New insights into the effect of Solanum nigrum extract supplementation on growth, digestibility, carcass, hematological indices, and antioxidant status in Oreochromis niloticus

Herbal supplements can effectively boost fish growth and are a cost-effective alternative to antibiotics. The main objective of this research was to explore the efficacy of leaf extract of Solanum nigrum (SNE) on the growth parameters, digestibility, carcass, blood indices, and antioxidant status of Oreochromis niloticus fingerlings (5.75±0.03 g/fish). Canola meal was used as basal diet. Six experimental treatments having different levels of SNE (0 %, 0.5 %, 1 %, 1.5 %, 2 % and 2.5 %) were formulated. 15 fingerlings were placed in each of 6 triplicate tanks. The feeding trial continued for 70 days and then the results showed improvement in growth indices, body composition (fat, protein, ash and moisture) and nutrient absorption (crude fat, gross energy and crude protein) of O. niloticus. Moreover, SNE treatment showed better results of blood indices. Best outcomes for all these parameters were observed at 1.5 % SNE supplementation (test diet-IV). Additionally, SNE treatment enhanced the antioxidant activity of O. niloticus. The serum antioxidant enzymes status (catalase, superoxide dismutase and peroxidase) were enhanced by SNE treatment. Antioxidant activity increased with increasing SNE supplementation. In conclusion, SNE improved the growth and overall health of O. niloticus and the optimum inclusion level suggested for SNE is 1.5 %. However, further research is necessary to ensure its safe and effective use in different fish species.