The Effect of Feed Supplemented with Different Sodium Bentonite
Treatments on Broiler Performance
Bentonites are excellent aflatoxin binders due their
affinity for polar substances. The in vitro experiments
conducted by the Pakistan Council of Scientific and
Industrial Research Laboratories, Lahore, showed that
bentonite bound 90% of the aflatoxins present in feed
and made them effective and un-absorbable from the
gastrointestinal tract (2). The improvement in weight
gain observed in the present study could have been due to
the presence of NaB in the diet, which might have
increased feed retention time in the gut of the chicks,
thus subjecting the nutrients to enzymatic action for quite
a long time, or could have been due to the action of
bentonite on the enhanced digestibility of certain
nutrients. These results are in agreement with previous
studies (3,5,14,15) in which NaB significantly improved
body weight gain in broiler chicks.
Increased feed intake in all treatment groups could be
attributed to the presence of NaB in the rations, which
can act as a pellet binder and improve not only pellet
quality, but also feed intake. These results are supported
by previous research (4,14) that found NaB increased
feed intake and growth performance in broiler chicks.
The high weight gain and feed consumption in the birds
fed 0.5% and 1.0% NaB + 0.5% and 1.0% AA,
respectively, indicates that NaB’s qualities can be further
enhanced by AA; however further studies are required to
investigate the relationship between NaB and AA.
The non-significant differences between the PER
values of the different experimental groups may have
been due to the fact that NaB mainly acts on feed when
in the gastrointestinal tract. This hypothesis can be
further supported by our protein retention data
indicating that the presence of bentonite prolonged feed
passage time and improved nutrient metabolism. The
protein retention results of the present study are in
agreement with previous findings (2) of improved energy
and protein utilization in the presence of bentonite.
Differences between ileal and excreta digestibility in the
present study clearly demonstrate that amino acid
metabolism by hindgut microflora in chickens may be
substantial and that digestibility measured in the terminal
ileum is a more accurate measure of amino acid
availability than that measured in the excreta.
It can be concluded from this trial that NaB alone at
the 0.5% level or treated with 0.5% or 1.0% AA can be
incorporated into broiler rations for improving growth
and feed utilization. Although no statistically significant
differences were observed in PER values, PER values
increased when birds were fed rations containing 0.5%
and 1.0% NaB + 0.5% and 1.0% AA , respectively
(treatments F and G). Thus, it can be suggested that NaB
+ AA improved protein digestion. These results are
further supported by the significantly increased protein
retention values observed in the birds fed rations
containing 0.5% and 1.0% NaB + 0.5% and 1.0% AA,
respectively.
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