The effect of early and prolonged exposure of growing cockerels to selected photoperiods and wavelengths of light on pineal gland weight and lipid composition was investigated. The six treatments included 14L:10D white (control), 24L:OD white, OL:24D dark, and 14L:10D narrow-band blue, green or red light. Pineal gland fresh and dry weights were greatest under the white light treatment and least under the dark and red treatments. Examination of histological preparations and biochemical analysis both indicated that the absence of light depleted pineal lipid. When expressed as a percent of dry tissue weight, lipid from the colored light treatments was significantly greater than from the control. We conclude that both the photoperiod and the wavelength of light are capable of influencing pineal gland lipid metabolism in the cockerel.
All Science Journal Classification (ASJC) codes
- Animal Science and Zoology