The Effect of Management System and Breed Ewe on Lambing Performance at 12 and 24 Months of Age

Production data for 1977 and 1978 have been collected on Finn x Targhee, Suffolk x Targhee and Targhee ewes mated to Suffolk rams. All ewes were exposed at the Brookings Sheep Research Unit when they were 7 to 8 months of age. Following weaning (approximately June 1) of the first lamb crop, one-half of each ewe breed group was taken to the Antelope Range Field data. Percentage of ewes exposed that lambed at 12 months of age was highest for Finn x Targhee (73.8), intermediate for Suffolk x Targhee (65.8) and lowest for straightbred Targhee ewes (31.0). Number of lambs born per ewe lambing were 1.65, 1.19 and 1.13 for Finn x Targhee, Suffolk x Targhee and Targhee ewes, respectively. At 24 months of age (second lambing), a higher pecentage of the Targhee ewes lambed under both the farm flock (Brookings) and range (Buffalo) management systems than for the two crossbred groups. However, fewer of the Targhee ewes had lambed at 12 months of age. Finn x Targhee ewes weaned more pounds of lamb in both management systems than either Suffolk x Targhee or Targhee ewes. Subsequent production data should be evaluated on these ewes before final conclusions are drawn