spectrum: One stood six hands, three inches (27 inches) at the withers and the other measured 10 hands, one inch (41 inches).
After reviewing the combined data, the researchers concluded that a specific variant in a gene known as HMGA2 is an important regulator of height in Shetland Ponies. One copy of the mutant allele0 leads to height reduction of almost four inches. Ponies that carry two copies of the mutant allele on average are almost eight inches shorter than ponies that do not have the mutant allele.
The researchers found the mutant allele in Shetland Ponies and, less frequently, two other pony breeds, the German Riding Pony and the New Forest Pony. It has not been found in fullsized horses.
A slight but significant human tendency to prize extremes in equine head or neck shapes may have negative implications for horses, according to Australian researchers.
“The welfare issues surrounding the position of horses’ heads and necks in some disciplines such as dressage and reining are well known,” says Georgina Caspar, a PhD candidate at the University of Sydney. “Of particular concern is the practice of hyperflexion, also called rollkur, which forces the horse’s neck into an extremely arched position, sometimes for extended periods.”
The issue extends beyond training, Caspar continues. “There is also a concern that breeding choices that produce foals which have a certain ‘look’ or ‘type’ might negatively affect a horse’s athletic ability and general health.”
With those concerns in mind, Caspar and her colleagues decided to survey Australians about their preferences for particular equine head and neck shapes and positions. Respondents were asked to choose their ideal shape from a series of silhouettes representing various