Affiliation: | 1. CSIRO, Division of Animal Production , PO Box 239, Blacktown , New South Wales , 2148 , Australia;2. Agricultural and Food Research Council's , Poultry Research Centre , Roslin, Midlothian , EH25 9PS , Scotland;3. CSIRO, Division of Mathematics and Statistics , P.O. Box 218, Lindfield , New South Wales , 2070 , Australia |
Abstract: | Plasma luteinising hormone (LH) concentrations were measured during the ovulatory cycle in lines of Australorps and White Leghorns selected for reduced oviposition interval and maintained under continuous light and noise. 2. Selection significantly increased plasma LH concentrations in mid‐sequence ovulatory cycles of Australorps but not in the White Leg‐horns. 3. Selection in the Australorps apparently increased the rate of ovarian follicular maturation, resulting in more frequent LH peaks. 4. The effect of selection on plasma LH concentrations is a function of the lighting condition to which the hens are exposed. |