INCREASING THE ACTIVITY OF ANTIOXIDANT SYSTEM IN BROILER CHICKS DURING SUMMER SEASON: 1-EFFECT OF SOME ANTI-HEAT STRESS AGENTS ON BROILER PERFORMANCE, IMMUNE RESPONSE AND HEAT SHOCK PROTEIN 70

The present experiment was conducted during the summer months to study
the effects of glutamine injection glutamic acid and ascorbic acid supplementation and its
combination, on broiler performance, some physiological parameters and immune response.
Moreover effects of these anti-heat stress agents on antioxidant system, heat shock protein
70 and the relation between them was one of the aims of this study. A total number of two
hundred and forty one day old Arbor Acres broiler chicks were individually weighed and
randomly divided into 6 treatments. Chicks in the 1st group fed control basal diet during 3
rearing periods. Chicks in the 2nd group fed control basal diet supplemented with 1000 ppm
glutamic acid only during starter period. Chicks in the 3rd group injected with glutamine in
1day- old and fed control basal diet. Chicks in the 4th group fed control basal diet
supplemented with 40 ppm ascorbic acid during 3 rearing periods. Chicks in the 5th group
fed control basal diet supplemented with 1000 ppm glutamic acid during starter period + 40
ppm ascorbic acid during 3 rearing periods. Chicks in the 6th group injected with glutamine
in 1day- old and fed control basal diet supplemented with 40 ppm ascorbic acid during 3
rearing periods. The results demonstrated that glutamine injection at 1day old and glutamic
supplementation during starter period improved body weight and body weight gain during
the starter and finisher periods. Erythrocytes count, hemoglobin concentration and
hematocrit values significantly increased when birds injected with glutamine and fed diets
supplemented with glutamic and ascorbic acids. Amino acids and ascorbic acid
significantly increased lymphocytes and decrease heterophilus and H/L ratio. Glutathione
peroxidase significantly increased by amino acids and ascorbic acid, other plasma
antioxidant enzymes did not affect. Moreover MDA and TAOC significantly improved by
glutamine injection and glutamic acid supplementation. Heat shock protein 70 improved by
glutamic supplementation and glutamine injection. There were no differences in meat
cholesterol profile between experimental treatments. Glutamine injection and glutamic acid
supplementation significantly decreased bacteria total count of meat and MDA significantly
decreased. The results of the present study suggest that single glutamine injection, glutamic
acid and ascorbic acid supplementation able to improve broiler performance, cellular
immunity and activity of antioxidant system.