Effect of dietary Chinese tea on growth performance, disease resistance and muscle fatty acid profile of channel catfish (Ictalurus punctatus)

Six types of Chinese tea were incorporated into diets at four different levels (0, 1, 2 and 4 %) in order to determine their effects on the growth performance, fatty acid composition of muscle lipids and resistance to Aeromonas hydrophila infection of Ictalurus punctatus (channel catfish) fingerlings. Each diet was fed to catfish in triplicate tanks for 8 weeks. Results show that a 1 % Dragon Well tea (DWT) and Maofeng tea were significantly better than other diets (including the control) in improving weight gain (WG) and feed conversion rate (FCR) of fish; while the 4 % DWT increased FCR (P < 0.01) but decreased WG (P < 0.05). In addition, 4 % DWT resulted in a significant decrease in muscle lipid content. Pu-erh tea in 2 and 4 % dietary addition decreased saturated fatty acid and increased monounsaturated fatty acid content in muscle. The hepatosomatic index decreased significantly in fish fed the 4 % DWT diet. The mortality (%) of catfish challenged with A. hydrophila decreased with increasing addition of tea to the diet, and the mortality in DWT and Huangya tea (HYT) was lower than control groups (P < 0.05). In conclusion, diets supplemented with a low dose (1 %) of Chinese tea increased growth performance and enhanced the fish fillet quality. Addition of DWT or HYT tea at 4 % in channel catfish diets can improve resistance against A. hydrophila, but growth performance is reduced.