Australian and New Zealand champion jockey Greg Childs, whose is best known as the regular rider of legendary racemare Sunline, will hang up his tack at the conclusion of the Saturday race card at Flemington.

The 46-year-old New Zealand native, who began his career in 1978, has guided in approximately 2,100 winners, including 72 in Group 1 races, during his 30-year career.

Childs said lack of motivation was a key factor in his decision to retire.

“I'm tired. I've lost that aggression, not so much on the track, although that's probably right as well to a lesser extent, but certainly the aggression to chase rides," Childs told Australia’s The Age.

"I've always worked hard to chase good rides. It's a tough business with plenty of competition and I've tired of it."

Childs rose to international prominence with Sunline, a multiple Horse of the Year in Australia (2000,’ 01, and '02) and New Zealand (1999, 2000, ‘01, and ‘02) and member of the Australian Racing Hall of Fame. Childs and Sunline teamed to win 22 races, including the 1999 and 2000 BMW W. S. Cox Plate (Aus-G1) and the ’00 Hong Kong Mile (HK-G1) for co-owner and trainer Trevor McKee and partners.

"She was so strong and just so brilliant," Childs said about Sunline, who is now 13 years old and currently battling life-threatening laminitis. "She could win left or right-handed and won Group 1s in New Zealand, Australia, and Hong Kong. I rode her 32 times and won 22 races, including 11 Group 1s.

"She was the horse of a lifetime for me."

Childs also scored wins in the Carlton Draught Caulfield Cup (Aus-G1) aboard Northerly in 2002 and Railings in 2005. His record includes nine Oaks winners and six Derby winners.

After riding his first career winner in New Zealand in August 1978, Childs was honored as New Zealand’s champion apprentice jockey for the 1978-’79 season. He also captured the Australian champion jockey title for 1991-’92 and '97-’98.  

Childs will remain in racing by boarding racehorses on his property and manufacturing the Vipa safety vest for jockeys and other equestrians.

Childs said he has seen many changes during his three decades in racing, but points out the basic elements of the sport are intact.

“You go around in circles and the fastest horse wins,” Childs told The Age.