Speed Gene Sheds Light on Why Mac Swiney is Derby Type

Jim Bolger has made public the speed gene designations of his two classic-winning colts of 2021, with QIPCO Two Thousand Guineas (G1) hero Poetic Flare  a C:C—the type most suited to running over five furlongs to a mile—and Tattersalls Irish Two Thousand Guineas (G1) victor Mac Swiney  a C:T, for which the optimum trip is seven furlongs to a mile and a half.

Poetic Flare is a son of Bolger's champion 2-year-old and Two Thousand Guineas winner Dawn Approach , who famously competed in the Investec Epsom Derby (G1) despite being a C:C and ran no sort of race stepped up to a mile and a half. In turn, Dawn Approach is by New Approach  (C:T) out of Hymn of the Dawn (C:C).

Poetic Flare's dam Maria Lee, by top miler Rock of Gibraltar, and maternal granddam Elida, by Carroll Foundation July Cup (G1) and Breeders' Cup Mile (G1T) hero Royal Academy, have both been confirmed to be C:T.

The colt's speed gene designation sheds light on why Bolger never entered him for the Derby.

Mac Swiney, who figures among the leading fancies for the June 5 classic at Epsom, is by New Approach, himself a son of Galileo , who is widely known to be T:T—the type most suited to tests of stamina, from a mile and a half upwards.

His unraced mother Halla Na Saoire is a T:T, with both her sire Teofilo  (C:T) and dam Siamsa (T:T) having passed down a 'T' copy of their genetic marker to her.

Bolger has used such information to inform his breeding and training decisions since the speed gene was identified by Professor Emmeline Hill and her team at University College Dublin around a decade ago and a commercial test launched onto the market soon afterwards.

Bolger and Hill co-founded Equinome, the company that marketed the Speed Gene Test until it was purchased by Plusvital in 2015.

Hill, who serves as Plusvital's chief science officer, said: "This is a great example of the value of genetics and how it can provide information beyond the pedigree. We have trainers and owners across the world using this information every day as part of their decision-making around race selection.

"Simply running racehorses at the suggested distance ranges from our genetic test will lead to outperformance, because so many horses are currently run outside their optimum range."

Perhaps the best known application of the Speed Gene Test in its relatively short existence came when connections of Two Thousand Guineas winner Galileo Gold  used his C:C designation to justify their decision to swerve the Derby with him.

Galileo Gold went on to win the St. James's Palace Stakes (G1) and at the end of his racing career he was retired to Tally-Ho Stud. His first-crop son Ebro River  was a wide-margin winner of the listed Coral Beaten By A Length National Stakes over five furlongs at Sandown last week.