Page 27 - Chow Life - Winter 2025
P. 27
cases, breeders must be even more vigilant, using • “COI and AVK are genetic tests.” Incorrect —
these metrics to guide pairings that maintain health they are pedigree-based calculations, not DNA
and vitality. These two metrics complement each tests.
other but measure different aspects:
• “Line breeding always dangerously increases
• Low COI + High AVK: COI.” Not always — skilled breeders may line
Best case: low inbreeding, high diversity. breed responsibly while monitoring COI.
• High COI + Low AVK: These metrics are guides, not guarantees. They must
Worst case: high inbreeding, low diversity. be combined with health testing, temperament
evaluation, and breeder experience.
• Low COI + Low AVK:
Not much inbreeding, but still reduced diversity. PRACTICAL BREEDING GUIDELINES
• Moderate COI + High AVK: Aim for COI below 6.25% to reduce hereditary
Acceptable in rare breeds with limited risks. Strive for AVK above 85% to maximize genetic
populations. diversity. Always combine pedigree metrics with:
Breeders should evaluate both numbers together. A o Health certifications
pedigree with a high AVK but also a high COI may o Temperament evaluation
look diverse on paper but still concentrate genes o Breeder knowledge of bloodlines
from a few ancestors. Conversely, a low COI with
a low AVK may avoid inbreeding but lack broad Numbers are helpful, but they don’t replace the
genetic input. breeder’s judgment. A responsible program blends
science, experience, and care for the breed’s future.
INTEGRATING PEDIGREE METRICS WITH
DNA TESTING APPLYING AVK AND COI IN A
BREEDING DECISION
While AVK and COI are calculated from pedigree
data, modern breeders also have access to DNA- Imagine a breeder evaluating two potential mates:
based tools. These can reveal:
• Dog A: COI = 5.2%, AVK = 90%
• Hidden carriers of genetic diseases
• Dog B: COI = 12.5%, AVK = 70%
• Actual heterozygosity (genetic variation)
Dog A offers lower inbreeding and higher diversity
• Breed-specific mutation risks — ideal for expanding the gene pool. Dog B may
carry valuable traits but poses a higher risk of
Combining pedigree metrics with DNA testing concentrating genes. A breeder might choose Dog
offers a more complete picture. For example, a dog A for a foundation litter, then use Dog B selectively
with a low COI might still carry multiple recessive with health-tested mates to preserve specific traits
mutations — something AVK and COI alone without compromising diversity.
wouldn’t reveal. Responsible breeders use both
pedigree analysis and genetic screening to make
informed decisions.
COMMON MISCONCEPTIONS
Here are some common misconceptions that exist in “
relation to AVK and COI: AVK counts ancestors.
• “High AVK guarantees health.” False — AVK
only counts unique ancestors, not whether they COI counts genes
carried harmful genes.
• “Low COI means no risks.” Not entirely true —
recessive genes can still cause problems. “
- 25 -
