title: Light intensity can influence plasma FSH and age at sexual maturity in domestic pullets.
abstract: 1. Shaver White and ISA Brown pullets were reared to 140 d in cage groups of 8 on a 10-h photoperiod of incandescent light and maintained at an illuminance of 3 or 25 lux, or transferred from 3 to 25 lux or from 25 to 3 lux at 63 or 112 d of age. 2. Plasma follicle stimulating hormone (FSH) concentration at 63 and 112 d was higher in both breeds for pullets maintained at an illuminance of 25 lux compared with 3 lux. After 2-4 d, and relative to constant-illuminance controls, plasma FSH increased significantly for ISA Brown transferred from 3 to 25 lux at 63 d and for Shaver White transferred at 112 d. Irrespective of genotype, plasma FSH for pullets given a decrease in illuminance at 63 or 112 d showed a tendency for less change than did constant-illuminance controls. 3. There was no significant difference in sexual maturity for ISA Brown maintained on 3 or 25 lux, but Shaver White pullets exposed to constant 3 lux matured later than those maintained on 25 lux. Shaver White matured later following an increase from 3 to 25 lux at 63 and 112 d, and earlier subsequent to a decrease from 25 to 3 lux at 112 d. ISA Brown pullets were not significantly affected by a change in illuminance at 63 or 112 d, though their responses were in the same direction as Shaver White. 4. Changes in plasma FSH in the 2- to 4-d period following a change in illuminance at 63 or 112 d were not significantly correlated with sexual maturity.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Canada. peter.lewis@ds1.pipex.com
authors.forename: P D
authors.initials: PD
authors.lastname: Lewis
authors.forename: N
authors.initials: N
authors.lastname: Ciccone
authors.forename: P J
authors.initials: PJ
authors.lastname: Sharp
authors.forename: S
authors.initials: S
authors.lastname: Leeson
mesh_terms: D000375:Aging / Q000502:physiology / Q000528:radiation effects*; D000818:Animals; D002645:Chickens / Q000097:blood* / Q000235:genetics / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D005838:Genotype; D008027:Light; D012741:Sexual Maturation / Q000528:radiation effects*
chemical_list: D005640:Follicle Stimulating Hormone