What determines the colour of a chicken's egg? I know it has something to do with what the chicken is fed, but what are the critical ingredients?

gtho4

The colour of the egg shell is determined by the breed of chicken. Feed mix (ingredients) determines the colour of the egg yolk. One of my clients has imported the ISABROWN as it consistently lays brown eggs, rather than the more common white egg - market surveys had shown consumers preferred brown table eggs to white table eggs. ISA in France have bred the chicken over decades to produce brown eggs (the mother has brown feathers), e.g. http://www.rirdc.gov.au/reports/EGGS/00-179sum.html There are many articles on brown egg layers vs. white egg layers. This is one of them: http://ask.yahoo.com/ask/20000523.html Mar 17 05, 7:12 AM

antedeluvian

Shirley Corriher (internationally renowned culinary expert) writes in her book CookWise that the color of an egg is determined by breed, but more specifically you can determine the color of an egg for an individual chicken by looking at its ears. If you carefully push back the feathers on the sides of a hen's head, you will see the hen's ears. White ears correspond to white eggs. Reddish brown ears correspond with brown eggs. This correlation supposedly holds up for light green and bluish eggs, as well. Dec 04 07, 3:15 PM

myrab51

White shelled eggs come from chickens of Mediterranean background. Brown shelled eggs come from American breeds. Blue and green shells come from a South American breed called Araucana. The feed the chickens eat can effect the flavor and nutritional value of the egg, but not the shell color. Information from 'Your Chickens, a Guide to Raising and Showing' by Gail Damerow. ISBN: 0882668234 I have several varieties of chicken here at home. They are all fed the same feed, but I have brown, white, light blue and green egg laying varieties. I'm going to have to go look behind their ears now though. :D Dec 04 07, 5:27 PM