Effect of black cumin seed oil (Nigella sativa) and nettle extract (Quercetin) on enhancement of immunity in rainbow trout, Oncorhynchus mykiss (Walbaum)

The study was performed to examine the efficacy of dietary black cumin seed oil (Nigella sativa) and nettle extract (Quercetin) on the immune response of rainbow trout, Oncorhynchus mykiss. Fish were divided into 7 groups before being fed for 14days with 0.1%, 0.5% and 1% of Quercetin, 1%, 2% and 3% of N. sativa oil and with unsupplemented commercial diet as the control. Humoral immune parameters including lysozyme, antiprotease, total protein, myeloperoxidase, bactericidal activity, and IgM titers were investigated. Treatment groups recorded enhancement in all parameters compared to their respective controls. Groups fed the highest doses, i.e. 1% Quercetin and 3% N. sativa oil, showed a highly significant difference (p