The National Council of Societies for the Prevention of Cruelty to Animals, or NSPCA, said it wasn’t able to say for certain how many other chickens had already died by the time its officers reached several neglected poultry farming sites because of the “mass cannibalism” that took place among the birds.

The NSPCA managed to save more than 500,000 chickens, it said.

The chickens were owned by Daybreak Foods, a major poultry supplier owned by South Africa’s state asset management company Public Investment Corp.