Protein and energy utilisatoin in two Mekong catfishes, Pangasius bocourti and Pangasius hypophthalmus

1998

Colloque

Le Thanh Hung, Lazard J., Tu H.T., Moreau Yann

Legendre Marc (ed.), Pariselle Antoine (ed.), The biological diversity and aquaculture of clariid and pangasiid catfishes in South-East Asia : proceedings of the mid-term workshop of the "Catfish Asia project"

Jakarta (IDN) ; Can Tho : IRD ; Can Tho University, 1998, p. 167-174

Characterisation, Utilisation and Maintenance of Biological Diversity for the Diversification and Sustainability of Catfish Culture in South East Asia, Can Tho (VNM), 1998/05/11-15

Fish unlike terrestrial animals, use a large amount of protein as an energy source for their energy metabolism. When fed on a high protein raiton, the fish itself may choose which amount of protein in food will be converted into body growth and which will be burned through the catabolism. Therefore, in the study one diet was designed with a high protein content and fed to fish with different levels : 0, 5, 15, 25, 35 and 45 g crude protein kg/d. P. bocourti has a higher growth rate than P. hypophthalmus at the same food intake. However, the higher growth observed in P. bocourti is obviously associated to higher fat accumulation in the body. The protein efficiency, NPU and PER, tends to be reduced at higher protein intake in both species. Energy and protein requirements for maintenance were calculated to be 128 and 92 kJ/kg/day, and 5.16 and 3.24 g/kg/day, and P. bocourti and P. hypophthalmus, respectively. P. bocourti has nearly a double protein and energy requirement for maintenance. The event may be linked to the fact that P. bocourti has a higher growth rate and higher ability to synthesise a large amount of body lipid than P. hypophthalmus. An estimate of protein requirement was in the range of 12-13 and 11-12 g/kg/day in P. bocourti and P. hypophthalmus, respectively. The DP/DE ratio was estimated to be 18 and 17 mg/kJ in P. bocourti and P. hypophthalmus, respectively. These low DP/DE ratios may be related to the fact that the protein requirement was relatively low in the two species. (Résumé d'auteur)