Populationsgenetische Analysen zur Ellbogen- und Hüftgelenksdysplasie beim Labrador Retriever
Bibliographic record
Abstract
The aim of this study was the analysis of environmental factors and estimation of genetic parameters for hip dysplasia in Labrador Retrievers. We analysed hip dysplasia scores of 2970 dogs from the official screening programme of the Labrador Club Deutschland (LCD) according to the FCI protocols. Traits evaluated were HD-Mit (average value of HD scores), HD-Max (higher score of both hip joints), HD-LI and HD-RE (HD score of the left or right hip joint). A linear animal model was employed to estimate heritabilities, additive genetic and residual correlations using Residual Maximum Likelihood (REML). Only inbreeding was significant after testing all non-genetic effects. Higher inbreeding coefficients were associated with higher HD scores. Heritability estimates and their standard errors were 0.38 ± 0.04 for HD-Mit, 0.40 ± 0.04 for HD-Max, 0.33 ± 0.03 for HD-LI and 0.38 ± 0.04 for HD-RE. The additive genetic correlation between HD-LI and HD-RE was 1. Heritability for female dogs was 0.31 and 0.30 for male dogs. The analysis of HD scores of Labrador Retrievers showed that the highest HD score of the hips should be used in breeding programmes, that heritabilities are not different among females and males, and that genetic components are much more important than environmental factors. Further on the aim of this study was the analysis of environmental factors and genetic factors influencing elbow dysplasia (ED) in a Labrador retriever population. We analysed scores of elbow dysplasia from the official screening programme of the Labrador Club Deutschland (LCD) following the protocol of the International Elbow Working Group. The data set included X-rays from 2931 Labrador retrievers. These dogs were born between 2000 and 2004 and originated from 834 litters and 315 kennels. The pedigree file contained 27,305 dogs pertaining to 20 generations. We analysed four different traits including ED-Mit as the averaged result of ED scores from both elbow joints, ED-Max as the higher score of both elbow joints and ED-links and ED-rechts as the ED score of left or right elbow joint. Animal models were employed to estimate heritabilities, additive genetic correlation and residual correlation using residual maximum likelihood (REML). Significant effects for all four ED-traits were gender, month of birth and inbreeding coefficient. The fixed effect of birth year showed only significant effects for ED-Mit and ED-rechts. Age at examination was not significant. Heritability estimates for ED-Mit were 0.13 ± 0.03, for ED-Max 0.12 ± 0.03 and 0.14 ± 0.03 for ED-links as well as 0.08 ± 0.02 for ED-rechts. Heritability for female dogs was 0.12 ± 0.03 and 0.10 ± 0.03 for male dogs. The additive genetic correlation between ED-links and ED-rechts was 1 and the residual correlation 0.64. The heritabilities for ED were low to moderate and taking this into consideration, selection response will be small when employing phenotypic ED scores from future breeding animals as the sole selection criterion. Therefore, breeding programmes should be supported by breeding values as tools for selection of breeding dogs. There was no difference in heritabilities between the mean ED score of the joints or the ED score of the joint with the higher ED grade. Furthermore, either specific genetic effects from a body side or sex-specific genetic effects could be observed for the expression of ED. Dogs showing radiographic signs of ED or dogs having been submitted for a surgery due to clinical signs of ED have to be precluded from breeding. The veterinary practitioner can help to reduce the frequency of dogs exhibiting a genetic disposition to ED when the radiographs of the elbow joints of many as possible purebred dogs are submitted to the respective dog breeding associations. 2867 Labrador Retriever from the Labrador Club Deutschland, which where born between 2000 and 2004, were radiologically examined. Estimation of the genetic and phenotypic trends for hip dysplasia followed. Relativ breeding values (mean value 100, standard deviation 20) were predicted using best linear unbiased prediction method (BLUP). There is a little improvement concerning the genetic and phenotypic trend in the examined years. Breeding values are higher in male dogs as in female dogs. If there is a consideration of parental breeding values by the process of selection it reflects in the hip quality of progeny. Low breeding values of parents ensure high hip quality of progeny.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".