Resources - USA - Equine

  • October 2, 2017

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    Colic in horses can be defined as exhibiting signs of distress caused by abdominal pain. It is one of the most frequent causes of emergency treatment annually and is …

  • A cowboy loops his lasso while a herd of cattle look on.

    July 27, 2017

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    On a weight basis, the horse’s body consists of approximately 60 to 65% water, 30 to 35% of protein, fat, and stored energy sources, and 4% in minerals.  While minerals only …

  • A blonde woman feeds a brown and black horse from a bucket.

    June 22, 2017

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    Molds are single-celled fungi that are found everywhere in nature.  They grow on plants among other substrates in nature and play a role in the natural process of plant decay. …

  • A group of colts on a green field look over a fence toward camera.

    May 4, 2017

    By Matt McMillan, PhD and Chris Morrow, DVM

    It’s the goal of every horse owner who intends to breed a mare to produce a good, strong, healthy colt.  To accomplish this goal, there are many considerations to be taken into account from …

  • Hunter Meinzer hand feeds a horse

    April 13, 2017

    By Chris Morrow, DVM and Matt McMillan, PhD

    Tying-up in horses is a ‘catch-all’ term used by many horse men and women who are referring to a muscle cramping, soreness, or unwillingness to move in horses that is generally brought …

  • Dr. Chris Morrow examines a brown horse.

    March 2, 2017

    By Dr. Chris Morrow, DVM

    As equine practitioners, we use the word choke to describe an esophageal obstruction. This condition will present itself as a horse begins to exhibit signs of distress including the expelling of feed from …

  • A horse walks across a lot with a purple blanket on.

    January 17, 2017

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    As winter weather approaches, temperatures will begin to fall with the possibilities of rain, snow, ice, and wind. Because of these environmental changes, increased …

  • Black and white photo of horse with his mane braided at a rodeo

    November 17, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    Nutrient requirements of the horse can change depending upon several factors related to the type, and weight of the horse, stage of life and level of activity. When …

  • Brown horse grazes green grass with a sunset backdrop.

    October 10, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    The senior horse has become more prevalent in modern times due to the change in workload, and activity of horses in general compared to what was required of the horse many …

  • A bowl of soybeans sits next to a bottle of vegetable oil on its side.

    September 12, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    At one time, it was generally thought by the equine scientific community that horses could not digest and utilize fat at a rate that would be sufficient to contribute to …

  • Two horses eating oats.

    August 8, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    Distiller’s Dried Grains with Solubles (DDGS) are the by-products produced from the manufacturing process of ethanol. These products have been readily available in …

  • A mare grazes green grass while her colt looks ahead.

    July 18, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    As breeding season for mares comes to a close, many considerations should be taken into account so that a live, healthy foal can be produced in the springtime next year.  …

  • A horse pokes it's head out of a trailer window.

    December 22, 2016

    By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

    While some equine enthusiasts haul their horses throughout the year, many more begin to look towards taking their horses down the road to their favorite equine event as …

  • Two horses graze on green grass with a sunset in the background.

    April 14, 2016

    By Dr. Chris Morrow, DVM

    As a student of the horse it is evident that the species was evolved on varied grass diets.  They are designed to walk around foraging ready to run away from anything that would eat them.  The health of the …

  • A brown horse eats Alfalfa hay from a trough.

    March 17, 2016

    By Matt McMillan, Ph. D, Equine Nutritionist, Hi-Pro Feeds

    For many years, feeding oats and alfalfa hay has been a very common diet for the working and performance horse.  However, with more and more research being conducted in the …

  • A brown quarter horse with black halter stands in profile.

    January 29, 2016

    By Matt McMillan, Ph. D, Equine Nutritionist, Hi-Pro Feeds

    As any good scientist would say, the answer to this question is “It depends…”.  So what about starch?  It seems that starch is, and has been the hot topic of discussion …

Kentucky Equine Research

  • Cold Weather Weaning Practices Impact Foal Health

    weanling horse

    No matter how one goes about weaning a foal, the process remains one of the most stressful events in a horse’s life, alongside transport and introduction into a new herd. Stress often causes immunosuppression, leaving the foal’s immune system weaker than normal and unable to fight off infection. Because of this, respiratory tract infections occur commonly in foals at the time of weaning.

