Feeding level and nutrient content of diets used in DE content measurement for grains do not reflect practical conditions and prevent measurement of voluntary feed intake. The DE content of three barley samples was analyzed using four combinations of measurements. The measured DE content was 2.5% lower using pigs with free access to feed than pigs with restricted access to feed, while diet composition did not affect barley DE content. Furthermore, voluntary feed intake was indicative of performance and tended to vary among barley samples.