Searches on the application of a method of induction and syncronization of estrus in cows postpartum based on two doses of GnRH and prostaglandin F2 α, with programmed insemination

Abstract

The researches were realized in the dairy cattle farm from S.C.D.C.B. Dancu, Iasi, on an experimental lot, composed of 41 cows of Romanian Black Spotted breed (BNR), (Lot E), compared to a control group composed of 45 cows (Lot M). The purpose of this study was to determine the effectiveness of using a new protocol for the induction and synchronization of estrus at dairy cows, using the hormonal products, such as GnRH and PGF2α. The treatments applied to the cows from the experimental group were performed between 31.01.2017 and 23.06.2017, within an average value of 52 days after calving. The therapeutic protocol consisted in the following: administration of the first dose of GnRH (2.5 ml, Receptal=10 μg Buserelin, intramuscularly) on day 0, (regardless of the stage of the estrous cycle); administration of one dose PGF2α (2ml Estrumate=500 mcg Cloprostenol) on the seventh day; administration of the second dose of GnRH on the ninth day and artificial insemination at 18-24 hours after the second dose of GnRH, (without estrus detection). The application of this therapeutic protocol for estrus induction and synchronization at dairy cows with two doses of GnRH and PGF2α in the 45-80 days postpartum period has reduction effects of the intervals: calving to the first insemination and conception, with a positive impact on the reproductive management of dairy farms and the economic implications by the reduction of unproductive costs and of the workforce for the detection of cows estrus.