The effects of hawthorn, Crataegus monogyna, berry (CMB) on growth, hematology, antioxidant, digestive enzyme activity, gut microbiota, and disease resistance of African catfish, Clarias gariepinus

This study evaluated the effects of dietary supplementation of hawthorn ( Crataegus monogyna ) berry (CMB) on growth performance, hematological parameters, antioxidant status, digestive enzyme activity, gut microbiota, and disease resistance of African catfish ( Clarias gariepinus ). A total of 600 fish were randomly assigned to four dietary treatments containing 0% (C), 0.5% (CMB5), 1.0% (CMB10), and 2.0% (CMB20) CMB, with three replicate tanks per treatment, and fed for eight weeks. Compared with the control diet, fish fed CMB-supplemented diets exhibited significantly greater final weight, weight gain, and specific growth rate, together with a lower feed conversion ratio, with the greatest improvement observed in the CMB20 group ( P < 0.001). Blood analysis showed significantly higher red blood cell count, white blood cell count, hemoglobin concentration, and hematocrit in fish fed the CMB20 diet than in fish fed the control diet ( P < 0.001). Intestinal digestive enzyme assays demonstrated significantly higher amylase ( P < 0.001) and lipase ( P < 0.001) activities in CMB-fed fish than in the control group, whereas protease activity was significantly higher only in fish fed the CMB10 diet ( P = 0.016). Hepatic antioxidant analyses demonstrated significantly higher catalase, superoxide dismutase, and glutathione peroxidase activities in fish fed CMB-supplemented diets, compared with fish fed the control diet, under both normal and thermal stress conditions ( P < 0.001). Following Edwardsiella tarda challenge, fish fed the CMB10 and CMB20 diets exhibited significantly higher cumulative survival rates than fish fed the control diet ( P < 0.03), demonstrating enhanced resistance to E. tarda infection. Intestinal microbiota analysis showed significantly higher relative abundances of the putatively beneficial genera Cetobacterium , Phocaeicola , and Akkermansia , together with lower relative abundances of putatively pathogenic taxa, in CMB-fed fish than in the control group ( P < 0.05). Overall, dietary CMB supplementation significantly improved growth performance, physiological health, antioxidant capacity, digestive function, gut microbial composition, and resistance to E. tarda , supporting its potential as a natural phytogenic feed additive for sustainable African catfish aquaculture.