The ‘available lysine’ content of fish meals

The ‘available lysine’ content of a number of different fish meals has been determined and results are given for the effects of preservation, putrefaction and of azeotropic and steam drying of the fish. Fish flours have been examined and also meals prepared from commercially unwanted species and fish guts. Results have been compared with the ‘available lysine’ and pepsin digestibility of Peruvian fish meal. Digestibility values >89% were associated with ‘available lysine’ contents of 5–7.5 g./100 g. of protein. Neither azeotropic drying nor solvent washing in the preparation of fish meal reduces the ‘available lysine’ content.