The Effects of Phytobiotic-Enriched Diet on Immunity Index and Hematological-Biochemical Changes in Common Carp Fish (Cyprinus carpio)

The present study compared the effects of four medicinal herbs on the growth, digestive enzyme activity, innate immunity, and oxidative status of common carp juveniles (Cyprinus carpio). The juvenile fish (average weight: 80.01 ± 0.34 g) were fed with four diets, including 1% Zataria multiflora oil (T2), Zingiber powder (T3), garlic essential oil extract (T4), garlic peel extract (T5), and control diet (T1) without any additives, for seven weeks (20 individuals per replicate). The results showed that weight gain and specific growth rate were highest in the treatment fed with garlic and ginger extracts (T3 and T4). The protease and lipase activities in the medicinal herb treatments (especially the garlic extract treatment; T4) were significantly higher than in the control. Fish fed with medicinal herb-supplemented diets (except for Z. multiflora oil; T2) also displayed higher levels of serum lysozyme, alternative complement, total immunoglobulin, superoxide dismutase, and total protein levels compared to the control diet. The highest levels were observed at the 1% level of Zingiber powder (T3) and garlic extract (T4). Medicinal herb supplementation at a level of 1% is a natural immunostimulant and growth promoter supplement recommended for common carp.