U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


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Published in Proceedings: Conference on Estrous Cycle Control in Domestic Animals, July 9-10, 1964. Published by the Cooperative State Research Service and Agricultural Research Service, U. S. Department of Agriculture, in Cooperation with University of Nebraska. Miscellaneous Publication 1005 (1965).


There are many advantages which result from synchronizing the estrous period in a ewe flock. In situations where the ewes are not hand bred to the ram, the synchronization of estrus makes the application of artificial insemination (AI) techniques more efficient. Detection of estrus usually is more reliable in a synchronized flock. Only 3 to 4 days are needed to detect estrus in 90 percent of a synchronized flock, whereas 16 to 18 days are normally required. This allows the AI technician to plan the number of breedings and have semen available. When hormones are given in the feed, an opportunity is presented for improving the nutritional status of the flock during the breeding period. Synchronization coupled with AI will increase the genetic uniformity of the lamb crop as well as uniformity of age. Attention and labor required at lambing could be easily scheduled and concentrated within a short period of time.