What is the Difference between Linebreeding and Inbreeding?

Inbreeding vs. Linebreeding, what’s the difference? Inbreeding and linebreeding are two related concepts in the world of animal breeding. Both terms are about animals who are related, producing offspring. The difference is in how the animals are related and in some cases why the breeding is taking place. 

Linebreeding

Linebreeding is a technique used by breeders of many types of animals like horses, cows, and dogs, who want to have the offspring show specific traits. A breeder who is interested in linebreeding usually picks a specific animal that has those traits and then focuses on breeding descendants of that animal together to try to get those traits in the offspring. Traits that can be bred for include physical traits, like good joints and a strong body, or mental traits, like a great temperament and excellent trainability. 

Most breeders try to pick animals with which to start a linebreeding program that have a diverse heritage with the exception of that one ancestor. For our example, we will call that ancestor Super Dog. An English Labrador breeder might pick a boy dog whose great-grandfather is the Super Dog and breed that boy dog to a girl dog whose grandfather was also the Super Dog. While these two dogs do share a common ancestor, they are not closely related, which means that the puppies that they produce are likely to be healthy and also may show the desired traits from the common ancestor, Super Dog. 

When breeders are working on linebreeding they often use what is called the coefficient of inbreeding (CoI) or inbreeding coefficient as a mathematical way to check on how closely the dogs that they are breeding are related. It is also a way to check the odds of duplicated genes in potential future litters. Most reputable breeders, and the breed registration organizations they work with, try to keep this number low to prevent issues that can happen when animals that are too closely related are bred. 

One of the ways reputable breeders keep the coefficient of inbreeding (CoI) or inbreeding coefficient numbers low and increase genetic diversity is by outcrossing some generations of the dogs they breed. Outcrossing is a term that means that they also add animals that are totally unrelated to that Super Dog ancestor to their breeding program. 

Inbreeding 

While animals which are line-bred are also slightly inbred, inbreeding is more commonly used to talk about animals that have been bred to other very closely related animals. An example of this would be breeding a boy dog and a girl dog who are full siblings, meaning that they have the same mom dog and dad dog.

For a pair like this, the coefficient of inbreeding (CoI) or inbreeding coefficient would be a much higher number than our example above. It also means that the puppies from those full siblings would be less likely to be healthy. 

Because of the potential for genetic health issues coming from this type of close genetic relationship of the parents, most reputable breeders try to avoid extremely close inbreeding. 

Why does this matter? 

As you are looking for a new pet dog or a new working dog, understanding the difference between linebreeding vs. inbreeding can help you to find out more about the traits or health issues your new dog may have. 

If you find a reputable breeder who linebreeds for traits like a good temperament, trainability, and strong joints, that breeder will be able to tell you a lot about what the puppy will be like as it grows up with those traits. In many cases, you will find that breeders who linebreed also use genetic testing to ensure that they are breeding the healthiest dogs that they can. 

On the other hand, finding out that the breeder you are considering getting a puppy from has extremely inbred dogs may be a sign that you should be cautious and ask questions about their puppies’ health. 

Learn more about our Breeding Program!

If you are interested in learning more about our breeding program, please check out our Boys and our Girls!