Abstract:
Antibiotic growth promoter alternatives are urgently needed in the poultry industry to
maintain or improve poultry health and performance. Bacteriophage (BP) therapy
mainly utilizes lytic phage to kill their respective bacterial hosts and exhibit no activity
against animal and plant cells. They can be considered novel alternative solution to
combating the emergence of antibiotic resistance in poultry. A total of 600-day-old mix
broiler chicks (Hubbard Classic Efficiency Plus) with the initial body weight of
41.9±1.0 g were reared for 35-days experimental period. Birds were randomly allotted
into 1 of 5 treatments according to a Completely Randomized Design (CRD). Dietary
treatments consist T
0
Control (no antibiotics and no BP), T
1
xiv
(0.5 gm BP/kg of feed), T
2
(0.75 gm BP/kg of feed), T
3
(1.0 gm BP/kg of feed) and T
4
antibiotic control group
(0.055 g antibiotic BMD/kg feed) (bacitracin methylene disalicylate). The group T
1
(P
<0.05) showed higher body weight (2251.58± 15.10 g) compared to T
0
(2027.78± 6.11
g) and T
4
(2093.93± 20.28 g). Best FCR result was found in T
1
(P <0.05) (0.5g BP/kg)
group (1.49) compared to the T
4
antibiotic treated group (1.54) and T
0
Control group
(1.58). The group T
3
(P <0.05) showed higher feed consumption compared to T
0
and
T
4
. Escherichia coli concentration in excreta is higher (6.84 log10CFU/g) in T
0
differ
significantly (P<0.05) with other groups. Salmonella concentration is higher (4.28 log10
CFU/g) in T
0
and differ significantly (P<0.05) from other groups however not
significantly different (P = 0766.) from T
4.
The weight of the spleen in the control group
T
0
is the highest and is differ significantly (P<0.05) with other groups. Similarly, the
bursa of fabricus' weight is the highest in T
0
group and differs significantly (P<0.05)
with other groups. Among the three-bacteriophage dietary treatment group T
1
showed
better body weights and FCR than group T
2
and T
3
. In conclusion, dietary
supplementation of 0.5 g/kg BP reduced FCR and increased body weight with inhibiting
of pathogens. Therefore, the research recommended inclusion of 0.5 g BP/kg of feed as
an alternative to antibiotic growth promoters in broiler diets.
Description:
A Thesis
Submitted to the Faculty of Animal science & veterinary medicine
Sher-e-Bangla Agricultural University, Dhaka-1207,
In partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
IN
ANIMAL NUTRITION