    One weaning approach involves introducing foals from different farms into a loose housing system with access to a paddock and shelter. According to one research group*, this approach, used for approximately 30% of weanlings in Finland, allows foals to move freely, engaging in normal social behaviors with peers. Researchers found this method of weaning satisfactory for the health and development of young horses.

    Mixing horses always brings a risk of respiratory tract infections. Foals in Finland and other countries in northern climates are typically weaned during the winter when temperatures can fall as low as -4° F (-20° C) for several weeks. Therefore, a better understanding of the impact of unheated, loose housing for newly weaned foals mixed from different farms on respiratory health will benefit these foals.

    To achieve this, the research team observed two groups of foals from 11 different farms. In total, 36 foals were kept in unheated loose housing systems and 24 were maintained in insulated stables with daily turnout in paddocks. The researchers found:

    • Older foals were less likely to develop respiratory diseases than younger foals;
    • When the available space for sleeping was reduced and when the sleeping area was not insulated, foals had higher blood fibrinogen levels—a measure of systemic inflammation; and
    • Foals in loose housing systems had lower body condition scores than stabled foals, possibly due to increased mobility.

    “The housing system did not impact respiratory health in this study. The researchers suggest, however, that foals in unheated loose housing systems may need additional feed to maintain appropriate body condition, and that stabling foals over the winter might be a better approach,” summarized Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research (KER).

    Supplementing a mare’s diet with omega-3 fatty acids during pregnancy and lactation provides natural protection to the foal by minimizing stress and inflammation associated with weaning. Look for EO•3, a marine-derived oil rich in the omega-3 fatty acids DHA and EPA, to support mare and foal health. Australian horse owners should look for these research-proven products.

    To help determine the best way to feed your foal at time of weaning, consult with a KER nutrition advisor.

    *Junkkari, R., H. Simojoki, M.L. Heiskanen, et al. 2017. A comparison of unheated loose housing with stables on the respiratory health of weaned foals in cold winter conditions: An observational field-study. Acta Veterinaria Scandinavica. 59(1):73.

    Category Headline Image: 
    process of weaning horse foals
    Article Type: 
    Overview: 
    The weaning process is one of the most stressful events in a horse's life. Stress often causes immunosuppression, leaving the foal’s immune system weaker than normal and unable to fight off infection.
  • Gene Therapy for Tendon, Ligament Injuries in Horses

    equine soft tissue injury

    Even with extensive rest and appropriate rehabilitation equine tendon injuries frequently recur. Some owners rely on the “kitchen sink” approach in an effort to help their horses, mixing complementary and regenerative therapies with traditional care Despite the best care, recurring tendon injuries prematurely end many athletic careers.

    “Regenerative therapies such as stem cells and platelet-rich plasma have helped horses return to athletic function following a soft tissue injury, but equine researchers and veterinarians know that we can still do better,” explained Laura Petroski, B.V.M.S., a veterinarian for Kentucky Equine Research (KER).

    A novel approach to treating therapies was recently described by a group of scientists from the United Kingdom. Their technique involved using gene therapy to create specific genes that, once injected into the horse, produce proteins that help heal the injury.

    “The use of recombinant proteins and gene therapy is the most advanced and promising approach in the treatment of musculoskeletal disorders in human medicine. To date, direct gene therapy of equine tendon injuries has never been employed,” explained the researchers.

    In the study, the researchers selected two “therapeutic” proteins: vascular endothelial growth factor 164 and fibroblast growth factor 2. Both of these proteins were chosen due to their roles in restoring normal tissue strength and elasticity instead of producing weak scar tissue.

    To test whether gene therapy is a viable option for soft-tissue injuries, two horses with naturally occurring lesions were selected to study. DNA encoding the two therapeutic proteins was injected directly into the lesions (one was a suspensory ligament injury, the other had a defect in the superficial digital flexor tendon) within three months of lameness onset.

