Use of GnRH and PGF for synchronized ovulation and fixed-time inseminations (1994)

Authors

Y. Kobayashi
Jeffrey S. Stevenson

Keywords

Dairy Day, 1994; Kansas Agricultural Experiment Station contribution; no. 95-141-S; Report of progress (Kansas Agricultural Experiment Station); 716; PGF; GnRH; Ovulation synchronization; Pregnancy rates

Abstract

Holstein cows and virgin heifers were treated with GnRH and PGF in a novel 2a ovulation synchronization protocol, which involves one fixed-time insemination. One injection of GnRH is given on a Monday morning, followed in 7 days with an injection of PGF . Approximately 32 hr later, ovula- 2a tion is induced with a second injection of GnRH, and one insemination is made 18 hr later. Control cattle were given one injection of PGF and inseminated at estrus. Preg- 2a nancy rates measured between 28 and 35 days after insemination by ultrasonography were slightly, but not significantly, higher in controls (52.9%) than in the ovulation synchronization treatment (44.3%). This treatment may be particularly well suited to cows in which estrus is rarely observed, as well as for synchronizing first or repeat services.; Dairy Day, 1994, Kansas State University, Manhattan, KS, 1994;

Recommended Citation

Kobayashi, Y. and Stevenson, Jeffrey S. (1994) "Use of GnRH and PGF for synchronized ovulation and fixed-time inseminations (1994)," Kansas Agricultural Experiment Station Research Reports: Vol. 0: Iss. 2. https://doi.org/10.4148/2378-5977.3286