French Marans Club Australia

                                                Finishing touches

The two essential trademarks of the Marans are feathered shanks and dark red-brown eggs.

                Egg colour

Of the original breeds used in the Marans, except the unknown landrace birds that were local to the Marans – La Rochelle area, none are noted for dark red-brown eggs. Most are cream tinted, except for the Langshan having a rose-brown tint. It is possible the dark brown pigments originated in the landrace fowl, as similar, but lighter tints are found in other European breeds, Welsummer, Barnevelder & Penedesenca. The closest French breed, in origin, to the Marans is the Faverolles and it does not lay a dark egg.

The genetics of brown eggs have shown it to be polygenic, being dependent upon more than one gene, and thus not simple. There is also evidence that the effects of these genes are cumulative in action. The extra-red colour is provided by impregnation of a liquid colouring on the shell of the egg.  This liquid is provided by a spongy fabric in the oviduct, situated in the last l0cm from the end. The liquid is deposited just before laying. Length of time the egg takes to pass through the oviduct affects egg colour, the slower the passage the greater the pigment deposit. As crossing to other breeds results in lose of egg colour it could be concluded the genes involved are recessive, but as egg colour is not easily recovered this may not be so. An alternative hypothesis

is that for the presence of two dependant dominant genes, as is the case for sprigs in single combs. Both of these dominant genes need to be present for any effects to show, each on its own has no effect. The evidence also indicated one or more of the brown egg genes is sex linked, thus the recommendation to breed from males hatched from the darkest eggs.

Observation shows that pullets lay darker eggs than hens; first eggs in a clutch are darker than later ones; very high or low temperatures, or any other causes of stress cause a decline in egg colour.

Top Centre, an extraordinary eggs colour, caused by a very slow passage of a few days, through the oviduct allowing an accumulation of porphyrin pigments on the shell.                Nearly a black-violet colour. 

Top Left, same colour as the egg to the right but with a brilliance that shows extra quality. A Mahogany shade.

Top Right, A frequent colour with the pigment deposited in very fine dot points. 

Bottom Pair, Eggs showing pigment deposited in splotches.

It should be noted that selection for the black-violet coloured egg would drastically reduce egg production.

Partial discolouration shows that the extra red colour comes from impregnation of' a colouring liquid.

With the egg broken, it’s apparent that the internal colour of the shell is perfectly white, offering an unexpected contrast

                                             An extract from BIG, BROWN AND TASTY EGGS.

Text by: Hans L. Schippers - Amstelveen - Holland

As well as the conformation of the bird, accurate markings and colour, the eggs must also be dark drown – the browner the better. The pigmentation to produce this colour comes from certain elements in the blood. This pigmentation is put on the shell by glands in the oviduct at the same time the shell is formed. Only a limited number of colours can be produced in the oviduct namely:
Oöcyaan, this produced from the waste product of the bile and bilirubin, dark green in colour resulting in blue to blue green eggshells laid only by one or two poultry breeds.
Oörhodein or porphyrin, made from blood by products, is very important for the dark
brown shell of the Barnevelder, Marans and Penedesenca and other breeds laying dark brown and brown-shelled eggs. Bilihumin and Biliprasin are very dark pigmentations, which are sometimes responsible for darker spots or freckles on brown-shelled eggs. A mix of these pigments is responsible for the characteristic egg colour for each breed. Many of the Asiatic poultry breeds produce brownish-shelled eggs while most of the Mediterranean breeds lay white-shelled eggs.

Egg Form
Immediately after the shell is formed; osmosis takes place drawing the thin albumen in the egg, after which some extra pigmentation is added. It is thought that the longer the shell remains in the uterus the more
pigmentation is added. It's a known fact that the smaller, oblong eggs pass through the reproductive system faster than the larger rounded eggs. This is thought to be the reason why the large rounded egg that is
slower to pass through the oviduct, is darker brown.
To calculate the ideal shape of the egg you divide the width by
the length times 100. The resultant measurement is called the form index.
The ideal 'form index' for a 58 gram egg is 5.7cm long by 4.2cm wide.
As the length of the form index is reduced so the egg becomes longer and conversely when it increases the egg becomes more rounded. The ideal form index is about 74, and at this figure the shell colour
will be at its genetic best! Eggs of this size are generally thought to
have stronger shells and are easier to pack. However, it is acknowledged that the better the production, the lighter the shell colour becomes over the period of lay.

                                            Change in Eggshell Colour Over Time
As the pullets aged, the shells of the eggs they laid became lighter in colour. Eggs shown are from Commercial Layers.

                                                                                Changes in Brown Eggshell Color with Age.

Experiment in out crossing Marans and the recovery of the dark red-brown shell pigment

Welsummer x Marans pullet. The first 3 eggs she laid.  She is the product of a Marans male and Welsummer female.  The egg colour is impressive. It is obvious that the second pigment coating has been applied to the third egg.  Haze Goulden April 2009

A Wheaten Marans cockerel was mated to a Black Australian Langshan hen, whose eggs are shown below.

An egg of the F1 is shown at the right hand side of a Commercial ISA Brown egg for comparison.

                                                                Feathered Shanks

Of the original breeds used to make the Marans only three were feather shanked. They were the Coucou de Malines, the Brahma and the Langshan none were vulture hocked. Marans of today are required to have sparse feathering, and this feathering should be only on the exterior of the shank and on the outer toes. The required feathering on the Marans is as found on the Faverolles, Breda and Langshan, it is due to the presence of the Pti-1 gene. The feathering of the Silkie and Brahma, exterior of shank and both outer and middle toes is a disqualifying fault. The even heavier shank feathering of Belgian d’Uccle, Cochin and Sultan is also a disqualifying fault. The Pavloff breed has sparse feathering but as this feathering is located on the interior of the shank it too is a disqualification. No Marans should have vulture hocks; these feathers are long stiff and pointing backwards and downwards.

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