Determinants of Thoroughbred yearling sales price in the UK.

Background: Industry-level figures suggest that up to two-thirds of Thoroughbred breeding operations in the UK are unprofitable and that around half of sales transactions of Thoroughbred yearlings, commercial breeders' predominant income source, return a loss. The industry strategy currently endorses investment in stallion covering fee; however, to date, a comprehensive evaluation of sales price determinants in the UK setting is lacking and could better inform economic decision making to improve profitability.

Methods: Sales catalogue and Weatherbys' stud book data from all Thoroughbred yearlings sold at the 2020 Tattersalls October yearling sale in the UK were used to build a hedonic sales price model. Explanatory variables representing sire, dam, yearling and sales attributes were evaluated. The final model's accuracy was assessed using out-of-sample data from all yearlings sold in the equivalent 2021 sale.

Results: In 2020, a total of 1506 catalogued yearlings, representing around 30% of the UK Thoroughbred foal crop, were sold, with a median price of £42,575 (interquartile range 15,750‒105,000; range 840‒3,570,000). The sires' covering fee, maternal siblings' race performance attributes, whether the yearling was the dams' first foal, consignment size, catalogue book and day of sale within book significantly influenced auction price; however, relationships were complex with significant interaction and confounding observed. The mean model forecasting error was £2074. The use of data from only one sale could affect generalisability.

Conclusions: These novel findings can inform breeding decisions to maximise profitability, give context for current industry strategies and can inform valuations of breeding stock.