This study was conducted to assess the performance of broiler chickens based on hematological and immunological profile, upon inclusion of aqueous extract of Withania somnifera (W. somnifera) in their drinking water. For this purpose, two hundred forty (240) one-day-old broiler chicks were purchased from a local hatchery and divided into four groups i.e. WST-0, WST-I, WST-II and WST-III. Group WST-0 was kept as control, while chicks in group WST-I, WST-II and WST-III were administered in their drinking water with an extract of W. somnifera at 10, 20 and 30g/L, for 35 days, starting from day 1 of age. Feed intake, body weights were recorded on regular basis and hematological and immunological profile of the birds was analyzed at the end of experiment. Administration of W. somnifera extract in the drinking water resulted in significantly higher feed intake and body weights of the birds at all the dose levels. An increase in the values of Hb, PCV and TLC was also noted in the treatment groups. A non significant difference was noted in the count of neutrophils, lymphocytes, eosinophils and monocytes in all treatment groups as compared to control. Antibodies titers against IB and IBD were significantly higher in all treatment groups as compare to the values shown by the chicks in control group. Findings of this study indicated that administration of W. somnifera extract to broiler chicks improve their feed intake, body weight gain, hematological profile and immunological status.

Key words: Body weight;Broiler chicks; Feed intake; Hematology; Immune system; Withania somnifera