top of page

Building the Barn

An analytical look at the importance of bone structure in Marans.

By Cassandra Everly

Copied from the The Marans Club Quarterly Newsletter, 2nd quarter 2020


In order to understand how to properly breed a Marans, one must first look into the purpose a Marans was created - a hardy, dual-purpose fowl to provide sustenance for a particular region in France. Not for their dark eggs. That unique quality was a coincidence that was selected for at a later time and proceeded to make the Marans famous worldwide. The American Standard of Perfection states that a Marans ought to “ give the appearance of solidity and strength, without being coarse”. To have this, there are certain attributes that must be bred forward constantly - or you lose it altogether. Without these attributes, they are not true, quality Marans, and it all begins within the bones. 

The bones of a chicken are like the structure of a barn. The dimensions of the beams determine the capacity within, and without capacity, the organs cannot perform properly. Lack of size, depth, and width can greatly alter the health, productivity, adaptability, and performance of your Marans. Great care and consideration MUST be given to your breeders based on their structure, in order to improve your flock’s vigor. This in turn saves you money from wasting feed on a weak stock that will be poor producers. 

The head is the first indicator of the vitality of a bird. Some breeders cull chicks directly from the hatcher on head width alone. This is a practice that has been followed consistently by serious breeders since the 1920s. Smaller, narrow-headed chicks rarely turn into anything of breeding quality. While larger-headed, brighter-eyed chicks will always grow better and become healthier adults.  This goes for adults as well.  Shrunken combs, shrunken faces, dull eyes, long overgrown beaks, and narrow, excessively flattened skulls (a condition called crow-headed) are all indicators of lack of vigor, and should not be used in a breeding program. 


Example of a strong head vs. a weak, crow head. Note the narrow, elongated skull,

the overgrown beak, and shriveled comb/wattles.  

The rest of the body as well are a key indicator of vitality.  Parts of the American Standard of Perfection are quoted and then expounded upon from Poultry Science articles on why these attributes are important to the constitution of your Marans, and how to identify the weak stock that should not be bred forward. 

The Neck - moderately long, but full and curved so the head is centered over the breast. Birds hanging their heads forwards, appearing slouched or straining are of weak constitution, either from weak genetics or physical ailments. 

The Back - Long, flat, slightly elevated at the shoulders, and wide - with the width evenly carried through the tail. Birds that taper in width from shoulder to tail ( referred to as wedge-shaped) have pinched pubic bones, and will not be good producers. A mature bird should comfortably fit at least 3 fingers between the pubic bones as shown below. This space is important for adequate room to store and digest food, and manufacture eggs.  Birds with larger abdominal capacity live longer, more productive lives than birds who are smaller and lighter framed.


A bird exhibiting health and production, vs a bird of weak constitution. Notice the points of the pelvic bones on each picture, as well as the condition of the skin. The bird on the right clearly has digestive and malabsorption issues, which go hand in hand with smaller frames and smaller heads. 

The Breast - Dual purpose birds like the Marans must be a balance of width for egg production, with depth for meat production. Breasts should be strong, broad, and full. Well rounded when viewed from both the front and the side.  The sternum bone - often referred to as the keel has an important role to play in chest depth. A full breast should never be confused with a full crop or loose feathering. The best way to determine the quality of the breast is to handle the bird. Feel the keel bone and both sides of the breast with your hands. At all stages, and in all sexes, the breast should feel similar to an inflated football. The keel bone which splits the breast ought to be well expounded outward from the chest cavity. Making a smooth, rounded chest.

Strong Weak Dia1.jpg

A strong, well-rounded body compared to a body that lacks overall depth. 


Cockerel on the left is an excellent example of good breast and body capacity, while the cockerel on the right exhibits shallow breast and poor capacity.

Wings - Short, carried closely to the body, carriage nearly horizontal. Shorter, tight wings are a sign of good health and vigor. Loose droopy wings are a sign of weakness or stress. Improper wing angles, twisted wings, and slipped wings are hereditary and must be paid close attention to when breeding.

Legs and toes - Medium in length, sturdy, set well apart (another sign of vigor and good body width), and straight when viewed from the back and the front. Knees not turned inward towards the other (a defect known as knock-kneed) nor bowed outward.  Toes should be straight, strong, and well separated. 4 toes on each foot with the 4th toe straight back like a prop, providing good balance and agility. Deformities of the legs and feet can be hereditary and should be critically culled against.  Deformities include enlarged or misshapen hocks, twisted legs, webbed feet, duck-footed (back toe turned frontwards with the rest of the toes) knock-kneed, or bow-legged. 


While there are many important factors to a proper Marans, this article discusses bone structure only as a foundation point in our newsletter to build on in the future. Many of the illustrations are not Marans - but serve as good illustrations of the points being made.

bottom of page