carcass traits and physical characteristics of eggs in japanese quail as affected by genotype, sex and hatch

the effect of genotype, sex and hatch on carcass traits and physical characteristics of eggs was investigated in the japanese quail. two strains of japanese quails including the white (p1) and wild (p2) genotypes were chosen as the parental generation and crossed reciprocally (10 single-pair mating) to create the f1 progeny. the f1 birds (27 males and 81 females) were mated randomly to produce the f2 progeny (1320 birds). the white and wild birds were simultaneously reared with f1 and f2 birds as control groups. the statistical model included the fixed effects of the genetic group, sex and hatch. orthogonal comparisons were used to test the observed heterosis including the f1:p1+p2; f2:p1+p2 and f1+f2:p1+p2. the effect of sex on slaughter weight and carcass percentage was significant (p < 0.01). slaughter weight was higher in females than in males. effects of genetic group and hatch on the egg weight were significant (p < 0.05). the genetic effects on slaughter weight, carcass weight and carcass percentage were also significant (p < 0.01). the f1 progeny had the highest slaughter weight and carcass weight but the carcass percentage of f1 birds was lower than that of f2 birds. the f1 birds performed better than the average of the parental strains showing heterotic rates of +10.09 and +8.56% for slaughter and carcass weights, respectively.