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Understanding Equine Metabolism

Updated: Mar 11

  1. Metabolism refers to the chemical reactions that occur within the body to provide it with the components required to sustain life. In horses, this involves breaking down complex materials into simpler substances, which then become “building blocks” for the body to use as needed.

  2. Horses have a complex digestive system designed to derive energy from a grass-based diet. The hindgut of a horse is full of living organisms that break down cellulose into simple volatile fatty acids. These acids are then absorbed and used as the horse’s primary energy source.

  3. When we feed horses easily digestible foods, such as cereal grains, legumes, and oils, it can change the balance of the hindgut. If these foods are fed in excess or in the wrong proportions, the horse may be more predisposed to systemic problems and digestive upsets.

  4.  Metabolic disorders can affect energy production or damage tissues critical for survival. They may be inherited or acquired. Acquired metabolic disorders are more common. For example, Equine Metabolic Syndrome (EMS) links the risk factors of fat accumulation and the inability of insulin to do its job to the development of laminitis even in young horses and ponies.

  5. Metabolic supplements are daily formulas that include ingredients such as magnesium, iodine and adaptogens like chaste tree berry to help maintain normal insulin and glucose levels. It’s also important to limit stress, promote a relaxed attitude, and ensure the horse’s diet is high in fibre. Horses eat grass and hay. They don't eat meals like dogs and pigs.

Metabolic disorders normally progress and become more severe over time.

Insulin Resistance: In the old days we called them 'good doers'. Insulin resistance occurs when a horse's cells become less responsive to insulin, a hormone responsible for regulating blood sugar levels. This can lead to elevated blood sugar levels and increased risk of laminitis. These horses run on the smell of an oily rag. You know a good doer when you see one. You will need to limit grass intake, particularly in Spring. Being proactive about diet for your good doer will delay progression towards Cushings.

Equine Metabolic Sybndrome: EMS is a condition characterised by obesity, insulin resistance, and an increased risk of laminitis. Proper diet and exercise are crucial in managing EMS and improving the horse's overall metabolic health.

These are the horses that predictably founder. You may need to keep these horses off pasture altogether. Supplements are going to help you manage symptoms.

Cushing's disease, also known as pituitary pars intermedia dysfunction (PPID), is a hormonal disorder commonly seen in aging horses. It results in excessive production of cortisol, leading to a range of symptoms including weight loss, muscle wasting, and a compromised immune system. They are recognisable by their curly coats that often don't shed. Generally speaking a horse that has Cushings will need ongoing medication.

While the exact causes of metabolic disorders in horses are not fully understood, certain risk factors have been identified. These include poor diet, lack of exercise, genetic predisposition, and hormonal imbalances.

Just like people, horses diets are more full of sugar and they typically move less than they used to. To prevent and manage these conditions, it is essential to provide a balanced diet, low in sugar and promote regular exercise.

Iodine is essential for healthy metabolic function. 

Proper thyroid function relies on adequate iodine levels.

Iodine is necessary for the synthesis of thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3). These hormones are vital regulators of various metabolic processes in the body, including basal metabolic rate, heart health, nutrient absorption, brain/muscle/skeletal development.

Severe deficiency can lead to goiter, characterised by an enlarged thyroid gland. Foals born to mares with inadequate iodine intake may experience growth abnormalities and weakness.

Most soils have low concentrations of iodine, resulting in forages and grains being typically low in this mineral. (Note: if your property is right on the beach then your soils may have adequate iodine.) 

Depending on the weight of your horse, supplement between 2 to 4 mg of iodine daily. Tolerances are low so supplementation should not exceed this amount.

Just 10 grams per day of our Sound Advice Australian Seaweed Meal supplies a daily dose of iodine.

Chaste Tree Berry is an adaptogenic herb that influences hormonal balance by supporting hypothalamic and pituitary function in horses.

It helps to regulate hormones generally, but is a natural and cost effective supplement to support metabolic function. Both of these supplements are only 10g per day.



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