Feeding Horses with Special Nutritional Needs

in the hindgut of the horse. There are several metabolic conditions of horses requiring the regulation of carbohydrate intake in their diets.
Insulin Dysregulation
The metabolic conditions insulin resistance IR equine metabolic syndrome EMS and pituitary pars intermedia dysfunction PPID often called Equine Cushings disease can all be impacted by the intake of carbohydrates that affect the insulin status of the horse. Horses with any of these metabolic conditions usually have some degree of insulin dysregulation in other words they have lost the ability or possibly never had the ability to regulate glucose and insulin in their bodies.
These horses must be on a diet containing minimal simple sugars ESC andor starch as the blood glucose spikes initiated by the consumption and digestion of these nutrients will cause corresponding insulin spikes and consequently the potential for poor health and performance outcomes. Problems such as regional adiposity accumulation of fat in certain areas tying up poor energy status often misdiagnosed as laziness as well as laminitis can all be the result of the failure to regulate the intake of starch and ESC in horses with these metabolic conditions. These horses need small meals fed regularly with sugar and starch avoided as much as possible. Feeding management should include minimizing soluble carbohydrate to amounts that will not precipitate a large blood glucose increase. A summary of peer reviewed research conducted over the last 15 years on this subject Equine Applied and Clinical Nutrition R. Geor P A. Harris M. Coen pub 2016 suggests that starch and sugar intake in excess of 1 5 grams per kg of body weight BW per meal will precipitate a blood glucose spike and a corresponding insulin increase. Research suggests that horses with insulin dysregulation should not consume more starch or sugar during any meal than 0 3 gramskg of BW to avoid blood glucose and insulin spikes. Feeding forage like hay does help regulate the uptake of glucose from the equine foregut but it is important to source a hay with nonstructural carbohydrates or NSC watersoluble carbohydrates plus starch of less than 10 to 12 percent.
There have been discussions as to whether fructooligosaccharides fructans need to be regulated or even quantified in the diets of horses with insulin dysregulation. Because fructans are large complex molecules that resist digestion in the foregut and therefore are unlikely to influence insulin status of the horses some think they are of no consequence