Some time we use the term "Pure" loosely.
If you are doing a lot of test mating to determine the genome of your potential breeders you may start with 10 birds that are full siblings from birds that have a pedigree that goes 10 generation back but as you test for traits a, b, c, and d. You may find that less than half of the birds are pure bred for all four of the desired traits. You made term those that have the desired traits fixed pure and those that aren't as impure. That isn't to say that if someone else were to test made the birds that you tested for a 5th trait that they would call them all "Pure".
If they aren't out crossed from the original imported gene pool then you can call them "pure", but the original gene pool has a lot of things it it that can pop out and produce birds that don't look right so it won't be the same meaning of the term "pure" that the guy that test breed for 5 different traits is talking about.
If you are doing a lot of test mating to determine the genome of your potential breeders you may start with 10 birds that are full siblings from birds that have a pedigree that goes 10 generation back but as you test for traits a, b, c, and d. You may find that less than half of the birds are pure bred for all four of the desired traits. You made term those that have the desired traits fixed pure and those that aren't as impure. That isn't to say that if someone else were to test made the birds that you tested for a 5th trait that they would call them all "Pure".
If they aren't out crossed from the original imported gene pool then you can call them "pure", but the original gene pool has a lot of things it it that can pop out and produce birds that don't look right so it won't be the same meaning of the term "pure" that the guy that test breed for 5 different traits is talking about.
