Effects of Wheatgrass Juice Supplementation in Common Carp (Cyprinus carpio): Growth Performance, Biochemical Profile, Oxidative Status, and Cultivable Intestinal Bacteria

Aquaculture faces numerous challenges related to fish health. To explore new solutions, the objective of this study was to test the effects of wheatgrass juice (WGJ) as feed supplement on growth performance, blood biochemical profile, bacteriological balance, and oxidative stress in common carp (Cyprinus carpio). Carp fingerlings (8.8 g initial body weight) were fed diets containing 4% or 8% WGJ in a recirculating aquaculture system for eight weeks. Most growth performance parameters did not differ significantly among dietary treatments, although the viscerosomatic index (VSI) was significantly lower in WGJ-supplemented groups. WGJ supplementation was associated with changes in oxidative-status parameters, including increased antioxidant enzyme activities and reduced malondialdehyde levels, particularly at the 8% inclusion level. Blood biochemical parameters showed no evidence of adverse effects on liver or kidney function. Total protein, globulin, and albumin did not differ significantly among treatments. Microbiological examination highlighted a decrease in pathogenic bacteria, including sulfite-reducing clostridia, with a 4% WGJ diet showing the most pronounced inhibitory effects. These results indicate that WGJ supplementation may influence selected biochemical, oxidative-status, and cultivable intestinal bacterial parameters in common carp. Further studies are required to determine the underlying mechanisms and the practical relevance of these effects.