Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Light intensity and age at first egg in pullets.

P D Lewis1, T R Morris, G C Perry

  • 1Department of Clinical Veterinary Science, University of Bristol, Langford, United Kingdom. peter@clatford.demon.co.uk

Poultry Science
|September 3, 1999
PubMed
Summary

Investigating light intensity effects on pullet development, this study found that very dim light can alter biological clocks, impacting age at first egg. Threshold light intensity for photoperiodic response in caged pullets is between 0.9 and 1.7 lx.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Functional and Behavioral Trade-Offs between Terrestrial and Aquatic Locomotion in the Amphibious Fish Kryptolebias marmoratus.

Integrative and comparative biology·2023
Same author

Histological Features and Tissue Microarray Taxonomy of Nigerian Breast Cancer Reveal Predominance of the High-Grade Triple-Negative Phenotype.

Pathobiology : journal of immunopathology, molecular and cellular biology·2016
Same author

Reply to the letter to the editor 'Measured and estimated glomerular filtration rate for carboplatin dose calculation' by Cathomas et al.

Annals of oncology : official journal of the European Society for Medical Oncology·2014
Same author

Effect of ewe urine and vaginal secretions on ram investigative behavior.

Journal of chemical ecology·2014
Same author

Detection of Lewis antigen structural change by FTIR spectroscopy.

Carbohydrate polymers·2013
Same author

Modeling freezing of gait in Parkinson's disease with a virtual reality paradigm.

Gait & posture·2012

Area of Science:

  • Animal Science
  • Avian Physiology
  • Photobiology

Background:

  • Photoperiod is a critical environmental cue regulating reproductive development in poultry.
  • Understanding light intensity thresholds is essential for optimizing lighting programs in commercial layer strains.

Purpose of the Study:

  • To determine the effect of varying light intensities, including very dim and marginal levels, on the age at first egg (AFE) in layer strain pullets.
  • To investigate the threshold light intensity required for photoperiodic stimulation in caged pullets.
  • To explore potential phase-shifting effects of sub-threshold light intensities on the avian biological clock.

Main Methods:

  • Pullets were reared under an 8-hour photoperiod and then transferred to cages with controlled light intensities.

Related Experiment Videos

  • Experimental groups received different photoperiod regimens: 8h L:16h D (negative control), 14h L:10h D (positive control), and regimens with 3 hours of dim light (0.03-0.42 lx or 0.6-3.0 lx) preceding or supplementing the main light phase.
  • Age at first egg was recorded for all groups, with light intensity measured at the feed trough.

    • Main Results:

    • A significant difference of 30 days in AFE was observed between positive and negative controls.
    • Pullets exposed to very dim light (0.03-0.42 lx) matured 10 days earlier than negative controls but 20 days later than positive controls.
    • Marginal light intensity (0.6-3.0 lx) showed varied results based on tier position, with top tiers (1.7-3.0 lx) maturing similarly to positive controls and bottom tiers (0.6-0.9 lx) to negative controls.

    Conclusions:

    • The threshold light intensity for photoperiodic response in caged pullets is between 0.9 and 1.7 lx.
    • Very dim light, even below the stimulation threshold, can influence the biological clock, potentially causing phase shifts and affecting reproductive timing.
    • No intensity of dim light can be universally equated with darkness due to potential phase-shifting effects.