Johannesburg – Bystanders attacked NSPCA staff after a truck carrying 3 000 chickens overturned on the N12 highway between Lenasia and Westonaria, a spokesperson said on Wednesday.Occupants of a nearby informal settlement threw stones at officials when they tried to catch the chickens after the accident on Tuesday, NSPCA spokesperson Jaco Pieterse said."There is an informal settlement just across the road from where the accident occurred, and several people came to take the chickens.No NSPCA staff or volunteers were injured, but one NSPCA vehicle was damaged by stones.The NSPCA said several injured birds had to be euthanised at the scene. The remaining chickens were transferred to another truck and taken to a nearby farm, where more were euthanised.About 100 birds were put down. The chickens were destined to be sold at an informal market, when the NSPCA rescued them.They had been used as "intensive breeding machines" and, once they were no longer of commercial use, were packed into crates and destined for sale in the open air on the informal market. "In most cases, these birds are handled inhumanely, placed for sale without food, water or protection from the elements," Pieterse said.