effect of dietary electrolyte balance on performance and immune responses of broiler chickens reared in the heat stress environments

this study was conducted to evaluate the effect of different levels of electrolyte dietary balance (deb) on performance and immune function of broiler chickens reared under the heat stress condition. three hundred oneday chickens were distributed randomly in 25 separate pens with 12 chicks in each. this experiment was in the form of a completely randomized design with five treatments and five replications and different levels of electrolyte dietary balance (edb), including 50, 150, 250, 350 and 450 meq/kg dedicated on corn - soybean based diets . to study immune responses , 0.5 ml intramuscular injection of sheep red blood cells (5%) on days 18 and 30 and antibody response against newcastle and bronchitis was used. in 28 to 42 days, chickens for 4 hours under 35 ° c heat stress were studied. the average weight of chickens in the fourth week in deb 250 was higher while sixth week the highest mean weight in chickens was deb 350. maximum feed intake in the third week in 250 deb, but the fourth to sixth weeks greatest amount of feed intake in 350 edb were observed. effect of different levels of edb on feed conversion ratio was not significant. effect of edb on primary and secondary immune responses was significantly in 6 and 12 days after inoculation (primary immune response), most srbc antibody response in 450 edb . similarly, in 6 and 12 days after injection (secondary immune response), the highest antibody, respectively, 350 and 450 edb was observed. equilibrium level of 350 deb was highest antibody titer against newcastle and bronchitis (p<0.05). the results of this experiment showed that levels of edb 250 and 350 improved the performance and immune response of broiler chickens , level of 250 edb for normal rearing temperature and level of 350 edb in the high temperature and thermal stress conditions are suitable