U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Vanraden, Paulitem
                                            O'CONNELL, J - University Of Maryland
  Submitted to: Journal of Dairy Science
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 2/24/2011
                                    Publication  Date: 6/30/2011
                                    Citation: Van Raden, P.M., O'Connell, J.R. 2011. Overview of genomic selection in dairy cattle populations. Journal of Animal Science 89(E-Suppl. 1)/Journal of Dairy Science 94(E-Suppl. 1):664(abstr. 597).Interpretive Summary:
                                Technical Abstract: Genomic selection is most successful for traits recorded over many years in large populations. Holstein breeders have reference populations >10,000 proven bulls via cooperation among major countries, and countries with smaller Holstein populations can contribute additional bulls. Scandinavian red dairy cattle breeders have 8,000 reference bulls, and Brown Swiss breeders have a global population of 4,500 reference bulls at Interbull. Jersey breeders have genotyped but have not yet merged their 6,000 reference bulls. Denser chips can transfer genomic information across breeds if all breeds are in the same dataset. Less dense chips with imputation to higher densities allow affordable selection for smaller populations or more recently recorded traits. The North American database now includes Illumina 2,900 marker (3K) or 50,000 marker (50K) genotypes for 74,389 Holsteins, 8,905 Jerseys, and 2,008 Brown Swiss, plus 777,000 marker (HD) genotypes for 435 animals. To determine how many HD animals within each breed may be needed for imputation, 600,000 marker genotypes were simulated for either the youngest animals or for older bulls with highest reliability, and the other animals had 40,000 markers. After imputation using findhap.f90 version 2, percentages of estimated genotypes that matched true genotypes ranged from 96.1 to 98.7% when numbers of HD genotypes ranged from 250 to 1000 within each of the three breeds. Imputation accuracy was about 1% less if the youngest animals instead of the older bulls had HD. The value of matching cow phenotypes to their own genotype instead of to their sire’s genotype was demonstrated by excluding bulls and using only the 13,935 cows in the Holstein reference population instead of all 25,131 reference bulls and cows (official). For milk yield of young animals, the correlation was 0.86 between cow-only and official evaluations vs. 0.71 between parent average and official. Smaller populations can increase genomic reliability by exchanging information with large populations and by lower cost genotyping.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov