April 2013 - AFMA

feed form variety. Although mash and pelleting
impacted effective caloric value, the
greatest effect of feed form was in birds experiencing
a feed form change.
Birds being switched from mash to pellet,
or vice versa, exhibited the most voracious
eating. Indeed, birds that were switched to
a different feed form, independent of form,
spent half the time eating more feed than
these not having their feed switched.
Consequently, variety may also be an
important aspect of behaviour-influencing
efficiency in the production environment,
as the highest effective caloric value energy
come from birds eating quickly and then
resting.
In the second study, the influence of
feed form on bird behaviour and effective
caloric value was again examined so that responses
to varying pellet quality might be
better defined.
Six feed form treatments were used:
Heat-processed mash served as a negative
control; 20% pellets: 80% pellet fines; 40%
pellets: 60% pellet fines; 60% pellets: 40%
pellet fines; 80% pellets: 20% pellet fines;
and 100% pellets.
The daily body weight and feed conversion
data were transformed into dietary caloric
density as effective caloric value and
then examined as deviations from the mash
diet to produce an estimate of the Kcal/kg
efficiency added by pellet quality.
The results
As expected, pelleting of the feed improved
body weight, feed conversion and
effective caloric value. When the effective
caloric value is examined, relative to the
mash ration, it progressively increased to
+187 Kcal/kg of diet for the highest pellet
quality. Note also that effective caloric
value and bird behaviour were highly correlated.
When viewed together, resting and effective
caloric value form nearly parallel
lines, both increasing as pellet quality improves.
Any combination of management
factors that decreases time spent eating
and increases time spent resting, appears
to offer the potential to increase the effective
caloric value of the diet fed.
In an effort to make data from the second
study field applicable, effective caloric
value differences are expressed as that
achieved by making a switch to higher (caloric
density gain) or lower (caloric density
loss) pellet quality.
What change in pellet quality would be
needed to compensate for a 55 Kcal ME/kg
ration reduction? Increasing pellet quality
from 30 to 70% will exactly counter the effect
of reducing the feed energy by 55 Kcal
ME/kg.
Considering the above example, to have
equivalent bird performance, expressed
as equivalent body weight and feed conversion
for the flock, the producer would
need to add the equivalent of 55 Kcal ME/
kg ration – this will achieve another 225
Kcal MEI.
This may be achieved via improving pellet
quality as long as the initial pellet quality
is equal to or less than 70%. Since the
pellet quality response curve is not linear,
it is necessary to examine the relationships
at specific points.
Observable benefits
Results indicated that broilers typically
spend their time in the following order
(from greatest to least): resting, eating,
standing, drinking, preening, walking,
dust bathing, pecking and other activity. It
was common for the combination of eating
and resting to account for 60 to 85% of
broiler activity.
Broilers respond to pelleted feed by
spending less time to eat the same or
more feed. This decreased time spent eating
is then spent resting, which decreases
animal energy expenditure, leaving more
energy available for gain.
Changing the feed form presented to
the broiler results in more voracious eating
and may offer additional advantage.
Depending on the current producer pellet
quality, it appears possible to compensate
for a reduction in feed energy by improving
pellet quality.
Processing