Although a cockerel is not necessary for egg production, of course he is needed if breeding is to be successful.

It takes different times for the egg to pass through the different areas of the oviduct, the addition of the shell taking the longest time:

• 15 minutes in the infundibulum (fertilised here if cockerel available plus chalazae added)
• 3 hours in the magnum to add albumen (white of egg)
• 1.5 hours in the isthmus to add shell membrane
• 20 hours in the uterus/shell gland for shell deposition plus pigment
• 1 minute in the vagina which is extruded out past the vent to avoid the faeces.

This total of 25 hours to lay an egg explains why hens do not lay every day as the hen will ovulate 30 minutes after laying and eventually it is dark when this should happen: she then misses producing an egg the next day.

The hybrid hens have been selected for a slightly shorter time to produce an egg, hence they lay on consecutive days for longer. Brown eggs have pigment placed on the outside of the shell which can scratch or wash off.

The only egg which has pigment all the way through the shell is from the Araucana and is blue/green. The shell is porous and so if eggs are to be washed, water warmer than the eggs should be used (with Virkon, a safe disinfectant) so that the shell membrane expands and blocks the pores. If water colder than the eggs is used, the shell membrane will shrink and draw in any bacteria on the shell.

When purchasing eggs, if you are not already producing your own, do make sure that you understand the codes and regulations. The NFU have produced a booklet to explain all these.
NFU Guide to Buying British Eggs