US Chicken producer Tyson Inc has announced a reward to help track down the vandals responsible for the loss of approximately 75,000 chickens at two of its Kentucky farms last month.

Ventilation fans were shut off, suffocating the tightly packed broilers and causing at least US$60,000 in losses. The incidents happened three weeks' apart in areas 50 miles from each other.

Tyson and two farmers' groups have offered a US$10,000 reward. "We want to see justice served for our growers, our company and the agricultural community, and to make certain this type of thing doesn't happen again," said Tyson's Jeff Power.

By Philip Fine, correspondent