Paramedics released and treated the 36-year-old driver who had been trapped in the truck, which had been transporting 50 cows, at Glenmore Park in western Sydney.

"A number of cows were located deceased at the scene, and a number were required to be humanely euthanised," police said.

The driver was taken to Westmead Hospital suffering minor injuries while police cleared the road.

Motorists are advised to avoid the area, with Mulgoa Road closed in both directions.

Australian Associated Press