Indian Journal of Poultry Science

A population of White Leghorn selected for a period of 15 consecutive generations to improve part period (141–280 days) egg production was evaluated for response to selection. Regression analysis showed that there was an increase in the trait though not significant (1.432±0.527). The magnitude of selection differential (SD), phenotypic standard deviation (δP) and intensity of selection (i) varied from 10.9 to 17.00 eggs, 10.95 to 24.52 eggs and 0.469 to 1.097, respectively over generations. The average effective number of parents (Ne) over generation were 243.837 and increase in the rate of inbreeding (ΔF) per generation was 0.21%. The cumulative inbreeding over 15 generations of selection was 3.22%. The inbreeding co-efficient would not probably have any effect on response to selection. However, the down ward trend of heritability estimate of the trait (EP140) has shown that expected response was higher in earlier generation in this population.