the physiological changes, growth performance and whole body composition of common carp, cyprinus carpio fed on diet containing wood betony, stachys lavandulifolia extract

the effect of different levels of wood betony (wb), stachys lavandulifolia extract, as complement in feed, on the performance of common carp, cyprinus carpio was evaluated. the fish (44±0.62 g) was assigned to four treatments, three replicates each. the fish was fed on normal diet with no wb (control) vs. diet containing 2, 4 and 8% of wb extract. fish were successively fed on the diet, 2% live body weight, three daily for 70 days. the results revealed that final weight, mean weight gain and specific growth rate were significantly improved by increasing wblevels in the diet. the highest growth performance and the lowest feed conversion ratio were recorded for 8%wbtreatment. no significant changes were observed in the proximate whole body composition among different groups. hemoglobin content and hematocrit value increased significantly in the second group in comparison with the others (p< 0.05). the highest serum total protein (5.05±1.4 g dl-1) and globulin (2.47±0.3 g dl-1) were recorded in the fish fed on the highest dose of wb (8%). inclusion of 2% of wb in the diet reduced serum triglycerides (317.44±89 mg dl-1) and cholesterol (141.51±35 mg dl-1) in comparison with control (p< 0.05). it could be concluded that feeding common carp with the diet enriched with wb extract could enhance growth rate, improve some hematological and biochemical characteristics with no adverse effects on body composition.