Effect of dietary citric acid and microbial phytase on broiler chicken performance and some carcass parameters

A trial was conducted to determine the effects of dietary citric acid and microbial phytase on broiler chicken performance and some carcass parameters. The dietary treatments consisted of untreated control feed. Treated feeds with the microbial enzyme phytase and citric acid were formulated using three levels of 0, 500 and 1000 U/Kg of microbial phytase and three levels of 0, 3 and %6 citric acid using 270 male Ross 308 broiler chickens were placed in an experimental design consisting of nine dietary treatments with three replicate cages of 10 broilers per cage. The dietary treatments consisted of untreated control feed, three microbial phytase-supplemented diets (0, 500 and 1000 U/kg), three citric acid feed (0, 3 and %6), 500 U/kg phytase + 3% citric acid, 1000 U/kg phytase + 3% citric acid, 500 U/kg phytase + 6% citric acid and 1000 U/kg phytase + 6% citric acid diets prepared on corn and soybean basis. The chickens were maintained on these dietary treatments from 7 to 42 d of age with feed and water made available for ad libitum consumption. Feed intake, body weight gain, final body weight, feed conversion ratio, live body weight, carcass weight and some relative internal organs weight were determined. There was a significant (P< 0.01) effect of citric acid diets in, feed intake, body weight gain and final body weight in the broilers fed the citric acid feeds but there was no significant effect in feed conversion ratio. Also, carcass weight was significantly affected by citric acid in the diet (P< 0.01) but relative internal organs weight was not significantly affected by citric acid of the diet. The microbial phytase treated diets significantly improved body weight and body weight gain (P< 0.05) but had no significance effect in feed intake and feed conversion ratio. At the same time, the microbial phytase diets significantly improved relative neck weight but relative carcass and related carcass factors were not significantly changed by affected by the microbial phytase diets. The results also indicated that there is an interaction between microbial phytase and citric acid and citric acid has a synergetic effect on phytase state of action in the body.