There are many reasons farm owners or managers might want a horse's intake of hay to be slowed or reduced. That might include reducing wear-and-tear on your barns and stalls from a bored horse once the allotted hay is finished; giving the horse a "more natural" feeding regimen for "grazing" on hay while confined; or reducing the amount of hay that an easy keeper can consume. In the following article by Kentucky Equine Research nutritionist Kathleen Crandell, PhD, she explains some recent research that looked into the question of whether the size of holes in a hay net will slow hay consumption.
Horses on pastures will spend 12 to 18 hours each day grazing, while horses on hay-only diets often spend less than eight hours a day consuming their forage. There has been much interest in finding ways to stretch out the time it takes horses to consume the hay portion of a meal so it more closely simulates the amount of time normally spent consuming pasture.
At this year’s meeting of the Equine Science Society, researchers from Minnesota presented information on a study that investigated whether hay net design had an effect on slowing consumption of hay. Researchers used eight mature horses and exposed them to each treatment of being fed hay at 1% of body weight either on the ground or in hay nets with 15.2-cm openings, 4.4-cm openings, or 3.2-cm openings for four-hour periods twice per day. They weighed any hay left at the end of the four-hour period. There was no difference in the amount of hay consumed between the different four-hour periods in a day, so all of the data was combined.
Researchers found no difference in the speed at which the horses completed their hay or the total amount consumed when the hay was fed on the ground or in the largest opening (15.2 cm) hay net. There was, however, a significant effect on the speed of intake and total amount consumed from the hay nets with openings that were 4.4 cm and 3.2 cm; in fact, not all of the horses were able to finish the hay within the four-hour period from either opening size. The slowing of consumption was greatest for the smallest opening at 0.88 kg per hour, down from the control, which was 1.49 kg per hour.
The researchers concluded that offering horses hay in hay nets with reduced opening size is an effective manner to slow consumption and decrease intake of hay.