The tolerance and safety assessment of taurine as additive in a marine carnivorous fish, Scophthalmus maximus L.

Abstract

The effects of dietary taurine on growth performance, liver and intestine morphology, serum physiological and antioxidant parameters, serum thyroid hormone level, muscle taurine content and fatty acid composition of turbot were first evaluated, for the safe utilization in marine fish feed and for human food safety. Four experimental diets were formulated to contain 0, 10, 50 and 100 g/kg taurine. Each diet was randomly assigned to six replicates of 30 juvenile turbot (initial mean weight of 7.46 g). The feeding trial lasted for 10 weeks. The growth performance of fish was significantly enhanced by 10 g/kg dietary taurine. The integrity of the distal intestine was impaired and the absorptive surface was found to be significantly reduced by 100 g/kg dietary taurine. The obvious pathological changes in liver were observed in fish fed 100 g/kg taurine. Dietary taurine with 10 and 50 g/kg significantly increased the activities of serum superoxide dismutase, lysozyme and thyroid hormone. The taurine content in muscle was found to be significantly increased by dietary taurine; however, no significant differences were observed among taurine-supplemented treatments. This study suggested that 10 g/kg taurine was safe in turbot feed, and fivefold of safety margin was obtained.