While the season of the year influences estrous behavior in beef cows, season does not influence the interval from the onset of estrus to ovulation, say Oklahoma State University researchers. Therefore, the onset of estrous behavior can be used to determine when to artificially inseminate in all seasons. Researchers used the HeatWatch system to observe estrous behavior for two consecutive estrous cycles in winter, spring and summer. The cows' behaviors were characterized by the number of mounts, duration of estrus and the longest interval between mounts. Transrectal ultrasonography was used to determine time of ovulation.
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