Protein digestion, growth and food conversion in Atlantic salmon and Arctic charr with different trypsin‐like isozyme patterns

Protein digestibility and food conversion were determined in groups of Atlantic salmon (Salmo salar L.) and Arctic charr (Salvelinus alpinus L.) with or without the trypsin‐like isozyme TRP‐2*92. Determinations were made at two salinities, 0 and 27 ppt; at two temperatures, 6 and 10° C and on large (200 g) and small (30–90 g) fish. The overall digestibility of protein was found to be 81.4±0.2% and was unaffected by the presence of the isozyme or the other variables. The feed conversion ratio of Atlantic salmon possessing TRP‐2*92 was observed to be significantly lower with significantly higher specific growth rate than in fish without this isozyme.