to attain a reduction in length of both the
upper and lower mandibles of approximately one-half.
A second batch of 24 chicks (12 pairs, n = 12) were
trimmed using an automated infrared beak treatment
system (NOVA-Tech Engineering Inc., Willmar, MN)
preset to trim both mandibles at a hatchery. The remaining
24 chicks were picked up and handled to somewhat
simulate the handling stress being experienced by
the chicks in the other 2 treatment groups, but their
beaks remained untrimmed.