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, Paul
  Submitted to: Journal of Dairy Science
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 4/29/2004
                                    Publication  Date: 10/1/2004
                                    Citation: Van Raden, P.M. 2004. Selection on net merit to improve lifetime profit. Journal of Dairy Science. 87(10):3125-3131.Interpretive Summary: Genetic selection has made dairy cows more profitable. Terms defined by early animal breeders are still very useful and are now applied to very large populations. Selection indexes provided by USDA included yield traits beginning in 1971, productive life and somatic cell score in 1994, conformation traits in 2000, and cow fertility and calving ease in 2003. This latest revision should result in faster progress worth $5 million per year nationally, with improved health and fitness, but slightly less progress for yield. Inclusion of more traits provides breeders a more accurate summary of lifetime profit. Many other nations provide selection indexes similar to U.S. net merit.
                                Technical Abstract: Genetic selection has made dairy cows more profitable producers of milk by changing a number of income and expense traits. Yield and conformation traits are more heritable than longevity, fertility, and health traits, but many traits may deserve selection because of large economic values and coefficients of variation. Selection indexes provided with USDA evaluations included yield traits beginning in 1971, productive life and somatic cell score beginning in 1994, and conformation traits in 2000. In August 2003, cow fertility and calving ease were included in net merit calculations. Selection using the new formula should result in faster progress for several measures of health and fitness, but slightly less progress for yield. Breeders may prefer to select for fertility instead of longevity because cows have several fertility records but only one longevity record, which is incomplete until the end of life. Fertility and longevity evaluations have similar reliability even though the heritability of longevity is greater. Multiple selection indexes are needed for different production systems and markets; milk volume has positive value for fluid use, but negative value for cheese production. Breeding programs must consider future costs and prices, but these are difficult to estimate. Lifetime profit can be estimated more accurately if more traits are evaluated. Many other nations have derived selection indexes similar to U.S. net merit.


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