Trigger ability on gizzard erosion by fish meal concerning with a kind of and freshness of raw fish, and manufacturing conditions.

Gizzard erosion of chicks observed in fish meal feeding is becoming a serious problem ano the causative substance was cleared by OKAZAKI et al.To obtain an useful knowledge for manufacturing safe fish meal, a degree of trigger ability of gizzard erosion was ascertained with various Japanese domestic fish mean (13 kinds) by feeding test on chicks. The same ability was tested with the sample meal prepared by pilot plant equipped with indirect dryer, differing in the kind and freshness of raw fish, and with or without antioxidant (EMQ) treatment. Further, apart of these meals was subjected to EMQ addition and to additional heat treatment were also tested.As a result, it was found that the meal prepared from round fish with fish solubles addition and dried by direct dryer was apt to show a higher trigger ability; while those from puterfied raw fish exhibited clear trigger ability when dried by hard heating, or even stored in slightly higher temperature, such as 80°C. Although oil oxidation in the meal may somewhat promote the formation of this inferior activity, addition of antioxidant, EMQ, should be expected to retard the increase of trigger ability by preventing the temperature increase caused by self heating of the meal.