Effect of prostaglandin F2 alpha administered before estrus synchronization with norgestomet and estradiol valerate on calving rates of beef cows

Author: Written by Kesler, D. J., D. B. Faulkner, R. Machado, F. A. Ireland, and K. E. Tjardes

Journal: J Anim Sci 1996 74: 2076-2080

Abstract: Three experiments were conducted to evaluate the effects of prostaglandin F2 alpha treatments 5, 9, and 14 d before Syncro-Mate B on calving rates of 1,072 beef cows from inseminations at a pre-set time. The administration of prostaglandin F2 alpha 5 d before Syncro-Mate B decreased (P < .01) calving rates. This reduction was associated with lower (P < .05) calving rates in cows administered Syncro-Mate B in the first half of the estrous cycle. Calving rates were unaffected n cows administered prostaglandin F2 alpha 9 d before Syncro-Mate B. The administration of prostaglandin F2 alpha 14 d before Syncro-Mate B reduced (P < .05) calving rates in previously anestrous cows. In summary, prostaglandin F2 alpha should not be administered to postpartum cows 5 to 14 d before Syncro-Mate B synchronization.