    “Both horses experienced full recovery and complete restoration of the affected ligament and tendon based on repeated ultrasound examinations,” said Petroski. “Additional data regarding safety and efficacy are needed, but this preliminary study certainly suggests that gene therapy is worthy of continued study.”

    Products traditionally classified as joint supplements may also benefit tendons and ligaments.

    Glucosamine and chondroitin sulfate products, including KER•Flex, support soft tissues,” Petroski recommended. In Australia, look for Glucos-A-Flex.

    Category Headline Image: 
    soft tissue injuries in horses
    Article Type: 
    Pull Quote: 
    Products traditionally classified as joint supplements may also benefit tendons and ligaments.
    Overview: 
    A novel approach to treating therapies was recently described by a group of scientists. Their technique involved using gene therapy to create specific genes that, once injected into the horse, produce proteins that help heal the injury.
  • Horse Management Practices: Room for Improvement

    horse management

    What does a domesticated horse need?

    If you consider only the five freedoms, horses need remarkably little: feed, water, a pain- and disease-free life, the ability to express normal behavior, and an environment free of fear and distress. Is providing only the basics enough, or do we owe our equine companions more?

    Considering the lifestyle of a “free and feral” horse, equine behaviorists suggest that many domesticated horses do not receive the care they require.

    According to a recent study*, “Free-roaming horses graze from a diverse range of vegetation and travel considerable distances daily to obtain food and water. Their movement and opportunity to graze are largely unrestricted, and they have considerable decisional latitude. In contrast, domesticated horses are commonly managed in stables or other forms of confinement…and/or on pasture that varies in area, forage length and quality.”

    In the study, data were analyzed from 505 Australian horse owners who responded to an online survey regarding horse-keeping practices. Some of the key findings of the study included:

    • Most horses (83%) were managed on pasture;
    • One-quarter of horses were housed individually and an additional one-quarter were housed with only one other horse; and
    • Most owners provided water and hay on a daily basis, even to horses maintained on pasture.

    The most concerning data, according to the researchers, were:

    “Considering horses are herd animals, minimal social contact and exercise were specifically identified as welfare issues,” relayed Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research (KER).

    She added, “Lack of exercise and other facets of domestication leave horses reliant on humans to provide the bulk of their nutritional needs. Some owners may not have the know-how or experience to properly care for horses, especially from a diet perspective. Owners with questions regarding forage quality and dietary requirements should reach out to a KER nutrition advisor.”

    This study also noted that a substantial number of horses had access to only natural sources of water. Horse owners relying on natural water sources were encouraged to monitor water carefully for drought, disease (e.g., giardia, leptospirosis), and toxins such as blue-green algae.

    *Thompson, K.R., L. Clarkson, C.B. Riley, et al. 2017. Horse-keeping practices in Australia: findings from a national online survey of horse owners. Australian Veterinary Journal. 95(11):437-443.

    Category Headline Image: 
    stalled horse
    Article Type: 
    Pull Quote: 
    Considering horses are herd animals, minimal social contact and exercise were specifically identified as welfare issues.
    Overview: 
    Is providing only the basics enough, or do we owe our equine companions more? Considering the lifestyle of a “free and feral” horse, equine behaviorists suggest that many domesticated horses do not receive the care they require.
  • Equine Protozoal Myeloencephalitis (EPM) Vaccine Studied

    EPM in horses

    Vaccination remains one of the most important ways to help protect horses against disease. While some vaccines, like rabies, prevent disease, others are intended to aid in disease control. A vaccine against Sarcocystis neurona, a causative agent for equine protozoal myeloencephalitis (EPM), has been available since 2000, but its efficacy has been unclear. A recent study reveals researchers might be headed back to the lab.

    According to the study*, approximately 50% of all horses in the United States come into contact with S. neurona, and an estimated 14 of every 10,000 clinical cases are attributed to EPM each year. Even with treatment, only 70-75% of horses show an improvement in clinical signs. Further, relapses occur commonly, and residual neurological deficits are frequent.

