Influence of Preen Gland Removal on the Lipid over the Plumage of Roosters

Abstract

The lipids distributed on the plumage of roosters were divided into two types; lipids in granules probably originated from the skin and lipids in masses from the preen gland. The former spread all along the barbs and barbules, while the latter irregularly adhered to the ends of feathers and to barbs and barbules. The amount of mass typed lipids did not change up to 43 days after the preen gland removal, but decreasing gradually, the masses completely disappeared 95 days after the operation. This fact seems to have an intimate relationship with moulting. The amount of lipids from the skin also tended to decrease 53 days after the removal, though some tail feathers long kept such lipids on, the amount of which getting less than that of untreated roosters. The reason and mechanism of the decrease in lipids from the skin are yet unknown.