This article has some breeding tips for Marans chickens to obtain the right colour and quantity of dark brown eggs.
The Marans (and please note they are called ‘Marans’ after the port town in Charente Maritime, France, not ‘Maran’ as you will see written on many webpages) is one of a few breeds that lays beautiful chocolate brown eggs.
As a utility bird, both the colour and the number of eggs are essential, and it is relatively easy to select for both of these characteristics with a little care.
Without trap nesting (where a bird is ‘trapped’ in the nest when she lays so we can note her leg ring number), it is difficult to know who the flock’s best layers are. The way to overcome this is to hatch eggs laid very early and very late in the season. To lay more eggs in a year, hens will extend their laying season, so the birds laying early and late eggs are usually the best layers in your flock.
Egg colour selection
Good Marans eggs are dark brown. Whilst the genes responsible for eggshell colour are tough to isolate, we know that dark brown eggs contain the brown pigment protoporphyrin.
The more that is present, the darker the egg.
Blue eggshells such as from Cream Legbar hens have a different gene at work. It is worth noting that these eggshells are blue through to the inside. In Marans eggs, the pigment is deposited on the outside of the shell. You will notice if you scratch the outside surface, the colour rubs off.
To improve the colour of Marans eggs, you should only select the darkest brown eggs to hatch. Breeding from hens (and Cocks) that come from dark brown eggs themselves will ensure that you concentrate this gene in your strain and get more of the same thing.
The darkest Marans eggs will be laid early on in the season towards the beginning of lay. It is still not completely understood why, but hormone levels are believed to be responsible for this change. When a bird is coming up to a moult, her hormones change considerably, and the difference in brown shade will be most noticeable.
Whilst you should be thinking about hatching dark, early season, eggs, it does not mean you can’t hatch lighter shades over the year. Select the darkest eggs that your hens are laying because although there is less Protoporphyrin deposited on the eggshells, it is all relative so providing you select the darkest eggs; you are still choosing the right eggs to hatch.
General egg selection advice
I would recommend only hatching eggs of the right shape and the right size for the breed. There is a tendency amongst some of us to breed as quickly as possible. Breeds can spoil by hatching the wrong shape of eggs. It is harder for chicks to hatch from the wrong shape eggs, so hatchability goes down.
When pullets come into lay, they will lay smaller ‘pullet sized’ eggs. Egg size will increase with age, but with slower-growing large fowl, it is often necessary to wait until they are in their second season of lay to get the best size eggs. I find eggs from my 2nd-year hens are bigger and better for hatching.