feeding for eggshell colour?

[Guest]

Hi, I\'m wondering if any of the experienced folks here might know the answer to my question.  I understand that the colour of blue eggs becomes fainter as the laying cycle progresses and the hen\'s body starts to run low on the pigments used to produce the colour.  So ... does anyone know what the pigment is made of?  Could you add the necessary nutrients to the chickens\' feed and increase the saturation of the shell colour again?

[bantamhill]

What a great question! I personally have not scene anything that would suggest that egg shell color can be improved  through feed. That being said, I would suspect that a hen with a varied diet rich in both micro and macro nutrients would have the best chance for a good shell producing system that would maintain shell color over time. I will be interested in what others may have found.

Michael

[Guest]

Hi, I\'m wondering if any of the experienced folks here might know the answer to my question.  I understand that the colour of blue eggs becomes fainter as the laying cycle progresses and the hen\'s body starts to run low on the pigments used to produce the colour.  So ... does anyone know what the pigment is made of?  Could you add the necessary nutrients to the chickens\' feed and increase the saturation of the shell colour again?

The pigment that causes the blue color in an egg shell comes from the break down of old red blood cells. The membrane of a red blood cell is largely made up of a protein called hemoglobin.  The hemoglobin is what binds oxygen and then delivers the oxygen to our cells or a chicken\'s cells. These red blood cells get damaged and need to be recycled. The liver breaks down the hemoglobin in the red blood cells to heme and globin ( both are specific kinds of proteins). The shell gland in the chicken extracts the heme from the blood and coverts the heme into biliverdin. Zinc is added to the biliverdin during the process. This action produces the pigment that is added to the shell. The pigment is called a \"zinc biliverdin chelate\" which is a blue in color. The shell gland adds the pigment to the shell as the shell is placed upon the egg.

A bird deficient in zinc would not be able to produce enough of the pigment to add to the egg. Zinc is a trace element and is obtained from the meat an organisms eats. You could increase the amount of zinc in a chickens diet and see if the color improves.

I would be careful because if too much zinc is in the animals diet it will effect how the chicken uses iron and copper. I would run a test with one chicken and only give the the chicken the extra zinc for a short period of time. I do not know what levels of zinc to use. I worked for 6 years on blue egg color but quit when my interest and lack of facilities forced  me to work in another area of genetics.


Tim

[HarryS]

Would feeding back the shells from eggs you have eaten supply the pigment if you sterlize them first?  HS

[Mike Gilbert]

Rooster, that was the most complete explanation I have heard yet, thank you.   Another fellow was promulgating the idea that feeding foods rich in copper would cause better egg color.   It made sense to me, because copper sulfate in liquid form is a nice shade of blue.    One food rich in copper would be sweet potato - according to this source.   Personally, feed is costly enough without adding expensive supplements IMHO.
I have always found other traits more important to breed for than a specific egg color. especially if more or less artificially induced.   But each person will have their own priorities.

[Guest]

Would feeding back the shells from eggs you have eaten supply the pigment if you sterlize them first?  HS

Allowing the birds to eat the blue egg shells will add additional zinc to the birds diet. My guess is that the zinc would be absorbed into the blood stream and become available to be used by the animal. I am not  familiar with the digestion of chelates but that would be my guess.  

Tim

[Guest]

Tim, thank you for your detailed explanation!  It all makes so much more sense now ...

[Guest]

Studies seem to indicate that the pigment isn\'t synthesized in the bloodstream as originally thought; it is actually synthesized in the egg shell pouch:

A Study on Eggshell Pigmentation: Biliverdin in Blue-Shelled Chickens

However, this specific study was performed on a variety of Chinese blue-egg laying chickens (Dongxiang fowl). The genetic background is claimed to be similar. I don\'t think this would change anything as regards trying to feed some additional zinc for color, though, as the color still comes from the same element, whether synthesized by a breakdown of blood cells, or synthesized in the egg shell pouch.

However, it may be more worthwhile to simply select breeding stock for darker eggs if that\'s what you\'re interested in. I\'ve seen a lot of variation, with some \"bluer\" eggs even toward the end of the season when eggs (in general) are lighter in color. Sometimes slower layers will lay these... and sometimes not. Sometimes one hen just seems to lay darker eggs.

I seem to recall a very good site selling Ameraucana chicks and even offering individual breakdowns of how docile each color was, how well they laid, how blue their eggs were, etc. I think this was chickhatchery.com? Yes... the information is on this page:

FAQs

You will want to scroll down for the nice chart. For me, docile, friendly birds are the most important. I have wheatens and they are wonderful. I see buffs are listed as even more docile than the wheatens in this stock, so I am intrigued...

Looks like some of the bantam stock may lay some of the darkest eggs there.

[Guest]

I began feeding diatomaceous earth (I make a mash with crimped oats now that wheat is too $, as it dries the DE sticks to the oats and is consumed) for tape worm contol last fall. I have noticed that my egg color has very little fading with hens aproaching molt and wondered what could be the source/cause, but somehow thought it was just better health from better utilization of feed (no worms).
This spring I consulted with organic plant specialists and was recommended diatomaceaous earth for trace mineral supplementation for tom.s & peppers ... perhaps this is a good source for poultry as well.

[Guest]

I investigated this (diet/color) subject and remember some type of experiment that used meal worms as a biliverdin supplement.  You can order worms but really have to raise them to make it economical.
I like raising maggots. It\'s easy and the chickens are crazy about them.