Study of Whole Genome vs Pedigree analysis of Golden Retrievers – study link
Whole-genome-sequence-SNP-chips-and-pedigree of multiple dog breeds study in 2016. Here on this page our article features facts from this study of Golden Retrievers. Please reference this original study for more details on all the breed’s data collected.
10 Golden Retrievers in the study in 2016
Golden Retrievers have an effective population size of 6.5. This is due to popular sire syndrome. Golden Retriever pedigrees are backing up to 6.5 dogs. Papillons pedigree backs up to 182 dogs as a comparison.
When evaluating pedigree inbreeding levels, three categories were made.
- Whole pedigree = 16% COI
- 10 generations = 8% COI
- 5 generations = 3% COI
SNP = Genetic DNA Inbreeding calculation of all 10 dogs in the study was 28% COI
WGS = Whole genome DNA calculation of only 1 dog in the study was 22% COI
💙 The calculated pedigree inbreeding is rarely accurate to DNA testing of genetic inbreeding. DNA proves the legitimate inbreeding of a dog.
💙 In the “Gold Inbreeding Coefficients” (chart below), the blue line is the full pedigree of inbreeding, red is 10 generations calculated, green is 5 generations calculated. 10 Golden Retrievers were analyzed.
💙 Goldens have a much higher level of inbreeding when utilizing the whole pedigree going back over 100 years, vs, traditional 10 generation calculations of inbreeding.
💙 High levels of inbreeding are correlated to shorter life and worse health.
💙 Pedigree analysis is regularly a lie. We cannot calculate a pedigree in most breeds and come close to the legitimate calculations of inbreeding. DNA testing proves the actual inbreeding of a dog.
💙 25% inbred shows on the chart as 0.25. The offspring of full siblings, with 4 unrelated grandparents is 0.25. With this reference, you can better understand how inbred most pure-bred dogs are.
Quote from study:
“Population characteristics reflect breed history
As expected, pedigree records for all breeds were erratic and often incomplete prior to breed establishment in their country of origin. In spite of these inconsistencies, considerable across-breed patterns, as well as breed- or situation-specific fluctuations, were identified through pedigree analysis (Fig. 5). Breed recognition by a kennel club registry both requires and facilitates pedigree tracking, thus improving records for each breed relative to the point at which the origin registry granted breed status. Concurrent with establishment of a breed, we observe that levels of inbreeding increase steadily and often immediately. Additional increases are noted when the breed achieves registry recognition. This implies that organization of a breed reduces the available gene pool, first by closing the registration database or ‘studbook’ to the introduction of non-breed-associated genetic variation, imposing an artificial population bottleneck. In addition, it provides a merit system through organized competitions in the sense that a small number of individuals ‘win’ at dog shows and the genetic contribution of those popular dogs are overrepresented in subsequent generations of the breed, recognized as the ‘popular sire effect’, thus decreasing variability in the breed pool still further. This is displayed clearly in the ten-generation and all-generation inbreeding graphs of the Australian Cattle Dog, Golden Retriever, Norwich Terrier, Bernese Mountain Dog, Borzoi and Basenji (Fig. S1). This trend is likewise reflected in pedigree-calculated Ne values, where the Golden Retriever, despite being ranked among the top five most popular dog breeds by the AKC from 1993 to 2015 (www.akc.org), has an Ne of 6.5, and the Papillion, with popularity ranking of 48th for 2015, records a substantially higher Ne of 182.3. The large range of Ne values does not necessarily coincide with the total number of breed individuals registered per year or the breed’s relative popularity. Rather, it speaks to the general within-breed diversity of the breeds and the contribution of popular dams and sires to the subsequent generation”
SNP is the DNA analysis showing 28% inbred. Ped-full is the whole pedigree analysis inbreeding showing 16%. The correct inbreeding level is 28% for these Goldens in the study. The pedigree shows 14 points less inbreeding than the legitimate inbreeding of the 10 dogs in the study. Pedigree analysis is not the truth when calculating a Golden Retriever’s pedigree.
10 Golden Retrievers analysis of pedigrees in 2016
Blue = full pedigree 16% COI
Red = 10 generations 8% COI
Green = 5 generations 3% COI
- Pedigree analysis of inbreeding varies drastically between full pedigree and traditional 10 generations used by most breeders
- 0.16=16% inbred COI pedigree analysis of the whole pedigree
- DNA analysis of the same dogs puts them at 28% inbred
- The inbreeding of the 10 Golden Retrievers in this study is actually 28%, not 16%