Mare

How Important is the Mare
in Sport Horse Breeding?

It might interest you to know that the mare was the primary focus of Tesio. He structured his breeding program on his broodmares- he seldom stood a stallion at his farm. For his broodmare herd he sought out mares that carried specific bloodlines he was interested in- for instance he chose Catnip because she was a Spearmint daughter and got her at a bargain price because Spearmint was not a bloodline in demand at the time. Spearmint, although a great racer also had poor front legs, so he was avoided as a sire- at least for a while- until it became obvious to all he was a great sire of winners. Tesio of course was looking at his genotype not his phenotype so he snatched up Catnip. He was always searching out sources of impulsion and he thereby made it his goal to build up multiple lines of the mare Brown Bess in the background of his pedigrees because she was a source of soundness and tremendous impulsion coming from strong hocks (found close up in Spearmint). For each of his mares he painstakingly sought out the best genetic match for her from horses that had been 'performance' tested at the classic races. In addition, he was so committed to a particular match that if he could not obtain a breeding to the stallion of his choice then he would seek a breeding with a full brother or son- rating the genetics above the performance quality of the near relative. Tesio can teach us alot.

Understanding your breeding stock's genetic strengths and weaknesses can be the greatest tool you have in your quest for sport horse excellence. Recently a recognition of the power of the mare has become a focus in equine breeding. Although the genetic contribution of both parents is very important, a realization has surfaced that the maternal strength might instead be responsible for more of the foal's attributes.
The discovery of the large heart gene, a sex linked trait, was one exciting example of this. Another instance is the advances that have been made into Mitochondrial DNA research, both in humans and equines.

"Around the globe you will see the most successful farm operators active at acquiring quality mares and fillies, they know maternal strength is the pathway to success."(McLean)

It took them quite a while to get to this point of view. In the early days of the stud book mares seldom got a name of their own, more often they carried names like "daughter of Glencoe" or "Sedbury Mare" identified only in relation to their sire. This had made the study of early Thoroughbred pedigrees difficult. It is worse trying to study Warmblood and Sport Horse lineages- often the mare is just "unknown".

Knowledge in any field comes from the hard work of many people. The advances in equine genetics and breeding are no different. Following are just a few of the "giant's shoulders" we are standing on today.

Frederico Tesio, the father of balanced linebreeding, was an intuitive genius, instinctively he chose broodmares with reserves of nervous energy- this was long before Mitochondrial DNA was ever imagined.

Ken McLean in his "Genetic Heritage" announced the importance of the dam's x chromosome and he anticipated the future findings in Mitochondrial DNA.

Bruce Lowe attempted to trace and classify those female families that were potent for racing excellence in a number system that is still in use today.

Ellen Parker has developed a 'reine-de-course' list to identify the top producing broodmare lines in the Thoroughbred.

Clive Harper gave us the statistics that have clearly shown that sex balancing pays in his "Thoroughbred Breeders' Handbook" and then explored the power of the mare in depth in his "The Thoroughbred Broodmare Book".

Marianna Haun thrilled us with her "The X Factor" which traced the large heart gene coming down the x chromosome.

The above is a partial list, but enough for you to see that all of these ground breakers were ON TO SOMETHING.

What does this mean for the breeders of Sport Horses? Briefly, because equine genetics work the same no matter the breed of horse, we should employ all the knowledge the Thoroughbred Industry is providing. In particular, we should make breeding decisions with an awareness of the strength of superior mare lines- and we should take steps to bring forward this power to our sport foals.

Just as in human research, the equine researchers are able to trace the Mitochondrial DNA back and determine true ancestry. This is a huge help now, and will be even more in the future, when we will be able to fill in those gaps in our sport horse pedigrees. For example, it was discovered by this method, that the general stud book (Thoroughbred) had far fewer foundation mares than they originally thought. And it also turned out that some of the foundation mares were recorded several times, but with different names, plus many of the mares were also found to share a common mother. Never before have we had a tool like this-one that can verify bloodlines.

It is well established that proper energy conversion in the cells is essential for good muscle performance. As breeders of horses that we hope will excel in sport we should pay close attention to any new developments in Mitochondrial research.

