Comparative effects of savory (Satureja hortensis), dill (Anethum graveolens), and mooseer (Allium hirtifolium) essential oils on growth, digestive, and immunoantioxidant parameters and resistance to Aeromonas hydrophila in juvenile common carp (Cyprinus carpio)

Abstract

This study investigated the effects of savory (Satureja hortensis), dill (Anethum graveolens), and mooseer (Allium hirtifolium) essential oils on growth, digestive, immunity, and antioxidant parameters, as well as resistance to Aeromonas hydrophila in juvenile common carp (Cyprinus carpio). Experiments were performed on 630 fish with an average weight of 23.89 ± 0.13 g; (Mean ± SE) within seven feeding treatments for 60 days. The treatments contained no essential oils (control treatment) and levels 1 and 2% of each of the savory (SEO1, SEO2), dill (DEO1, DEO2), and mooseer (MEO1, MEO2) essential oils. After 60 days of feeding, the results indicated a significant improvement in the final weight, weight gain, specific growth rate, feed conversion ratio, intestinal protease, and lipase activity, and serum lysozyme (LYZ) activity in SEO treatments, as well as a serum level of total protein (TP) globulin (GLO), alternative complement pathway hemolytic (ACH50), nitroblue tetrazolium (NBT) and myeloperoxidase (MPO) in the SEO2 treatment compared to the control treatment (P < 0.05). The serum levels of superoxide dismutase, catalase, and malondialdehyde were significantly improved in the DEO treatments compared to the control treatment (P < 0.05). Mucosal levels of protease, total immunoglobulin, and LYZ were increased in the MEO2 treatment compared to the control treatment (P < 0.05). Moreover, Serum levels of TP, GLO, LYZ, ACH50, NBT, and MPO were increased significantly in the MEO treatments compared to the control treatment (P < 0.05), but not compared to the SEO2 treatment (P > 0.05). The lowest cumulative mortality rate (CMR) after 14 days of challenge with A. hydrophila was recorded in the MEO2 (28.88%), MEO1 (33.33%), and SEO2 (35%) treatments, respectively, with a significant difference, compared to the control treatment (59.99%) (P < 0.05). The results revealed that 2% SEO2 could promote growth, digestive function, humoral immunity, and resistance to A. hydrophila in juvenile common carp.