Effects of Replacement of Fish Meal with Black Soldier Fly Larvae Meal on Antioxidants and Enzymes Activities in the Serum of Clarias Gariepinus

Abstract

Insect meals (IM) have been proposed as a potential alternative protein source for replacing fishmeal (FM), the key ingredient in aquaculture diets, yet the most expensive. However, not much work has been done on the effects of replacing FM with black soldier fly larvae meal (BSFLM) on the growth performance of African catfish (Clarias gariepinus) juveniles. This study investigated the effect of replacing FM with BSFLM on the growth performance, antioxidant status, and digestive enzyme activities of Clarias gariepenus . Five diets were formulated to replace fish meal at various inclusion rates: Diet T0 (Control) – 100% Fish meal inclusion; Diet T1 – 25% BSFLM and 75% Fish meal; Diet T2 – 50% BSFLM and 50% Fish meal; Diet T3 – 75% BSFLM and 25% Fish meal; and Diet T4 – 100% BSFLM. One hundred and fifty (150) juveniles of mean weight 5.46 ± 0.02 g were stocked in 15 plastic tanks (10 juveniles/tank, in three replicates/treatment). The fish were fed manually at 5% body weight twice a day for eight weeks. Physico-chemical properties of water (pH , temperature and dissolved oxygen)in the experimental tanks were also monitored and from the result there was no signicant difference (p>0.0.5). The data obtained were subjected to statistical analysis. Results indicated significant differences (P<0.05) in final body weight, body weight gain, length increase, mean weight gain, and specific growth rate. The best growth performance was recorded in fish fed Diet T1 (25% BSFLM and 75% Fish meal). Antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase) were significantly enhanced in fish fed BSFLM-based diets, particularly at 25–50% inclusion rates, while lipid peroxidation (MDA levels) was reduced, indicating improved oxidative stability. Furthermore, digestive enzyme activities (protease, amylase, and lipase) were positively influenced by BSFLM inclusion, suggesting better nutrient utilization. The study demonstrated that BSFLM is a cost-effective and functional alternative to fish meal in diets of and can replace up to 25% without negative effects on growth, while also enhancing antioxidant capacity and digestive enzyme activity.