The Breeding Systems contâ€Ś. *Janus was one of those successful sires of colonial winners. Michaelis tells us, "After the arrival of *Janus it was within the *Janus family that most of the winners were found. Some of the Janus-bred horses had so many crosses to *Janus that modern writers questioned their pedigrees." Michaelis went on the explain that *Janus stood at stud 28 years and that the Colonists believed in *Janus blood. She credits this Colonial attitude to the philosophy of, "if one Janus cross was good-several should be better." Michaelis' report tells us that the outcome of this inbreeding, "resulted in a horse that could not run a full quarter of a mile.â€? Thus the concentrated blood of *Janus may have shortened the distance of the Colonial Quarter Horse but it gave him a tremendous burst of early speed and uniformity of conformation. Thus the foundation of the Colonial Quarter Running Horse had unknowingly set the "type" of animal known today as the American Quarter Horse through the practice of inbreeding. The key to what made Bakewell successful was the fact that he culled or removed the undesirable individuals and kept only the genetically sound animals. Strong culling and the retaining of only the best or genetically strong is a key to any inbreeding program or venture. This is why many of the successful breeding programs that practice inbreeding were successfulâ€”They used rigid culling levels using only the genetically superior to achieve the desired results.
Volume 1, Issue 1
The early King Ranch breeding program is synonymous with inbreeding and linebreeding in the quarter horse industry. The King Ranch breeding program developed the Old Sorrel line of quarter horses, because Old Sorrel was the best cow horse they had ever seen on the ranch.
that the King Ranch was successful in their breeding program by carefully selecting only the best horses for their breeding herd. They had rigid standards and culled all horses that didn't meet their criteria.
The genetic text ANIMAL BREEDING-AN INTRODUCWhen the King Ranch started using TION by Rodney B. Harrington gives Old Sorrel as a breeding stallion, they us another example of rigid culling were pleased with his colts. In order through plant breeders. Plant breeders will use high culling levels to to perpetuate the line they started breeding him back to his daughters. achieve their goal in producing an outstanding inbred line of plants. In But they were not satisfied with the some cases they will save only 1% of results. So they started breeding to the progeny over several years and Old Sorrel through his sons and they will work with thousands of daughters. They found this to be a plants. This is not practical for the better then close inbreeding of Old animal breeding industry but it tells Sorrel being bred to his daughters. us that to use inbreeding as a breeding system, we need to use only the best The sons and daughters of Old most genetically sound individuals Sorrel that were used as breeding and cull the rest. horses on the King Ranch were all tested and proven to be good using Bakewell was unable to use the horses. The individuals that carried the desirable genes were the only ones genetic knowledge available to modmoved to the Old Sorrel breeding pro- ern breeders. Bakewell's idea was to gram. introduce and keep the best genetics in his herd by selection. Through The quality individuals the King proper selection, he retained the deRanch required in their breeding pro- sired animals, making his herd gram may best be demonstrated by "homozygous" for the desired traits. the number of sons that were signifi- Homozygosity is the basis for breeds cant contributors to the breeding pro- passing on the same traits generation gram. Bob Denhardt in his book, after generation. THE KING RANCH QUARTER HORSE, discusses 14 sons of Old The genetic condition of homoSorrel that were used as breeding zygosity is best defined through a horses in the Old Sorrel breeding pro- short discussion of basic genetics. gram. Of these 14 only 6 made a sig- The horse's genetic makeup is connificant contribution. The 6 were tained on 64 chromosomes. The Solis, Cardenal, Little Richard, genes are located on the 64 chromoMacanudo, Babe Grande and Hired somes. The genes are strands of deHand. oxyribonucleic acid (DNA). The DNA is the code to tell the bodybuilding The significance of these 6 stallions materials how to form the different and their contribution is put into per- systems. Thus the genes carry the spective when we see that Old Sorrel genetic material that gives the animal was used on the King Ranch for 22 his physical characteristics. years from 1921 to 1943. This tells us