A stock transporter carrying cattle on Victoria Parade lost its load when the gates of the vehicle were not properly secured.

Five bullocks fell onto the road and Police had to destroy all five of the animals.

The 26-year-old driver from Deniliquin New South Wales was fined $518 for an insecure load.

The incident disrupted traffic when the animals began falling out just before 8am near McDonald's, but no damage was done to any passing vehicles.

"If you had been in a car travelling behind it and a cow fell out on the bonnet you would surely know about it," Operations Senior Sergeant Rod Malkin said.

The carcasses were removed from the road by Port Augusta City Council workers and the incident was cleared up after about two hours.