The reproductive efficiency of milk cows is a determining factor for their productivity and economic importance in all countries of the world, so attention is focused on introducing technologies to improve the reproductive management of the herd of cows. This article shows the effect of application of OVSynch and two injections of PGF2α at an interval of 11 days, on pregnancy after blind artificial insemination (without the need for detection of feathers) in heifers and Holstein-Friesian dairy cows. OVSynch was applied by injecting the synthetic derivative of GnRH (buserlin acetate) at a dose of 2ml at a concentration of 0.0042mg in 1ml on the first day, and on the seventh day, she was injected with a dose of the synthetic derivative PGF2α (cloprostenol-Na) at a dose of 2ml at a concentration of 0.263mg in 1ml, and she was treated with a second dose. of buserlin acetate 56h after the dose of PGF2α and then blind artificial insemination was performed 16h after the last injection The research clarified the recommendations necessary to raise reproductive efficiency in proportion to the cost and economic feasibility.