Many factors are considered when choosing which dogs to use in breeding programs including conformation, temperament, genetic disease mutations, and much more. Assessing the impact of inbreeding should be another factor.
Studies show that excessive inbreeding can have a profound impact on a dog’s health and lifespan. Many breeding programs utilize linebreeding and inbreeding as a means of maintaining breed characteristics and emphasizing desired traits. However, as inbreeding increases in a breed so do some negative effects, such as reduction of litter size, reduced fertility, decreased disease resistance, and failure to thrive in puppies.
Genetic Coefficient of Inbreeding
Track the impact of inbreeding
Genetic coefficient of inbreeding (COI) is the most accurate method for measuring inbreeding. Unlike pedigree based COI calculations, genetic COI evaluates the actual pieces of DNA in your dog to identify which proportion traces back to inbreeding. Embark’s genetic COI can detect inbreeding in far more past generations, as well as better inform on strategic breeding crosses than typically expected from pedigree-based calculations.
Why COI matters
Excessive inbreeding can have profound impact on a dog's health and lifespan
Oedipus Rex: Dog Inbreeding, its Consequences, and its Quantification
For millennia, breeders mated relatives as a way to fix traits in a lineage despite the known reduction of fitness in offspring of close relatives.
How to calculate expected litter COI
Pair Predictor tool makes it easy to predict litter outcomes
Embark offers a unique tool for breeders to evaluate the expected litter outcomes for any two potential mating dogs that have used an Embark DNA test for Breeders. This first-in-the-industry breeder tool provides the estimated COI (eCOI) for a planned litter, and more.
Pair Predictor works like an automated Punnett square, and can be used on your own Embark-tested dogs or other dogs that another breeder has shared with you. Works with all breeds and breed mixes.
What Pair Predictor includes:
- The expected genetic COI of the litter, providing easy comparison to that of the mating dogs’ COI score to assess if the degree of inbreeding in the line will decline as a result of the mating
- The expected occurrence of genetic disease mutations of the proposed litter
- The expected occurrence of relevant physical traits of the proposed litter
Genetic vs. Pedigree-based COI
Differences between Genetic and Pedigree-based COI
Breeders have traditionally relied on the pedigree evaluation method to measure the coefficient of inbreeding, which assumes that each parent passes on 50% of their DNA evenly across each chromosome. In practice, however, the percentage of an individual’s own parent’s DNA transmitted to their offspring varies due to recombination. Over many generations these differences in inheritance can add up to a significant variation between the dog’s actual COI and the estimated COI from the parentage method (genetic based COI results can vary from pedigree-based COI by as much as 70%).
The pedigree-based method also assumes that founder dogs in a given pedigree are completely unrelated, though breed analyses show this is rarely the case. Additionally, the pedigree method requires the careful record-keeping of each litter across dozens of generations, and errors can occur.
While keeping detailed pedigree records is certainly important, utilizing a genetic COI is an easier and more accurate means of assessing inbreeding impact and long term health within breeding programs.
Featured articles
Incorporating COI into breeding decisions
Partnerships
Join our pack with your breed organization
Embark partners with breed organizations to assist in population diversity assessments and to guide in long term strategies to ensure the health and vigor within a breed. Partnership benefits include access to genetic data, compiling trend reports, and making Embark for Breeders testing available to organization members.
Contact us to learn how your breed organization can work with Embark.
