Abstract

This experiment was conducted to examine the effect of dried aerial parts of the herbHypericum perforatum L. (HP) as an antibiotic growth promoter substitution on performance, carcass traits, immune responses, and serum biochemical parameters of broiler chicks. In this study, 192 one-day old chicks (Ross 308) were allocated to four treatments with four replicates based on a completely randomized design. Dietary treatments included control, antibiotic (flavophospholipol), and 5 and 10 g HP/kg diet. Dietary supplementation of flavophospholipol increased final body weight of broilers at day 42 compared with those fed diets supplemented with 5 and 10 g HP/kg (P<0.05). Birds fed 5 and 10 g HP/kg in the diet had the highest feed conversion ratio at day 42, compared with other treatments (P<0.05). Antibody titer against avian influenza virus (AIV) increased in the group treated with 10 g HP/kg diet compared with those fed basal diet and basal diet supplemented with antibiotic (P<0.05). Total and high-density lipoprotein cholesterol (HDL-C) levels in antibiotic group were significantly higher than those fed basal diet or basal diet supplemented with 5 g HP/kg (P<0.05). In conclusion, the result of this study showed that addition of St. John’s Wort powder seem not to have a positive influence on growth performance and it could not be considered as a antibiotic growth promoter substitution for broiler chicks.

Key words: Broilers, Hypericum perforatum L., performance, immune responses, biochemical parameters, carcass characteristics.