Conference:Cattlemen's Day, 1999, Kansas State University, Manhattan, KS, March 5, 1999 Starting Page:68, Ending Page:70 Publisher:Kansas State University. Agricultural Experiment Station and Cooperative Extension Service
The Select Synch protocol (GnRH at day -
7, PGF2 at day 0, AI at detected heat) was
compared to protocols using either MGA +
prostaglandin (Colorado system) or two injections
of prostaglandin to synchronize estrus in
replacement heifers at three locations. Percentage
of heifers detected in heat before, during, or
after the target breeding week was not different
among treatments but varied in percentages
among locations. Overall conception rates
ranged from 64 to 69%. Pregnancy rates
varied from 46 to 56% and tended to be greatest
in the MGA + PGF2" treatment. Costs of
these treatments ranged from $3.50 to $8 and
were lowest for the MGA + PGF2 protocol.
Keywords: Beef; Heifers; Estrus-synchronization; GnRH; PGF2; AI