    “Because there is no cure for EPM, disease prevention plays a prominent role in protecting horses,” said Laura Petroski, B.V.M.S., a veterinarian for Kentucky Equine Research (KER).

    “To help protect horses against EPM caused by S. neurona, a vaccine was developed and conditionally licensed. Although the product was considered safe, post-vaccination challenges to determine the efficacy of the product were not performed,” Petroski explained.

    One research team successfully developed an equine model of EPM to test the vaccine. Researchers recruited 70 healthy, neurologically intact horses void of antibodies against S. neurona—an indicator that none of the included horses had been exposed to the pathogen previously. A subset of horses was vaccinated, and all horses were subsequently administered S. neurona sporocysts, the infective form of the protozoa.

    The research team found that almost all horses exposed to S. neurona sporocysts developed neurological signs consistent with EPM, including the vaccinated group, prompting researchers to conclude that the vaccine did not protect horses from developing neurological deficits.

    Experts recommend limiting opossum access to barns, sealing concentrates and other feeds or supplements in bins with tight-fitting lids, and using haynets or feeders, even in fields, to limit exposure to S. neurona.

    Vitamin E is a valuable component of the EPM treatment regime, as the EPM disease cycle includes an oxidative phase. “Experts recommend administering between 5,000 and 10,000 IU of natural vitamin E per day for horses with EPM because of its proven antioxidant action. KER offers Nano•E, a natural form of vitamin E that is water-soluble and rapidly absorbed,” shared Petroski.

    *Saville, W.J.A., J.P. Dubey, A.E. Marsh, et al. 2017. Testing the Sarcocystis neurona vaccine using an equine protozoal myeloencephalitis challenge model. Veterinary Parasitology. 247:37-41.

    Category Headline Image: 
    equine protozoal myeloencephalitis
    Article Type: 
    Pull Quote: 
    Because there is no cure for EPM, disease prevention plays a prominent role in protecting horses.
    Overview: 
    A vaccine against Sarcocystis neurona, a causative agent for equine protozoal myeloencephalitis (EPM), has been available since 2000, but its efficacy has been unclear. A recent study reveals researchers might be headed back to the lab.
  • Intra-articular Corticosteroids and Equine Joint Health

    horse joint pain

    If your horse isn’t performing well due to joint inflammation and pain, a veterinarian may suggest injecting an anti-inflammatory corticosteroid into the affected joint. Four products currently have approval by the U.S. Food and Drug Administration for intra-articular use, including isoflupredone acetate (IPA). Surprisingly, little data has been collected on the impact of IPA within the joint or its duration of action.

    “Based on research involving two other intra-articular medications, methylprednisolone and triamcinolone, equine experts* suggest that IPA may actually exert beneficial effects long after it can be detected in the blood,” explained Laura Petroski, B.V.M.S., veterinarian for Kentucky Equine Research (KER).

    To test this theory, Knych and colleagues from the School of Veterinary Medicine at the University of California, Davis, devised a system to measure the effect and duration of effect of intra-articular corticosteroid drugs. Specifically, the system measured the expression of various pro-inflammatory mediators and degradative enzymes that can harm the joint.

    “Previous studies on triamcinolone showed that this particular intra-articular corticosteroid had a long duration of action, exerting beneficial effects long after the medication could be detected in a horse’s bloodstream,” relayed Petroski.

    In the current study, 12 healthy horses undergoing a stringent exercise regime received either 8 mg of IPA into the radiocarpal joint (the topmost joint of the knee) or just saline. Blood and synovial fluid samples were subsequently collected at specific time points up to 42 days following administration. Key findings included:

    • In treated horses, IPA levels in blood and synovial fluid were below the “level of detection” between 14 and 21 days following intra-articular administration;
    • Compared to the expression of various genes at baseline, immediately prior to IPA administration, altered expression—both increased and decreased—was noted for thousands of genes in synovial fluid; and
    • Of those, a significant increase in the expression of the Annexin A1 gene was noted up to 42 days after IPA administration. This gene produces a potent anti-inflammatory protein that blocks key steps in the arachadonic acid cascade and was not increased in the control horses;
    • In addition, significant decreases in the levels of the inflammatory mediator interleukin 23A as well as enzymes that degrade articular cartilage (matrix metalloproteinases 1 and 9) were noted for up to 42 days following treatment.

