The popular back-to-parent is not ideal
A popular inbreeding method is the mating of offspring back to father or mother. This is also a method of line breeding. The method calls for a series of back to original parent mating. It is what most breeders of game fowl, old and new, know and do. It is popular because many teach this method. This is the only method they teach in the belief that this is the only way of line breeding. Others even think that this is not inbreeding but line breeding.
This is also being practice by many because those who teach don’t explain the risk in such method and its limitations. The truth is successive back to parent method is risky as it is intense inbreeding. It is not ideal either as line breeding or inbreeding method.
With this usual practice of back to parent mating, in the first generation, 50% of the offspring’s blood come from the father and 50% from the mother. When you back breed further the son or daughter to either of the parents the result will be that the stag or pullet will carry ¾ of the blood of one parent and 1/4 of the other. If you again breed the grandson/daughter back to the parent then 7/8 of the blood is attained. Then 15/16, 31/32, 63/64 so on and so forth.
One important thing we have to bear in mind is that in back to parent methods, each generation differs in genetic composition from the previous generation. That means no genetic composition has been maintained, thus no composition has been maintained. The genetic composition changes from generation to generation as the blood of one parent increases while that of the other decreases.
Let's make it clear. The back to parent is not the only way of line breeding. There are other better ways. Also, although the above method of back to parent mating is the most known, it is by no means the only back to parent method. There are others. Although the objective, might in most cases, remains the same, there will be differences between methods, as each has its own advantages and disadvantages.
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