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 2002





- 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.
 New Test May Help Increase Sheep ProductionBy Amy SpillmanMarch 1, 2002Traditionally, rams in the United States have been selected for breeding purposes on the basis of how quickly they grow and the size they ultimately attain. Soon, however, farmers may have a way to identify another important breeding characteristic before they make their selection. Agricultural Research Service scientists with the U.S. Sheep Experiment Station in Dubois, Idaho, and their collaborators have developed a test to help identify sexually active male sheep.Between 15 and 25 percent of all male sheep in the United States may ignore ewes mating overtures, a statistic that has major ramifications for the U.S. sheep industry. Breeding rams are usually priced between $200 and $400, and their care and maintenance can run up to $100 per year. Buying just one sexually inactive breeding ram can therefore cost a farmer up to $500; the figure goes up even further when considering lost potential.Some livestock industries use artificial insemination as a way of sidestepping the problem of variable male libidos, but this approach incurs additional labor costs. Most of those who raise range and farm flocks of sheep prefer to let their animals breed naturally.The new test--based on research by ARS animal scientist John Stellflug, colleagues at Dubois and collaborators--is based on the premise that libido is closely linked to the ability to secrete testosterone. It measures testosterone response in sires using an injection of naloxone, which blocks certain hormones to stimulate testosterone release. When a male mammal is given an injection, his testosterone response predicts whether he is sexually active or inactive.This test could impact the sheep industry by helping identify which male sheep are sexually active, thus increasing the reproductive potential of entire flocks. By replacing nonproductive males, the industry could save itself both time and money.ARS has obtained a patent on this technology and is seeking a company that may be interested in licensing it and developing a commercial product. Because some researchers have speculated that the technology may be effective for testing other species, its potential impact could be high.ARS is the chief scientific research agency of the U.S. Department of Agriculture.


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