Current equine management practices have led many of us to feed our horses two large concentrate meals a day, in addition to hay and pasture, to meet their nutrient needs. This practice, however, can lead to issues such as hindgut acidosis, gastric ulcers, and undesirable behaviors such as cribbing when horses finish their feed quickly and must wait hours until their next meal.
So how can we increase the time per day that horses spend eating? Katy Brinkley-Bissinger, a graduate student at the University of Florida, in Gainesville, and her colleagues studied the effects of soluble fiber (fiber that dissolves in water) on feed intake behavior to find out. She presented their findings at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina.
Brinkley-Bissinger hypothesized that feeding horses high-soluble fiber would cause them to chew more and feel “full” sooner. In her study she fed four adult Quarter Horse geldings four diets over four treatment periods:
- 100% long-stem orchardgrass hay
- 60% long-stem orchardgrass hay and 40% crimped oats, split into two meals
- 60% long-stem orchardgrass hay and 40% shredded beet pulp, a soluble fiber source, split into two meals
- 60% long-stem orchardgrass hay and 40% almond hulls, another soluble fiber source, split into two meals
During each two-week treatment period, Brinkley-Bissinger evaluated the horses’ feed intake behavior, logged the amount of feed they chewed and swallowed, measured feed particle size, and measured fecal particle size. She found that:
- Horses chewed oats the least and almond hulls the most;
- Horses ate oats and beet pulp the fastest and almond hulls the slowest, which could be influenced by the almond hulls’ palatability, she said;
- Orchardgrass hay had the largest average particle size, followed by almond hulls, beet pulp, and oats; and
- Horses had the largest average fecal particle size on the hay diet and the smallest on the oat diet, but Brinkley-Bissinger noted this wasn’t statistically significant.
She concluded that horses eating high-fiber meals composed of shredded beet pulp or almond hulls chewed more and ate slower than horses eating crimped oats. They also consumed their daily hay rations slower, perhaps due to a feeling of satiety. Owners can potentially increase the time their horses spend eating by offering them high-soluble-fiber feeds, she said.