Abstract
Five experiments, four for rainbow trout and one for chicks, were conducted to examine effect of dietary histamine or its related compounds on growth and stomach of rainbow trout by feeding them diets containing different levels of histidine or histamine, or diets containing whole meal which caused gizzard erosion and ulceration (GE) in chicks after heat treatment (HT). Effect of of dietary α-tocopherol (VE) levels on appearance of GE-like abnormality in rainbow trout was also examined.
The results indicated that abnormality of stomach in both rainbow trout and chicks was induced by HT of whole meal with histidine or histamine. In rainbow trout, thickness of stomach walls tended to decrease in proportion to dietary histamine levels. In histological observation, pycanosis and necrosis of gastric gland cells were found in fish fed diets containing high levels of histamine, HT-histidine and HT-histamine. Moreover, body color of fish was darkened by addition of histamine to white fish meal. Feeding the histamine diet without supplement of VE resulted in lower growth and higher GE score than the diet with VE.
