comparison the effects of rosemary, thyme, propolis, antibiotic and probiotic on broiler performance

to compare the effects of two herbal extracts, antibiotic, probiotic, and ethanol extract of propolis on performance, relative weight of internal organs, carcass characteristics and morphology of the small intestine of broilers challenged with salmonella enteritidis a trial was performed based on completely randomized design. four hundred and twenty day old male broiler chicks including 7 treatments with 4 replicates of 15 birds per replicate were reared for six weeks. on day 10, except for the negative control group, other groups were inoculated orally with salmonella enteritidis. the results showed that antibiotic had significant effect on the relative weight of the breast, increased the relative carcass weight and enlargement of the liver compared to the other groups improving its metabolism and feed conversion ratio. this study showed that plant extracts in addition impact on abdominal fat reduction can increase the height and crypt depth in the small intestine and provide a greater surface area for absorption. in addition, the maximum amount of feed intake and weight gain were observed in the propolis fed group.