پديد آورندگان :
قوچخاني، رويا دانشگاه تبريز - دانشكده كشاورزي - گروه علوم دامي , ابراهيمي، مرضيه دانشگاه تبريز - دانشكده كشاورزي - گروه علوم دامي , دقيق كيا، حسين دانشگاه تبريز - دانشكده كشاورزي - گروه علوم دامي , رافت، عباس دانشگاه تبريز - دانشكده كشاورزي - گروه علوم دامي
چكيده لاتين :
Introduction:Nowadays , in ovo injection is being used for increasing hatchability and growth, while
reducing mortality rates and disease prevalence in poultry (Moran 2007). Methionine is the first
limiting amino acid (Dilger and Baker
2007)
and
lysine
is
the second limiting amino acid
in broilers
(Tessseraud et al. 1996). Lysine has been used as a standard in ideal relationships of other amino
acids (Baker 2009). Paradox results were observed using different ratios of methionine to lysine
during
the
growth period in a way that some rep
orted no effect (Lee et al. 1991; Si et al. 2004), while
others reported positive effect on growth (Hickling et al. 1990; Mehri et al. 2012). Al
-
Murrani (1982)
reported that the optimal methionine to lysine ratio for 7 d old chick embryo is 50.5%. Therefor
e, the
aim of this study was to evaluate the effect of
in ovo
injection with different ratios of D
-
L methionine
to L
-
lysine
at 14
th
d of incubation on body weight parameters and blood metabolite concentrations
in a day
-
old Ross 308 broiler chicks.
Materi
als and method
s
:
In this experiment, 210 fertile Ross 308 broiler breeder eggs were randomly
assigned into 7 experimental groups with 30 individual eggs per each group. Experimental treatments
including control (non
-
injected), sham
-
control (injected steril
e water), and 40.5, 45.5, 50.5, 55.5 and
60.5 D
-
L methionine to L
-
lysine ratios were injected into the amniotic fluid at 14 d of incubation
through the broad end of eggs.
On day 22 (one day post hatch),
4 chickens per replicate were selected,
bled, and
then slaughtered to measure
internal organ weights
. Results and Discussion:
Hatchability rate was not affected by treatments (P>0.05), though the
highest hatchability was observed in 45.5%
D
-
L methionine to L
-
lysine ratio (Fig 1)
. In other studies,
no effe
ct (Mottaghitalab and Shafiymanesh 2015) or reducing effect (
Coşkun et al. 2014
) of
in ovo
injection with
D
-
L methionine was observed.
A
ll
the treatment groups showed higher chick weight
in comparison with control groups
(P<0.01)
. Similar to our results,
Coşkun et al. (2014) reported
increasing effect of
in ovo
injection with methionine on chick weight.
Treatments
had an increasing
effect
on relative scalped carcass weight
(P<0.01), carcass efficiency (P<0.
01), relative breast weight
(P<0.05), and
relative
heart weight
(P<0.05),
(Table 1)
.
Different ratios
of
D
-
L methionine to L
-
lysine up to 55.5% ratio had higher weight in comparison with control groups. Though a reverse
effect of 60.5% D
-
L methionine to L
-
lysine ratio was observed on weight parameters.
Some
researchers showed positive effect of methionine and lysine on body weight parameters
including
Finkelstein
(
1990
),
Vazquez
-
Anon et al.
(
2006
),
Luo and Levine
(
2009
), and
Bouyeh (2012)
.
Methionine is an essential amino acid in protein synthesis (Nikofard et al. 2011).
Lysine is
also
important for protein synthesis and stimulating secretion of insulin, glucagon, GH, and IGF
-
I (
Deng
et al. 2005
).
Also, L
-
carnitine, which biosynthesized fro
m lysine, has some growth stimulatory effects
(
Arsalan et al. 2004)
. The significant increasing effect
(P<0.05)
of
in ovo
injection with different
ratios of D
-
L methionine to L
-
lysine on gizzard and liver weight was observed. Although the
increasing effec
t of treatments was observed up to 55.5% D
-
L methionine to L
-
lysine, the highest
amount was observed in 45.5% ratio
(Table 1)
.
Since gizzard is responsible for grinding and
digestion, this increasing effect of treatments means better digestion during grow
th period. Also, as liver is the main place for metabolism of nutrients, effect of treatments on liver means improve in
metabolism during rearing period. Results also showed improving effect
(P<0.05)
of
different ratios
of
D
-
L methionine to L
-
lysine on he
art weight and relative heart weight and this improving effect
was observed up to 55.5% D
-
L methionine to L
-
lysine ratio (Table 1)
.
In accordance with the present
result, Bouyeh (2012) reported that increase in methionine and lysine increased heart weight
. Since
increasing in heart weight is an indicator of improving heart capacity (Lorenzoni and Ruiz
-
Feria
2006; Ebrahimi et al.
2013, 2014
) and can increase heart output in accordance with metabolical
requirement of poultry (Bautista
-
Ortega and Ruiz
-
Feria 2
010); then, it was concluded that improving
effect of different ratios
of
D
-
L methionine to L
-
lysine on heart weight might prevent ascites during
rearing period.
In ovo
injection with different ratios
of
D
-
L methionine to L
-
lysine
had no effect on
cholesterol and glucose (P>0.05), while reduced sera triglyceride (P<0.01) and 45.5%
D
-
L
methionine to L
-
lysine ratio had the lowest amount (Table 2)
. Part of this effect might be mediated
by attaching lysine to lipoprotein
(a)
and removi
ng it from
the
blow flow (Lowe and Thompson 1962;
Overbeck and Clark 1975). Also, biosynthesis of L
-
carnitine from lysine may facilitate fatty acid
transport
into embryo tissues (Casillas and Newburgh
1969
).
Different ratios
of
D
-
L methionine to
L
-
lysine
had an increasing effect
on sera total protein concentration (P<0.05) and the highest amount
observed in 45.5% ratio
(Table 2)
. It seems that the role of
lysine and methionine (Deng et al. 2005;
Luo and Levine 2009) in stimulating protein synthesis may be
responsible for higher sera protein
(Guyton and Hall 2000).
Moreover, decreasing effect of
in ovo
injection with different ratios
of
D
-
L
methionine to L
-
lysine
on urea concentration (P<0.01) was observed and the lowest amount was in
45. 5 and 55.5% ratios
(Table 2)
. It was indicated that amino acids in a balanced way cause increase
in protein synthesis, while reduces blood urea concentration (Ebrahimi et al.
2013
). Accordingly,
in
ovo
injection of
different ratios
of
D
-
L methionine to L
-
lysine
up to 55.5%
ratio did not cause
imbalance and then,
improved growth, while reduced urea concentration
.
Conclusion:
The
overall results of the present experiment indicated that
in ovo
injection of
different
ratios
of
D
-
L methionine to L
-
lysine
up to 55.5% ratio had an increasing effect on carcass efficiency,
muscle production, and protein, while a decreasing effect on triglyceride and urea concentration in a
day old
Ross
broiler chicks.
