Stobart R H, Blackwell R L, Cartwright T C, Bassett J W
Montana Agricultural Experiment Station, Bozeman 59717.
J Anim Sci. 1987 Oct;65(4):929-35. doi: 10.2527/jas1987.654929x.
The relationships between various measures of growth and productivity of range sheep were investigated, utilizing records of 1,109 range ewes sired by 269 rams. Body weights and degree of maturity of body weight at birth, weaning, 12 mo, 18 mo, 30 mo and absolute growth rate, absolute maturing rate and relative growth rate over various age intervals were studied relative to their relationship with productivity characters. Measures of ewe productivity were average annual production for the 4-yr period, 2 through 5 yr of age, for grease fleece weight, number of lambs born, number of lambs weaned and weight of lambs weaned. Heritability estimates were .31 +/- .11 for grease fleece weight, .42 +/- .12 for number of lambs born, .08 +/- .10 for number of lambs weaned and .03 +/- .10 for weight of lambs weaned. All production characters had positive phenotypic correlations (.04 to .22) with body weight at all ages. Both number of lambs born and weight of lambs weaned had small positive phenotypic correlations with growth rates over the 12- to 18-mo age interval. The genetic correlations between ewe productivity and weights at different ages were variable, ranging from -.71 between weaning weight and grease fleece weight to values greater than 1.00 for correlations between weight of lambs weaned and weights at birth, weaning and 18-mo. Degree of maturity at 12 mo had positive genetic correlations with all production characters. Estimated genetic correlations between number of lambs born and absolute growth rate, relative growth rate and absolute maturing rate over the 12- to 18-mo age interval were positive.
利用269只公羊所生1109只草原母羊的记录，研究了草原绵羊生长和生产力的各种指标之间的关系。研究了出生、断奶、12月龄、18月龄、30月龄时的体重和体重成熟度，以及各年龄区间的绝对生长率、绝对成熟率和相对生长率，及其与生产力特征的关系。母羊生产力指标包括4岁期间、2至5岁时的平均年产毛量、产羔数、断奶羔羊数和断奶羔羊体重。产毛量的遗传力估计值为0.31±0.11，产羔数为0.42±0.12，断奶羔羊数为0.08±0.10，断奶羔羊体重为0.03±0.10。所有生产性状与各年龄体重均呈正表型相关（0.04至0.22）。产羔数和断奶羔羊体重与12至18月龄的生长率均呈较小的正表型相关。母羊生产力与不同年龄体重之间的遗传相关各不相同，从断奶体重与产毛量之间的-0.71到断奶羔羊体重与出生、断奶和18月龄体重之间大于1.00的相关值。12月龄的成熟度与所有生产性状均呈正遗传相关。产羔数与12至18月龄的绝对生长率、相对生长率和绝对成熟率之间的估计遗传相关为正。
