effect of substituting dietary oxytetracycline with aqueous prangos ferulacea extract on growth performance, prececal nutrient digestibility, cecal microbiota and carcass traits in hubbard broiler chickens

This research aimed to compare the effect of substituting dietary oxytetracycline with aqueous prangos ferulacea extract (apfe) as a phytobiotic on growth performance, prececal nutrient digestibility, cecal microflora, and carcass traits in broilers. in this experiment, a total of 300 hubbard broiler chickens were used in a factorial arrangement with two factors: oxytetracycline (0 or 0.1 %) and apfe (0, 2, or 6 %) in a completely randomized design. the experiment consisted of 6 treatments of 5 replicates each with 10 birds.  all birds reared for 42 das and received feed and water ad libitum. the results showed that the use of oxytetracycline improved the daily weight gain, but decreased fat digestibility, the relative weight of the pancreas, and the escherichia coli population during days 12 to 42 of the exeriment. the use of apfe improved the daily weight gain, feed conversion ratio (fcr), fat digestibility, and carcass percentage, but decreased the cecal escherichia coli population. the interaction effect of using the apfe and oxytetracycline for feed intake and fcr‏ was not significant. regarding the reducing effects of apfe on the cecal escherichia coli population and improved growth performance, apfe at 6 percent could be introduced as a natural antibiotic and an appropriate replacement for oxytetracycline.