Body Capacity

Often production characteristics are overlooked in exhibition birds. This is to the detriment of their flock. Productivity, livability and fertility are all tightly coupled and when you lose one, you tend to lose them all.

Of course you need to take the breed’s individual optimum physique into account when assessing. You want good body capacity on both your Leghorns and your Cornish but you would not expect them to be the same measurement. Rather you would look at the capacity as compared to type and conformation. We’ve all seen those Leghorns that are so narrow they produce undersized eggs or those Cornish that are so wide as to be unable to mate.

Body Capacity

by Rip Stalvey

One measure of a good, productive bird is abdominal body capacity. Birds with good body capacity have the abdominal capacity to convert food into flesh and/or eggs.

An indicator of good abdominal capacity is a bird’s width between the legs. Birds with narrow bodies don’t have the optimum room for their internal organs to function at peak efficiency.

This picture show a meat type pullet with excellent width between the legs. Notice how far her legs are apart and how they come straight down the side of her body. Select birds, both males and females, like this to produce chicks with good body capacity.

Next we see the classic graphics used in many textbooks from the 1950s. Not only can you see the physical size difference it’s also easy to see the difference in the amount of fleshing on the bodies.

The first photo shows a side by side comparison of a bird with poor capacity to a bird with good capacity, first using a live bird and then the same bird after processing.%MCEPASTEBIN%

The second photo illustrates how to use the fingers on your hands to measure the width between the pubic bones and then the distance between the pubic bones and the end of the keel bone. The more fingers that can fit between those respective points the greater the capacity.


When I’m at poultry shows, one fault that a see on a regular basis is lack of god leg structure. It seems that breeders pay attention to color and type well enough. However, it seems some folks forget to look any lower than a bird’s keel bone when selecting breeders.

A chicken’s legs should be straight when view from the front. I’m seeing those who are either knock kneed (cow hocked) or bow legged, curved outward, not straight. Remember, a bird with leg issues will not be able to move naturally and can develop leg problems later in life. I’ve attached an illustration of knock kneed and bow legged birds so you can see what they look like. So when you’re evaluating birds for potential breeders, give the legs the attention they deserve. You’ll produce better birds when you do