The Influence of Body Weight on the Experimental Production of Perosis by Manganese Deficiency ,

NUMEROUS investigators have noted differences in the manganese requirements of various breeds of chickens for perosis prevention. Chickens of the heavy breeds generally require more manganese than those from light ones. (Gallup and Norris, 1939; and Golding et al., 1940.) The gross appearance of the perotic tibia has been described by several workers (Serfontein and Payne, 1934; Gallup and Norris, 1938; and Caskey et al., 1939). In most cases the tibia is shorter and increased in diameter, and the hock joint enlarged. Since no previous attempts to assess the role of body weight in the development of perotic lesions in the limbs has been made, it was considered desirable to do so. EXPERIMENTAL Six-hundred Barred Plymouth Rock chicks of both sexes were distributed equally into three groups and fed diets containing 7, 20, and 100 p.p.m. of manganese. The manganese-deficient basal diet (Table 1) was analyzed for manganese using the…