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| Articles
by
T. Settle |
Total Records (
2 ) for
T. Settle |
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T. Settle
,
S.S. Leonard
,
E. Falkenstein
,
N. Fix
,
K. Van Dyke
and
H. Klandorf
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Phytogenic feed additives are plant-derived products used in poultry feeding to
improve overall performance of broilers. In this study, 588 one day-old Cobb 500
chicks were fed one of four diets and housed on either dirty or clean litter for
3wks. Treatments included: Group I: commercial diet with no additive and housed
on clean litter; Group II: commercial diet with no additive and housed on dirty
litter; Group III: commercial diet with a 0.05% inclusion of the anitobiotic,
BMD (bacitracin methylene disalicylate); Group IV: commercial diet with a 0.05%
inclusion of a phytogenic feed additive (PFA). The study was designed around a
random block assignment of treatments allocated to groups of twenty-one birds
per pen. Blood samples were obtained from chicks at 18 days of age for measurement
of leukocyte oxidative activity by a bioluminescence technique. Results of the
study showed that chicks in the treatment groups fed the PFA had significantly
lower oxidative stress (p<0.02) when compared to the BMD treatment group. Once
this was determined, electron spin resonance (ESR) spin trapping was used to detect
and measure hydroxyl or superoxide radicals in. Fenton chemistry was utilized
for production of hydroxyl radicals and a xanthine/xanthine oxidase reaction for
the production of superoxide radicals in the diet and in RAW 264.7 mouse peritoneal
monocytes exposed to the diet. Results from the reactions showed that the antibiotic
scavenges hydroxyl and superoxide radicals more efficiently than the phytogenic.
The results were comparable to those measured in the RAW 264.7 cells. |
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T. Settle
,
E. Falkenstein
and
H. Klandorf
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Uric acid is considered the most significant factor in amelioration of oxidative burden in birds. Uric acid is formed in the terminal reactions of purine degradation by the enzyme xanthine oxidoreductase (XOR). In this study, inosine, a purine precursor, was fed to 3 groups of 5 birds: Group 1 was fed 0 (control), Group 2, 0.6 mols inosine/kg feed (INO) and Group 3, INO treatment plus 50 mg allopurinol/kg BM (INOAL). Allopurinol is a known inhibitor of XOR and thereby reduces uric acid (UA). INOAL birds showed lower total liver XOR activity (p = 0.005) but kidney XOR activity was not affected. Both INO and INOAL treated birds had higher plasma and kidney UA concentrations than controls. Liver uric acid (LUA) was significantly reduced in INOAL birds when compared to other treatments. XOR gene expression was increased (p = 0.007) in the liver tissue of INOAL birds when compared to CON and INO birds. However, there were no significant changes in XOR gene expression in the kidney tissue. To our knowledge, this is the first report of XOR gene expression measured under these conditions. These results suggest that regulation of UA production is tissue dependent. The results also indicate a compensatory effect of allopurinol on XOR gene expression which can be linked to a decrease in antioxidant protection from UA. |
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