ANCESTOR LOSS COEFFICIENT (AVK)
Indicates the suspected loss of ancestors, when computed with which one can reconstruct the in-breeding in earlier generations. The AVK for an n-generation family tree is calculated by the number of actual (independent - unrepeatable) ancestors, and the total number of possible ancestors. The program calculates for AVK (defined as unique ancestors / expected ancestors, where expected ancestors is 2^(N+1) - 2). This is the correct calculation and is the most accurate calculation and is what the program uses.
While AVK can be a useful metric, but it’s not perfect and should be taken together with other data such as health certifications and COI values, as well as intangibles from experience with certain lines including your own line, and what they may produce when bred. Imagine if you just counted the different kinds of fruit in a bowl but didn’t look at how many of each kind of fruit there are in the bowl, how fresh the fruit is, or how sweet and tasty the fruit is. You’d miss some important details of the fruit in the basket.
The AVK number tells us how many different ancestors an animal has, not how much each ancestor affects the animal’s genes. Taken by itself this can sometimes give a skewed view of an animal’s genetic diversity. For instance, two animals could have the same AVK but very different genetic makeups.
The AVK number does not tell us anything about the good or bad traits the ancestors have/had. You can wind up knowing a dog has a lot of relatives but not knowing anything about their health or personalities.
COEFFICIENT OF INBREEDING (COI)
Other metrics like the Coefficient of Inbreeding (COI) can show us how closely related the animal’s parents are.
When animals are closely related and bred together, it increases the COI and can lead to a higher risk of offspring inheriting genetic defects or health issues. This is because close relatives are likely to carry the same recessive genes for certain conditions, and when paired together, these genes can manifest as health problems in their young. For instance, in dog breeding, a high COI could increase the risk of hereditary diseases like hip and elbow dysplasia.
While animals can certainly be bred that are related (line breeding), it does increase the health risks, but it also helps maintain the good traits of a particular line. It works both ways. By careful selection of breeding pairs the breeder can increase the desired traits and can also increase good health traits. This is why if you look at kennel dog histories and especially older kennels that may have had hundreds of dogs, you can instantly tell what kennel a dog may have come from just bu looking. Those breeders and kennels know their particular line very well and also know that an out cross
There are no easy choices. Since we track health certifications in the database, the pedigree database can help show what health issues might be common in an animal’s family, how many common relatives a dog may have within the pedigree and how closely related those relatives are. Breeders can use this information to avoid breeding animals that might pass on bad health traits, or to increase good traits or maintain a certain desired look. Pedigrees help breeders see which good qualities (a friendly nature, strong build, good hips/elbows) are passed down through families.