Total apparent digestibility and glycemic response of diets for horses containing maize subjected to different processings

Abstract

In order to assess the effect of corn processing on apparent digestibility of dry matter, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, starch, and glycemic response in horses, four crossbreeding adult mares weighing 450±51.15 kg, and aging 36±5 month , were fitted in a 4x4 Latin square design during 44 days. The animals were fed four isocaloric diets, whose only difference was kind of processing of maize: grinding, rolling, flocculation or extrusion. Significant differences (p < 0.05) were observed in apparent digestibility of organic matter and acid detergent fiber, where the diet containing flaked corn showed better digestibility these nutrients than diets containing corn rolled and ground corn. The diet containing extruded corn showed glycemic response and the area under the curve higher than the other treatments, while inclusion of ground corn resulted in lower glycemic response and area under the curve, when compared to other diets. Extrusion and flocculation of corn are important tools for feeding horses with high energy requirement, by providing a greater energy balance, whose use should be careful to avoid problems associated with high rates of post-prandial glycemia.