Biomaterial Database

Effect of photoperiod on the mean oviposition time of two breeds of laying hen. 1995

P D Lewis, and G C Perry, and T R Morris

Department of Clinical Veterinary Science, University of Bristol, Langford, England.

1. Oviposition times were recorded for brown and white egg-laying hybrids under 8, 10, 13 and 18 h photoperiods. 2. Mean oviposition time for both breeds was advanced relative to dusk by approximately 0.5 h for each 1 h extension of photoperiod. 3. Mean oviposition time for the brown egg hybrid was 1.2 to 1.4 h earlier than that of the white egg hybrid under each lighting regimen. 4. A genetic difference in phase setting of the Open Period for Luteinising Hormone (LH) release is the likely reason for the difference in mean time of lay of the two breeds. The difference is possibly one between brown and white hybrids generally, rather than between the particular varieties of hen used in this trial. 5. The proportion of the day in which eggs are laid is shorter under long photoperiods presumably because light at the end of the photoperiod inhibits the pre-ovulatory surge of LH.

UI	MeSH Term	Description	Entries
D010058	Oviposition	The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.	Larviposition,Larvipositions,Ovipositions
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D017440	Photoperiod	The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.	Dark-Light Cycle,Daylight Cycle,Light Cycle,Light-Dark Cycle,Cycle, Dark-Light,Cycle, Daylight,Cycle, Light,Cycle, Light-Dark,Cycles, Dark-Light,Cycles, Daylight,Cycles, Light,Cycles, Light-Dark,Dark Light Cycle,Dark-Light Cycles,Daylight Cycles,Light Cycles,Light Dark Cycle,Light-Dark Cycles,Photoperiods