Both male and female seem to
be responsible for the age-related
decline in fertility, but it is thought
to be mainly a male problem
because fertility can be maintained
by artificial insemination and
increased by the replacement of
old males in commercial flocks.
Also, in natural mating flocks, a
male mates with an average of 8 to
10 females, therefore the impact of
the male in the overall fertility of
the flock is extremely high. The
male contribution to flock fertility
depends on two main factors:
mating activity and sperm quality.