Effects of different concentrations of St.John's Wort (Hypericum perforatum) extract on performance, blood parameters and physical and chemical meat quality of broiler chicks

This experiment was conducted to examine the effect of different concentrations of St.John's Wort (Hypericum perforatum) extract (HPE) and antibiotic neomycin on performance,blood parameters and meat quality of broiler chicks. The experiment was performed on 180 one day old male broiler chicks of Ross 308 strain in a completely randomized design with 5 treatments consisting of 3 replicate with 12 broiler chicks per each. The treatments include a control treatment (basal diet), three different levels of HPE (0.25, 0.50 and 0.75 gr HPE /kg diet) and one treatment with 0.2 gram per kilogram antibiotic (neomycin). Broilers fed the diet containing antibiotic had higher feed intake compared to treatments HPE during in growth period and overall experimental periods (P<0.05). Broilers receiving neomycin diet had lower feed conversion ratio compared to broilers receiving 0.25 or 0.75 g HPE /kg during finisher and entire experimental periods. The serum cholesterol had significantly decreased in the treatment with 0.75 gr HPE /kg diet, in sixth week (P <0.05). Adding of HPE were significantly dry matter decreased and protein increased in broiler breast and drumastick (P<0.05). Between the physical characteristics of the drumstick, treatments of 0.50 gr HPE /kg had lowest hardness, Cohesiveness and chewiness index (P<0.05).In conclusion, the result of this study showed that addition of St. John’s Wort extracthas not a positive influence on growth performance but can improving physical and chemical characteristics of meat quality.