Research On Animal Production

In this study, male and female birds of two strains including pure white (P₁) and pure wild (P₂) were chosen as parental generation and were crossed reciprocally to create the F₁ progeny. The F₁ birds were mated randomly to produce the F₂ progeny. The studied traits were body weight at different ages, slaughter weight, carcass weight, carcass composition, internal organs, tonic immobility (TI) and rectal temperature. The statistical model included the fixed effects of the genetic group, sex, color, and age. Orthogonal comparisons used to test the observed heterosis included F₁:P₁, P₂; F₂:P₁, P₂ and F₁, F₂:P₁, P₂. F₁ birds performed better than the average of the parental strains showing heterosis rates of +10.1 and +8.6% for slaughter weight and carcass weight, respectively. The effect of sex on slaughter weight and carcass percent was significant (P < 0.01). Duration of TI in white strain was higher than those of the wild strain and F1 progeny. The results indicated significant genetic effects for production traits and tonic immobility, a fear indicator, in Japanese quail.