Relation of Castration to Fat Stores in Male Pheasants

During 1958 and 1959 we studied the effect of castration on lipids in male gamefarm pheasants confined to outdoor pens. In both years the visceral fat stores of control birds decreased from January to June and then increased. Among the orchidectomized pheasants, visceral fat was minimum from February to April 1958 and maximum thereafter, but did not change seasonally in 1959. Liver and plasma lipid showed no regular periodicity and were not associated with levels of visceral fat nor influenced by castration. The weight of the adrenals in intact pheasants increased 20% from February to June 1958 and then decreased. During 1959 the adrenals of these birds weighed most in April, when they were 30% heavier than in January; subsequently they involuted. In 1958 the seasonal pattern of adrenal weight in gonadectomized pheasants was opposite to that of controls, whereas in 1959 the pattern was like that of intact birds. Thyroid weight was stable seasonally.