin-resistant horses. Add the ESC and starch values from your report to assess the forage’s insulin impact.
• Non-structural carbohydrates (NSC) – Often confused with more relevant values, NSC is calculated as WSC + Starch. It’s no longer used as a reliable indicator for insulin resistance because WSC includes fructans, which do not influence insulin. For this reason, ESC + Starch is now the preferred measure.

Use the Dry Matter column to compare pasture to hay

When analyzing hay for insulin-resistant horses, we aim for an ESC + Starch value of less than 10% on a dry matter basis. To evaluate your pasture in the same way, refer to the “Dry Matter” column in your pasture analysis report. Add the ESC and Starch values together—ideally, this combined number should also be below 10%.

Another key value to watch is Digestible Energy (DE), which indicates the caloric content of the grass. DE is expressed in megacalories (Mcal) per pound or kilogram. For pasture to be considered low enough in calories for an overweight insulin-resistant horse, the DE should be below 0.94 Mcal/lb (or 2.08 Mcal/kg) on a dry matter basis.

Do we still consider NSC?

Not usually—not when evaluating forage for insulin-resistant horses. Most cases of laminitis related to pasture are driven by elevated insulin levels, not fructans. However, reviewing the NSC (Non-Structural Carbohydrates) can still offer insight, particularly into fructan content.

Here’s a quick refresher on the calculations:

• NSC = WSC + Starch
• WSC = ESC + Fructans

Let’s break down an example:

• WSC = 11%
• ESC = 6%
• Starch = 2%

In the past, we would calculate NSC by adding WSC and Starch:
11% + 2% = 13%, which was considered the upper limit for safety. But today, the more accurate approach is to look at ESC + Starch, because these are the components that directly raise insulin levels:

6% + 2% = 8%, which is well under the 10% threshold—making this pasture suitable for an insulin-resistant horse.

A Real-Life Example: Best-case vs Worst-case Scenario

The following results come from actual pasture samples collected at 7:00 AM and again at 6:00 PM on the same day. Both days—prior to and including the sampling day—were sunny, and the testing took place during the summer.

7:00 AM Sample – Best-case scenario for an IR horse

(Dry Matter Basis):

• Digestible Energy (DE): 0.85 Mcal/lb
• ESC (Simple Sugars): 4.7%
• Starch: 0.2%
• ESC + Starch: 4.9%

6:00 PM Sample – Worst-case scenario for an IR horse

(Dry Matter Basis):

• Digestible Energy (DE): 0.86 Mcal/lb
• ESC (Simple Sugars): 6.9%
• Starch: 3.4%
• ESC + Starch: 10.3%

What these numbers tell us…

The morning sample is ideal for insulin-resistant horses, with an ESC + Starch total of just 4.9%—well below the recommended 10% maximum. Grazing during early morning hours under these conditions is generally safe and beneficial.

By contrast, the evening sample shows a significant rise in sugar and starch content after a full day of sun exposure. The ESC + Starch value climbs to 10.3%, which may be too high for sensitive horses, particularly those prone to insulin spikes or laminitis.

The digestible energy levels in both samples are suitably low for managing an overweight horse.

This example clearly illustrates how pasture sugar and starch levels can change significantly throughout the day—highlighting the importance of timing when managing grazing for insulin-resistant horses.

While midday values were not measured in this case, it’s well established that sugar and starch levels tend to rise steadily as sunlight increases. For added safety, consider removing your horse from pasture and transitioning to a dry lot with properly tested, low-sugar, low-starch hay around midday—when the sun is at its peak.

Bottom line

Putting in a little effort to test your pasture can make a substantial difference in supporting your insulin-resistant horse’s natural way of life—as a grazing animal. Since pasture conditions vary with weather, season, and management, it’s wise to test multiple times throughout the year to understand how your grass responds under different circumstances. You may find that your pasture is safer than expected -- good news for both you and your horse.

