DNA testing is providing Irish breeders with information extending beyond parentage. Horse Sport Ireland’s senior geneticist, Dr Jennifer Doyle, explained how it works and why it is useful for breeders on the ground, as well as for international studbooks.

HSI’s transition towards SNP testing, using single nucleotide polymorphisms, enables genetic markers to be examined from a hair sample, supporting disease screening, chromosomal checks and ancestry research. Not always easy to understand, Doyle outlined testing for fragile foal syndrome within the Irish Sport Horse population. Stallions presented for inspection and selection are tested, with results published in the stallion book, while wider mare testing was under consideration.

She also described carriers of hoof wall separation disease identified in Irish Sport Horses, Irish Sport Ponies and Irish Cobs with Connemara ancestry. Carrier status differs from being affected: testing provides information that can help prevent affected foals without automatically excluding valuable breeding animals.

Chromosomal screening had identified abnormalities associated with fertility problems. Early detection could spare owners unsuccessful breeding attempts and considerable expense.

Research into breed composition was helping investigate ancestry, including horses with unknown pedigrees, although the mixed origins of sport horses make interpretation complex.

Doyle also highlighted differences between pedigree-based estimates of inbreeding and measurements using DNA. Incomplete pedigrees can conceal relationships, while genomic analysis examines the genetic information present.

Genomic evaluations offer potential for earlier assessment of difficult-to-measure traits, distinct from the studbook’s existing traditional evaluation for lifetime show jumping performance.

DNA also supports investigations where passports, markings or microchips give misleading information. These applications illustrate how genetic testing is becoming relevant to breeding decisions, fertility investigations and equine identification.