Is there a relationship between the colour of the hen and the eggs they lay?
P. HABIB RAHMAN Madurai, Tamil Nadu The colour giving substances in the eggshell are ooporphyrins and oocyanin. The ooporphyrins, derivatives of haemoglobin in the blood give brown colour and oocyanin, a product of bile formation gives bluish green colour to the shell. The eggshell devoid of these pigments is white in colour. Combination of these two substances in different proportion gives different shades of colour to the eggshell. The genes determining shell colour are entirely different from those responsible for feather colour. Therefore the shell colour in chicken has no relationship with the plumage colour. The colour of the shell is characteristic to breeds. Breeds like Leghorn, Minorca and Andalusian lay white eggs; while, Rhode Island Red, New Hampshire, Cornish and Plymouth Rock are the few breeds that lay brown eggs. Irrespective of the plumage colour, both brown and white varieties of Leghorns lay white coloured eggs. Similarly, Cornish, be it a red or white variety lays o
