Short-term effects of a moderate fish oil or soybean oil supplementation on postprandial glucose and insulin responses in healthy horses

The aim of this study was to investigate the effects of fat supplementation on postprandial glycaemic and insulinaemic responses in horses fed a corn meal. Four horses were fed three different diets: (1) cracked corn (CC), (2) cracked corn with soybean oil (CC + SBO), and (3) cracked corn with fish oil (CC + FO). Each diet was adjusted so there was a starch intake of 2 g/kg bodyweight (BW) and an intake of 0.2 mL/kg BW of FO and SBO. The increases in mean plasma glucose and insulin concentrations, peak values, and areas under the curve were similar for all diets (time P < 0.05, diet not significant). The addition of FO or SBO at 0.2 mL/kg BW to a starchy meal did not affect acute glucose and insulin responses. To avoid high postprandial glycaemic and insulinaemic responses feeding strategies should be designed primarily to reduce starch intake rather than the addition of fat.