Clearbody1.jpg (13310 bytes)

 

The Clearbody
Kevin Eatwell BV.Sc.(hons) MRCVS

 

left: Ken & Sylvia Stalder's CC winning Clearbody cock. Photo by Mick Freakley,

The Clearbodies are well established in the UK and the initial enthusiasm for them has now been reduced down to the more serious breeders of the variety.

There has been a great improvement in quality of this variety, but sadly many individuals are not making headway as quickly as they could. This mutation is sex-linked and recessive to the wild type, but has an unusual relationship to the Ino mutation to which it is dominant. Because of this many individuals are mating Clearbodies to Inos to increase their production of these birds. However this generates two types of Clearbody cocks, the pure bred (double factors) and the split inos (single factors). When paired together clearbodies breed like any other sex linked mutation.

Breeding Expectations
Pairings Expectations
Clearbody cock Clearbody hen 50% Clearbody cocks
50% Clearbody hens
Clearbody cock Normal hen 50% Normal/split Clearbody cocks
50% Clearbody hens
Normal/split Clearbody cock Clearbody hen 25% Clearbody cocks
25% Normal/split Clearbody cocks
25% Clearbody hens
25% Normal hens
Normal/split Clearbody cock Normal hen 25% Normal/split Clearbody cocks
25" Normal cocks
25% Clearbody hens
25% Normal hens
Normal cock Clearbody hen 50% Normal/split Clearbody cocks
50% Normal hens
Normal cock Normal hen 50% Normal cocks
50% Normal hens
When paired to Inos, the split Ino cocks are visually
identical to the pure Clearbody cocks
Clearbody cock Ino hen 50% Clearbody/Ino cocks
50% Clearbody hens
Ino cock Clearbody hen 50% Clearbody/Ino cocks
50% Ino hens
Clearbody/Ino cock Ino hen 25% Clearbody/Ino cocks
25% Ino cocks
25% Clearbody hens
25% Ino hens
These Clearbody/Ino cocks are of grave importance when using
them to any mutation other than Ino. This is clearly seen below:
Clearbody/Ino cock Clearbody hen 25% Clearbody cocks
25% Clearbody/Ino cocks
25% Clearbody hens
25% Ino hens
Clearbody/Ino cock Normal hen 25% Normal/Clearbody cocks
25% Normal/Ino cocks
25% Ino hens
25% Clearbody hens

In the first case it is impossible to tell which are pure Clearbody cocks and in the second case only half the cocks are split Clearbody despite being bred from a visual Clearbody. This results in a great number of birds of uncertain genetical make up and this limits the usefulness of pairing these birds out to normal varieties to increase the improvement of this mutation.

I feel the best method of improvement is to avoid the Ino mutation and just breed pure Clearbodies. Improvement can be rapid, not only because of improvement of the outcrosses used but also by using a different approach. When mating a Clearbody hen to a Normal cock all her sons will be split Clearbodies. These birds can be used to Clearbody hens which will generate a stock of Clearbodies, but the quality will only be marginally improved on the original hen.

A quicker way of development is to use a split cock to a Normal hen. This will generate only possible split sons which should be discarded, but half of the daughters will be Clearbody hens of a greater quality. These can be used to generate yet more split sons and the cycle can continue. Productivity of Clearbodies will remain low but sufficient birds for the next season should be bred. As a result the quality of the Clearbodies will increase quickly and once the quality is acceptable then the split cocks can be mated to Clearbody hens to raise the numbers of Clearbodies bred.