A crossbreeding experiment was carried out using two selected lines of Japanese quail,( Early and Lately age at Sexual Maturity) (EASM&LASM lines were established for early and lately age at sexual maturity). A total number of 1310 crossbred birds of quail produced from two mating groups among three hatches were used for the present study to estimate direct heterosis, direct additive and maternal effects on the following traits: growth traits: body weight recorded at 0, 2, 4, 6 weeks of age (BW₀, BW₂, BW₄, BW₆) and average daily gain between the different growth period studied 0 - 2, 2 - 4, 4 - 6, 0 - 6 weeks of age (ADG_0-2, ADG_2-4, ADG_4-6, ADG_0-6).Carcass traits: Slaughter weight, meat, bone, giblets and dressing percentages (SW, M%, B%, G%, D%).
The results obtained can be summarized as follow:Crossing sires of EASM with LASM dams had the highest body weights and body weight gains recorded from hatch to 6 weeks of age followed by reciprocal crossing between sires of LASM with EASM dams., Highly significant positive direct heterosis effect for most body weights recorded at different ages was observed except BW₄ and body weight gains calculated between different growths periods studied. , Crossing sires of EASM with LASM dams had the highest carcass performance followed by reciprocal crossing between sires of LASM with EASM dams., positive direct heterosis effect for most carcass traits studied was observed except M% and G% direct heterosis was non-significant