Do oats wheat corn or barley give horses the most energy?

According to a feed table, (related link below), the energy level of each grain is the following (in Total Digestible Nutrients, not Digestible Energy):

Barley: 84%

Corn: 88%

Oats: 89%

Wheat: 88%

So, oats has the highest amount of energy for horses. Oats also has the highest Crude Fibre content (at 11%) than all other grains do. (Corn as CF of 2%, Barley of 5%, and Wheat of 3%).