Many years ago, a group of scientists in Cambridge discovered that certain characteristics are passed down from parent birds to their sons and not their daughters and vice versa.
Some of these characteristics are down colours and markings that can be used to identify male and female chicks when they hatch. This is a very useful characteristic for commercial or hobby producers of hybrid laying hens, it effectively halves the rearing costs since unwanted cockerels need not be grown on un-necessarily.
It was found that cocks with a genetically ‘gold’ plumage crossed with hens that had a genetically ‘silver’ plumage produced male and female chicks of different colours. Here is a list of the most common Silver and Gold plumage breeds that are used for a sex-linked cross:
|Rhode Island Red
In order to get sex-linkage we must mate a gold plumage cock to a silver plumage hen. The female chick will take after the sire and be the same ‘gold’ colour and the male chick will take after the dame and be ‘silver’.
Tinted eggs are dominant over white eggs – so if either parent mated lays tinted eggs, this will be passed on to the offspring.
Rhode Island Red Male crossed with Light Sussex Female produces sex-linked offspring.
Silver Plumage is dominant to gold, but silver hens are able to transmit gold plumage to their sons.
The resulting chicks from a Rhode Island Red X Light Sussex mating. The female is on the left. Photo courtesy of Grant Brereton.
A reverse mating (Silver Cock to Gold Hens) does not work. Silver is dominant and all of the chicks will be ‘silver’.
Light Sussex Male crossed with Rhode Island Red Female does not produce sex-linked offspring.
Poultry Genetics expert Grant Brereton discusses some common Sex-Linkage questions in his recent blog post that explores Gold and Silver Sex-Linkage further.