A comparison of White Leghorns, Australorps, and their reciprocal crosses

Abstract

Six hundred pullets comprising White Leghorns, Australorps, and their reciprocal crosses were compared in several commercial characters in cages and housed intensively on litter, until 500 days old. The pullets were produced from matings in which purebred sires left pure and crossbred half-sib progeny. Age at first egg, survivors' production, and hen-housed average production showed a considerable response to hybrid vigour. The reciprocal crosses were not significantly different. Both were consistently though not significantly better than White Leghorns and much better than Australorps in these three characters. Breed of dam had a large effect on mortality during the laying period. All other variables had insignificant effects. Breed of sire had the greatest effect on final body weight. Dams within breed also exerted a significant effect. Birds in cages wore heavier and laid more eggs than birds on litter.