International Journal of Agriculture and Forestry 2015, 5(1): 23-29 DOI: 10.5923/j.ijaf.20150501.04 Synergistic Effect of Electrolytes and Ascorbic Acid on Performance and Physiological Response of Broiler Birds in Hot Humid Tropics Bukola Christiana Majekodunmi, Olugbenga Adeniran Ogunwole * , Olujide Adedamola Sokunbi Department of Animal Science, University of Ibadan, Ibadan, Nigeria Abstract The study was aimed at determining the synergy of electrolytes (ammonium chloride, sodium bicarbonate, calcium chloride) and ascorbic acid water supplementation on performance and selected physiological response of broiler birds reared during hot period (March-April) in Ibadan, South West Nigeria. Two hundred and forty, one-day old Arbor Acre broiler chickens were randomly allotted to eight treatments: Treatment 1(control- without any supplementation), Treatment 2 (0.5% ammonium chloride), Treatment 3 (0.5% sodium bicarbonate), Treatment 4 (0.5% calcium chloride), Treatment 5 (300ppm ascorbic acid), Treatment 6 (0.5% ammonium chloride + 300ppm ascorbic acid), Treatment 7 (0.5% sodium bicarbonate + 300ppm ascorbic acid), Treatment 8 (0.5% calcium chloride + 300ppm Ascorbic acid). Each treatment was in triplicate of 10 birds each. The design of the experiment was a completely randomized design. Feed intake (FI), weight gain (WG) and feed conversion ratio (FCR) were similar (p>0.05) among treatments. Significant (p>0.05) variations were observed in the relative weights of lung, gizzard and intestine among treatments. Rectal temperature ranging from 41.89 to 41.98 o C and respiratory rate of 64.93 to 75.43 breath/minute across treatments were not significantly different (p>0.05). Mortality (%) was significantly higher (p < 0.05) for birds on T1 (20.0), T7 (13.3) and T2 (13.3) with the lowest value recorded for birds on T4 (3.3) while birds on treatments 3, 5, 6 and 8 each recorded 10% mortality. Combination of electrolytes and ascorbic acid did not confer any beneficial effect compared to when any of the electrolytes or ascorbic acid was used solely. Keywords Heat stressed broiler chickens, Vitamin-Mineral synergy, Supplemental nutrients, Organs weight, Physiological response 1. Introduction High ambient temperature accompanied with high humidity that characterises the tropics and sub tropic areas of the world has been identified as a major problem affecting performance and physiological attributes of chickens [1, 2]. Broilers respond to high temperature by increasing respiratory rate [3], body temperature [4], water consumption [5] and decreasing feed consumption [6]. Several therapeutic agents have been suggested to alleviate negative effects of environmental temperature on performance of poultry [7-10]. There has been reported alteration in ascorbic acid endogenous synthesis and utilization in poultry under high environmental temperature which became inadequate for optimum performance [11]. Ascorbic acid and electrolytes supplementation have been observed to improve performance of broilers reared in a hot * Corresponding author: droaogunwole@gmail.com (Olugbenga Adeniran Ogunwole) Published online at http://journal.sapub.org/ijaf Copyright © 2015 Scientific & Academic Publishing. All Rights Reserved environment [12-15]. Combinations of vitamins and electrolytes supplementation of drinking water are often employed in the poultry industry as a prophylaxis for stress-induced morbidity and heat-stress mortality. Most reports are limited to the use of these nutrients solely [16] with less emphasis on the effects on performance and physiological response when combined [15, 17, 18]. This study was therefore undertaken to evaluate the synergy of electrolytes (ammonium chloride, sodium bicarbonate and calcium chloride) and ascorbic acid water supplementation on performance characteristics and selected physiological responses of heat stressed broiler chickens. 2. Materials and Methods 2.1. Experimental Birds and Management The study was carried out at the Teaching and Research Farm of the University of Ibadan, Ibadan which is located between latitudes 60°10” and 90°10” north of the equator and longitudes 30° and 60° of the Greenwich during hot dry season (March to April, 2012). Two hundred and forty,