A recent study found that frequent mowing reduced concentration of non-structural carbohydrates (NSCs) in grass.

Too much consumption of NSCs found in cool-season grasses has been linked to pasture-associated laminitis. The consumption of NSCs may cause increased glucose and insulin response, but the exact reaction is not clear.

According to Horsetalk.co.nz, researchers at North Carolina State University found that frequent mowing and shorter pastures reduced NSC concentration in grass.

“Mowing pasture during seasons of the year when cool-season grass NSC concentrations are highest (e.g., spring and fall) could maintain forage in a ‘re-growth’ phase that consumes stored NSC, thereby decreasing overall NSC concentration,” according to researchers Paul Siciliano, Jennifer Gill and Morghan Bowman in the Journal of Equine Veterinary Science.

They also suggested “leader-follower” grazing systems, where farm animals with higher grazing requirements, such as lactating sheep, grazed an area before horses were allowed to do the same.

To conduct their experiment, the researchers first set up a series of grazing areas of less than an acre each. In the areas, a non-toxic endophyte-infected variety of Lolium arundinaceum was grown.

The grazing areas were mowed to 15cm 32 days before the experiment began. Half of the areas were mown to 15cm again 11 days before the start of the experiment, while the other half were left long at 30 to 40cm.

Horses grazed on either the tall or short grass for 10 hours per day in 7-day blocks. Blood samples were taken regularly to check insulin and glucose concentrations and the pastures were tested for start and water soluble carbohydrates to estimate NSC concentrations.

In the shorter pastures, NSC concentrations were estimated to be lower and the insulin and glucose levels in the horses grazing there remained average. However, horses that grazed in the tall grass were found to have higher insulin levels.

Siciliano, Gill and Bowman’s findings could be significant in efforts to prevent insulin resistance in horses.