"Something in alfalfa (lucerne) hay tends to buffer acid production," said Dr Pete Gibbs, extension horse specialist at the university.
Stomach ulcers are a common problem in performance horses. Up to 90 per cent of racehorses and more than 50 per cent of arena performance horses have ulcers of varying severity, he said.
When they have ulcers, horses "don't eat as well, work as well and don't feel as good", Dr Gibbs said.
Feeding grain, confinement, exercise and overall environmental stress factors are thought to cause ulcers, he said. Studies have shown that horses will heal if provided less acidic diets.
The recent research project in the department of animal science's equine science programme was part of Travis Lybbert's master's degree thesis, in collaboration with the College of Veterinary Medicine.
Gibbs served on Lybbert's academic research committee.
In the research, 24 quarter horses from 12 to 16 months of age were separated into two treatment groups. One group was fed Bermuda grass hay and the other fed lucerne hay to meet the daily roughage needs. The yearlings received forced exercise during the study.
The horses were examined internally with an endoscope at the beginning and end of two 28-day trials.
It is commonly thought that horses turned out on pastures are better off than those that are confined. However, if grass hay is the only hay they are fed, horses can still get gastric ulcers, he said.
In this study, ulcer scores increased when lucerne was removed from the horses' diets, and they were turned out on pasture. Under the ulcer-scoring system, 0 signified no ulcers, with severity increasing to level 4.
Horse owners - especially those with performance horses - have one of two options, Gibbs said.
They can give their horses a pharmaceutical product that will decrease acid production, he said. Or they can manage horses' diets.
The second option does not stop acid production but offers buffering capabilities, Gibbs said.
Further work is needed to look at horses with varying degrees of ulceration in order to better determine the full extent to which lucerne or lucerne-based products might help from a feeding management standpoint.
"Based on what we know right now - for horses that are kept in confinement, eating feed and getting forced exercise - it makes sense to consider some alfalfa (lucerne) as part of their diet," he said.
Until further research is done, he recommends, horses weighing between 450kg-590kg (1000-1300 pounds) should be fed about 450 grams (1 pound) of lucerne after a grain meal.
This isn't the first research conducted on gastric ulcers in horses, but it lays the groundwork for further research at Texas A&M, Gibbs said. The next study will investigate what it is about alfalfa and alfalfa products that lessens the occurrence and severity of horses' ulcers.