This is the first time in a UK field setting that the effect of early-life exposures, in particular exercise and turn out, on later-life milestones and race performance in Thoroughbreds has been comprehensively evaluated. These novel findings can be directly applied at stud farms to help retain Thoroughbreds within the industry and achieve their maximum athletic potential – outcomes that align with priorities of the Horse Welfare Board’s strategy to support the welfare of horses bred for racing.
Conducting the research, the team, led by Dr Rebecca Mouncey, a veterinary surgeon and Post-Doctoral Research Fellow at the RVC, followed 129 flat race-bred Thoroughbred foals, born in 2019 and 2020 on six stud farms across the UK, from birth into training for racing. Each dam’s reproductive history, and details of her health and management during pregnancy were collected, as were daily records of the foal’s health and management from birth until they left the stud farm. Race performance records up to the end of their fourth year of life were collated from racing industry databases.
The team then used statistical modelling to evaluate relationships between gestational exposures and early-life experiences and whether or not horses entered training and their subsequent race performance. Findings suggested that the use of more extensive turnout practices during the first six months of life and later weaning benefited the attainment of career milestones, productivity (the number of races) and financial returns (total prizemoney won).
Key findings include that:
- Foals that spent more time turned out at pasture in the first six months of life, and foals that were weaned at an older age, were more likely to race at least once by the end of their fourth year of life
- The older the foals were at weaning, the greater number of race stats they made
- Foals that were turned out in larger paddocks during the first six months of life earned more prizemoney
Published in Equine Veterinary Journal, these findings demonstrate that the first six months of life is a critical period of development in Thoroughbreds, during which it is essential that turnout and weaning practices provide sufficient opportunity for positive tissue adaptation and optimal development. Breeders are therefore encouraged to maximise turnout whenever possible, and to consider weaning after this critical period.
Dr Rebecca Mouncey said: “This study is the first of its type to evaluate the effect of early-life experiences on later-life performance in Thoroughbred racehorses, providing important novel findings that can be directly applied at the stud farm level to reduce wastage and improve performance in this population.
“Our findings highlight that the first six months of life are a critical period of development in Thoroughbreds, during which we must be mindful to ensure that our management practices provide sufficient opportunity for positive tissue adaptation and optimise development.”
