Dietary phytoimmunostimulant Persian hogweed (Heracleum persicum) has more remarkable impacts on skin mucus than on serum in common carp (Cyprinus carpio)

Inclusion of H. persicum in the diet significantly elevated several immunological factors such as immunoglobulins, lysozyme, protease and alternative complement activities in carp. Interestingly, the changes were more pronounced in the skin mucus than in the serum. Performance was significantly improved in the fish groups that received the candidate phytoimmunostimulant. Specifically, final weight, weight gain, specific growth rate and feed conversion ratio were significantly improved in the fish that received dietary H. persicum at inclusion levels 5 g kg−1 and higher. This study demonstrated the potential of Persian hogweed as a candidate dietary phytoimmunostimulant in carp, impacting mainly the skin mucosal defenses. The study supports the current trend in the exploration of sustainable plant-based dietary supplements that are capable of boosting the immunological defenses of farmed fish.