Silvestre A M, Ginja M M D, Ferreira A J A, Colaço J
Department of Animal Science-CECAV, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal.
J Anim Sci. 2007 Aug;85(8):1880-4. doi: 10.2527/jas.2007-0166. Epub 2007 Apr 27.
Genetic parameters, breeding values, and genetic trends of hip dysplasia in Estrela Mountain Dogs were estimated using a linear model (LM) and a threshold model (TM). A database with 313 animals was used. Right and left hip joints were individually scored, according to the Fédération Cynologic Internationale grading rules of the canine hip dysplasia system, as normal (1), borderline (2), slight (3), moderate (4), and severe (5 and 6). The estimate of repeatability was lower in LM (0.86) than in TM (0.90). The same tendency was verified with the heritability because its estimate in LM was 0.38 and in TM was 0.43. However, these results did not establish any statistical differences between the models. The genetic trend of canine hip dysplasia for LM and TM showed a similarity in shape, but considerable individual differences were found in the EBV ranking lists. Therefore, the selection of breeding animals would not be the same with the 2 methodologies. To select the best method for genetic evaluation of hip dysplasia, further studies using more data and other dog breeds are required.
利用线性模型（LM）和阈值模型（TM）估计了埃斯特雷拉山地犬髋关节发育不良的遗传参数、育种值和遗传趋势。使用了一个包含313只动物的数据库。根据国际犬业联合会犬髋关节发育不良系统的分级规则，对左右髋关节分别进行评分，分为正常（1级）、临界（2级）、轻度（3级）、中度（4级）和重度（5级和6级）。线性模型（LM）的重复性估计值（0.86）低于阈值模型（TM）（0.90）。遗传力也呈现相同趋势，线性模型（LM）中的估计值为0.38，阈值模型（TM）中的估计值为0.43。然而，这些结果并未表明两种模型之间存在任何统计学差异。线性模型（LM）和阈值模型（TM）的犬髋关节发育不良遗传趋势在形状上相似，但在估计育种值（EBV）排名列表中发现了相当大的个体差异。因此，两种方法选择的育种动物不会相同。为了选择评估髋关节发育不良遗传的最佳方法，需要使用更多数据和其他犬种进行进一步研究。
