This study was done to investigate the effect of inclusion of ascorbic acid (AA) in drinking water of broiler chicken on haematological and oxidative stress parameters during the hot-dry season. Sixty day old chicks were used for the experiment, and were assigned to two dietary treatments with 30 birds per treatment and five replicate in a completely randomized design. Treatment 1 was the control with no supplements, treatment 11 was supplemented with AA at the rate of 500 mg/L in drinking water termed the experimental group. On the last day (58th) of the experiment half of the birds were randomly selected from each replica group and blood sample (2 ml) was obtained through the wing web and divided into 2 parts; one for determination of haematological parameters while the second part was centrifuged and the resultant serum harvested and stored. The results indicated that the values of PCV (24.25 ± 2.80%), haemoglobin (8.08 ± 0.83 gm/dl) and total erythrocyte count (4.35 ± 1.13 x 106/ l) obtained in control were all significantly lower than the recorded corresponding value in the experimental group 31.50 ± 13.13%; 10.50 ± 4.38 gm/dl and 5.94 ± 1.28 x 106/ l) respectively. The recorded values of malondialdehyde obtained in control (2.18 ± 0.22 ng/ml) was significantly higher than the values recorded in experimental group (0.93 ± 0.09) while the values of superoxide dismutase, catalase and glutathione peroxidase were significantly higher in the control than the obtained values experimental group. The fragiligram shifted more to the left in the control than the experimental group and was statistically significant. In conclusion AA administration mitigate the adverse effects brought about by heat stress in broiler chicken; its supplementation is thus recommended during the hot-dry season to alleviate heat stress.

Ascorbic acid, heamatology, oxidative stress parameters, broiler chicken, hot-dry season