Day to Day Chicken Egg Development

DAY TO DAY CHICKEN EGG

DEVELOPMENT

A guide to what is happening each of the 21 days inside the egg. A

great resource for students!

DAY ONE The appearance of

the vertebral column occurs.

The nervous system begins to develop.

The head starts to form.

The eyes are beginning to develop.

DAY TWO The heart forms on

day two. The ears form on

this day. The heart begins

beating after the first forty two hours of development.

DAY THREE The nose begins

to form. The wings begin

to develop on this day.

The legs have started to form.

DAY FOUR The tongue

begins to form on this day.

DAY FIVE The reproductive

system begins to form.

It is now possible to determine the gender (male or female) of the baby chick.

DAY SIX The beak of the

baby chick begins to form on this day.

The egg tooth begins to form as well.

DAY SEVEN The beak

continues to form.

The baby chick now weighs more than half a gram.

DAY EIGHT The feathers of

the baby chick begin to form.

The baby weighs over a gram now.

DAY NINE The feathers

continue to form. When candled,

some parts of the chick can be identified.

DAY TEN The beak begins

the hardening process.

DAY ELEVEN

The legs continue to grow.

The wings also continue to extend and grow.

DAY TWELVE

The legs are fully developed at this time.

By this day the chick looks like a chick, but needs to grow in size to fill the egg.

DAY THIRTEEN

The scales and claws appear on this day.

The legs are fully formed now.

DAY FOURTEEN

The baby chick gets into a suitable position for breaking the shell and hatching.

DAY FIFTEEN The baby chick is

gaining weight and strength every day.

DAY SIXTEEN The scales, claws

and beak have become firm and horny in texture.

DAY SEVENTEEN

The beak of the baby chick now turns toward the air cell.

The beak pierces the membrane so it can breathe using the air cell.

DAY EIGHTEEN

The baby chick can be heard cheeping inside the egg now that the beak is in the air cell.

DAY NINETEEN

The yolk sac begins to be absorbed into the chick’s body cavity.

The chicks can communicate with one another and their mother now.

DAY TWENTY

The yolk sac is now completely drawn into the chick’s body cavity.

The baby chick occupies all of the space inside the egg except the air cell.

DAY TWENTY ONE

The fully formed baby chick hatches!