ESC, starch, NSC, what do they actually mean? Short answer: for laminitis risk and insulin, look at ESC starch, not NSC. Why ESC starch? These are the carbs a horse digests in the small intestine and that drive the insulin response. You will often see this called hydrolysable carbohydrates (HC). On a hay or feed analysis, HC is best estimated as ESC starch. The general safety target for at-risk horses is 10% or less on a dry-matter basis, and some individuals need lower. Why not NSC? NSC = WSC s