Analysing Pedigrees

Pedigree analysis can be extremely daunting even on a five generation pedigree chart. How do we interpret and analyse a pedigree, how do the names all fit together and what does it all mean?

Pedigree terminology is bewildering : inbreeding, linebreeding, outcrossing, filly and colt factors, breeding pedigrees, pre-potency, sex balancing, sex linked genes – what do these really mean, what is the significance of each and how do they all relate to each other?

Interpreting pedigrees is a learned skill, but anyone is capable of learning some of the basic principles. It can add an entirely new dimension to your breeding program, your understanding, and can even ignite your passion for breeding. I suggest going through the genetics and the balanced breeding sections of the website first, working down to analysing pedigrees, to become familiar with the terminology and structure references.

This work is technical and can be difficult. Think of it like learning to ride a horse, and how many years you were prepared to put into learning to ride. Many times you will face discouragement. Learning to read pedigrees takes the same kind of commitment for the very serious student, but even a basic understanding of the methods of breeding – inbreeding, linebreeding and outcrossing, as well as sex balancing bloodlines, can drastically improve your breeding program.

For looking at pedigrees I prefer to use AllBreedPedigree.com. This site allows you to look at pedigrees up to five generations for free and up to 9 for a small fee. Membership is recommended, as five generations is very limiting for viewing patterns. I find the all breed pedigree site is much easier to view extended generations  all in one condensed page. It is a wonderful resource – but it relies on users to add pedigrees. This means users can also unwittingly change pedigrees, so they become inaccurate. Therefore, it is very important to always cross reference accuracy on HorseTelex or sporthorsedata, or breed registration papers. Once you have been looking at pedigrees for a while you become familiar with many of the bloodlines and will know if they have been changed, but while you are learning, always check accuracy – this is extremely important.

Horse Telex is very difficult view extended pedigrees on. It highlights both parents of a duplicated horse, making it very difficult to see what you are actually looking at. The Allbreed site will only highlight the dams name if the mare has more than one of her progeny present in the pedigree.

I will show five generation pedigree charts here for ease of explanation but I recommend if I am talking about dominances further back in my article section, that you follow along on the Allbreed site and look up it up, and make sure that you understand, and can see where the duplications are, and whether they are coming through sons, daughters or siblings. This is the best way to learn and much more beneficial than just reading along with what is being said. For those who really want to learn to analyse pedigrees, it is important to make sure you can can see and understand each duplication and how it is presented.

Basic terminology

Stallions are in a blue colour and mares in a pink colour area.

On the Allbreed site, where an ancestor is duplicated, that horse will appear with its own color code bar to the right of its name. So, if Donnerhall appears three times he will always appear in the same colour. If a pedigree has 4 different ancestors duplicated in 5 generations, each ancestor will have its own colour, which makes it easier to see and follow.

Balanced Breeding Theory – see this link for discussions on general principles  – colt and filly factors, sex balanced linebreeding, inbreeding, linebreeding and outcrossing.

Pedigree position

This is denoted by numbers, such as 4 x 4, meaning the ancestor appears twice on the 4th generation.  Similarly means the 3 x 6 means the horse is duplicated on the 3rd and 6th generations.

Pedigrees should be read top to bottom – so below in Capitol I’s pedigree, son and daughter of the mare Vase – Grand Vikar and Folia, are at 2 x 1 .
Ramzes appears at 4 x 3 x 3.

The following examples are five generation pedigree charts of horses that show a reasonable number of duplications within five generations. Therefore they are generally inbred or line bred horses, because it is easier to see them on a chart this size. Make sure you see and understand the duplications – which generation they are on and how they are presented – whether the bloodlines are coming through a son and daughter, sons only, or daughters only, and any sibling relationships.

Pay strict attention when you see a mare’s name highlighted – this means she is present by two or more of her progeny and this is usually the power line of the pedigree.

The first generation in numbering starts with the parents, not the horse itself – so the first generation in Capitol I are the parents – Capitano and Folia.

Pedigree of Capitol 1: Top Jumping Sire: A Stallion with filly factors

Top jump sire Capitol I – He is 2 x 1 to son and daughter of the mare Vase – the son is Grand Vikar and the daughter is Folia. He also exhibits daughters of a sire –  He has 3 daughters of the stallion Ramzes –  both sides of the pedigree, and the daughters are Vase and  Retina  (moving top to bottom) at 3 x 2 x 2.

Pedigree of Grand Prix horse Sky Diamond: Inbreeding to a mare

Sky Diamond is an example of inbreeding to top mare Loretta (the dam of Sandro Hit).

He is  2 x 1 to a son and daughter of  Loretta .  The son is Sandro Hit and the daughter is Loreana. There is sex balanced line breeding to Donnerhall at 3 x 3 via son  Don Schufro and the daughter Contenance D.