Bermudagrass intake and efficiency of utilization in Katahdin, Suffolk, and reciprocal-cross lambs 1

of as-fed intake per kilogram of gain for 3 yr of the experiment. Averaged over the 2 d per week and weeks of the study, DMI as a percent of BW averaged 2.92, 2.57, 3.05, and 2.60% in Katahdin, Katahdin × Suffolk, Suffolk × Katahdin, and Suffolk, respectively (sire breed listed first). Intake was highest in the Suffolk × Katahdin and Katahdin ewe lambs (P < 0.05) compared with Katahdin × Suffolk and Suffolk lambs. There was little evidence for direct heterosis or direct breed effects for DMI as a percentage of BW, but there was evidence of maternal breed effects in favor of Katahdin ewes (0.48 kg/kg of BW, P < 0.01). Efficiency of forage utilization averaged 0.110, 0.094, 0.112, and 0.092 kg of ADG per kilogram of daily DMI for Katahdin, Katahdin × Suffolk, Suffolk × Katahdin, and Suffolk, respectively. There was a trend for efficiency to be more favorable in lambs from Katahdin ewes compared with lambs from Suffolk ewes averaged over sire breed (P < 0.07, data not shown). These results indicate that genetic effects associated with breed can play an important role in regulating intake and efficiency in grazing animals and that breed composition should be considered in the design of efficient grazing systems.