Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Advanced Embryology - University of Illinois Extension
Document related concepts
no text concepts found
Transcript
Advanced Incubation and Embryology Ken Koelkebeck U of I Extension Poultry Specialist [email protected] The Life of a Chick • Life begins with single cell formed by joining of two parent cells: ovum (yolk) and sperm = fertilization • Fertilization occurs about 24 hours before egg is laid • After fertilization, single cell beings to divide to 2, 4, 8, 16 cells and so on. This occurs on germinal disc/blastoderm Chick Development • Cells begin to divide into segments during incubation • 3 segments - ectoderm - mesoderm - endoderm • Ectoderm – skin, feathers, beak, claws, nervous system, eye, mouth Chick Development • Mesoderm – bone, muscle, blood, reproductive and excretory tracts • Endoderm – lining of digestive tract, secretory, respiration organs Chick Formation • Extra-embryonic membranes of importance 1) 2) 3) 4) Yolk sac Amnion Chorion Allantois • Yolk sac – tissue layer growing over the yolk – digests and absorb yolk material Chick Formation Amnion • Fluid filled sac that surrounds embryo and serves as protection • Fluid allows embryo to move, change position, and shape • Fluid keeps embryo parts from sticking together Chick Formation Chorion • Serves to contain both amnion and yolk sac • No function at first, but then joins with allantois to form chorio-allantoic membrane • Allows calcium reabsorption through capillaries of allantois from the shell Chick Formation Allantois • Serves as respiratory organ for embryo • Holds excretions from embryo • Absorbs albumen (nutrient protein) for embryo • Absorbs calcium from shell for embryo • Allantois origin within body of embryo Embryonic Blood Vessels • One – vitelline vessels carry yolk material to embryo • Two – allantoic vessels – respiration and waste material Hatching Days 19 & 20 - Abdominal wall surrounds yolk sac - Chick withdraws rest of yolk into body - Fluid decreases in amnion Day 21 - Chick forces egg tooth through air cell- head under right wing takes first breath – internal pipping – chick peeping inside Hatching Day 21 - Egg tooth breaks through shell – external pipping • Process last from 4 to 12 hr • Chick emerges very wet, tired and rests for several hr • After exiting shell, egg tooth (beak) dries and falls off Thank You
