Charles Bourns, poultry board chairman of the NFU, keeps up to 70,000 barn chickens at South End Poultry Farm, Charfield, Gloucestershire, and swears by Classic FM.

"I've tried pop music but it's too changeable, with lots of talking - the birds prefer Classic FM, much to my childrens' disgust," he says. He introduced music to the farm about five years ago, as part of a television programme to combat anti-chicken farming propaganda.

"Compassion in World Farming always had a go about leg weakness and so on, which I've never had on my farm," he says. "So we decided to get our message over and did a film of the chickens dancing around a radio in the barn, and the local radio station took requests to play to them."

Mr Bourns noticed such a difference in the chickens that he has played music to them ever since. They are so passionate about their music that he can't introduce it to them until they are at least two or three days old. "I don't play it to day-olds, as they follow the noise and crowd round the radio."

Farmers Weekly Interactive reports that the music is played 24 hours a day, deadening other noise in the sheds, and making the birds more peaceful. It also improves growth rates, he claims. "If the birds get startled they rush around and fight and don't eat, so it is bound to help. Not being stressed is much better for all of us."

Stuart Retallack, who keeps 500 free-range laying hens at Trekennick Farm, Altarnun, Cornwall, agrees. "The background music covers up loud noises such as low aircraft, keeping the hens more relaxed in their environment." However, Radio 1 is his station of choice. "I prefer it - the hens don't seem to have any preference," he says.

Organic egg producer James Maclean, who owns Border Eggs near Berwick on Tweed, prefers playing Radio 2 to his flocks.