    The researchers concluded that the results of this study advance understanding of the anti-inflammatory nature of intra-articular administration of IPA and that IPA appears to have a prolonged effect relative to detection time in the bloodstream and joint fluid.

    Either in lieu of or in addition to intra-articular corticosteroids, the use of certain oral joint health products can also help maximize the health of equine joints. Consider using high-quality products such as KER•Flex and Synovate HA to help maintain the health and integrity of the joint tissues, including the articular cartilage lining the ends of bones within joints.

    “In Australia, horse owners should look to Glucos-A-Flex, a blend of glucosamine hydrochloride, vitamins, minerals, and amino acids, for joint support,” recommended Petroski.

    Each of the four FDA-approved corticosteroid drugs has clear guidelines regarding the amount to be injected into a joint, the total amount used in the horse, and the number of hours or days the medication must be administered prior to competition to avoid a positive drug test result.

    *Knych, H.K., L. Harrison, N. Chouicha, et al. Expression of inflammatory and structural matrix genes in synovial fluid following intra-articular administration of isoflupredone acetate to exercised horses. Equine Veterinary Journal. In press.

    Category Headline Image: 
    horse joint inflammation
    Article Type: 
    Overview: 
    Used to treat joint inflammation and pain through intra-articular administration, equine experts suggest that isoflupredone acetate may actually exert beneficial effects long after it can be detected in the blood.
  • Embryo Transfer, Placental Alterations, and the Developing Foal

    horse foal

    With the widespread adoption of assisted reproductive technologies, horse owners have the freedom to essentially inseminate any embryo into any mare at almost any point in time. In cases of embryo transfer, for example, recipient mares are frequently selected based on the character or availability of the mare rather than her suitability as an optimal surrogate.

    Previous research shows that transferring embryos between pony breeds and larger breeds, such as drafts, Thoroughbreds, or Saddlebreds, can impact the size and metabolism of the foal. Whether or not the foal was adversely affected depended on whether the embryo was placed in a growth-enhanced (i.e., a pony breed in a larger recipient mare) or a growth-restricted (i.e., a larger breed in a pony recipient mare) environment.

    “We know that the placenta does more than simply nourish the developing foal. The placenta also transmits stimuli from the maternal environment to the fetus. Those stimuli result in placental adaptations in terms of function, size, and shape,” explained Laura Petroski, B.V.M.S., veterinarian for Kentucky Equine Research (KER).

    She added, “The genetic makeup of the recipient mare can also influence the genetics of the foal—a process now referred to as epigenetics.”

    Despite realizing that the foal’s environment, be it richer or poorer, impacts growth and lifetime development, researchers still have much to learn about the exact changes that occur in different mare and foal combinations.

    Recently, a group of European researchers took the next step in this research, transferring embryos between pony, Saddlebred, and draft mares. Their research confirmed that:

    • Foals transferred from Saddlebred to pony mares were growth retarded and had an increased gestational length;
    • Placental weight was reduced in these growth-restricted pregnancies but the surface density and volume were increased; and
    • Genes involved in growth, development, and the transfer of nutrients between the placenta and foal were also strongly reduced.

    Interestingly, changes in gene expression in the placentas of draft recipient mares carrying pony and Saddlebred foals (i.e., a growth-enhanced environment) were not markedly altered.

    “Further research in this field is important considering that approximately 22,000 equine embryos are transferred worldwide each year. Having a better understanding of the dynamic relationship between the recipient mare and the embryo can optimize the health of the developing foal and minimize the occurrence of potentially avoidable diseases in the future, including insulin resistance, obesity, metabolic syndrome, and laminitis,” Petroski emphasized.

    In the meantime, optimizing mare nutrition for appropriate fetal growth will also benefit the long-term health of both mare and foal. Consult with a KER nutrition advisor today to learn how.

