Mitochondrial DNA in Horse Breeding: Your Stallion Ain’t Jesus and Your Mare Ain’t the Virgin Mary By Heidi Schlenker Breeding stallions and mares is a blend of mitochondrial DNA, structure, and pedigree: not a sermon. This article explains why structure, genetics, and mitochondrial DNA, not miracles, make the difference. Breeding…
“A pedigree saturated with Hall of Fame horses is a pedigree full of exceptional horses.” Her study dug through thousands of pedigrees across disciplines and found what many of us old-school breeders already suspected: when it comes to breeding on, conformation and genetic influence are everything. But Susan didn’t just highlight fancy names on paper. She tracked how deeply those names were embedded using a 3-part system: • How many unique AQHA Hall of Fame horses showed up in the first 20 generations • How many total occurrences of those HOF names appeared across those 20 generations • And how many duplicated ancestors were in the first 8 generations
Outcrossing is more than a trend—it's a science-backed solution to inbreeding, health decline, and performance loss in horses. This article explores how strategic outcrossing has shaped success in Thoroughbred programs and how Quarter Horse breeders can adopt smarter, data-driven practices to preserve conformation, temperament, and long-term genetic vitality.