Synchronization Protocols Enhance AI in Commercial Herds

Using a synchronization program can help commercial producers increase the average calf age, and therefore weight, at weaning, said Dave Patterson, University of Missouri?Columbia.

BILLINGS, Mont. (July 6, 2005) — As a warm-up to this year’s Beef Improvement Federation (BIF) meetings, the National Association of Animal Breeders (NAAB) symposium offered a discussion of technologies that facilitate fixed-time artificial insemination (AI). Speaker David Patterson, University of Missouri, lamented the fact that, despite development of multiple protocols for synchronizing estrus among heifers and cows, commercial cow-calf producers have been slow to adopt AI.

“Other countries are adopting new technologies for animal production more rapidly than the U.S.,” Patterson said, noting how only 10% of U.S. producers currently use AI.

Patterson said beef producers in Brazil AI nearly five times more cows annually than do U.S. producers. Unless owners of commercial cow herds more aggressively implement proven reproductive technologies, he fears the United States will lose its competitive advantage in production of high-quality beef.

“We stand at a unique point in time where we can take advantage of improvements in methods to control the estrous cycle in cattle, as well as a changing market structure where quality is being rewarded,” Patterson said.

The most common reasons that producers shy away from AI include perceptions of high cost and demands on time and labor resources. However, Patterson said a calculated investment in synchronized AI can foster more rapid genetic improvement and better reproductive management.

Currently available procedures involving traditional progestins used sequentially with a GnRH-prostaglandin protocol allow for synchronization of estrus in cycling females, but also allow producers to induce estrus and ovulation in heifers that have not reached puberty or cows that have not returned to estrus after calving. Consequently, females can be bred “by appointment,” through fixed-time AI, rather than through the time-consuming process of heat detection.

Patterson said evidence suggests that protocols for fixed-time AI may result in higher pregnancy rates than use of more traditional synchronization protocols followed by heat detection. But the real payoff to producers comes from the ability to tighten calving distribution. Later calving cows can be bred to calve earlier in the next calving season — during the first or second 21-day interval. Profitability may be increased by reducing the amount of labor required during the calving period, while a more concentrated calving distribution results in an increased average age of calves and more pounds at weaning.

“We’re not to the point with heifers that we are with cows,” Patterson admitted. “But protocols are coming to improve timed AI for heifers. It should further enhance the potential for synchronized AI to improve commercial herds.”

— by Troy Smith, field editor, Angus Productions Inc. © Copyright 2005 Angus Productions Inc.

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