The Effects of Oregano Essential Oil on Intestinal Health and Muscle Nutritional Components of Crayfish (Procambarus clarkii).

This study used crayfish (Procambarus clarkii) as the experimental animal and conducted comparative feeding trials by adding oregano (Origanum vulgare L.) essential oil to the diet, systematically revealing its regulatory effects on body weight, muscle quality, intestinal health, and gut microbiota structure. Results showed that oregano essential oil increased the average body weight of crayfish by 12.6%, significantly raised the meat yield from 10.67% to 13.46%, and improved the levels of C22:6n3, cysteine, and umami amino acids in muscle tissue. Additionally, oregano essential oil significantly enhanced intestinal lipase activity, boosted superoxide dismutase and lysozyme activities, optimized gut microbial composition, markedly increased the abundance of beneficial bacteria such as Bacilli, and elevated microbial species richness. The study demonstrated that oregano essential oil can simultaneously improve body weight and intestinal lipase activity without disrupting intestinal physiological homeostasis, providing a reference for the application of oregano essential oil in shrimp farming.