BLACK VOMIT, GIZZARD EROSION AND GIZZEROSINE

Gizzerosine [2-amino-9-(4-imidazoyl)-7-azanonanoic acid] was isolated from a fish meal which caused black vomit in broiler chicks. Those giv en a diet containing fish meal which caused black vomit or synthetic D L-gizzerosine secreted excess gastric juice. The excess juice resulted in gizzard erosion and black vomit. In all the experiments, amongst c hicks that died, those without gizzard perforation were greater in num ber than those with such lesions. It is considered that gizzard perfor ation by excess gastric juice is not the most serious lethal effect of gizzerosine. Chicks have been found to exhibit wide variation in sens itivity to gizzerosine. In a 4-week feeding trial of a fish meal that caused black vomit, 25 out of 100 died but nine grew normally. It shou ld therefore be possible to estimate the maximum permissible concentra tion of gizzerosine in practical broiler diets. In the case of manufac turing facilities in which vapour is used to dry the fish meal indirec tly, the conditions which avoid gizzerosine formation are known. It is desirable to determine safe conditions for fish meal drying when the process uses hot air heated by a flame.