A lack of fluctuation in xanthophyll concentrations in blood in laying hens at night and absence of pigmentation rings in the yolk.
Alternate white and yellow layers in the yolk are described in most textbooks. However, it was impossible to distinguish the presence of these layers when hard-cooked yolks from hens fed commercial type diets were examined. Serum xanthophyll concentrations were measured at different times during a 24-h period. Concentrations did not vary significantly due to time of day.
Nelson
D S
DS
Department of Poultry Science, University of Florida, Gainesville 32611.
Janky
D M
DM
Harms
R H
RH
D000818:Animals; D002645:Chickens / Q000097:blood / Q000502:physiology*; D002940:Circadian Rhythm; D004530:Egg Yolk; D005260:Female; D014975:Lutein / Q000097:blood*; D010858:Pigmentation
D014975:Lutein