Oregano (Origanum vulgare) extract as phytogenic feed additive: Enhancing growth, carcass, hepatic biochemical indices and immune response in Labeo rohita

Abstract

In aquaculture, plant extracts offer a sustainable solution by reducing costs and environmental impact compared to conventional pharmaceuticals. This study explored the effect of oregano (Oregano vulgare) extract on growth, carcass composition, blood parameters, mineral profile, liver biochemical parameters and immune response in Labeo rohita. Fish (n = 15 fingerlings/ group in triplicate) were fed with various percentages of oregano extract including 0 (T0; control; no extract), 0.5 (T1), 1 (T2), 1.5 (T3), 2 (T4), 2.5 (T5) and 3 (T6) kg−1 for 13-weeks. After the feeding trial, growth indices, including weight gain, protein efficiency ratio and specific growth rate were significantly improved (P < 0.05) in the T2 and T3 groups and all other treatment groups. Moreover, protein retention in muscles was significantly highest in the T2 and T3 groups whereas fat deposition was lowest in these same groups. Furthermore, the addition of 1 % oregano extract to fish diets was found to enhance hematological parameters and mineral absorption throughout the body. The inclusion of 1 and 1.5 % oregano extract significantly (P < 0.05) enhanced the activities of hepatic enzymes such as catalase, glutathione peroxidase, and superoxide dismutase. While malondialdehyde level was found to be the lowest in the T2 group. In conclusion, incorporating up to 1–1.5 % oregano extract into the diets of L. rohita can significantly enhance overall performance.

Keywords

• Fish
• Extract
• Oregano
• Growth
• Liver
• Immunity