B. Anwar, S. A. Khan, A. Aslam, A. Maqbool¹ and K. A. Khan

Department of Pathology, ¹Department of Parasitology, University of Veterinary and Animal Sciences, Lahore-54000, Pakistan

    A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97^oF) to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR), immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during heat stress had beneficial effects on FCR, immune status and ratio of bursa, thymus and spleen to body weight. Grossly, bursa, thymus and spleen of heat stressed birds were atrophied but in ascorbic acid and acetylsalicylic acid supplemented birds these organs were not atrophied. No specific histopathological changes were observed in all groups.

Key words: Ascorbic acid, acetylsalicylic acid, heat stress, chicks