Immunohematological parameters of rainbow trout (Oncorhynchus mykiss) fed supplemented diet with different forms of barberry root (Berberis vulgaris)

<p>In this experiment, the effect of barberry root powder and methanol extract on the growth and immunohematological parameters of rainbow trout (<i>Oncorhynchus mykiss</i>) was studied. A total of 306 rainbow trout fingerlings (15.55 ± 0.76 g) were fed for 8 weeks with six experimental diets: control (C), BRP10 (10 g kg⁻¹ of barberry root powder), BRP20 (20 g kg⁻¹ of barberry root powder), BRE250 (250 mg kg⁻¹ of barberry root extract), BRE500 (500 mg kg⁻¹ of barberry root extract), and oxytetracycline OTC30 (30 g kg⁻¹). The results indicated BRE250, BRE500, and OTC30 had significantly higher weight gain (93.04, 92.52, and 90.48 g, respectively) compared with other dietary treatments (<i>P</i> < 0.05). The highest levels of WBC (26.5 × 10³), RBC (1.8 × 10⁶), HB (9.47 g dl⁻¹), MCHC (22.19 g dl⁻¹), lymphocytes (67.67%), lysozyme (65.67), and ACH50 (139) in fish fed BRE500 diet were observed (<i>P</i> < 0.05). Also, inhibition zone appeared with the barberry against <i>Aeromonas hydrophila</i> in vitro<i>.</i> Totally, it is suggested that the BRE500 diet can be used as a natural stimulant of growth and immunity in the aquaculture industry.</p>