Effects of dietary taurine levels on immunity and digestive enzyme activities of redfin puffer Takifugu rubripes
ZHOU Jing, WANG Xu, LIU Xia, CHEN Ming-kang, HAN Yu-zhe, JIANG Chen
Key Laboratory of Mariculture & Stock Enhancement in North China’s Sea, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fish Applied Biology and Aquaculture in North China in Liaoning Province, Dalian Ocean University, Dalian 116023, China
Abstract: A feeding trial was conducted to investigate the effects of dietary taurine levels on immunity and digestive enzyme activities of juvenile redfin puffer Takifugurubripes.Juvenile redfin puffer with initial body weight of (32.28±0.20)g were reared in a 200 L square polyethylene tank at stocking density of 15 fish per tank and fed five diets containing taurine at a dose of 0%(group T1, control)，0.5% (group T2)，1.0% (group T3)，2.0% (group T4) and 5.0% (group T5) at water temperature of (23.0-24.5)℃ with triplication for 56 days.The results showed that there were significantly higher total antioxidant capacity(T-AOC), activities of superoxide dismutase(SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) and significantly lower malondialdehyde (MDA) level in liver of redfin puffer fed the diets supplemented with taurine than those in juveniles in control group(P<0.05), with the peak activities of SOD, CAT and GSH-PX in group T3 (P<0.05).The liver alkaline phosphatase (AKP) activity was found to be significantly increased first and then decreased with increasing levels of dietary taurine, with the peak in group T3 (P<0.05)and without significant difference in AKP activity (P>0.05).Significantly higher lipases (LPS) activity was observed in intestine in group T4 than those in other groups (P<0.05), with the maximal LPS activity in group T4.However, there was no significant difference in intestinal protease activity in various groups (P>0.05).The redfin puffer juveniles had significantly higher lysozyme (LZM) activities in mucus in groups T3, T4, and T5 than that in control group (P<0.05), with the maximum in group T4.Analysis of T-AOC, intestinal LPS and surface mucus LZM indicates that the optimal addition amount of taurine is 1.35-2.21 g/100 g(dry feed) in juvenile redfin puffer.
2019, Vol. 34 
