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MU says new protocol improves pregnancy rate in AI cows

The University of Missouri has developed and evaluated a new estrus protocol it says greatly improves heat response and pregnancy rates to fixed-time A-I in beef cows.

Jordan Thomas, MU Extension beef reproduction specialist, says results from a large field trial found 82% of cows came into heat before the timed A-I service using the protocol 7 & 7 Synch. That compares to 64% of cows in heat using the standard protocol. MU researchers say cows that come into heat before timed A-I generally achieve higher pregnancy rates.

MU graduate students Rachael Bonacker and Carson Andersen have worked in the Thomas lab the past two years developing and evaluating the protocol. Andersen led the large timed-AI field trial, with research results across two states, five operations, 11 cowherds and more than 1,500 cows.

They say pregnancy rates vary depending on whether conventional or sex-sorted semen was used, but rates were improved with both semen types using the 7 & 7 Synch protocol.