Team Marketing | 06.10.20In spring it doesn't take long for the fresh grass to turn our quiet horses into raving lunatics! With the spring grass comes the increased risk of Laminitis, Obesity and metabolic related disorders. Research has shown that pasture-induced laminitis occurs at times of rapid grass growth. The accumulation of certain carbohydrates including fructans, starches, and sugars known as Non-Structural Carbohydrates (NSC) in pasture forage during the spring, early summer and autumn, particularly after rainfall precipitate this laminitis.
Types of CarbohydratesCarbohydrates found in equine diets can be divided into two types: Structural and Non-structural. Structural carbohydrates are often referred to as fibre and are critical in the equine diet. Non-structural carbohydrates (NSC) are sugars and starches that are broken down by enzymes in the horse’s small intestine into simple sugars. These simple sugars are absorbed from the small intestine and circulate in the blood as glucose. The hormone insulin removes glucose from the blood and stores it in the liver and muscle as glycogen, or when an excess amount of NSC is consumed, it is converted to fat and stored throughout the body. Common examples of non-structural carbohydrates in horse diets include cereal grains (oats, corn, barley, etc) and molasses. Research has shown that metabolic disorders such as Obesity, Insulin Resistance, Laminitis, Cushings, Tying-Up as well as behavioural excitability are associated with excess NSC (sugar and starch) and not with structural (fibre) carbohydrates in the diet. Expert nutritionists and veterinarians researching in this field have determined “low carb” to be less than 10% NSC.
Feeding ManagementWe must carefully manage pasture turnout and forage and grain intake in horses and ponies that are at risk for developing laminitis or are currently affected. We also understand that horses suffering from insulin resistance (IR) and/or Cushings as well as horses and ponies with the ‘‘easy keeper,’’ phenotype that are often overweight or obese, and may be persistently hyperinsulinemic should also be managed carefully with regard to their carbohydrate intake. The following points summarize current advice regarding strategies for avoiding high NSC intakes by horses and ponies at risk for pasture laminitis:
- Animals predisposed to laminitis should be denied access to grass pastures, particularly during the spring.
- At other times of the year, limit the amount of turnout time each day (e.g., 1–3 hours) and turn animals out late at night (after 8:00pm) or early in the morning, removing them from pasture by midmorning at the latest (before 10:00am, because NSC levels are likely to be at their lowest late at night through early morning).
- Alternatively, limit the size of the available pasture by use of temporary fencing to create small paddocks or use a grazing muzzle.
- Do not turn horses out onto pasture that has been exposed to low temperatures in conjunction with bright sunlight, such as occurs in the autumn after a flush of growth or on bright cool winter days, because cold temperatures reduce grass growth, resulting in the accumulation of NSC.