This present study was carried out during three successive generations to improve body weight through selection in developed Dokki-4 chicken strain and to study correlated response of some economic traits. The chicks in each generation represented two lines, selected line for high body weight and control line. The results showed that body weight at different ages studied were improved in selected more than control line (P < 0.01). There were significant differences (P < 0.05) between generations, lines and sexes body weight (BW), daily weight gain (DG), feed conversion (FC), and body weight measurements (shank length, keel length and body circumference) at 4 , 8 , and 12 weeks.
Selection differentials of male 12-weeks body weight were 71.0 gm and 57 gm in the selected generations. The corresponding values for females were 54.0 gm and 48.0 gm. The cumulative realized and expected responses, were 130.3 gm and 28.16 gm for males, and were 83.9 gm and 22.4 gm for females over two generations, respectively. The cumulative realized response to selection for body weight was 26.01, 58.0 and 81.95 for body weight at 4, 8 and 12 weeks of age , 0.92, 1.14, 0.94 and 1.03 for daily weight gain, 0.31, 0.82 and 1.46 for shank length, keel length and body circumference at 12 weeks, while, were with feed conversion -0.89, -1.27 and -1.32 at 4, 8 and 12 weeks of age.
Heritability estimates based on sire component of variance (first and second generation) for all traits studied were ranged between high, medium and low values. Positive genetic and phenotypic correlations were found body weight at 12 weeks of age and body weight at different ages, daily weight gain, and body measurements (shank length, keel length and body circumference), the range between the values of high, medium and low. But among body weight and feed conversion were negative.
In conclusion, the high positive correlation obtained in this study indicate that an improvement in body weight might lead to an improvement in other traits and body measurements. This is a good indicator of body conformation and may be used in selection programmer.