4H Embryology

Mrs. Hayes

PledgeMy head to clearer thinking

My heart to greater loyaltyMy hands to larger ServiceMy health to better livingMy club, my community and my world

Chicken TriviaChicken Trivia

Chickens are birdsChickens are birds– Chickens have two waddlesChickens have two waddles– Chickens have a combChickens have a comb

Hens are female chickensHens are female chickens Roosters are male chickensRoosters are male chickens Chickens have navelsChickens have navels Chickens need to eat gravelChickens need to eat gravel Chickens have earlobesChickens have earlobes

– Indicate an eggIndicate an egg’’s colors color

Picture from Moyer’s Chicks, Inc. – Moyer’s Broiler/Roaster Chicks

Free Range Chicken Farms

Industrial Chicken Farms

A chicken embryo growth spanA chicken embryo growth spanis . . .is . . .

Twenty-one daysTwenty-one days

Embryo Growth – Day 1Embryo Growth – Day 1

Germinal spot grows and cells begin to split into Germinal spot grows and cells begin to split into specific types of cellsspecific types of cells

Picture courtesy of Phillip J. Clauer, Penn State 4-H Embryology in the Classroom Web Resource, Fertilized

verse Non Fertile

Embryo Growth – Day 3Embryo Growth – Day 3

Question mark-shaped embryo visibleQuestion mark-shaped embryo visible Blood vessels on yolk sac definedBlood vessels on yolk sac defined Brain, head, and beating heart visibleBrain, head, and beating heart visible Amnion completeAmnion complete

Picture from The Sacramento Zoo — E Feature: Egg Development; Artwork from North Carolina Extension Service

Embryo Growth – Day 5Embryo Growth – Day 5

Eye and organs formedEye and organs formed Sex of the embryo is knownSex of the embryo is known Day 6 – 7: Embryo will begin to move and resemble a chickDay 6 – 7: Embryo will begin to move and resemble a chick

Picture from The Sacramento Zoo — E Feature: Egg Development

Embryo Growth – Day 10Embryo Growth – Day 10

Bones and beak hardenBones and beak harden Skin pores and down feathers visibleSkin pores and down feathers visible

Picture from The Sacramento Zoo — E Feature: Egg Development

Embryo Growth – Day 15Embryo Growth – Day 15

Scales, claws, and feathers completeScales, claws, and feathers complete Small intestines taken into bodySmall intestines taken into body Albumen nearly goneAlbumen nearly gone Turns head toward large end of eggTurns head toward large end of egg

Picture from The Sacramento Zoo — E Feature: Egg Development

Embryo Growth – Day 19Embryo Growth – Day 19

Growth completeGrowth complete Shell is full – except the air cellShell is full – except the air cell Day 20Day 20

– Embryo breaks into air cell and takes first breathEmbryo breaks into air cell and takes first breath– Yolk sac is completely drawn into abdomenYolk sac is completely drawn into abdomen

Picture from The Sacramento Zoo — E Feature: Egg Development

Egg ToothEgg Tooth

The egg tooth is only present to help the chick hatch. The egg tooth is only present to help the chick hatch. Within 12 to 24 hours after the chick hatches the egg tooth Within 12 to 24 hours after the chick hatches the egg tooth will dry and fall off.will dry and fall off.

Picture courtesy of Phillip J. Clauer, Penn State 4-H Embryology in the Classroom Web Resource, Hatching

Embryo Growth – Day 21Embryo Growth – Day 21

Chick will pip at the shell until it hatchesChick will pip at the shell until it hatches Not an immediate process -- 8 to 12 hoursNot an immediate process -- 8 to 12 hours Should not assist chicks with their hatchingShould not assist chicks with their hatching Egg tooth visible for a day or two after hatchingEgg tooth visible for a day or two after hatching

Picture from The Sacramento Zoo — E Feature: Egg Development

Male or female?Male or female?

For only the first day or twoFor only the first day or two– Males: short, fluffy wing feathersMales: short, fluffy wing feathers– Females: longer, more distinct wing feathersFemales: longer, more distinct wing feathers

Picture courtesy of Phillip J. Clauer, Penn State 4-H Embryology in the Classroom Web Resource, Hatching

Farm HatchingFarm Hatching

Hen lays an egg, one per day, until she has a group of 8 Hen lays an egg, one per day, until she has a group of 8 to 13 eggs, called a clutchto 13 eggs, called a clutch

She will sit on her clutch all the time, except for leaving She will sit on her clutch all the time, except for leaving for food and waterfor food and water

Her body heat warms the eggs to 100Her body heat warms the eggs to 100°F - 1°F - 10101°F°F She provides humidity by bringing back moisture from She provides humidity by bringing back moisture from

the environment on her legs and feathersthe environment on her legs and feathers She turns the eggs on a regular basis by scooping and She turns the eggs on a regular basis by scooping and

rolling them with her beakrolling them with her beak

Classroom HatchingClassroom Hatching

Incubator replaces henIncubator replaces hen– Eggs need to be kept between 99Eggs need to be kept between 99°F°F and 101 and 101°F°F

Control temperature with a thermostat and thermometerControl temperature with a thermostat and thermometer Control humidity by adding room temperature water once Control humidity by adding room temperature water once

a daya day– Balances the moisture that escapes through the shellBalances the moisture that escapes through the shell’’s poress pores– Humidity fluctuations can cause the chicks to stick to their shellsHumidity fluctuations can cause the chicks to stick to their shells

Control rotation by gently rolling the eggs onto their Control rotation by gently rolling the eggs onto their opposite side three times a day until the end of Day 17opposite side three times a day until the end of Day 17– Turning the eggs allows the embryos to not rest on one side for Turning the eggs allows the embryos to not rest on one side for

too long and stick to the shell or cause developmental defectstoo long and stick to the shell or cause developmental defects

Brooding boxBrooding box

A box, tank, or cage that will keep the newly A box, tank, or cage that will keep the newly hatched chicks safe and warm and allow hatched chicks safe and warm and allow access to food and wateraccess to food and water

Prepare the brooder before the chicks hatchPrepare the brooder before the chicks hatch

HandlingHandling

Always remember to wash your hands before Always remember to wash your hands before and after handling the chicksand after handling the chicks

Always remember that the chicks are babiesAlways remember that the chicks are babies Always hold them gently by cupping them in Always hold them gently by cupping them in

your handsyour hands Always hold them over a table or at floor Always hold them over a table or at floor

levellevel