Distl O, Grussler W, Schwarz J, Kräusslich H
Institut für Tierzucht und Tierhygiene, Ludwig-Maximilians-Universität München.
Zentralbl Veterinarmed A. 1991 Jul;38(6):460-71.
The importance of environmental and genetic influences on the frequency of hip dysplasia was studied in 10,595 German shepherd dogs. Systematic effects were analysed using mixed linear and mixed nonlinear threshold models. Following effects were regarded in the models applied: sire and mother of the dog as random effects, age at x-raying, sex, birth year and season of the x-rayed dogs, litter size, percentage of x-rayed dogs in each litter and sex ratio of the litter as fixed effects. Sire, mother, sex and age at x-raying showed significant influence on the occurrence of hip dysplasia. The heritability estimates in a hierarchical data design (sire, mother within sire) for the polychotomous trait hip dysplasia were for full sibs h2 = 0.30, for maternal half sibs h2 = 0, 48, and for paternal half sibs h2 = 0.11. Only the heritability estimates of the paternal half sibs seem to be reliable because kennel and breeder effects are confounded with the mother effect. Analysing the frequency of hip dysplasia as all-or-none traits, the heritability estimates were usually lowered by 50%. Selection programmes to reduce frequency of hip dysplasia can be improved if the estimation of breeding values with respect to environmental effects and frequency of hip dysplasia in all relatives will be implemented.
在10595只德国牧羊犬中研究了环境和遗传因素对髋关节发育不良发生率的影响。使用混合线性和混合非线性阈值模型分析系统效应。在所应用的模型中考虑了以下效应：犬的父亲和母亲作为随机效应，进行X光检查时的年龄、性别、出生年份和季节，每窝的仔犬数量、每窝中接受X光检查的犬的百分比以及窝内的性别比例作为固定效应。父亲、母亲、性别和进行X光检查时的年龄对髋关节发育不良的发生有显著影响。在多分类性状髋关节发育不良的分层数据设计（父亲、父亲内的母亲）中，全同胞的遗传力估计值h2 = 0.30，母系半同胞的遗传力估计值h2 = 0.48，父系半同胞的遗传力估计值h2 = 0.11。只有父系半同胞的遗传力估计值似乎可靠，因为犬舍和饲养者效应与母亲效应相互混淆。将髋关节发育不良的发生率分析为全或无性状时，遗传力估计值通常会降低50%。如果实施考虑环境效应和所有亲属中髋关节发育不良发生率的育种值估计，减少髋关节发育不良发生率的选择计划可以得到改进。
