Police have confirmed about 2500 of the chickens being transported on the truck this morning were killed.
Acting Senior Sergeant Stuart Gale of Ballarat Highway Patrol told The Courier that the driver, who was travelling from Trawalla to Geelong, was cooperating with police.
Police are continuing to look at a number of causes for the crash, including speed, fatigue, distraction and impairment.
The company involved assisted emergency services with the clean-up process.
Acting Senior Sergeant Gale said given there had been two incidents involving heavy vehicles and livestock in the past month, police would begin to look at why it is occurring and evaluate their enforcement around heavy vehicles.
The Avenue was closed for much of the day, only re-opening to traffic around 3.30pm.
The Avenue of Honour remains closed in both directions after a truck rollover near Whites Road.
Thousands of chickens from the B-double truck are scattered across the road and at least five trees on the Avenue of Honour near Cardigan, west of Ballarat, have been damaged in the crash shortly after 7.30am.
Police, ambulance and other emergency services are on scene.
A 38-year-old man, the truck driver, has been taken to Ballarat Base Hospital in a stable condition, with minor injuries.
DRU Acting Detective Senior Sergeant Brett Robinson said the truck was carrying 3700 chickens but it was not yet known how many had been killed or injured.
Police have not yet determined the cause for why the truck, the only vehicle involved in the incident, rolled.
He said the man was "shaken up" and was being treated in hospital.
The remaining live chickens - stock which were being transported to be killed for meat - will be collected and transported to their original destination.
Acting Senior Sergeant Robinson said police had not yet determined the cause for the truck rollover but they were investigating a range of causes including speed, fatigue and distraction.
Vets are on scene assessing the injuries to the animals and are euthanising those that survived but are badly injured.
The clean up is expected to take several hours and the road will remain closed during that time.
Drivers are recommended to use alternative routes, such as the Western Highway or Cuthberts Road.
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