dietary wood betony, Stachys lavandulifolia Vahl extract as a growth promoter and immune enhancer in common carp [Cyprinm carpio]

ABSTRACT

The present study was conducted to evaluate the efficacy of wood betony [WB], Stachys lavandulifolia extract on growth performance and some immune responses in common carp, Cyprinus carpio. Different concentrations of the WB extract 0, 2, 4 and 8% [g per 100 g of diet] were added to commercial diet. Each treatment was randomly assigned to triplicate groups of fish having average initial weight of 44 +/- 0.62 g for 10 weeks. The results showed that final weight, food conversion ratio, specific growth rate and condition factor were significantly improved by WB in a dose dependent manner, where the best growth parameters were achieved in the group of fish receiving the highest concentration of WB [P<0.05]. Feeding fish at 2 and 4% W/W by WB in the diet improved lysozyme activity, ACH[50] and IgM levels significantly in comparison to the control [P<0.05]. Group offish fed on 4% WB in the diet had the best levels of the immune characteristics [P<0.05]. Based on the results of this study, it is recommended to feed common carp with WB to improve growth and non-specific immunity