Mainstay is a thoroughbred horse born in Australia in 2005. Race horse Mainstay is by Portland Pirate (AUS) out of True To You (AUS) , trained by Darryl Dodson. Mainstay form is available here. Owned by R STARR, MRS M STARR, J CARTER, DR M CARTER, T HUTCHINSON, A BOYD, J WAUGH, G MCPHERSON, DR J WILLIAMS & J CARTER..