4-H Embryology

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4-H Embryology

• An Overview

The Institute of Food and Agricultural Sciences
(IFAS) is an Equal Opportunity Institution
authorized to provide research, educational
information, and other services only to
individuals and institutions that function
without discrimination with respect to race,
creed, color, religion, age, disability, sex,
sexual orientation, marital status, national
origin, political opinions, or affiliations.
USDA, UF/IFAS Extension, FAMU and Boards of
County Commissioners Cooperating
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Lets begin with eggs.
EACH YEAR IN THE U.S. COMMERCIAL LAYING HENS
PRODUCE BILLIONS OF TABLE EGGS FOR US TO
EAT BECAUSE THEY ARE VERY NUTRITIOUS
HOWEVER IN NATURE THE EGG IS NOT FOR EATING IT
IS FOR REPRODUCTION AND ONLY FERTILE EGGS WILL
HATCH
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Lets begin with eggs.

• Fertile eggs come from special farms called
  breeder farms where roosters and hens live
  together and these eggs are incubated to produce
  chicks.
• The eggs you buy at the grocery store are grown
  at hen only farms and they are not fertile so
  they will not hatch when they are incubated.

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How does an egg work?
THE EGG HAS MANY PARTS AND EACH PART HAS AN
IMPORTANT FUNCTION DURING CHICK DEVELOPMENT
FOR INSTANCE
THE SHELL PROVIDES PROTECTION GASEOUS
EXCHANGE (O2 ENTERS AND CO2 LEAVES) CALCIUM FOR
BONES
YOLK
THE YOLK PROVIDES PROTEIN FAT (FOR
ENERGY) VITAMINS AND MINERALS
THE GERMINAL DISC IS WHERE FERTILIZATION OCCURS
AND THE CHICK BEGINS DEVELOPING
THE CHALAZA KEEPS THE YOLK IN THE CENTER OF THE
EGG
THE ALBUMEN PROVIDES PROTEIN VITAMINS AND
MINERALS
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Startup day!

• MAKE SURE THE INCUBATOR IS FUNCTIONING PROPERLY
  AND READY FOR THE EGGS

• CLEAN FERTILE EGGS WILL BE PLACED IN THE
  INCUBATOR

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An incubator..

• provides and maintains a favorable environment
  for hatching fertile eggs.
• replaces the hen.
• must function properly and should be checked
  daily.

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Important factors to successful incubation are

• Temperature
• Between 98-103º F
• Ventilation
• Clean fresh air must flow through the incubator
• Turning the eggs
• Eggs must be turned carefully 3 times each day.
  Some incubators have an automatic egg turner.
• Humidity (water)
• There must be moisture to keep the chick
  developing normally and prevent dehydration.

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Candling eggs

• Candling is the process of looking inside of an
  egg without cracking it to see if the chick is
  developing. A bright light is used to candle
  the egg.

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Candling Day 3

• Notice the blood vessels. This is the embryo
  growing and eventually it will be developing very
  quickly and fill up the entire inside of the egg.

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Candling Day 7
Notice that the entire embryo is growing bigger
and is developing all of its body systems.
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Hatching time!

• Most chicks hatch on day 21, but sometimes
  hatching begins a day or two earlier or later
  depending on the conditions during incubation
  such as temperature, humidity, etc.
• Be patient when hatching begins because it may
  take several hours for a chick to exit the
  shell.
• It is best not to help the chicks hatch
• The struggle to hatch is necessary
• for survival.

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Hatching start to finish.
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Hatching
Chicks hatching and drying in the incubator.
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The chicks have hatched, now what ???

• Chicks stay in the incubator until they are
  dry and fluffy.
• It may take several hours for the chicks to
  dry.
• Once they are dry, place them in the brooder.
• Teach them to drink water by placing each
  chicks beak in the water source and then place
  them next to the feed source so they will find it
  quickly.

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What is a brooder?

• A pen for chicks that provides protection,
  heat, feed and water and space to move around.
• Absorbent bedding material is required so the
  chicks can walk on it and scratch in it. Wood
  shavings, paper towels, shredded newspaper work
  great!
• A heat lamp provides the chicks light and
  warmth.

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What should the chicks be fed ?

• A pre-mixed commercial chick starter. This may
  be purchased at a local feed store. Pet stores
  usually do not sell this type of feed. Grit is
  not necessary at this age.
• DO NOT feed scratch feed or ground corn
  because the chicks require more protein, vitamins
  and minerals than are in these feeds.

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Keep your brooder CLEAN!!

• Change out daily
• Bedding
• Water
• Food

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Happy Hatching!
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References
Connelly, R., Mores, C. Simonne, A. (2009).
What are the risks of contracting diseases
associated with chickens? (EDIS ENY-724).
Gainesville. University of Florida Entomology
and Nematology Dept. DeCubellis, C. (2007).
Care of baby chicks (EDIS AN-170). Gainesville.
University of Florida Animal Science
Dept. National 4-H Curriculum (2008). Hatching
Classroom Projects Helpers guide beginner
grades 2-5 (BU-07595). Washington, DC National
4-H Council. National 4-H Curriculum (2001).
Experiments in poultry science Helpers guide
advanced grades 6-8 (BU-07596). Washington, DC
National 4-H Council.
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This program was made possible by a University of
Florida Enhancement Grant
4-H Embryology Working Group Team Members Andy
Toelle, Extension Agent Duval County Lori
Wiggins, 4-H Agent Taylor County Chris
DeCubellis, 4-H Agent Gilchrest County Dr Sandra
Tenbroeck, Associate Professor, Animal Science Dr
Richard Miles, Professor, Animal Science