Quote:
Kelly,
The term refers to an unexpected genetic mutation occuring in an otherwise stable genetic population.
An example would be a pair of birds that come from the same line and are typical examples of the breed, or a pair of birds that are of the same breed but different lines and have produced normal offspring that resemble the parents. Suddenly in one of the broods an offspring appears that is a totally different color pattern than it's parents. So if you have two black chickens, that have normally produced black chicks, and then all of a sudden they have a white chick in one of the broods, that white chick would be the sport.
To propagate the sport, you would then breed it back to the parent of the opposite sex. From that you would take the chicks resulting from that breeding and breed back to both the parents and grandparents as well as sibling breeding. This will establish three lines for you to work with, paternal, maternal and sibling.