Just like people, some horses have a high metabolism and can eat more food without becoming overweight. Therefore, it is important to tailor each horse's feeding program to meet his individual needs, according to the results of a recent study by a team of Icelandic researchers.

The researchers compared the ability of two breeds–Icelandic horses and Standardbreds–to digest and use nutrients from two types of grass haylage–which is hay that has been fermented as silage. They found that the Standardbreds required more feed and better hay quality to maintain weight than the Icelandic horses, and that the Icelandic horses were able to get nutrients from poorer quality sources.

According to Carey A. Williams, PhD, equine extension specialist at Rutgers University in New Jersey, the findings of the study emphasize the need for every horse to have an individualized hay feeding program to ensure they maintain a proper body weight.

"Some barns try to feed a cookie-cutter feeding program," Williams said. "Different breeds metabolize food differently, which is the biggest reason why horses need to be fed as individuals. More fibrous or poorer quality hays might not be appropriate to feed a Thoroughbred or Standardbred, but might actually be more appropriate for other breeds