Boost Flock Fertility
August 26, 2005
August 26, 2005 -- Animal scientists from the U.S. Sheep Experiment Station in Dubois, Idaho, continue their work to help producers get the most breeding from their rams. Instead of trying to find the source of the trouble, the researchers discovered it is easier to identify the best performers.
Scientists John Stellflug and Gregory Lewis recently completed their most extensive study on the problem of low sexual performance in rams.
Using about 1,000 ewes and 15 rams, the two researchers wanted to find out which of the tests currently used by the industry is most accurate for predicting mating performance. They even used the latest molecular genetics technology -- including a sheep "paternity test" -- to confirm which rams had impregnated the most ewes and sired the most lambs.
The researchers confirmed that serving-capacity tests, which have been used for at least three decades, are a simple and effective way to identify promising performers. For these tests, producers document how many times a ram attempts to mate when exposed to female sheep in estrous.
For a relatively small investment in time and money, this approach allows producers to spot which of their animals are "high-performance" rams. Stellflug and Lewis calculate that producers could cut the number of rams needed by half, if they were to identify the most promising breeders through screening techniques such as the serving-capacity test.
The Dubois researchers are now conducting experiments to further streamline the serving-capacity test for easier use by breeders who raise and sell rams to sheep producers.