Abstract THE nutritive value of fish meal may decline following storage because of oxidative changes affecting the lipid fraction and changes which are little understood affecting the availability of some of the amino acids in the protein fraction. The literature in this connection has been reviewed elsewhere (March, 1962). It has been found that treatment of fish meal with antioxidant retards oxidative changes (Meade, 1956; Aure, 1957; Lea et al., 1958; Flanzy et al., 1962) and protects against loss of nutritive value of the lipids during storage (Potter et al., 1961; March et al., 1962). March et al. (1961) found that whereas butylated hydroxytoluene (BELT) stabilized the lipids in herring meal against oxidation, the protein nutritive value of the treated and untreated meals after storage was similar. Further investigation of the problem seemed warranted and in the following experiments the effects of treating herring meals with BHT or with 1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline (EQ * )…