Genetic variation and covariation for ewe reproduction, lamb growth, and lamb scrotal circumference in a fall-lambing sheep flock.
Genetic variation and covariation for ewe reproduction, lamb growth, and lamb scrotal circumference in a fall-lambing sheep flock.
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秋季产羔羊群中母羊繁殖、羔羊生长和羔羊阴囊周长的遗传变异和共变异。
DOI：
10.2527/1996.7471490x
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发表时间：
1996
影响因子：
3.3
通讯作者：
D. Notter
中科院分区：
文献类型：
--
作者：
S. Al;D. Notter
采用多种动物模型，采用REML方法对多赛特羊、朗布依羊和芬羊各占50%、25%的秋季产羔能力组合群体的雌性繁殖、羔羊生长和羔羊阴囊周长的遗传参数进行了估算。考虑的性状包括春季繁殖力、窝产仔数、断奶体重（WWT）、90 d （WT90）和120 d （WT120）以及断奶阴囊围（WSC）、90 d （SC90）和120 d （SC120）。秋季产羔或未产羔的母羊的生育能力分别为1或0，平均值为0。成人（3岁及以上）59例。二胎母羊45；19岁母羊18岁；12个月大的母羊是11个。对生育率的遗传力估计在不同的模型中有所不同。07到0.11。秋季产仔数遗传力为0.10。对于体重，直接加性、母系加性、永久环境母系和凋落物效应作为表型方差的比例进行了估计。04。10日。05，和。11，分别为WWT，。09年。05年,。14、和。WT90为01；18日。0,。13、和。WT120是06。WSC、SC90和SC120的遗传力估计为。15日。25，和。分别02。体重之间遗传相关性的估计范围从。77 .团结。估计育性与落胎数、WT90和SC90的遗传相关性。56, - 0.31，和。分别为29。凋落落叶数与WT90和SC90的遗传相关。33和。分别为36。估计的遗传相关性显示，在秋季羔羊的能力没有主要的遗传拮抗。
Genetic parameters for female reproduction, lamb growth, and lamb scrotal circumference in a composite population of 50% Dorset, 25% Rambouillet and 25% Finnsheep breeding selected for ability to lamb in fall were estimated by REML using various animal models. Traits considered were spring fertility, litter size, weight at weaning (WWT), 90 d (WT90), and 120 d (WT120), and scrotal circumference at weaning (WSC), 90 d (SC90), and 120 d (SC120). Fertility was defined as 1 or 0 for ewes that lambed or failed to lamb, respectively, in fall and averaged .59 for adults (3 yr and older), .45 for second-lambing ewes, .18 for 19-mo-old ewes, and .11 for 12-mo-old ewes. Heritability estimates for fertility varied among models from .07 to .11. Heritability of fall litter size was .10. For body weights, estimates of additive direct, additive maternal, permanent environmental maternal, and litter effects as proportions of phenotypic variance were .04, .10, .05, and .11, respectively, for WWT, .09, .05, .14, and .01 for WT90, and .18, .0, .13, and .06 for WT120. Heritability estimates for WSC, SC90, and SC120 were .15, .25, and .02, respectively. Estimates of genetic correlations among body weights ranged from .77 to unity. Estimates of genetic correlations of fertility with fall litter size, WT90, and SC90 were .56, -.31, and .29, respectively. Genetic correlations of fall litter size with WT90 and SC90 were .33 and .36, respectively. Estimated genetic correlations revealed no major genetic antagonisms with ability to lamb in fall.