EFFICACY OF CITRIC ACID, NON STARCH POLYSACCHARIDE DEGRADING ENZYMES AND THEIR COMBINATION AS ALTERNATIVES TO ANTIBIOTIC GROWTH PROMOTER IN BROILER DIET
Loading...
Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
College of Veterinary and animal Science,Mannuthy
Abstract
An experiment was conducted in Department of Poultry Science, College of
Veterinary and Animal Sciences, Mannuthy to study efficacy of citric acid, non starch
polysaccharide degrading enzymes (NSPDE) and their combination as alternatives to
antibiotic growth promoter in broiler diet from zero to six weeks of age. One hundred and
sixty, day-old chicks were randomly divided into five dietary treatment groups viz., T1, T2,
T3, T4 and T5 each with four replicates having eight chicks, in a completely randomized
design. The birds in T1 (control) group was fed with standard broiler ration (SBR) formulated
as per BIS (2007). Standard broiler ration supplemented with 10 per cent oxytetracycline (0.5
g/kg) was fed to birds in T2, SBR supplemented with citric acid (10 g/kg) in T3, SBR
supplemented with NSPDE (0.1 g/kg) in T4 and SBR supplemented with combination of
citric acid and NSPDE for birds in T5.
The results of the study showed that the mean body weight of birds at weekly
intervals and the cumulative body weight (0-6 weeks) was not significantly different between
treatments. Mean daily feed consumption of birds (0-6 weeks) was significantly (p<0.05)
higher in antibiotic group (T2) and other treatment groups was statistically comparable with
control group. Overall, mean feed conversion ratio from zero to six weeks was not
significantly affected by dietary treatments.
The data on slaughter studies of birds did not show any significant difference among
the five dietary treatments.
The significantly (p<0.01) less Escherichia coli count and coliform count in intestinal
content of broilers was found in all treatment groups compared to control group. The mean
Enterococcus faecalis count was significantly (p<0.01) lower in antibiotic (T2), citric acid
(T3) and enzyme group (T4) than control (T1) and citric acid plus enzyme (T5) group.
The birds in T5 had significantly (p<0.01) higher ileal villi height followed by those
in T4, T1 and T3 and significantly lower villi height was obtained in the T2 treatment group.
The mean crypt width of ileum in T2, T3 and T4 were having significantly (p<0.05) higher
value than the combination and control groups. Goblet cell count was lower in all growth
promoter supplemented groups compared to control. The mean pH value of small intestinal
content of broiler was significantly (p<0.01) lower in growth promoter supplemented groups
compared to control group.
The cumulative per cent livability of T1, T2, T3, T4 and T5 was 93.75, 96.88, 100,
100 and 90.63, respectively. The net profit per kg body weight at six week of age was Rs.
12.36, 8.66, 14.10, 14.65 and 12.28 for the treatment groups T1, T2, T3, T4 and T5,
respectively.
The present findings, indicated that supplementation of antibiotic, citric acid, NSP
degrading enzyme and the combination of citric acid and NSP degrading enzymes did not
significantly influence the growth performance and carcass characteristics of broilers.
However, the parameters related to gut health such as ileal histomorphology, microbial count
and pH of ileal content were significantly (P<0.01) better in all the growth promoter
supplemented groups than control. Highest net profit per kg body weight was obtained in
NSP degrading enzyme supplemented group.
Based on the overall results of this study, it can be concluded that NSP degrading
enzymes (xylanase + glucanase) at 0.1 g/kg can be effectively used as growth promoter for
broiler diets with complete elimination of antibiotic usage in feed.