[Music]
so
is net energy superior to de or me for
predicting the performance
or in other words up the performance of
the animals such as body weight gain
better related to net energy intake than
to de or to amy intake
again if we come back to this uh table
showing that the hierarchy between feeds
uh it differs between the deme
and smg system you we have to keep in
mind that
protein sources are overestimated in the
de and me systems
while fat sources are underestimated in
the dermi systems
so is the response of the pig very
similar to
what should be observed or concluding
for the feed energy value
for doing that we have taken a trial
where two diets
were fed to growing pigs two diets a
normal protein diet and a low protein
diet supplemented with synthetic amino
acids
and you can see that the amount of
energy
per day for a given level of performance
was absolutely identical for the two
types of diets
but for de and amy
systems the energy required
for the same level of performance was
higher with the high protein diet
than with the low protein diet meaning
that
the high protein diet was overestimated
because of that higher proportion of
protein
similarly when you look at the
performance of growing pigs according to
the system
and in on pigs fed diets with different
fat contents you can see that if you
express
the values relative to the diet that
contain
no fat supplemented the amount of energy
per kilo of gain
is absolutely constant and independent
on the fat
inclusion level while for
de and amy the amount of energy per kilo
of gain decreased significantly
when you have more fat in the feed
meaning that again
the fat level or the fat
energy value is underestimated
in the de or me systems so both
trials indicate that the de
and me systems are unable to predict
the response or are not good predictors
of the performance of the animals
when you have diet changes either
protein levels
or fat levels so the first conclusion
is that the net energy
content is probably the best system
to predict the performance and the
production cost
in pigs and also in poultry production
we may have to come back to measurement
of net energy
in some specific situation indeed
the measurement of heat increment and of
net energy
may be required in this situation and
one example is the enzymes
where the fasting reproduction or the k
value
may be affected that's a study
which was conducted in a in the field
industry
where two diet or three diets were fed
with and without and with enzymes
as observed in many studies the
metabolisability
of the diet was improved by
enzymes but that was only a tendency
similarly the any over me ratio
was higher with the enzymes addition
so that means that the amy value of the
diet
was increased but not significantly on
your tenancy
by 1.3 percent in that study
but the combined effect of
increased metabolisability
and increased efficiency of me for net
energy
resulted in a significant increase
in the net energy value of the feed
due to the supplementation with enzymes
so at the end we can conclude
that clearly net energy prediction
equation
are available they are free they can be
used
very safely for both swine
and also for poultry i would stress that
there is no need to measure ingredients
net energy
as done many times in the recent years
and also some factors of variation
of d e or me should be
much more taken into account in the
future
since the de and the amy are the
predictors
used for calculating the net energy
we have seen that net energy is a better
predictor of performance
than d e or amy
and what is clear also is that net
energy
is a more robust criteria
for evaluating energy value of feed when
you have
important diet changes
you
