Correlations are a measure of genetic factors shared between two traits. When two traits are highly genetically correlated, the genes that contribute to the traits are usually co-inherited. They contribute to understanding the development and pathways of traits, population-level gene flow and the co-occurrences of traits. They also play an important role in evolutionary biology. In the present investigation it was found that the genetic and environmental correlations of age at first egg with body weight were negative in IWD and positive in IWF strains. The genetic and environmental correlations of body weight with egg weight and egg production were positive in IWD and negative in IWF strain. The genetic and environmental correlations of egg weight at 40 weeks with EP40 and EP64 weeks were found negative. The genetic and environmental correlations of egg production upto 40 weeks with EP64 weeks were positive in magnitude in both the strains.

Highlights

• Genetic selection played a major role in improvement in production efficiency of poultry.
• The genetic improvement in White Leghorn is paving the way for exploiting the production potential of this breed.
• The high positive genetic correlation in the present study could be due to the pleotrophic genes affecting egg weight at various ages.