Our study showed that all chemical agents significantly
decreased the number of feathers plucked and eaten. The
2% and 4% quinine treatment eliminated feather plucking
and consumption completely, whereas the other treatments
had a lesser effect. In the current study we used high
feather-pecking birds selected on high feather-pecking
activity over 10 generations. It would be interesting to test
if the chemical agents used in this experiment would be
more successful in deterring hens from feather plucking,
when commercial breeds with a lower motivation to peck
at feathers would be tested.