Nutritional Myopathy of the Gizzard in Turkeys

Abstract

This communication illustrates the fact that different species of animals may react in quite diverse fashion to the same abnormal diet. When growing chicks are given a simplified diet, lacking a still unidentified factor present in certain vegetable oils (Diet 108) extensive malacic lesions of the brain are produced.^1-4 The same diet fed to ducklings does not affect the brain, but leads to widespread degeneration of the skeletal muscles. 5 Pigeons appear to be refractory. We have recently found that the same diet given to turkey poults produces selective necrosis of the smooth muscle of the gizzard wall, unaccompanied by significant lesions in other organs or tissues. In this preliminary report, these alterations are described in detail. Further experiments are planned in the hope of obtaining more definite information as to the nutritional factors concerned.

Thirty-one day-old Bronze and White Holland turkeys were kept in batteries for 6 days on a commercial turkey starter. They were then divided into two lots. Lot 1, (20 poults) was given Diet 108.∗ Lot 2 (10 poults) was maintained throughout the experiment on the original starting mash, and served as controls. On the experimental diet, the majority of the poults developed severe perosis within 18 daysf whereas the controls remained free from this deformity. The growth rate of the experimental birds was inferior to that of the controls, but for the most part the turkeys were in good flesh, though of somewhat smaller size (Chart 1).

Most of the birds showed no definite signs of disease apart from the leg deformity and retardation of growth. Three, however, became weak and prostrated and acquired coarse tremors of the head— symptoms which could not be attributed to the perosis. At autopsy, the only significant lesion was found in the gizzard wall. The corneous lining was intact on gross and microscopic examination. There was nothing abnormal in the external conformation or tonus of the organ, but one could observe irregular greyish patches through the transparent serous covering. These were very conspicuous on section of the gizzard, appearing as rather circumscribed grey areas of firmer texture than the normal muscle (Fig. 1). Some of the patches had a pearly greyish luster, suggesting scar tissue. Others were more opaque. The lesions were not always sharply demarcated and conspicuous, but sometimes merged gradually into the healthy muscle, and were detectable only on close examination. The histological changes were in essence, hyaline necrosis of the smooth muscle fibers, with secondary inflammatory reaction, and later disappearance of fibers and replacement fibrosis. Individual fibers were swollen, lumpy and fragmented, staining more deeply with eosin than the normal elements (Fig. 2). The nuclei, instead of