Recombinant salmon (Oncorhynchus kisutch)/ trout (O.mykiss) Growth Hormone stimulates growth in salmon/trout and enhances the adaptability of salmon parr moving from fresh to sea water. GH levels increase naturally during the parr - smolt transformation in Atlantic salmon (Salmo salar). Dried under dry nitrogen at a slight vacuum (-25kPa) from a solution containing salmon/trout GH / mannitol/sodium bicarbonate (1:2:1 w/w).