پديد آورندگان :
درستي، فضيله دانشگاه اروميه - دانشكده كشاورزي - گروه علوم دامي , نجفي، رامين دانشگاه اروميه - دانشكده كشاورزي - گروه علوم دامي , ميرزا آقازاده، علي دانشگاه اروميه - دانشكده كشاورزي - گروه علوم دامي
كليدواژه :
جوجه‌هاي گوشتي , سركه , سيستم ايمني , باكتري پديوكوكوس اسيدي لاكتيسي
چكيده لاتين :
Introduction
:
Probiotics have been defined as live microbial feed supplements, which
beneficially
affect the host animal by improving its intes
tinal
microbial balance (Fuller
1989). A variety of
microbial species have been used as probiotics, including species of
Bacillus
,
Bifidobacterium
,
Enterococcus
,
Lactobacillus
,
Lactococcus
,
Streptococcus
, a variety of yeast species (Patterson and
B
urkholder 2003
; wang et al.
2010).
Among these
,
Pediococcus acidlactici
bacteria
(
probiotic PLA
)
belongs to the homofermentative gram
-
positive bacteria, able to grow in a wide range of pH,
temperatures and osmotic pressures, and thus able to colonize and inhabit the
digestive tract
and exert
antagonism against other microorganisms, including enteric pathogens, primarily through
the
production of lactic acid and secretion of
bacteriocins known as pediocins
(Lee et al.
2007
;
Daeschel
and Klaenhammer
198
5
)
.
Organic acid
supplementation
has
been reported to decrease
colonization of
pathogens and production of toxic metabolites
(
Hudha
et al.
2010
).
Material
and
m
ethods:
Three hundred and sixty, one
-
d
ay
-
old male
broiler
chicks (Ross 308)
were
obtained from a commercial
hatchery
.
The birds were initially weighed individually
so that the pens
had
similar initial weight distribution
and were randomly assigned to
six
experimental
groups,
with
five
replicates of 12 chicks
each.
The experimental design was
a completely randomized design with
a
2
×
3
factorial arrangement of treatments, which included
two
levels of
probiotic PLA
(
B
1
:
0% and
B
2
:
0.01%)
and three levels of vinegar
(
A
1
:
0
%
;
A
2
:
2% and
A
3
: 3%).
A lighting prog
ram
was used
according to the guidelines of the Ross 308.
Environmental
temperature
was maintained at 32 ± 1°C
during the first week and gradually reduced to 2
1
°C
until the end of the
experiment
.
The diet was
based on corn, soybean meal and wheat and
formula
ted according to NRC (1994) requirement for
two period of starter (0
-
21 d) and growth (21
-
42 d) days.
The composition and nutrient analysis of
the basal diet are shown in Table 1
.
Probiotic
used in this
experiment
brand
(
Bactocell). Bactocell
was purchased from
L
allemand animal health compang, france. The bacterial flora in the bactocell
probiotic has mentioned to
Pedicocos acidilactici
bacteria
in a concentration of 10
10
cfu/g.
Grape
vinegar was contain 6% acetic acid.
B
ody
Weight gain
and
Feed intake was measured weekly
and
calculated during the course of the
whole experiment
on a pen basis,
and the feed
conversion rates
were calculated subsequently.
At 42 days of age two broilers per pen were randomly selected,
weighed,
and slaughtered.
After
slaughter, percentage of body weight and percentage of body
components weight were measured.
Carcass
weight was measured, and carcass percentage was
expressed as a
ratio of live weight. The percentage of breast and thigh were calcul
ated
as a ratio of
the carcass weight. The percentage of abdominal
fat,
pancreas, liver
and
immune organs
(
b
ursa of
f
abricius,
s
pleen and thymus
)
were
calculated as a ratio of the live weight.
Data were analyzed using
the
g
eneral Linear Model procedures of
SAS 9.1 (SAS Institute 200
2
)
.
When the analysis of variance
was significant, Duncan's multiple
-
range test was used to separate the means. Statements of statistical
significance are based on P <0.05.
Result
s
and
d
iscussion:
The effect
of
dietary treatments on body weight gain, feed intake, feed conversion ratio
are shown in Table 2.
Results showed that 3% vinegar increased feed consumption in growth period (22
-
42 days) and entire experiment of period (0
-
42 days) (
P
<0.05).
This
result is
s
imilar to the finding of
Mohammadbagheri
and Najafi (2014)
,
who reported
that inclusion
2% vinegar
in diet
resulted in significantly
increase
feed consumption
.
I
t may add vinegar to mesh diet leads to
increase palatability and improved mixing ration items, resulting in increased feed intake and
consequently an increase in body weight gain.
Probiotic PLA
improved body weight gain and feed
conversion
ratio of chicke
ns
during starter (0
-
21 days) and through experimental period (0
-
42 days)
(
P
<0.05).
This
result is contrary to the findings of
Yeo and Kim (1997), who reported that average
daily weight gain of chickens fed probiotics was
significantly increased during the
first 3 wk of
growth
but not during the 4th to 6th wk of growth.
The best feed conversion
ratio
was observed in
diets containing
probiotic PLA
and 2% vinegar (
P
<0.05).
Improvement
production efficacy
of broiler
chickens fed
with
probiotic
and organic
acids also
reported
by
Taheri et al.
(
20
10
)
and
Rowghani
et al.
(2007)
.
Dressing percentage, weights
breast
, thigh
and
abdominal fat content
were not affected by
dietary treatments, however relative
weight
of
pancreas
in birds fed diet containing
2%
vinegar was
lower
compared
to control group.
The relative
weight of liver
was
increased
by vinegar
supplementation
(
P
<0.05).
The liver is a site of detoxification and bile production, thus it is suggested
that liver size is dependent on the amount of work
it does. Brenes et al. (1993) stated that after
absorption, the liver is the major site of SCFA metabolism, where propionic and butyric acids are
almost entirely taken up. Thus, they suggested that liver size is dependent on the gastrointestinal
microflora
and/or their fermentation products
.
T
he highest antibody titer of Newcastle disease
virus
was observed in diets containing
probiotic PLA
and 2% vinegar (
P
<0.05)
.
O
rganic acids
by
lowering
intestine pH of
broiler chickens can reduce harmful microorganisms
so that decrease sensitivity to
diseases
resulting in improving immune system and resistance against diseases
(
Dibner and Buttin
,
2002
).
C
onclusion
:
In conclusion, the combination
of
vinegar
and
0.01
%
probiotic PLA
improved
growth
performance and
Immune
response
in
broiler chickens.
