Research update: Meal frequency and NSC

Farm Forum

The inclusion of starch‐rich concentrate feeds is a common practice among horse owners in an effort to increase the caloric density of the horse’s diet. If a horse is fed ample concentrate (greater than 4.5 pounds per day), feeding these concentrate meals only one or two times per day may result in larger meal sizes and may result in altered insulin and glucose concentrations, fluid balance and behavior.

Researchers at North Carolina State University set out to determine if both meal frequency and dietary energy source affect postprandial changes in glucose and insulin concentrations in horses.

Eight mature idle gelding horses were rotated through treatments. Horses received either two or three meals per day for 7 days. Meals included a high (43%) and low (18%) NSC concentrated feed. Combined, treatments formed four groups: low NSC concentrate in two meals per day, low NSC concentrate in three meals per day, high NSC concentrate in two meals per day and high NSC concentrate in three meals per day. On day 7 of the treatments, blood was collected before feeding (baseline) and for 5 hours after feeding the morning meal.

Baseline insulin concentrations tended to be higher for horses fed high NSC compared to low NSC concentrates and in horses fed two compared to three meals per day. In addition, the baseline glucose-to-insulin ratio was higher in horses fed high NSC compared with low NSC concentrates. Horses fed high NSC concentrates had higher area under the curve and peak insulin after feeding compared to horses fed low NSC concentrates.

These findings suggest that NSC content of a concentrate feed has an impact on baseline insulin, glucose‐toinsulin ratios, and on insulin concentrations. Meanwhile, the number (and therefore size) of meals per day had fewer impacts on glucose metabolism.

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Summarized by Krishona Martinson, University of Minnesota.