Economics of treatment with GnRH agonist 7 - 14 days after artificial insemination in repeat breeder lactating dairy cows.

This study looked at the effectiveness and financial benefits of treating repeat breeder (RB) dairy cows with the GnRH agonist gonadorelin 7 to 14 days after artificial insemination (AI). One hundred and eighty-eight healthy dairy cows (2.4 ± 1.3 lactations) with average milk yield of 42.1 ± 6.8 kg milk/day, at 179 ± 38.4 days in milk with 3.8 ± 1 artificial inseminations were divided into two groups, experimental (E group, n = 98) and control (C group, n = 90). The GnRH agonist gonadorelin was given 7 - 14 days after AI to the E group to evaluate the embryo survival in RB cows. The control group did not receive any treatment. Recorded pregnancy rates and cumulative pregnancy rates were superior in the E group (49% and 64.3%) compared with the C group (37.8% and 55.5%). The interaction between therapy and repeat breeder had a significant impact on the pregnancy rate and accessory corpus luteum (CL), according to a binary logistic regression study. The UW-DairyRepro$ decision support tool utilized in this experiment demonstrated that by implementing this approach, the net present value can be increased by US dolars (US$)30.2/RB cow/year. Thus, the single therapy with GnRH agonist gonadorelin between 7 - 14 days after artificial insemination enhanced the potential for a second CL in repeat-breeder pregnant cows, presumably favoring embryo survival.