title: Lifetime lamb and wool production of targhee or Finn-Dorset-Targhee ewes managed as farm or range flock: I. Average annual ewe performance.
abstract: Lifetime (5 yr) lamb production and wool production from 207 straightbred Targhee (T) and 474 1/4 Finn-1/4 Dorset-1/2 Targhee (FDT) crossbred ewes managed in a range or farm flock system were evaluated for ewe fertility, prolificacy, ewe fleece weight, and total lamb weight weaned per ewe exposed. Data included 2,620 ewe exposures, 2,384 parturitions, 4,638 lambs born, and 3,498 lambs weaned. Ewes were born in 1984 through 1987 and lambed the first time as 2-yr-olds. Expressed as mean annual values, ewe fertility rates were similar (92.2 vs 91.0%, P = .30) for FDT and T ewes. Finn-Dorset-Targhee ewes had higher (P < .001) prolificacy (2.11 vs 1.75), weaned more lambs per ewe exposed (1.41 vs 1.18), produced more total lamb weight weaned per ewe exposed (33.8 vs 29.9 kg), and lambed 2 d earlier than T ewes. Targhee ewes produced more (P < .001) wool (4.5 vs 3.5 kg) than FDT ewes. Range flock ewes had a higher (P < .001) fertility rate (94.5 vs 88.7%), higher number of lambs weaned per ewe exposed (1.38 vs 1.22), and higher total lamb weight weaned per ewe exposed (34.7 vs 29.0 kg) than farm flock ewes. Farm flock ewes had a higher (P < .001) prolificacy (2.00 vs 1.86) and produced more wool (4.2 vs 3.8 kg) than range flock ewes. Targhee ewes had heavier lambs at birth (5.2 vs 4.6 kg; P < .001) and at weaning (25.8 vs 25.4 kg; P < .05). Range flock lambs were heavier (P < .001) at weaning than farm flock lambs (26.2 vs 24.9 kg). Lambs from FDT dams had a higher (P < .01) survival rate than lambs from T dams (75.6 vs 71.4%). Lamb survival from birth to weaning was higher (P < .001) for range flock lambs than for farm flock lambs (76.6 vs 70.4%). Incorporation of Finnsheep and Dorset breeding increased the reproductive performance in both management systems but decreased wool production.
authors.affiliation: Department of Animal and Range Sciences, South Dakota State University, Brookings 57007-0392, USA.
authors.forename: N Y
authors.initials: NY
authors.lastname: Iman
authors.forename: A L
authors.initials: AL
authors.lastname: Slyter
mesh_terms: D000375:Aging / Q000502:physiology*; D000822:Animal Husbandry; D000818:Animals; D001947:Breeding; D005260:Female; D005298:Fertility / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D012756:Sheep / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D014935:Wool / Q000254:growth & development / Q000502:physiology*