J. Amin. Prod. Res. (2015) 27:66-70 66 EFFECTS OF ASCORBIC ACID ON RECTAL TEMPERATURE IN RED SOKOTO GOATS EXPOSED TO HEAT STRESS DURING THE EARLY RAINY SEASON *1 Bello, T.K., 2 Ayo, J.O., 1 Chiezey, N.P., 3 Oyelowo, B.B., 1 Samuel, F.U., 1 Egbodo, B.E., 1 Ibrahim, M., 1 Maikaji, F.S., 1 Hassan, R. and 1 Haruna, M.H. 1 National Animal Production Research Institute- Shika, 2 Faculty of Veterinary Medicine, Department of Physiology, Ahmadu Bello University, Zaria Kaduna, 3 Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, Ahmadu Bello University, Zaria Kaduna State. *Corresponding author: tkbbello@yahoo.com ABSTRACT The aim of this study was to determine the effect of administration of ascorbic acid on rectal temperature of Red Sokoto goats exposed to heat stress during the early raining season. Ten goats of both sexes served as subjects for the study. Five goats(experimental) administered with ascorbic acid (AA) per os at a dose rate of 100 mg/kg thrice, a week apart. Five goats administered with distilled water per os served as controls. Rectal temperature (RT) was collected from an hour after each administration of ascorbic acid through 13 th hour. The goats administered ascorbic acid had a consistently lower RT values than those of control goats throughout the study period from 1hr – 13hr post administration of ascorbic acid. The lowest hourly temperature of 37.0±0.27 0 C was obtained in experimental goats at 12hrs post administration, while the highest value of 38.1±0.33 0 C was recorded at 1hr post administration. The overall mean values of RT in control and experimental Red Sokoto goats were 38.00 ± 0.09 0 C and 37.55 ± 0.08 0 C, respectively (P < 0.05).The goats administered ascorbic acid had a consistently lower RT values than those of control goats throughout the study period from 1hr – 13hrs post administration.Thus, the administration of ascorbic acid may be beneficial to goats during the early rainy season as it reduces the negative effects of thermal environmental stress on rectal temperature. INTRODUCTION It has been established that heat stress is evaluated by measuring the rectal temperature, which is a true reflection of internal body temperature and a reliable index of thermal balance (Bianca, 1976; Ayo et al., 1998). In heat stress, free radicals are generated in the body in such large quantity that the natural antioxidant defense systems of the body are overwhelmed (Sahota and Gillani, 1995; Altan et al., 2003). This results in lipid peroxidation of cytomembranes; and consequently cell damage and destruction (Freeman and Crapo, 1982). Heat stress results from negative balance between the net amount of energy flowing from the animal to its surrounding environment and the amount of heat produced by the animal. It reduces expression of estrous (Hansen et al., 2001). The best recognized effect of raised body temperature is an adaptive depression of the metabolic rate associated with appetite. Thus in domestic ruminants, a rise of body temperature marks the transition from aversive stage to noxious stage (Silanikove, 2000). The Northern Guinea Savannah zone has two broad seasons - dry and rainy seasons. The rainy season lasts for 5-6 months, while the dry season lasts for 6-7 months. According to Fricke (1977), the dry season can further be divided into cold-dry (harmattan) and hot-dry periods. As National Animal Production Research Institute Ahmadu Bello University P.M.B 1096, Shika-Zaria, Kaduna State, Nigeria. Email: japr@napri-ng.org Website: www.naprijapr.org