Gastric abnormalities in rainbow trout (Oncorhynchus mykiss) fed amine-supplemented diets or chicken gizzard-erosion-positive fish meal

Abstract

Fish meals produced from fish containing high levels of histamine can be acutely toxic to chickens, causing gizzard erosion (GE), black vomit disease, and death after 3–5 days of feeding. Fish meals are sometimes selected for aquaculture use on the basis of chicken toxicity testing, although little scientific evidence exists to support this practice. In this study, growth, feed intake, and development of gastric abnormalities were assessed in juvenile rainbow trout fed diets containing fish meal acutely toxic to chickens, or fed casein or fish meal diets supplemented with histamine and two suspected potentiators of histamine toxicity, putrescine and cadaverine, and abusively heated. No signs of acute toxicity or mortality occurred in the groups of fish during the course of the 16-week study. Fish fed diets containing GE-positive fish meal had distended stomachs, but no gastric lesions or cellular abnormalities. Similar effects were obtained by feeding diets containing casein or GE-negative fish meal supplemented with histamine (2000 mg/kg dry diet). The addition of putrescine and cadaverine (500 mg/kg dry diet each) to the histamine-supplemented diets had no further effect. Feed consumption, feed efficiency, and growth were similar among dietary treatments, indicating that stomach distention did not reduce feed intake or impair gastric function. This study showed that rainbow trout are less sensitive than chickens to GE-positive fish meal and that there is no correlation between positive GE score and the nutritional value of the fish meal for rainbow trout. This study also showed that stomach distention resulting from feeding diets containing GE-positive fish meal could be duplicated by feeding diets supplemented with 2000 mg histamine/kg diet.