Concepts and Methods of Poultry Genetic Selection
Single Line: Breeder uses a closed flock, continuously selecting the better birds each generation and breeding from them. Hybrid Vigor: Outbreeding which results in increased quality of the hybrid offspring.
Male Line and Female Line: Crossing of a Male line only line with a Female online line. The opposite sex of each line is destroyed at day 1 of age.
Strain Cross: Crossing of two or more different strains rather than selecting for traits within one strain. Only a few desired traits are selected within each strain rather than all the desired traits in one strain.
Two-line Cross: Allows for offspring to have positive traits from both lines, however, at a lower rate than the original lines.
Three-line Cross: First a two-line cross is done then the offspring of that cross are crossed with a third line to obtain more positive traits.
Four-line Cross: Two separate two line crosses are completed than the offspring of these two crosses are bred to obtain offspring with traits from all four lines.
Strains used for crossing must nick: This means that the two lines that are being crossed must complement each other.
Inbred Crosses: Crossing of related individuals to improve uniformity. This often reduces performance. Performance can be restored by crossing lines.
Sex-linked Meat Lines: Certain feather colors and speed of feather growth can be linked to the sex of the bird. The trait will only appear in one of the sexes, making separation of chicks at hatch easier
