Influence of taurine on the zootechnical performance and health parameters of juvenile Nile tilapia in a recirculating aquaculture system

Taurine is considered a conditionally essential amino acid for fish, so its supplementation may improve feed conversion. This study evaluated the supplementation of taurine on growth performance, hematological and immunological parameters, production costs, and survival of Nile tilapia (Oreochromis niloticus) juveniles raised in a recirculating aquaculture system (RAS). A control diet was formulated with 360 g kg^-1 of crude protein without fish meal and without taurine supplementation (Control). From the control diet, another diet supplemented with 9.7 g of taurine per kg of feed (Taurine) was produced. Fish fed diet supplemented with taurine had lower daily average weight gain and final average weight compared to the control diet (p < 0.05). It was observed that taurine had no influence on condition factor, survival, or hemato-immunological parameters of Nile tilapia juveniles, but there was a higher mean corpuscular volume and greater nitrogen retention in fish from the control group (p < 0.05). It is concluded that Nile tilapia juveniles do not benefit from taurine supplementation in RAS, even when fed diet containing plant-based protein sources.

Key words
amino acid; hematology; nutrition; Oreochromis niloticus; sustainability