    *Robles, M., P.M. Peugnet, S.A. Valentino, et al. Placental alterations in structure and function in intra-uterine growth-retarded horses. Equine Veterinary Journal. In press.

    Category Headline Image: 
    embryo transfer in horses
    Article Type: 
    Pull Quote: 
    In the meantime, optimizing mare nutrition for appropriate fetal growth will also benefit the long-term health of both mare and foal.
    Overview: 
    Despite realizing that the foal’s environment impacts growth and lifetime development, researchers still have much to learn about the exact changes that occur in different mare and foal combinations.
  • Regenerative Therapies for Laminitic Horses

    laminitis in horses

    Laminitis can strike at any time, contributing to pain, loss of function, poor quality of life, and economic losses associated with treatment. Medical therapies can help some affected horses, yet many cases remain unresponsive to treatment.

    Given the impact of laminitis on the equine industry, owners and veterinarians are often willing to try novel treatments, including administration of stem cells and platelet-rich plasma (PRP).

    "These regenerative therapies have traditionally been used for treating tendon injuries, wounds, and even joint disease. More recently, however, veterinarians have been exploring the use of these treatment modalities in laminitic horses with reported success," explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research (KER).

    While horse owners are fortunate to have these treatment options available, there is little science supporting the use of stem cells or PRP for laminitis in horses. To determine if these therapies benefit affected animals, a group of Italian scientists used a combination of adipose-derived stem cells and PRP on nine horses with chronic laminitis*. All horses had naturally occurring laminitis and were previously treated unsuccessfully with conventional therapies.

    The horses were administered the stem-cell/PRP slurry intravenously in a digital vein. Injection was repeated once monthly for three consecutive months. The researchers found neither short- nor long-term adverse reactions following injection and, importantly, all horses showed improvement in blood flow, structure, and function of the hoof. All nine horses reportedly returned to a comfortable quality of life.

    Other ways to maintain healthy hooves in horses to avoid life-threatening bouts of laminitis include routine farrier, avoidance of sudden access to lush pastures or high-grain feeds, and maintenance of optimal body condition scores to minimize the development of insulin resistance and metabolic syndrome.

    “In addition, a quality nutritional supplement designed to support hoof health and help with the healing process can be fed to horses with laminitis,” shared Crandell. “KER offers Bio•Bloom PS, a product that contains biotin, methionine, iodine, chelated zinc, lecithin, and essential fatty acids to promote healthy hoof growth and resilient hoof horn.”

    Australian horse owners should look for BioBloom.

    *Angelone, M., V. Conti, C. Biacca, et al. 2017. The contribution of adipose tissue-derived mesenchymal stem cells and platelet-rich plasma to the treatment of chronic equine laminitis: a proof of concept. International Journal of Molecular Science. 18(10). pii: E2122.

    Category Headline Image: 
    equine hoof health
    Article Type: 
    Pull Quote: 
    The researchers found neither short- nor long-term adverse reactions following injection and, importantly, all horses showed improvement in blood flow, structure, and function of the hoof.
    Overview: 
    Given the impact of laminitis on the equine industry, owners and veterinarians are often willing to try novel treatments, including regenerative therapies involving the administration of stem cells and platelet-rich plasma.
  • Selenium Supplementation in Exercising Horses

    selenium in horse diets

    Selenium plays many important roles in a horse’s body, one of which involves fighting off damaging free radicals produced during exercise. The mitochondrion—also known as the powerhouse of the cell—is a prodigious producer of free radicals during exercise. Trainers attempt to ward off free radicals by supplementing diets with selenium. Unfortunately, this strategy may negatively impact the mitochondrion’s ability to respond and adapt to exercise for maximal energy production to fuel working muscles.

    To determine the effect of selenium on the mitochondrion’s ability to adapt to athletic training, one research team* recruited 30 Quarter Horse yearlings. The horses were divided into two groups, a training and a nonexercised group. Within each of those groups, horses were supplemented with either 0.1 or 0.3 selenium mg/kg dry matter (DM). After 14 weeks, horses underwent submaximal exercise tests and researchers evaluated mitochondrial function.

