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Genetic testing of chickens

I have started using a genetic testing laboratory in Florida to test some of my breeders for the blue egg gene. The process is easy, but not cheap, and results can be disappointing. This last batch I tested all 5 of my Opal Legbar cockerels and 2 of the best looking pullets. The entire flock was sired by a genetically tested cockerel that was homozygous for blue eggs, so the expected results were to get at least half the flock to test homozygous (meaning they have 2 copies of the blue egg gene and so will breed “true” for blue eggs).

Of the 3 cockerels, only 2 were homozygous. I have since removed the other 3 to the “bull pen” where extra roosters live. This means that soon, all the eggs I collect from the Opals will produce chicks that have at least 1 copy of the blue egg gene (and therefore lay blue eggs, as that trait is dominant over white eggs). The conclusion from all this is that starting in April, every Opal pullet chick that hatches will have a (nearly) 100% chance of laying blue eggs. I say nearly because is it possible for a pullet to store sperm from one of the removed cockerels for several weeks, but generally breeders observe that the more recent breedings take precedence over the older breeding, making this less and less likely as time passes.

Now, as for the 2 pullets, they both tested heterozygous. That means they will lay blue eggs (and they do), but half their offspring will inherit a gene for white eggs. This makes them less valuable as the genetic basis for future breeders, as all their offspring would need to be tested to see if they were homozygous.

In a week or 2, I will be sending off samples of other pullets to test. Once I identify 1 or more homozygous pullets, they can be paired with one of the 2 cockerels and will be the foundation of next year’s flock of all homozygous Opal Legbars.

Good breeding practices can be tedious and/or expensive, but it is necessary to advance the breeding of these exciting birds.

If you would like info about the lab that does the testing, their website is