The way I heard it, chickens peck at bloodied chickens.
This cycle has severe positive feedback and tends to lead to either:
a) dead chickens, or
b) significant economic losses
depending upon whether one tends to sympathize more with poultry or
UT grads. Since neither interpretation is positive, the poultry
industry has come up with at least three solutions:
a) debeak the chickens, or
b) filter out the blood hues via light bulbs/contact lenses, or
c) house chickens in lower densities
Since (c) isn't economically attractive, and (b) apparently wasn't
such a great idea, (a) remains the system of choice.