    “The National Research Council currently recommends 0.1 mg/kg DM of selenium daily; however, optimal dietary selenium during periods of high demand, such as training, remain unclear and could, in fact, be higher,” explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research (KER).

    Nonexercised horses receiving 0.3 mg selenium/kg DM had higher citrate synthase activity—a measure of mitochondrial mass (the amount of energy-producing mitochondria in muscle)—than horses receiving only 0.1 mg selenium/kg DM. Further, when horses were originally supplemented with 0.3 mg selenium/kg DM then offered only 0.1 mg selenium/kg DM, a significant decrease in mitochondrial activity occurred (measured via the activity level of the cytochrome c oxidase enzyme), suggestive of impaired mitochondrial function.

    These findings prompted the researchers to suggest the following:

    • In addition to the antioxidant benefits of selenium, supplementation with selenium may also improve mitochondrial biogenesis, an increase in mitochondrial mass to improve energy production;
    • The reported improvements in mitochondrial density (as evidence by increased citrate synthase activity) in response to dietary selenium supplementation may improve diets for elite equine athletes; and
    • It may not be prudent to decrease dietary selenium during an exercise training program to preserve mitochondrial function during exercise.

    “This is a fascinating study because it provides some proof that the National Research Council recommended levels are minimal and perhaps not optimal like nutritionists have speculated. That said, owners need to appreciate that selenium has a narrow range of toxicity. Selenium supplementation should not exceed 2 mg/kg DM intake, which equates to approximately 20 mg selenium in the total diet for a 1,100-lb (500-kg) horse,” shared Crandell.

    Looking for an effective antioxidant supplement to help support your working horse’s mitochondria for maximal energy? Preserve PS fits the bill.

    Preserve PS is a powdered supplement containing a blend of powerful antioxidants, including selenium and vitamin E to help exercising horses ward off the damaging effects of free radicals,” Crandell relayed. “Preserve PS contains 2 mg of selenium per 30 g serving, as well as 1,500 IU of vitamin E.”

    Australian horse owners should look for Preserve.

    *White, S.H., S. Wohlgemuth, C. Li, et al. 2017. Rapid communication: dietary selenium improves skeletal muscle mitochondrial biogenesis in young equine athletes. Journal of Animal Science. 95(9):4078-4084.

    Category Headline Image: 
    selenium for horses
    Article Type: 
    Pull Quote: 
    The reported improvements in mitochondrial density in response to dietary selenium supplementation may improve diets for elite equine athletes.
    Overview: 
    In addition to the antioxidant benefits of selenium, supplementation with selenium may also improve mitochondrial biogenesis, an increase in mitochondrial mass to improve energy production.
  • Effect of Omega-3 Fatty Acids on Equine Semen

    Black stallion

    The outermost component of a sperm cell, called the plasma membrane, relies upon polyunsaturated fatty acids (PUFAs) for optimal structure and function. In an attempt to improve plasma membrane fluidity of spermatozoa through dietary modification, stallions are sometimes fed PUFAs, including docosahexanoic acid (DHA), an omega-3 fatty acid. A study* conducted in Brazil evaluated the effect of this practice on the quality of fresh, cooled, and frozen semen from Mangalarga Marchador stallions.  

    Ten mature stallions were divided into two groups. Stallions in one group received 150 mL of omega-3 enriched linseed oil added to the daily grain ration. All stallions were fed hay plus water and a mineral mix, and stallions in the supplemented group were given slightly less grain to balance the increase in energy from the supplement. Semen was collected on days 0, 15, 30, 45, and 60 of the study period, and sperm motility, vigor, viability, morphology, acrosome integrity, and osmotic tolerance were evaluated on untreated, cooled, and frozen/thawed samples.

    In this group of stallions, fresh and cooled semen showed no effect of dietary treatment, but frozen-thawed semen motility, vigor, and osmotic tolerance were higher in supplemented stallions. This result suggests that the addition of omega-3-enriched oil may be a way to improve semen quality by improving cell membrane integrity and functionality during cryopreservation processes.

