What’s the Difference Between COI & AVK?

Imagine a family tree, but for animals. This tree helps us understand who is related to whom and how closely. In the world of animal care, especially when planning which animals should have babies together, two important concepts come into play: the Coefficient of Inbreeding (COI) and the Ancestor Loss Coefficient (AVK).

Think of COI as a tool that measures how similar an animal’s parents are to each other genetically. If the parents are very closely related (like cousins), the COI number goes up. This is important because when animals have babies with close relatives, it can lead to health problems and less variety in their genetic makeup, which is not good for their overall well-being.

On the other hand, AVK helps us see how varied an animal’s family background is. It checks if an animal’s ancestors come from a wide or narrow family group. A wide variety means the animal has a rich and diverse family history, which is generally better for its health and survival.

Inbreeding is essentially when animals that are closely related, like siblings or cousins, have offspring together. This is a bit like having a very small town where everyone marries someone from the same town. Over time, everyone in that town becomes related in some way. In the animal world, this can happen naturally in isolated environments, or it might be done on purpose in breeding programs to maintain certain desirable traits, like a specific look or behavior in a breed.

However, inbreeding comes with its own set of challenges. When animals are closely related, they have a higher chance of sharing the same genes, including those that can lead to health problems. Just as a child might inherit blue eyes or curly hair from their parents, they can also inherit genes that make them more susceptible to diseases or genetic disorders.

In a broad genetic pool, these genes are less likely to pair up because there’s more variety. But in a small, closely related pool, the chances of these genes meeting and causing health issues increase.

For example, if both parents carry a hidden, faulty gene that can lead to a specific health issue, their offspring are much more likely to inherit two copies of this faulty gene and suffer from the condition. This is why inbreeding can lead to a phenomenon known as ‘inbreeding depression,’ where the vitality and health of a population decline over generations due to a lack of genetic diversity.

Inbreeding can also reduce the population’s ability to adapt to changes in the environment or to new diseases. With a narrow gene pool, there’s less chance that some individuals will have unique traits that could help them survive under changing conditions. In contrast, a genetically diverse population is more likely to have individuals with a mix of traits that can handle a variety of challenges.

This is why understanding and managing inbreeding, through tools like the Coefficient of Inbreeding (COI), is crucial, especially in controlled breeding environments. By keeping track of how closely related the animals are, breeders can make better decisions that ensure the health, diversity, and long-term survival of the species or breed they are working with.

The Coefficient of Inbreeding (COI) is like a score that tells us how closely related an animal’s parents are. Think of it as checking if a puppy’s mom and dad come from the same family tree. If they are closely related, the puppy’s COI is high, which means it might have more health problems because it gets too many of the same genes from both sides of its family.

To figure out this score, we look at the animal’s family history to see if the same names pop up on both the mom’s and dad’s sides. A high COI is a warning sign; it suggests that the animal might not be as strong or healthy because of this overlap in genes, leading to issues like getting sick easily or not living as long.

Breeders try to keep this COI score low when they decide which animals should have babies together. This helps make sure the next generation of puppies (or any animals they’re working with) are healthier, more varied in their genes, and less likely to have the problems that come from parents being too closely related.

Below you’ll find a simple chart showing the hypothetical coefficient of inbreeding between these familial pairings:

Relationship	Inbreeding Coefficient (%)
Parent/Offspring (Father/Daughter, Mother/Son, Brother/Sister)	25%
Grandparent/Grandchild (Grandfather/Granddaughter, Grandmother/Grandson)	12.5%
Half Siblings (Half-Brother/Half-Sister)	12.5%
Uncle/Niece, Aunt/Nephew	12.5%
Great-Grandparent/Great-Grandchild (Great-Grandfather/Great-Granddaughter, Great-Grandmother/Great-Grandson)	6.25%
Half-Uncle/Niece, Half-Aunt/Nephew	6.25%
First Cousins	6.25%
First Cousins Once Removed or Half-First Cousins	3.125%
Second Cousins or First Cousins Twice Removed	1.5625%
Second Cousins Once Removed or Half-Second Cousins	0.78125%
Third Cousins or Second Cousins Twice Removed	0.390625%
Third Cousins Once Removed or Half-Third Cousins	0.195%

Following the concept of the Coefficient of Inbreeding (COI), let’s explore the Ancestor Loss Coefficient (AVK), which offers a different perspective on an animal’s genetic background. While COI focuses on how similar an animal’s parents are genetically, AVK looks at how diverse an animal’s ancestors are. It measures the variety in an animal’s family tree, considering the unique ancestors it has.

The AVK is like a diversity score, showing us the breadth of an animal’s genetic heritage. A high AVK means the animal comes from a wide range of ancestors, indicating less inbreeding and more genetic diversity. This diversity is beneficial because it leads to stronger, healthier animals with a lower risk of inheriting genetic diseases. In contrast, a low AVK suggests that there are many repeated ancestors in the family tree, indicating potential inbreeding concerns similar to those signaled by a high COI.

In practical breeding, while COI helps identify the risk of too much genetic similarity, AVK helps ensure genetic richness and health by aiming for a broader ancestry. Breeders look at AVK to select mating pairs that bring a wide array of genes to their offspring, enhancing the overall health and resilience of the breed or species.

The pairings page is also useful to find potential pairings for your animals. You can input an animal’s details, and the app will suggest potential mates for it, predicting the COI and AVK for any potential offspring.

This feature is designed to help users make informed breeding choices, promoting genetic diversity by avoiding too much family overlap and ensuring a wide variety of ancestors.