Promoting Growth and Health of African Catfish, Clarias gariepinus, Through Dietary Novel Supplement, Ginger, Zingiber officinale Rosc, Leaf Powder

Abstract

African catfish is a popular freshwater aquaculture species as it can be farmed at high stocking density. However, high stocking density caused growth and health impairment. Hence, nutritional approach such as feed additive can be applied in fish farming to overcome this issue. This study evaluated the impacts of ginger (Zingiber officinale) leaf powder (GLP) on growth performance, digestive enzymes activities, antioxidative response, and disease resistance towards Edwardsiella tarda infection in African catfish. A feeding trial was performed using a control diet and four formulated diets with GLP at 1, 2, 3, and 4%. Ginger is an herb used in cuisine and traditional medicine. It was reported possesses medicinal values such as antimicrobial, anti-oxidant, and immune system modulator. After eight weeks, the growth performance of GLP-treated African catfish was significantly improved than control, and the best results were observed in the 2 and 3% groups (p<0.05). Meanwhile, fish supplemented with 1 and 4% GLP demonstrated comparable growth performance. There was a significant decreasing trend in FCR, HSI, and VI, where the lowest values were recorded by the 2 and 3% GLP diet groups, followed by 1% GLP, 4% GLP, and control groups (p<0.05). The digestive enzymes activity, including amylase, lipase, and protease, was significantly higher in dietary GLP groups than in control, where the highest activity was exhibited by groups 2 and 3% GLP (p<0.05), followed by 1% and 4% GLP groups. There was an increasing trend in the antioxidative response, where the GLP-treated groups had significantly higher catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities than the control, and the highest was observed in fish fed with 2 and 3% GLP (p<0.05). Furthermore, the GLP-treated groups had a significantly higher cumulative survival rate than the control, where 2 and 3% GLP groups demonstrated the highest survival (p<0.05), followed by 1 and 4% GLP groups. In summary, this study revealed that dietary GLP potentially enhanced African catfish production at recommended doses of 2 and 3%.