Effects of Genetic and Non-genetic Factors on Body Weight and Carcass Related Traits in Two Strains of Japanese Quails

The current study was conducted to investigate the effects of genetic and non-genetic factors on body weight and carcass traits of Japanese quails. Two strains of Japanese quail (150 wild quails and 150 white quails) were used as base population. Four mating groups were used to produce progenies: wild male × wild female, white male × wild female, wild male × white female and white male × white female. Quails were weighed then slaughtered at 35 days of age. The carcass traits consisting carcass weight, breast meat weight, thigh meat weight, skin weight, and abdominal fat weight were recorded after slaughter and after removing feathers, internal organs, and digestive system. Based on these weights, the percentages of carcass, breast, thigh, skin, and abdominal fat were estimated. The effects of sex, hatch, and mating group on body and carcass composition traits were investigated. Sex had a significant effect on all traits (P < 0.01), with the exception of the thigh percentage. Moreover, female birds showed higher values for all traits. There were significant differences between hatches and mating groups and wild male × wild female offspring showed highest values of carcass weight, breast weight, thigh weight, skin weight and abdominal fat weight (P < 0.01). The heritability estimates for body and carcass related traits were moderate to high (0.22 to 0.66). The carcass percentage traits showed lower heritability, ranged from 0.22 to 0.33. Genetic correlations between body weight and carcass weight, skin weight, breast weight, thigh weight, and abdominal fat weight were moderate to high (0.37 to 0.94). These results showed that selection for increasing body weight and decreasing abdominal fat will improve carcass related traits.