Inbreeding is defined as: Father to Daughter, Mother to Son, Brother to Sister and ½ Brother to ½ Sister. Everything else is Line Breeding. Fanciers may want to inbreed to purify a line, create a line or concentrate certain qualities in a top pigeon. Pairing two inbred pigeons together will result in hybrid vigor which is highly desirable in our racing pigeons. Inbreeding should not be attempted by novices!