About the Author - Juliet M. Getty, Ph.D. has been working with horse owners for more than 25 years. A pioneer in free choice forage feeding, Dr. Getty’s philosophy is founded on feeding a horse in sync with his natural needs and instincts. She approaches equine health from a holistic perspective and considers nutrition a critical (and too often overlooked) element in the prevention and treatment of disease and disorders. Her unbiased opinions and recommendations are based on scientific research and are independent of feed, supplement, or pharmaceutical company influence.

Through private consultations, she designs customized feeding plans to promote horses’ health, reverse illness, and optimize performance; she believes every horse owner should include sound nutrition practices to give every horse a lifetime of vibrant health. Dr. Getty lives in Denton, Texas, in the Dallas/Fort Worth area with her husband.

This article originally appeared on Getty Equine Nutrition and is published here with permission.

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by Molly Todd, intern at Kentucky Equine Research.

Over the last year, Kentucky Equine Research has used chewing halters to record chewing frequency and to analyze the health and welfare of horses by observing behavioral changes during feeding.

The RumiWatch system was originally designed by a Swiss company to track rumination, grazing, standing, and other behaviors of cattle. Once the precision and accuracy of this technology was confirmed, the manufacturer designed a version for horses, called EquiWatch, which passed similar validation trials (Cunningham, 2018; Werner et al., 2020; and Weinert et al., 2020).

According to one research team, “the EquiWatch system can generate data necessary for more fully characterizing feeding behaviors in horses. Data output from the EquiWatch system can be used to determine the specific timing and duration of grazing activity as well as the vigor of pasture forage consumption over a selected interval” (Weinert et al., 2020).

The EquiWatch chewing halter features a sensor that detects pressure changes in an oil-filled tube within the noseband. The sensor is attached to a data logger on the cheekpiece of the halter. The halter also features a battery-powered three–axis accelerometer that detects changes in head position and temperature. All the components are watertight, so the halters can be used in field conditions.

Fitting the halters correctly is important for accurate data collection. The noseband must be adjusted three fingers’ width below the cheekbone and be snug around the muzzle so only two fingers can lie flat between it and the nose bridge.

The halters record data to an SD memory card. Data include time spent eating and the total number of chews, both of which can be split into whether the chewing was performed with the head up or the head down.

In previous studies using the chewing halters, researchers have collected data from horses eating only forage. Scientists at Kentucky Equine Research are now using chewing halters to investigate common feeds used in the management of horses. Chewing halters are fitted on the horses before they are fed a defined amount of feed. Following the completion of the meal, any spilled feed is collected to determine feed intake. From the data collected from the chewing halters, we can calculate variables such as chews per minute, chews per gram of feed intake, and rate of intake. We can compare these variables among feeds with different nutritional compositions, physical form (pellets versus cubes versus textured), and palatability.

Factors that may affect chewing (ingestive behavior) include particle length, elasticity, moisture, flavor, volume, and fracture volume. Animal behavior also plays a role in ingestive behaviors, such as age, preference, condition, previous experience, health status, and temperament.

Chewing starts both chemical and mechanical digestion of feedstuffs due to the production and mixing of saliva and reduction of particle size. Observing and understanding jaw movement can also help researchers better understand how to reduce stomach ulcers as well as assist with dentistry (Werner et al., 2016).

To learn more about the work done at Kentucky Equine Research using chewing halters, read this research abstract: Chewing Requirements and Glycemic Response of Fibrous Feedstuffs.

This article was written by Molly Todd, a year-long intern at Kentucky Equine Research. As part of the intern program, participants are asked to contribute to Equinews. Learn more about the internship program.

Reprinted courtesy of Kentucky Equine Research. Kentucky Equine Research is an international equine nutrition, research, and consultation company serving horse owners and the feed industry. Our goals are to advance the industry's knowledge of equine nutrition and exercise physiology, apply that knowledge to produce healthier, more athletic horses, and support the nutritional care of all horses throughout their lives. Learn more at Kentucky Equine Research.

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