What is the primary function of iodine in a horse's diet?

The primary function of iodine in a horse's diet is related to thyroid hormone production. Iodine is an essential trace mineral that plays a crucial role in the synthesis of thyroid hormones, which are vital for regulating metabolism, growth, and overall energy levels in horses. These hormones, primarily thyroxine (T4) and triiodothyronine (T3), depend on adequate levels of iodine to function properly.

When a horse has sufficient iodine, it supports proper metabolic processes, including the conversion of nutrients into energy and the maintenance of body temperature. Deficiencies in iodine can lead to serious health issues, such as goiter or metabolic imbalances, demonstrating its importance in equine nutrition.

While other minerals and nutrients contribute to muscle repair, dental and digestive health, they do not have the specific and critical role that iodine plays in thyroid hormone production. Therefore, this makes iodine uniquely important in the dietary requirements of horses.