The
level
of
inclusion
of
by-products
and
alternative
grains,
legumes
or
pulses
into
the
diets
of
poultry
is
rarely
limited
by their nutritive values. The limiting factor is usually poor palatability caused by either secondary plant products that
detour herbivores or fibrous components that also provide protection as well as structural support. Although it is clear that
the small repertoire of bitter taste receptors does not limit the chicken’s sensitivity to several highly bitter compounds, an
unanswered
question
is
if
chickens
and
turkeys
are
able
to
taste
the
full
spectrum
of
bitter
compounds
that
can
be
identified
by humans. It might be that the three T2Rs of chicken (and the two predicted in turkey) compared to 25 in humans, results
in the insensitivity of chickens and turkeys to many of the compounds that humans find to be bitter. Knowing what bitter
compounds are sensed by poultry is critical information required to identify strategies to improve the utility of alternative
feedstuffs
in
their
diets.