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
 Animal Genomics and Improvement Laboratory: Beltsville, MD
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    Careers


        


                    AIP
                        Home
                                    About
                                    Publications
                                    Software
                                    People
                                    Collaborations
                                    Careers
                                    Centennial
                                    Contact
                                    Dairy industry links
                    DirectionsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Northeast Area Beltsville, Maryland (BARC) Beltsville Agricultural Research Center Animal Genomics and Improvement Laboratory 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
- IACUC
- Home
- About
- Publications
- Software
- People
- Collaborations
- Careers
- Centennial
- Contact
- Dairy industry links
- Home
- Queries login
- News
- Animal Evaluation lists
- Genotype counts

Title:   Author  item
                                            Vanraden, Paulitem
                                            Tooker, Melvinitem
                                            Wright, Janiceitem
                                            Cole, Johnitem
                                            Null, Danielitem
                                            LAWLOR, THOMAS - Holstein Association Usa, Inc
  Submitted to: Government Publication/Report
                                    Publication Type: Government Publication
                                    Publication Acceptance Date: 10/3/2014
                                    Publication  Date: 10/3/2014
                                    Citation: Van Raden, P.M., Tooker, M.E., Wright, J.R., Cole, J.B., Null, D.J., Lawlor, T.J. 2014. Genetic base changes for December 2014. AIP Research Report BASE3(10-14).Interpretive Summary: Genetic bases were updated previously in the United States in 1965, 1974, 1984, 1989, 1995, 2000, 2005, and 2010, and the next base change is scheduled for December 2014. Base changes for yield, health, fertility, and type traits in December 2014 are reported. Stepwise genetic bases allow estimates of genetic merit from new evaluations to be easily compared with previous estimates except at base changes, when accumulated genetic gain is subtracted so that all animals are compared with a more recent cow population. A particular animal's genetic evaluation is supposed to decrease when the base is changed and remain fairly constant between base changes. For most traits, genetic and phenotypic trends comparing cows born in 2010 with cows born in 2005 are equal to or slightly less than trends for the preceding 5 years reported at the previous base change in January 2010. However, cows born in 2010 were before genomic selection had much impact, and trends are faster for calves born during the last 4 years. Phenotypic progress due to environmental factors such as management is the difference between genotypic and total phenotypic progress. For Holsteins, genetic improvement is responsible for 86% of the increase in protein yield, 87% of the increase in fat yield, and 132% of the increase in milk yield during the past 5 years; the negative effect of environmental factors on milk yield caused the phenotypic change to be less than the genetic change. Phenotypic progress in yield traits for other breeds also was predominantly the result of genetic improvement. In general, positive progress has been made for most traits through management practices and genetics since the 2005 base change.
                                Technical Abstract: Genetic bases were updated previously in the United States in 1965, 1974, 1984, 1989, 1995, 2000, 2005, and 2010, and the next base change is scheduled for December 2014. Base changes for yield, health, fertility, and type traits in December 2014 are reported. Stepwise genetic bases allow predicted transmitting abilities (PTAs) from new evaluations to be easily compared with previous evaluations except at base changes, when accumulated genetic gain is subtracted so that all animals are compared with a more recent cow population. A particular animal's PTA is supposed to decrease when the base is changed and remain fairly constant between base changes. For most traits, genetic (PTAs) and phenotypic (standardized first-lactation traits) trends comparing cows born in 2010 with cows born in 2005 are equal to or slightly less than trends for the preceding 5 years reported at the previous base change in January 2010. However, cows born in 2010 were before genomic selection had much impact, and trends are faster for calves born during the last 4 years. As a result of updating the base year, the standard deviation (SD) of PTA for each breed is adjusted along with the mean. Yield and somatic cell score records are adjusted for variance within herd and year to have the same SD as the base year using an SD ratio based on calving year. Phenotypic progress due to environmental factors such as management is the difference between genotypic and total phenotypic progress. For Holsteins, genetic improvement is responsible for 86% of the increase in protein yield, 87% of the increase in fat yield, and 132% of the increase in milk yield during the past 5 years; the negative effect of environmental factors on milk yield caused the phenotypic change to be less than the genetic change. Phenotypic progress in yield traits for other breeds also was predominantly the result of genetic improvement. In general, positive progress has been made for most traits through management practices and genetics since the 2005 base change.


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