Article

Estimation of heritabilities, genetic correlations, and breeding values of four traits that collectively define hip dysplasia in dogs

Institute for Genomic Diversity, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA.
American Journal of Veterinary Research (Impact Factor: 1.21). 05/2009; 70(4):483-92. DOI: 10.2460/ajvr.70.4.483
Source: PubMed

ABSTRACT OBJECTIVE-To estimate heritabilities and genetic correlations among 4 traits of hip joints (distraction index [DI], dorsolateral subluxation [DLS] score, Norberg angle [NA], and extended-hip joint radiograph [EHR] score) and to derive the breeding values for these traits in dogs. ANIMALS-2,716 dogs of 17 breeds (1,551 dogs in which at least 1 hip joint trait was measured). PROCEDURES-The NA was measured, and an EHR score was assigned. Hip joint radiographs were obtained from some dogs to allow calculation of the DI and DLS score. Heritabilities, genetic correlations, and breeding values among the DI, DLS score, NA, and EHR score were calculated by use of a set of multiple-trait, derivative-free, restricted maximum likelihood computer programs. RESULTS-Among 2,716 dogs, 1,411 (52%) had an estimated inbreeding coefficient of 0%; the remaining dogs had a mean inbreeding coefficient of 6.21%. Estimated heritabilities were 0.61, 0.54, 0.73, and 0.76 for the DI, DLS score, NA, and EHR score, respectively. The EHR score was highly genetically correlated with the NA (r = -0.89) and was moderately genetically correlated with the DI (r = 0.69) and DLS score (r = -0.70). The NA was moderately genetically correlated with the DI (r = -0.69) and DLS score (r = 0.58). Genetic correlation between the DI and DLS score was high (r = -0.91). CONCLUSIONS AND CLINICAL RELEVANCE-Establishment of a selection index that makes use of breeding values jointly estimated from the DI, DLS score, NA, and EHR score should enhance breeding programs to reduce the incidence of hip dysplasia in dogs.

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    • "Another possible but purely hypothetical method in trying to screen CHD more strictly is by a combination of NA and FO. One study confirmed the validity of combining several measurements for hip joint confirmation, as this would provide more information on the dog's genetic potential (Zhang et al. 2009). A combination of both SFO and NA resulted in an acceptance rate of 59% instead of 65% (7% less) of the dogs used for breeding . "
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    • "Dogs used in this study were originated from close breeding colonies at the Baker Institute for Animal Health at Cornell University, the Guiding Eyes for the Blind in Yorktown Height, NY, and those admitted to the Cornell University Hospital for radiographic evaluation from January 1999 through October 2007 [42] "
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