Effects of ginger and garlic supplements on culture performance of blackchin tilapia (Sarotherodon melanotheron)
Previous studies suggest that plant products can be used in place of synthetic therapeutic chemical agents to improve the growth, health, and meat quality of cultured fish. These effects of plant supplements are specific on different fish species. Therefore, this study investigated the potential of ginger and garlic as feed supplements for the culture of blackchin tilapia, Sarotherodon melanotheron. This fish is an important source of protein to many coastal communities. Powdered forms of these supplements were fed to the fish at four levels (0.5%, 1%, 1.5% and 2%) as part of a commercial feed. Ten fingerlings per m2 (average weight = 2.74 ± 0.30 g each) were cultured for 24
weeks in hapas suspended in concrete tanks. The performance of these fingerlings was compared with those that were not fed with the supplements. Results showed that both supplements did not affect growth of the fish, its feed utilisation, blood constituents, serum biochemical composition and lysozyme activity. However, the condition index, protein, fat and mineral content of the fish were significantly higher when garlic content of the fish feed was ≥ 1.5%. In contrast, moisture, fibre and carbohydrate were reduced when the garlic content of the feed was ≥ 1.5%. Ginger, particularly at a concentration of 1.5% induced significantly higher protein and moisture whereas it decreased fat, fibre, carbohydrate and ash content of the fish. These results suggest that ginger and garlic can be used to enhance the physiological condition and nutritional quality of S. melanotheron under culture.