Pig tail biting clue
THE level of tryptophan fed to pigs might be a factor in reducing tail biting, studies by Jane MacIntyre of Newcastle University show.
Varying the amounts of the amino acid had a range of effects on pig activity.
Those with the lowest levels in their diet showed most interest in a blood soaked sash cord designed to imitate a pigs tail, she said.
But pigs given an excess spent more time sleeping and were less interested. *