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 News & Events News Articles Research News 2003





- ARS News & Events
- AgResearch Magazine
- Image Gallery
- News
- Search News & Events
- Pesticide Drift May Endanger Pollinators
- ARS Seeks a Fire Ant Fix
- Scientific Discoveries 2024
- ARS Featured Photos
- Down on the Farm
- Facebook Live Events
- Food and Nutrition Research Briefs
- News Archive
- Science in Your Shopping Cart
- Scientific Discoveries
- Social Media
- Under the Microscope
- AgResearch magazine
- ARS at Work
- ARS Memorial Lectures
- ARS Science Hall of Fame
- Citrus Disease (Huanglongbing)
- Contact Office of Communications
- Plant Hardiness Zone Map
- Mobile Apps
- Public Affairs Contacts
- Publications and Other Resources
- USDA Blog
- Videos

Archived Page
 This page has been archived and is being provided for reference purposes only. The page is no longer being updated, and therefore, links on the page may be invalid.
 Click image for caption and other photo information.
Read the magazine story to find out more.
Paving the Way for More Widespread Artificial Insemination of Beef Cows
By Don ComisApril 16, 2003
Procedures that cause cows' reproductive systems to have medium-sized, egg-containing follicles could ensure high pregnancy rates when artificial insemination is timed to synchronized ovulations, according to Agricultural Research Service scientists. This would also eliminate the need to detect when cows go into estrus ("heat"), thus removing the main barrier to a more widespread adoption of artificial insemination in beef cows.
Animal reproductive physiologists Tom Geary, with ARS in Miles City, Mont., and Michael F. Smith of the University of Missouri-Columbia, along with University of Missouri graduate student George Perry, learned that follicle size can be an important indicator for identifying less fertile cows, or cows that are prone to having miscarriages. The scientists found that cows which ovulate medium-sized follicles had the highest rate of successful pregnancies, about 70 percent. Those ovulating the smallest follicles had a successful pregnancy rate of only about 30 percent.
A follicle appears like a blister on a cow's ovary as she goes into estrus. Each contains an egg, along with cells that produce the estrogen that causes a cow be in heat.
The follicle-size indicator only worked for cows which were induced to ovulate at the time of artificial insemination. It could be that the most fertile cows grow medium-sized follicles, or it could be that certain ovulation-inducing techniques cause cows to grow medium-sized follicles that lead to higher fertility.
The follicle-size research should help scientists evaluate estrus and ovulation synchronization procedures before conducting large field trials.
The discovery came from two studies--the first with 45 cows in 2001, and the second study with 273 cows in 2002. Ovulation was induced in all cows and produced similar results. In the larger study, miscarriages occurred only in cows which ovulated smaller follicles.
More information about this research can be found in the April issue of Agricultural Research magazine.
ARS is the U.S. Department of Agriculture's chief scientific research agency.


Return to top


Research
                            Media
                            About ARS
                            Work With Us


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