a 6 week study was conducted to assess the effects of wood betony (wb), stachys lavandulifolia extract on growth performance, hematological and biochemical parameters of common carp, cyprinus carpio. different levels of the wb extract (0, 2, 4 and 8 % weight per weight, w/w, 0wb, 2wb, 4wb and 8wb) in the diet were used. the results showed that final weight and weight gain were significantly imp...