Gastric ulcers can affect horses of all breeds, ages, shapes, and sizes. Weanlings are among these: They are transitioning from a diet of milk to one of forages and concentrates, while also experiencing the stress of separation from their dams. So, what type of feed should an owner provide to ease the transition’s impact on a weanling’s GI tract? A team from the University of Illinois led by Kevin Kline, PhD, professor of animal science, recently completed a study in which they determined that a forage-rich diet caused the least amount of gastrointestinal (GI) problems.

Kline and colleagues evaluated the effects of three different diets (an all-alfalfa hay diet, a diet of hay cubes and grain, and one consisting of a pelleted complete feed) on the GI health of 16 Standardbred weanlings (six colts and 10 fillies). The weanlings were divided into two groups of eight (three colts and five fillies each).

Researchers fed each group of horses a different diet during three 28-day periods. Both groups of weanlings were fed the all-alfalfa hay diet for the first 28-day period. Then, researchers fed one group the hay cubes and grain diet and gave the other complete feed for 28 days. The groups switched diets for the final 28 days.

At the end of each 28-day period, each weanling underwent an endoscopic examination to determine the number and severity of gastric ulcers present in the stomach. The veterinarian performing the endoscopic exams was blinded to the weanlings’ most recent diets, except for the first round of exams in which all the horses were on the same diet.

"After Period 1 on the all-hay diet, the horses were fou