Chicken Egg Shape
Can a chicken egg come out round with no point?
The shape of a chicken's egg can vary a lot, depending on the size, age and health
of the chicken,
My very small and VERY old (nearly 12 years) silky bantam lays eggs very
occasionally - only about one a month. Her eggs are very small, about the size of
a walnut, and they are almost round. They are slightly oval shaped, but the two
ends are so close to the same shape it is very difficult, or even sometimes
impossible to decide which is the 'pointy' end.
Generally the shape of the egg is determined by the pressures exerted by the walls
of the oviduct ( egg passage ) within the hen. A good healthy hen has strong
muscles, which push the egg through fairly quickly, and mold the egg's shape as
the shell is being formed. The 'point' is produced by the muscles pushing on the
back half of the egg to move it through the passage. My old chicken has very weak
muscles and her eggs move very slowly. This allows time for the egg to take the
shape which is easiest for the egg - the same shape as a bubble - round.
The shape of the egg has an added advantage for the hen. It stops the egg from
rolling away from the nest. In the case of some seabirds who nest on cliff ledges,
the shape is so stretched that the eggs are actually tapered like a cone.
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Update: June 2012