Development inside the egg

Fertile/infertile

For a chick to come from the hen’s egg it needs to be fertilised by a cockerel otherwise it would just be a normal infertile egg without any chick in it that we can eat.

Day 1

By the end of the first day during incubation

· the head

· eyes

· nervous system

· Blood

have started to form.

Day 4

• The heart starts to beat
• The fluid that the embryo (developing chick) floats around in and feeds from is formed, this is called the ‘amniotic fluid’.

    Things that start to develop are,

• Legs
• Wing buds

Day 8

Things that are nearly formed are,

· the wings

· feathers

· legs.

Day 10

Bones also start to form about this point so the embryo starts to look like a chick.

  Day 13

• The feathers gain their colour.
• The beak and egg tooth (special tooth on the end of the beak that helps it break the shell) are formed
• Scales are formed
• Claws are formed
• The fluid is all used up leaving only the yolk as the food source.

Day 15

• The chick has eaten all the yolk
•  The muscles in the chick to twitch so its beak breaks through the air cell where it breathes in its oxygen and uses its lungs for the first time.

Day 16

• Chick starts to twitch again but this time its beak hits against the sides of the egg.
• The beak will break through and you will be able to see the its beak popping out if the shell, this is called ‘piping’.
• You will be able to hear the chick cheeping.