1a. Objectives (from AD-416):
To develop a technique that will enable sheep to be inseminated with frozen-thawed semen using a non-surgical artificial insemination method. Development of this technique will enable sheep producers to better utilize the genetics (semen) of desirable rams for flock improvement and provide the National Animal Germplasm Program (NAGP) with a more efficient, cost effective method for utilizing frozen ram semen samples contained in the repository.
1b. Approach (from AD-416):
The estrous cycle of ewes will be synchronized. Ram semen will be collected and cryopreserved. The ewes will then be inseminated using our newly developed technique at a designated time with fresh or frozen-thawed ram semen. The non-return to estrous rate, the pregnancy rate, and the prolificacy rate (number of lambs born per ewe lambing) will be determined. The results will then be evaluated to refine the techniques to improve the fertility rate in subsequent years.
3. Progress Report:
NATIONAL ANIMAL GERMPLASM PROGRAM (NAGP). Efforts this year focused on 1) identification of an improved estrous synchronization method; 2) determination of the effect of insemination depth on fertility; and 3) identification of a diluent for use with liquid cooled ram semen. Our research resulted in identification of an acceptable diluent, a proper insemination depth, and an adequate estrous synchronization technique in that the results from the artificial inseminations resulted in the same fertility as that achieved using a live ram and estrous synchronized ewes.