INS and obesity due to melanocortin 4 receptor deficiency: As both obesity and insulin dysregulation (which includes high basal insulins as well as abnormal insulin responses to oral hydrolysable carbohydrate feeding) are risk factors for horses to develop laminitis [5,26] the results of the present study suggests that replacing half of the daily forage allowance with straw may be beneficial to horse health in individuals prone to these conditions.