Mar 3, 2024 Grasping Genetics

Understanding pedigree crosses.

As we navigate through the complexities of breeding horses, we underscore the significance of a holistic approach that integrates pedigree analysis with considerations of conformation, disposition, and performance goals. By leveraging this multifaceted understanding, breeders can navigate breeding challenges with confidence and precision, ensuring the continued advancement and preservation of equine excellence.


Defining Important Terms

First, it’s important to understand the definition of linebreeding vs. inbreeding. They are considered two separate concepts stemming from the same baseline. Technically, all linebreeding is a form of inbreeding, but it’s not as “close up” in the generations.


Linebreeding refers to the repetition of a single ancestor within more than five generations, though many stock horse breeders consider it to be within the third generation or further back. Essentially, this method involves systematically choosing horses that possess a high percentage of desired genes and characteristics for the resultant foal, but not so closely related (as in the first or second generation).

Linebreeding
Above: An example of linebreeding and how you can trace the originating sire or dam through multiple generations. The originating line (such as King, Poco Bueno, Doc Bar, etc.) won't be seen physically in the first three generations of the pedigree, but will be found further back.

Inbreeding occurs when the same ancestor appears within the first three generations of the horse’s pedigree. However, in Thoroughbred horse breeding circles, inbreeding is considered as far back as the fourth generation.

Inbreeding
Above: An example of inbreeding in that you are able to identify a single originating horse more than once in the first three generations of a pedigree. This is how many breed "types" are established.

Types of Pedigree Crosses

Cross-breeding: the cross-breeding of two different breeds to create genetic diversity. For example, we see this a lot in the hunter under saddle ring, with a lot of Thoroughbred blood being infused, adding height, loft, and seriously floaty movers.

Outcross: breeding two horses that are completely unrelated, within the same breed, to one another. Though this can be difficult to find within a single discipline such as reining, western pleasure, etc. If you have a mare who is heavily line-bred to Zippo Pine Bar, and you'd like to incoporate some hybrid vigor, perhaps looking into Invitation Only bred stallions is a good idea. Invitation Only has zero traces back to Zippo Pine Bar himself, and only 2 infusions of Three Bars behind six generations.

Line-cross: breeding two horses together that are line-bred to different families. This is a type of outcrossing that combines the traits from two distinct genetic lines. For example, if you have a mare who is heavily King bred, perhaps you'd like to cross on a Skipper W linebred stallion in order to combine the two powerhouses.


How does this affect type?

It’s also important to remember that when further linebreeding is desired, that the concentration of both negative and positive traits are going to increase. Which is to say, linebreeding and inbreeding are not fail-safe – you have just as much of a chance of producing negative outcomes as you do positive. Keeping in mind that linebreeding eventually necessitates outcrossing for continued improvement in the breed.

Stay tuned for our next article where we dive into the nitty-gritty regarding outcrossing.

Want to learn more or have questions? Reach out to us on Facebook or send us a quick note to our email at hi@stallioncompare.com.


Natashya V.
Natashya V.

Founder, StallionCompare.com | Creative Director

Natashya, the founder of StallionCompare.com, is a dynamic force in both the equine and creative industries. As a lifelong equestrian, Natashya’s journey with horses began with Quarter Horses in her hometown in British Columbia, Canada. During her college years she took a brief (and eye opening) hiatus from Quarter Horses to work in the Thoroughbred industry – returning to the AQHA circuit as a young adult. Natashya was also able to reconnect with the quarter horse industry through design. She worked with former owners of Pleasurehorse.com and Show Horse Today on their design needs prior to Robyn Duplisea purchasing the business. Natashya also worked at Horse Canada (HPG) as the Creative Director for many monthly, quarterly, and annual equine magazines. Her passion (read: obsession) for breeding, genetics, and equine pedigrees ran ever-increasingly deep, which lead her to create StallionCompare.com.

Beyond her equine pursuits, Natashya is the Creative Director & Co-Founder of a leading design agency known for its boutique, customer-focused approach. With her expertise, she blends creativity and technology to make a lasting impact in both horse breeding and design.