hypericum perforatum and probiotic effects on performance, carcass characteristics and intestinal morphology in japanese quails (coturnix japonica)

background & aim:hypericum perforatum l. is native to iran. this herb is one of the most important medicinal plants and had many medical effects.this experiment was conducted to investigate the effects of feeding hypericum perforatum and protexin on performance, carcass characteristics and intestinal morphology japanese quails. experimental: a total of 240 ten days old quails were divided into eight treatments with three replicates as factorial randomized design. the treatments were divided as basal diet with no protexin and hypericum perforatum kept as control, and 0.2% (h1), 0.4% (h2) and 0.6 % (h3) hypericum perforatum with 0.02 % or without protexin as p0 and p1 were used respectively. the live body weight gains, feed intake and feed conversion ratio of quails were calculated weekly. at the end of the trial two birds (male) form each replicates were slaughtered and dressing percentage were calculated and some carcass traits were weighed separately as percentage of carcass weight.  results: data indicated that using of protexin and hypericum perforatum increased feed intake (fi) in treatments compared to control group. also body weight (bw) (g/d) and pre-slaughter weight (g) were higher in protexin and hypericum perforatum compared to the control. there were no significant differences (p