Heifers were adapted to Pinpointer 4000B Feeders 4 prior to the part of the study so that feed could be measured individually. They were penned within treatment group in groups of 12 with one pen per treatment and were rotated among pens at 28-d intervals to reduce effects due to pinpointer machine and pen. Diets were 40% roughage for the first 28 d, 25% roughage for the second 28 d, and 17% roughage for the remainder of the study (Table 1). All the diets were completely mixed and balanced to meet or exceed NRC (1984) requirements for an ADG of 1.1 kg.