Genetic parameter estimation and genetic evaluation of important economic traits in white and yellow broilers

1. This study calculated descriptive statistics for the production traits of two broiler populations: 1) the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF white broilers), including fat and lean lines; and 2) the Guangxi yellow broilers. Their genetic parameters were estimated, including (co)variance components, heritability (h²) and genetic correlations (r_g), using the REML method.2. Heritability estimates (h²) for NEAUHLF white broilers ranged from 0.07 to 0.61. Traits with high heritability (h² >0.3) included body weight at 3, 5 and 7 weeks of age (BW3, BW5, BW7), carcass weight (CW), metatarsal circumference (MeC), liver weight (LW), gizzard weight (GW), spleen weight (SW) and testis weight (TeW), while in Guangxi yellow broilers, heritability estimates ranged from 0.18 to 0.76, with every trait exhibiting high heritability, except for SW (0.18).3. Positive genetic correlations for NEAUHLF were found (r_g >0.3, ranging from 0.31 to 0.84) between BW7 and metatarsal length (MeL), MeC, body oblique length (BoL), chest angle (ChA), LW, GW, heart weight (HW) and SW. Genetic correlations between abdominal fat weight (AFW) and BW1, BW3, BW5, CW, MeL, keel length (KeL), BoL and LW were positive (r_g >0.3, ranging from 0.31 to 0.58).4. Among the Guangxi population, BW (125 d of age) showed strong positive genetic correlations with all other traits (r_g >0.3, ranging from 0.30 to 0.99), while AFW displayed strong positive genetic correlations with leg muscle weight (LeW), CW, BW and thigh diameter (TD) (r_g >0.3, ranging from 0.44 to 0.51).5. It was concluded that the characteristics of the two populations were different, which means there is a need to use different strategies when performing the breeding work to improve productivity and efficiency in both broiler populations.