Abstract:

The present study was aimed at determining the effects of wormwood (Artemisia vulgaris L) on the immune response and disease resistance against Vibrio anguillarum in rainbow trout (Oncorhynchus mykiss Wal- baum). Wormwood was incorporated into the diets as powder (0%, 0.1%, 0.5%, 1%, 2%) and ethanol extracts 250 and 1000 mg kg-1 of rainbow trout O. mykiss (20.48 ± 0.19--20.81 ±0.04 g). Some haematological (WBC, RBC, level) and immunological (NBTassay, lysozyme and phagocytic activity) parameters were determined in fish blood. In NBTassay, lysozyme and phagocytic activity were enhanced in wormwood treated groups compared with the control group (p<0.05). After 45 days, fish were challenged with V. anguillarum and mortality (%) was recorded up to day 10 post-challenge. The best survival (100%) was in the 1% and 2% wormwood diet groups. These results indicate that wormwood supplementation significantly increased the immunity and makes O. mykiss more resistant to infection by V. anguillarum. It could be concluded that wormwood could be used as immunostimulant for rainbow trout.

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