Genetic studies on certain economic traits in White leghorn and cross-bred chicken

A study was conducted by utilizing a total of 343 birds of two pureline WLH strains (IWD,IWF) under selection, 3-way (Delham Red x F1 females (RIR x WLH) and 2-way (F₁ x F₁) breed crosses, to evaluate their production performance and to estimate heritability, genetic and phenotypic correlations. Significant differences were observed among genetic groups for all the characters studied. The average age at first egg in 3-way breed cross was found to be 145 days and age at first egg was advanced by 5–8 days in 3-way cross over other genetic groups. The 3-way cross bred recorded higher body weight of 1596 and 1746 gm at 20 and 40 weeks of age respectively, followed by 2-way cross. The genetic groups differ significantly for 280 days egg production and two White Leg horn pure strains recorded higher egg number of 114 eggs followed by 93 and 83 eggs in 2-way and 3-way breed crosses respectively. The high egg number in White Leghorn indicates that it may be due to breed characteristic. The egg quality traits showed no significant differences in mean values and found to be nearer to the standard values.No significant differences were observed for heritability estimates for all the traits studied except 40 weeks body weight and shell thickness in IWD strain. The genetic correlations for many of the traits are non-estimable may be due to smaller sample size. The average age at first egg was phenotypically negatively correlated with egg production at 280 days. The inheritance of plumage colour pattern appears to be independent and significantly differ and the distribution of plumage colour is not in accordance to Mendalian inheritance.