synchronic use of multi-enzyme and probiotic on performance of broilers with wheat and barley based diet

the objective of this study was to evaluate the synchronic use of multi-enzyme and probiotic on broilers performance. this factorial experimental was conducted in a randomized complete design and included 480 ross broiler chicks (strain 308) which were divided into 6 treatments and each treatment into 4 replicates and 20 chicks in each replicate. the wheat and barley based diet was constant for all treatments. multi-enzyme is used in three levels (zero, half level and suggested level (500 gram) ) and probiotic in two levels (zero and suggested level). at the end of experiment, all chicks are weighted.  then from each replicate 2 chicks were killed to measure carcass traits and characteristics of different parts of intestine. at the total of the experiment period (1-45 days), the results showed that the application of multi-enzyme (at suggested level) was caused further weight gain and improvement of feed conversion ratio (p<0.05). no significant differences were observed in feed intake in application of only multi-enzyme or probiotic . use of only probiotic and only multi-enzyme was decreased  fcr in total period (p<0.05).carcass percentage was increased significantly in use of enzyme, probiotic and synchronic use of them (p<0.05). thigh and breast percent were not significant. abdominal fat percent was decreased in use of synchronic enzyme and probiotic (p<0.05).percentage of liver, duodenum and jejunum length declined significantly in use of only enzyme (p<0.05). use of only enzyme or only probiotic was advisable for improvement of fcr. but the use of synchronic enzyme and probiotic doesn’t have any additive effect on broiler performance.