lecture 6 2011 - Lecture 6 Light Light detection in birds...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 6 Light
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Light detection in birds
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Bottom line birds are being photo stimulated less than 12 hours Looks at birds/hen in lay. Genetics, age, food availability can override light.
Background image of page 6
Photoschedule Scotoperiod- dark Photoperiod: increasing daylight triggers cascade of neuroendocrine and endocrine events that lead to gonad development and an increase in sex hormones Termination of this process by the development of photorefractoriness.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Photorefractoriness: insensitivity to the same environmental cues that initiated gonadal development Adaptive measure/mechanism.
Background image of page 8
Photorefractoriness Absolute: Completely unresponsive to long days and any other cues Complete repression of reproductive organs GnRH synthesis inhibited Relative: Not completely unresponsive to long days or may be stimulated with artificial light or other cues Only release of GnRH is inhibited Flexible reproduction
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Both absolute and relative photorefractoriness begin to dissipate
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/28/2011 for the course POUL 4060 taught by Professor Davis during the Spring '11 term at University of Georgia Athens.

Page1 / 17

lecture 6 2011 - Lecture 6 Light Light detection in birds...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online