What's Pure?
The word pure is often used to describe purity of bloodline such as 100% sweater or 100% yellow legged hatch or 100% kelso. Most likely many also think of pure as invariably an inbred individual. No. In true breeding pure is not necessarily inbred. It is pure of a trait or characteristic. Example there is pure straight comb rooster even if it is a cross between a lemon and a hatch. Therefore, you may also have a rooster much heavy in characteristics that cause it to be fast or strong, even if this rooster is an outcross. The meaning, which is more genetically correct is pure of particular traits, not 100% of a bloodline. Basic knowledge in genetics will make one understand this meaning.
Many of us chicken breeders want to attain purity by duplicating or replicating genetic composition of a bloodline or a particular generation. Thats why we breed full sibblings to maintain, or a series of back to original parent matings, to restore a particular bloodline composition.
However, we can't attain 100% by doing so. No matter what there would be a fraction left. Micro, nano or pico fractions.
Just for a starter, the most intense inbreeding is a series of full sibbling matings, but after ten generations of full sibbling matings, the inbreeding coefficient is calculated at 88.62%. Ten generations and still far from 100%.
You can't purify genetic composition of a bloodline (You can purify name though, for example by breeding a roundhead to another roundhead.)
But, thank God, breeding is not mathematics we don't have to attain 100% of a particular bloodline composition.
Breeding is genetics. We only have to purify some traits. The traits that are included in the bloodline type. To be considered pure, it is enough that an individual can breed true-to-type.
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