Divergent selection for egg production in Coturnix coturnix japonica.

From a randombred control population of Coturnix coturnix japonica, strains were divergently selected for high (HE) and low (LE) 120-day egg production based on individual egg records. Based on five generations of selection, realized heritabilities for HE and LE were .063 +/- .055 and .353 +/- .020, respectively. The total change in number of eggs was 3 and -19, respectively, in HE and LE. Mortality to 4 weeks of age, 4-week body weight, egg weight, total plasma phosphorus (yolk precursor), liver weight, and number and weight of ovarian follicles in rapid development in the ovary did not change significantly in HE and LE. Mature body weight increased in LE with no consistent change in HE. Significant changes in the component parts of the egg occurred in HE and LE. Shell weight increased in HE with no change in LE while the reverse was true for yolk weight. Percent albumin decreased in both selected strains.