Comparative pathology of gizzard lesions in broiler chicks fed fish meal, histamine and copper

In order to elucidate the histopathogenesis of gizzard lesions occurring with various diets and in particular with fish meals, comparative studies were made on the gizzard and proventriculus of broiler chicks fed a diet containing 15% of a suspect batch of fish meal (group A), and normal fish meal containing diets to which were added 0.4% of histamine (group B) or 1,000 parts/10(6) of copper (group C). The gizzard lesions in group A were widespread and consisted of thickening and loosening of the lining, frequently with erosions and ulcerations. The lesions in group B were almost identical to those in group A, but were less severe and less associated with erosions and ulceration. The lesions in group C were widespread and consisted of a markedly thickened lining with numerous desquamated surface cells, sometimes with erosions. The surface and chief cells were swollen in most glands of groups A and C and in the cells of those glands under the altered lining in group B. A poorly-staining secretion was shown to be excreted into the lining. The proventriculus in the three experimental groups showed increased secretion in direct proportion to the severity of the gizzard lesions. It was suggested that the gizzard lesions caused by dietary fish meal might have originated from hyperactivity of the gizzard glands, followed by erosion and ulceration.