Evaluation done of the pedigrees in the Thoroughbred Industry revealed that particular pedigree patterns produce either better fillies or colts, and that there also was a difference between good breeding stock (both stallions and mares)when compared to the pedigree design of performance only winners. See Potency Primer page for more on this.

We are living in exciting times for sport horse breeders as every year there seems as if some significant discovery is made concerning sport talent and genetic transmission. For instance, in 2010 the Dr Mims Bower and her research team published their findings that the original foundation mares of the Thoroughbred were not 'arabian' as long believed, but were what she calls 'native' British and Irish mares- these individuals we know as Running Horse and Irish Hobby mares from the historical records (MacKay-Smith 'Speed and the Thoroughbred'). Then in January of 2012 Dr. Emmiline Hill and her associates further expounded on this, by tracing the 'speed' gene back to "..a British mare about 300 years ago, when local British horse types were the preeminent racing horses, prior to the foundation of the Thoroughbred racehorse." Read the articles below.

Dr. Emmiline Hill- speed gene article
Dr. Mims Bower- British and Irish Native mares

This is the same root stock that the American Colonists imported for race and saddle stock. The Irish team determined that the American Quarter Horse carries the speed gene also.

There is an irony in this, in that science is finally catching up with the conclusion that speed in the racehorse originates with the Hobby-bred mares of the old racehorse studs of Ireland and England. The scholars I mention are John Wallace who in the 1800s, after 50 years of pedigree research and the establishment of two registries for Trotting racehorses, determined that speed at both the gallop and the trot originated with the pacing bloodlines. What has this to do with the 'speed' gene? Those early racehorse mares were gaited, the Hobby was a gaited breed, which possessed large amounts of stamina as well. The racing trot, with its low straight forward motion developed from the pacers- the eleveated showy trot comes from a different source. (See Standardbred article for more on this).

A more modern scholar who came to the same conclusions is Alexander MacKay-Smith, he believed that speed originated with the Hobby. They published their work in : Wallace "The Horse of America in his Derivation, History and Development" 1897 and MacKay-Smith "The Colonial Quarter Race Horse" 1983 and "Speed and the Thoroughbred" 2000.

America is blessed with tremendous domestic resources for the sport horse breeder as we have 3 racehorse breeds (TB, QH, ST) plus a multitude of other light horse breeds that descend from this same root stock: Morgan, Saddlebred, Tennessee Walker and Missouri Fox Trotter.

We can capitalize on this science by making an effort to understand the proven mare lines our stock may carry. This will be easier for some breeds then others. For instance, the Holstein association has always put an emphasis on 'stamm' lines (maternal families), and therefore the genetically potent mares will be relatively easy to identify. The Trakehner Horse is another breed that has valued its exceptional female lines, to the point that the stallions are named by the first initial of the dam's name, rather than the other way around. Thoroughbred breeders have classified especially potent mares as 'blue hens' and Ellen Parker developed her 'reines-de-course' list and made an indepth study of the female families. With the computer databases available we can also trace our other American breeds back, and therefore find the early transmitters of this sport talent, then locate the modern carriers and build them up in our sport stock. With other breeds it may be harder, but not impossible.

To identify good target mares for your linebreeding, look to broodmares who have more than one excellent offspring. When you have identified a mare in the pedigree you believe is a good subject, then look for her siblings (full if possible) or her sons and daughters in your mating choices. Once you have found a good mare line in your gene pool lineage, make that mare one of your linebreeding targets. This is what the successful Thoroughbred breeders are doing - they are linebreeding to dominant mares- with spectacular results.

Case Study- The dynasty of Enniskeane Countess

Great maternal influences are much harder to find then those coming from stallions. Mares only produce an average of 5-10 foals in their lifetime, compared to a stallion average of 250-500 offspring. So, any mare that has more than a few good progeny is a mare to treasure.

Clive Harper, Thoroughbred pedigree expert, said: "Start with what strength the mare has- always looking very, very closely at the dam line- and build in the complimentary and supplementary names."

One of the most productive practices you can assume in your breeding program is to build up powerful broodmare famiies. When planning a mating for a stallion use your best mare.