According to our results, T3 level in group
supplemented with Se was the lowest among groups
(P<0.01) (Table
2). Tona et al.
21 reported that T3
hormone levels in standart broiler breeder lines were
3.84, 2.80 and 1.55 nmol/l at 14, 28 and 41 days,
respectively. T3 level (1.72 nmol/l) in group
supplemented Se at 40 days was in an aggrement with
Tona et al.
21. Significant reduction in T3 levels of Se
and Vit C groups in compared to control and high energy
groups may be result from antioxidant effects of Se and
Vit C
22,11.
Büyütmek İçin Tıklayın |
Table 2: Plasma triiodothyronine hormone (T3) levels and some biochemical parameters of in the study groups (n=10) |
In our study, we found that plasma glucose, total
protein, albumin and total cholesterol levels were not
different among groups. However, plasma triglyceride in
group supplemented with Se were significantly found
higher than control and high energy group. A study
indicated that the acute cold stress caused an increase
in plasma triglyceride because of lipid peroxidation23.
The control and high energy group without Se and Vit C
supplement may be increased lipid peroxidation, and this
following, lipid peroxidation may be increased plasma
triglyceride level23. Cold conditioning induced a
significant increase in MDA levels in liver and abdominal
fat, thus, suggesting cold stress during this treatment
(Table 3). Besides, in liver and abdominal fat, MDA level
of the high energy group in compared to that of control
group was similar, while its MDA level was increased in
compared to those of Se and Vit C supplement groups.
Alptekin et al.24 showed that stress induces a
significant increase in lipid peroxide levels in the liver and
small intestine. McArdle and Jackson25 have
demonstrated a significant increase in free radical
production together with an increase in the expression of
antioxidant enzymes during a period of non-damaging
exercise. These increases in antioxidant enzyme
activities have been considered as a protective response
against oxidative stress26. Hydrogen peroxide, a
precursor of more potent radical species, is scavenged at
higher concentrations by CAT. In the present study, the
CAT activity was increased significantly in liver and
abdominal fat of broilers exposed to cold (Table 3), while
it was similar in the heart. Kaushic and Kaur et al.27
reported that the activities of antioxidant enzymes such
as CAT and glutation peroxidase may change according to different tissues. They reported that the CAT activity
was increased significantly in the kidney of stressed
animals, while it was decreased in the heart, liver and
small intestine. In the liver and abdominal fat, hydrogen
peroxide produced in response to stress is taken care of
primarily by CAT, which is shown to be present in higher
concentrations in these tissues. The decreased activities
of CAT in the livers of groups supplemented with Se and
Vit C and in the abdominal fat of group supplemented
with Se indicate the highly reduced capacity to hydrogen
peroxide produced in these tissues in response to cold
conditioning28. Factors such as housing in low
temperature, rapid growth rates, high energy rations are
known to influence the occurence of ascites in broilers29. Previous studies reported that cold temperature is
one of the most effective factors ascites. In this study,
control and high energy group may have induced to
ascites29. The MDA levels of liver and abdominal fat,
and CAT activities of liver in control group and high
energy group without supplement significantly increased
(P<0.05). This may be due to rising tend to ascites in
these groups. Likewise, the previous study reported that
lipid peroxidation were elevated in birds with ascites8.
Moreover, it was found that the MDA and CAT activities
of groups supplemented with Se (group III) and Vit C
(group IV) decreased. In this study, especially, Se
supplemention on account of decreasing of lipid
peroxidation found the more effective than Vit C
supplemention as agreement with study of Stanley et al.28. Because, Se levels in diet could be also be critical
since Se has long been recognised to have antioxidant
proporties due to its importance for glutathione
peroxidase activity9. In this study, GSH activities of
liver, abdomial fat, lung and heart were not found
statistically significant between all groups (Table 4). In a
previous study indicated that GSH activities may be not
significant statistically as related to factors caused and
exposed period to oxidatif damage11.
Büyütmek İçin Tıklayın |
Table 3: MDA (nmol/mg protein) and CAT levels (k/g protein) of liver and abdominal fat in groups (n=10) (mean ± SE) |
Büyütmek İçin Tıklayın |
Table 4: Reduced glutation (GSH) levels (k/g protein) of some tissues in the groups (n=10) (mean ± SE) |
It was found similar effects on lipit peroxidation and
antioxidant enzymes of control and diet with high energy.
Lipid peroxidation and antioxidant enzyme activities
(CAT) were significantly affected negatively to diets of
control and group II in broilers exposed to cold
conditioning. The supplementation to diet of Se and Vit C
decreased significant these negative effects.