Some Thoughts on Hatchability of Dark Brown Marans Eggs

David Hancox, is a genetics adviser at the Marans of America Club and asks in the April 2010 Marans of America Club Newsletter "What Egg Colour Should We Be Aiming For? ....very dark eggs or eggs of an acceptable colour?" Very dark Marans eggs as we all know will certainly win at the shows but when speaking to breeders who hatch these eggs, they all say that the darker eggs are more difficult to hatch. David explores this in the newsletter that I would recommend you read.

"The eggs have to pass through the oviduct slower to become darker so by selecting for the darkest eggs, we may also be selecting for birds that produce fewer eggs. The Incubation handbook by Dr Anederson Brown and GES Roberts says "Dormant period after laying, cooling after laying prevents further progress and the embryo lies dormant until it is warmed again. The dormany embryo can survive quite happily for periods if a week or so, but if the egg was retained in the uterus too long, development can have reached a stage where normal chilling and storage are lethal. Some birds persistently lay eggs like these. They are not infertile but very early dead germs"

So my guess is that if you are having difficit is not your incubation technique, just a factor of the eggs being so dark. It could also explain why all Marans haven't just been selected to lay such dark eggs over the years.... Something to think about!