Development of a nutritional model to define the energy and protein requirements of cobia, Rachycentron canadum

Abstract

This study assessed the protein and energy requirements of Cobia (Rachycentron canadum) using a bio-energetic factorial approach. Using a series of interrelated studies, several parameters were defined to enable the construction of a bio-energetic factorial model for this species. The studies included two controlled laboratory experiments and also extensive field-data collection from commercial and research farms in Vietnam. The devised model includes parameters for both maintenance and protein demands; the effect of fish live-weight on maintenance protein (LW 0.697), lipid (LW 0.972), and energy demands (LW 0.815); the efficiencies of protein, lipid and energy utilisation at various protein, lipid and energy intake levels; and the variability in whole body composition with varying live-weight. The protein utilisation efficiencies (0.456 • [protein intake]-0.445), lipid utilisation efficiencies (1.292 • [lipid intake]-1.120) and energy utilisation efficiencies (0.651 • [energy intake]-48.41) were similar to other carnivorous fish species. However, the maintenance requirements for both energy (74.3 kJ/ kgBW 0.8 / dat 28ºC) and protein (0.99 g/ kgBW 0.7 /d at 27.9ºC) were about double to other species. Using this modelling approach it was possible to iteratively derive optimal dietary protein and energy specifications for this species.

Elucidation of the roles and requirements of sulphur amino acids in the diet of barramundi (Lates calcarifer)

“…This phenomenon has been accounted for in several fish feed utilisation models (Lupatsch et al, 2003;Booth et al, 2010;Van Tien et al, 2016) through the use of a body weight exponent for protein. While experimentally-derived values for this exponent can vary marginally (Beck and Gropp, 1995;Van Tien et al, 2016), the generally accepted value of 0.70 is widely used Helland et al, 2010;Glencross and Bermudes, 2012).…”