|Van Tassell, Curtis|
Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 1999
Publication Date: N/A
Technical Abstract: The availability of marker-assisted selection (MAS) may reduce the time and expense of traditional progeny testing schemes. In addition, MAS may accelerate genetic improvement for lowly heritable traits and allow for improved selection success where genetic antagonisms exist. However, before implementing MAS, markers must be identified that are located nearby chromosomal regions that affect economically important traits. Because the US dairy industry has used artificial insemination (AI) extensively for several decades, there are many large half-sib families of bulls. This population structure enables QTL identification using a granddaughter design (GDD). To facilitate research on the use of genetic markers for dairy cattle using the GDD, the Cooperative Dairy DNA Repository (CDDR) has been established at USDA-ARS-Beltsville with semen donated by 8 North American AI organizations. The CDDR will provide researchers with access to DNA of popular dairy bull families. This collection will attempt to provide a historical collection of semen from animals born in the 1980s and a current collection of animals undergoing progeny testing in cooperating AI organizations. Therefore, the CDDR will contain an unbiased population of sons of sires currently being tested in addition to samples from previous generations, adding power to QTL detection through the use of multiple generations and extended family relationships. The purpose of this collection will be to identify new QTL, verify previously identified QTL, and estimate allelic effects across families. Without such a collection it will be difficult to incorporate MAS into selection schemes and select the most beneficial alleles found in the dairy cattle population.