Thirty five pigs have been killed after a lorry carrying around 200 of the animals overturned near York in a crash involving a Warburtons bread lorry and a car.
Emergency services are currently at the scene, on the A59 Boroughbridge Road near Upper Poppleton.
The A59 near York is closed with queuing traffic in both directions between the Station Road junction and the A1237 York Outer Ring Road junction.
The crash was reported just before 10.30am and police have since put a diversion in place, with drivers warned of long delays.
Police said that none of the drivers of any of the vehicles suffered serious injuries.
North Yorkshire Police have appealed for witnesses to the collision, which involved a Volvo lorry, a Leyland DAF lorry and a Toyota Prius car.