"They come from the RMIT in Melbourne, they are used in research then they come up here," race starter Brett Maxwell told the Brisbane Times.
The races feature a number of important rules, including a strict ban on flying.
"Entrants thought to have gained an unfair airborne advantage will be disqualified," the event's website states.
Story Bridge Hotel owner Richard Deery called the event typically Australian.
"It lets everyone become an owner, from the youngest to the oldest. They can all be an owner of a thoroughbred," Deery told the Australian Broadcasting Corp.
Mark Alcorn, an Irish citizen living in Australia, won the first of the day's 13 races.
"As soon as I heard about it I said, 'I'm gonna go and I'm gonna win'" Alcorn said. "It's possibly the best day of my life."