Is dietary taurine required for white seabream (Diplodus sargus) juveniles?

This study assessed the effect of supplementation of low-fishmeal (FM) diets with taurine in white seabream (Diplodus sargus) juveniles. Four isoproteic (36% CP) and isolipidic (18% CL) diets were formulated to include 15%FM or 5%FM, supplemented or not with 1% of Taurine (TAU). Twelve groups of 15 fish (IBW = 58 g) were fed each diet to near satiation for 10 weeks. Growth performance, feed intake, and feed efficiency were not affected by dietary FM level. Nevertheless, dietary TAU supplementation increased growth performance and feed efficiency. Nitrogen and energy retention were improved by both dietary FM level and TAU supplementation. Plasma cholesterol, lactate, and bilirubin did not differ among dietary treatments, but dietary TAU supplementation decreased plasma glucose and triglycerides levels. Decrease of FM level reduced total bile salts while TAU supplementation had the opposite effect. No differences were noticed in innate immune parameters assessed. Overall, results indicate that white seabream can be fed with diets almost devoid of FM, and that dietary TAU supplementation increases growth performance and feed efficiency. Moreover, results suggest that dietary TAU was limiting both in 15% and 5% FM diets.