Genetic correlations and heritabilities for frequency of cracked eggs, egg number and egg weight in laying hens

Abstract

Abstract 1. Data on egg weight and egg number were obtained from two consecutive generations in a White Leghorn line. Each egg was candled and the frequency of cracked eggs was calculated. 2. The estimates of heritability for the frequency of cracked eggs ranged from 0.11 to 0.43, for egg number from 0.12 to 0.29 and for egg weight from 0.58 to 0.65. 3. The estimates of the genetic correlations between the traits were variable but in general showed no evidence of antagonism between a reduction in crack frequency and an increase in the production traits. 4. The efficiency of selection for reduction in the frequency of cracked eggs based on early measurements is briefly discussed.