Development of a nutritional model to define the energy and protein requirements of tilapia, Oreochromis niloticus

This study assessed the protein and energy requirements of tilapia (Oreochromis niloticus) using a bioenergetic factorial modelling approach. Several model parameters were examined using a series of inter-related studies to define key factorial parameters. Studies included both controlled laboratory experiments and field-data collection from commercial farms in the HaiDuong province of northern Vietnam. The model includes parameters for maintenance energy (25.9 kJ/kg0.80/d− at 28 °C) and protein (0.45 g/kg− 0.80/d at 28 °C) demands, the effect of animal live-weight on growth and maintenance energy demands, the efficiencies of energy and protein utilisation at various energy and protein intake levels and the variability in whole body composition with varying live-weights. The energy (0.440 
•  [Energy intake] − 15.45) utilisation efficiencies were substantially lower than that observed from carnivorous fish species, but similar to other omnivores, but the protein utilisation efficiencies were similar to that seen in most other fish species (0.520 
•  [Protein intake] − 0.284). Using this modelling approach it was possible to iteratively derive optimal dietary protein and energy specifications for this species.