Genetic changes in the performance of egg laying strains of hens in Australia

Abstract

Results from the South Australian Random Sample Tests in the period 1966 to 1978 were analyzed to determine if there had been any changes in the average performance of commercially available egg production strains. Average age at sexual maturity was found to have declined by about 0.5 days per year, and eggs per hen housed to have increased by about 1.7 eggs per year during the period analyzed. Non-linear trends were detected for feed consumption, feed conversion efficiency and income over feed and chick costs. For hen-day egg production, a non-linear upward trend was apparent with the most rapid progress having been made in the latter part of the period analyzed.