Introduction to 4-H Embryology: Understanding the Life Cycle of Chickens

1. 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

2. Let’s 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

3. Let’s 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.

4. 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

5. Startup day! • MAKE SURE THE INCUBATOR IS FUNCTIONING PROPERLY AND READY FOR THE EGGS • CLEAN FERTILE EGGS WILL BE PLACED IN THE INCUBATOR

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

7. 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.

8. 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.

9. 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.

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

11. 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.

12. Hatching start to finish.

13. Hatching Chicks hatching and drying in the incubator.

14. 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 chick’s beak in the water source and then place them next to the feed source so they will find it quickly.

15. 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.

16. 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.

17. Keep your brooder CLEAN!! • Change out daily • Bedding • Water • Food

18. Happy Hatching!

19. 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: Helper’s guide beginner grades 2-5 (BU-07595). Washington, DC: National 4-H Council. National 4-H Curriculum (2001). Experiments in poultry science: Helper’s guide advanced grades 6-8 (BU-07596). Washington, DC: National 4-H Council.

20. 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