the effect of citric acid and phytase on performance, blood lipid profile, immune system and some carcass characteristics of broiler chickens

this study was conducted to evaluate the effects ofcitric acid and phytase supplementation on performance, blood lipid profile, immune system and some carcass characteristics of broiler chickens.for this purpose 240, one-day old male broiler chicks were reared throughout 42 day production, in factorial experiment 2×2, including citric acid (0 and 1%) and phytase enzyme (0 and 500 ftu) based on completely randomized design with 4 treatments, 5 replicates and 12 chicks in each. result indicated that citric acid decreased the feed consumption in growth and total period. while phytase wasn’t any effecton performance of broilers. the means of body weight gain and feed conversion rate were not affected by treatments. citric acidreduced the level cholesterol and ldl of blood serum. also result showed that citric acid increased the hdl and vldl of blood serum. addingcombine citric acid and phytase decreased the ldl of blood serum. citric acid and its combine with phytase increased the relative weight of bursa. adding citric acid and phytase to the diet respectively decreased and increased the abdominal fat. the results of the present study showed that use of citric acid and phytase together didn’t have a negative impact on each other's effects, but in some cases they reinforce each other's effects.