Genetic Analysis of Growth Rate in a Synthetic Broiler Strain

615 Chicks were taken in the three hatches being the progeny of 96 females and 16 males. The average per day body weight gain between 0–2, 2–4, 4–6, 6–8 and 0–8 weeks of age were 7.46±0.09, 14.89±0.14, 43.44±0.28, 61.40±0.32 and 31.83±0.08g, respectively. The effect of hatch was found to be highly significant on growth traits except 4–6 week growth rate. The growth rate was significantly higher in males than females. The heritability estimates were low (0.136±0.085) for 6–8 week growth rate, moderate (0.237±0.117) and 0.385±0.160 for 0–8 week growth rate and 4–6 week growth rate and higher at 0.401±0.165 and 0.695±0.239 for 0–2 week and 2–4 week growth rate respectively. The genetic association of 0–2 week and 2–4 week with 6–8 week and 0–8 week were positive and moderate. The phenotypic association of growth rate between 0–2, 2–4, 4–6 and 6–8 week had positive and significant with growth rate of 0–8 weeks of age. Most of the environmental correlations among growth traits were low either positive or negative.