Changes in commercial laying stock performance, 1958-2011: thirty-seven flocks of the North Carolina random sample and subsequent layer performance and management tests

Thirty-seven layer performance tests have been conducted at North Carolina State University during the past 53 years. Originally established as the North Carolina Random Sample Layer Test (NCRSLT), all of the test flocks have been hatched and housed at the Poultry Unit of the North Carolina Department of Agriculture and Consumer Service's Piedmont Research Station at Salisbury, North Carolina. In 1988, the NCRSLT name was changed to the North Carolina Layer Performance and Management Test (NCLP&MT) reflecting changes in the testing procedures to include the evaluation of management practices used by commercial egg producers. Strain testing and evaluating the relative egg production of commercially available egg production stocks began in 1911, and the number of such Random Sample Tests in North America peaked at 23 in approximately 1968. The mission for the NCRSLT to provide an unbiased evaluation of the overall performance of strains, evolved to include the effects of various housing and husbandry practices on the performance of the genetic stocks entered into the test. Test results have been distributed to the industry throughout the USA as well as to producers in 22 other countries throughout the world. In addition, the internet site for the NCLP&MT http://poultry.ces.ncsu.edu/layer-performance/ allows the distribution of the results to many other interested university and government officials. This review of the first 37 North Carolina layer tests shows continuing improvements in egg production, reduction in body weight and feed consumption, increases in egg weight and feed conversion, improvements in liveability, and an improvement in egg quality from the commercially available white and brown egg strains. These changes have continued throughout the 50+ year history of the tests, and the changes observed have been brought about primarily by poultry breeding companies applying quantitative genetics for the improvement of the layer stocks used worldwide.