Understanding and Using COI and AVK in Your Breeding Program
- Catherine Poissant
- Jan 24
- 3 min read
Whether you are a breeder of purebred dogs or cats, it is crucial to understand the importance of genetic diversity to preserve the health and longevity of your lines. Two key indicators help assess this diversity: the COI (Coefficient of Inbreeding) and the AVK (Ancestor Vulnerable Kinship). These tools are invaluable for making informed decisions in your breeding program.
📌 What is COI (Coefficient of Inbreeding)?
The COI measures the level of inbreeding in an individual by analyzing the likelihood that the same ancestor has passed identical copies of a gene to a descendant.
How it works:
A COI of 0% means no common ancestors appear in the pedigree (no detected inbreeding).
A COI of 25% typically results from a mating between siblings or parent-offspring.
A high COI indicates significant inbreeding, increasing the risk of genetic disorders or issues related to reduced genetic diversity.
How to use it:
A low COI is recommended to maintain good genetic diversity and reduce the risk of hereditary diseases.
A high COI may weaken the overall health of a line, leading to reduced fertility, shorter lifespan, or decreased disease resistance.
Recommended goal: Maintain a COI below 6.25% (equivalent to a mating between distant cousins).
📌 What is AVK (Ancestor Vulnerable Kinship)?
The AVK measures the percentage of unique ancestors in a pedigree. Unlike the COI, which measures inbreeding, the AVK evaluates the diversity of the lines represented.
How it works:
An AVK of 100% means all ancestors in the pedigree are unique.
An AVK of 75% indicates that 25% of the ancestors appear multiple times in the pedigree, reflecting less diversity.
How to use it:
A high AVK is desirable, as it indicates greater genetic diversity.
A low AVK can signify hidden inbreeding risks and loss of genetic variability.
Recommended goal: Aim for an AVK above 85% to promote genetic diversity.
🎯 How to Use COI and AVK Together
Low COI + High AVK = Excellent balance: Low inbreeding and high genetic diversity.
High COI + Low AVK = Increased risk: Avoid this combination.
Low COI + Low AVK = Reduced diversity despite low inbreeding: Monitor carefully.
Moderate COI + High AVK = Acceptable for rare lines or breeds with limited populations.
⚙️ Our COI & AVK Calculator
We provide a COI and AVK calculator to help dog and cat breeders estimate the genetic diversity of their litters. However, the results are approximate:
Genetics cannot be reduced to a rigid mathematical formula.
A puppy or kitten does not inherit exactly 50% of its genes from each parent; transmission is random.
COI and AVK are theoretical indicators based on pedigree analysis and not actual genetic testing.
👉 These tools should be viewed as decision aids rather than absolute guarantees of health or genetic diversity in a litter.
✅ How to Integrate This Data into Your Breeding Program:
Mating Planning:
Before each pairing, calculate the COI and AVK for the potential litters.
Favor pairings with a low COI and a high AVK whenever possible.
Avoid High Inbreeding:
Avoid direct matings between siblings or parent-offspring.
Diversify the bloodlines used in your program.
Generational Monitoring:
Track COI and AVK over multiple generations to prevent genetic drift.
Record your results and adjust your breeding choices accordingly.
🧬 In Conclusion:
Whether you breed dogs or cats, COI and AVK are valuable tools for preserving the health, longevity, and robustness of your lines. Used together, they enable more informed and responsible breeding decisions, aligned with breed standards and animal welfare.