    EO-3, an excellent source of long-chain omega-3 fatty acids, was developed by Kentucky Equine Research as a palatable liquid supplement that can be fed to all classes of horses, including foals, breeding stock, and performance horses to improve the critical ratio of omega-3 to omega-6 in diets. The product contains the marine-derived long-chain fatty acids DHA and EPA, which are more efficiently used as precursors of local hormones than plant-based sources of omega-3 fatty acids.

    *Cunha, I. Influence of omega-3 fatty acid-enriched diet on semen quality of Mangalarga Marchador stallions. Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil.

    Category Headline Image: 
    Gray stallion
    Article Type: 
    Pull Quote: 
    EO-3, an excellent source of long-chain omega-3 fatty acids, was developed by Kentucky Equine Research as a palatable liquid supplement that can be fed to all classes of horses...
    Overview: 
    A study conducted in Brazil evaluated the effect of omega-3 fatty acid on the quality of fresh, cooled, and frozen semen from Mangalarga Marchador stallions.
  • Administering Furosemide to Racehorses

    furosemide for horses

    Exercise-induced pulmonary hemorrhage (EIPH) plagues many racehorses, with up to 75% of Thoroughbreds affected by this condition. Despite the relatively widespread use of furosemide (Lasix or Salix), this medication does not actually treat or cure EIPH. Instead, furosemide administration reduces EIPH “scores,” which means affected horses bleed less during exercise when they receive furosemide.

    “EIPH occurs during strenuous exercise due to increased pressure in the small blood vessels in the walls of the horse’s lungs. As a result, blood abnormally enters the lungs, which as one might imagine, decreases a horse’s ability to perform in competition,” explained Laura Petroski, B.V.M.S., a veterinarian for Kentucky Equine Research (KER).

    According to a recent study*, timing of furosemide administration greatly impacts efficacy of furosemide and therefore athletic performance.

    “Race-day medication rules vary between racing jurisdictions. North America typically allows administration of furosemide on race day, usually up to 4 hours prior to post time. Other jurisdictions do not allow any race-day medications,” Petroski said.

    Anecdotal evidence suggests furosemide is equally efficacious when administered 24 hours before post time (complying with international race-day medication rules) compared to 4 hours. If this is true, then no concerns surrounding furosemide administration and race-day performance would exist.

    “Unfortunately, the study by a group of researchers from the School of Veterinary Medicine at the University of California, Davis, demonstrated otherwise,” noted Petroski.

    Specifically, the research team found that EIPH scores were lower in horses receiving furosemide 4 hours prior to post time compared to 24 hours. The EIPH scores referred to in the study use a standardized scale ranging from 0-4, where 0 refers to no blood observed in the main airways and 4 indicates multiple streams of blood identified on endoscopic examination (“scoping”) covering 90% of the tracheal surface.

    The researchers concluded that EIPH was not altogether prevented regardless of whether furosemide was administered 4 or 24 hours prior to racing. Further, administration 24 hours before racing does not appear as effective as when horses receive furosemide 4 hours prior to competition.

    “Horses receiving furosemide lose valuable electrolytes in their urine. To replenish those losses, KER formulated an electrolyte product called Race Recovery. This supplement was specifically designed for horses treated with furosemide to ensure complete, optimally timed electrolyte replacement. In addition to sodium, chloride, and potassium, Race Recovery includes highly digestible forms of calcium and magnesium,” said Petroski.

    To find out more about Race Recovery and KER’s other electrolyte supplements for athletic horses, consult with a nutrition advisor now.

    *Knych, H.K., W.D. Wilson, A. Vale, et al. Effectiveness of furosemide in attenuating exercise-induced pulmonary haemorrhage in horses when administered at 4- and 24-hours prior to high speed training. Equine Veterinary Journal. In press.

    Category Headline Image: 
    racehorse nutrition
    Article Type: 
    Pull Quote: 
    Specifically, the research team found that EIPH scores were lower in horses receiving furosemide 4 hours prior to post time compared to 24 hours.
    Overview: 
    According to a recent study, timing of furosemide administration greatly impacts efficacy of furosemide and therefore athletic performance.