Genetic Analysis of Egg Quality Traits in Bovan Nera Black Laying Hen under Sparse Egg Production Periods

The present research was designed to examine the genetic analysis of egg weight, egg yolk weight and egg albumen weight of Bovan Neva Black laying hens at 25, 51 and 72 weeks. For this purpose, thirty birds were selected from the layer flock in the Babcock University Teaching and Research Farm. They were individually housed in separate labeled battery cage. A total of thirty eggs were collected daily from the birds continuously in five days of egg production, at each age of 25, 51 and 72 weeks. The total number of eggs collected at each age were 150. Data collected for egg weight, egg yolk weight and egg albumen weight were used to evaluate the descriptive statistics, influence of age and Pearson correlation coefficient on different age groups. The mean values of the traits revealed a consistent increase in egg weight 55.02-63.29 g, egg yolk weight 13.14-19.39 g and egg albumen weight 35.52-39.21 g by aging. A significant positive genetic correlation was obtained among traits with linear regression equations at different age groups. Restricted maximum likelihood (REML) of Wombat software was used to obtain the repeatability and heritability estimates. From the results, it was revealed that all the traits recorded high estimates of heritability and repeatability while egg weight is more heritable and repeatable than egg yolk weight and egg albumen weight indicating that fewer records would be required to adequately characterize the inherent production ability of each trait as laying age progressed.