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

Abstract

This study looked at the effectiveness and financial benefits of treating repeat breeder (RB) dairy cows with the GnRH agonist gonadorelin 7–14 days after artificial insemination (AI). A total of 188 healthy dairy cows (2.4 ± 1.3 lactations) with an average milk yield of 42.1 ± 6.8 kg milk/day, at 179 ± 38.4 days in milk with 3.8 ± 1 AIs 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 RB 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 dollars (US$)30.2/RB cow/year. Thus, the single therapy with GnRH agonist gonadorelin between 7 and 14 days after AI enhanced the potential for a second CL in repeat‐breeder pregnant cows, presumably favouring embryo survival.

Reproductive Outcomes in High-Yielding Holstein Cows Following Administration of GnRH on Day 5 After Artificial Insemination

“…However, when we evaluated the pregnancy rates and conception rates based on the number of AIs, the G5 group showed an improvement in reproductive activity for nulliparous dairy cows at 2 and +4 AIs and for the repeat breeder dairy cows at +3 lactations. This is consistent with our previous study [1], which showed that administering this therapy 7-14 days after AI improved reproductive activity in repeat breeder cows. This finding indicates that administering gonadorelin during earlier and latter in the luteal phase may increase the survival of embryos in repeat breeders heifers and dairy cows.…”

“…However, the data on the effectiveness of the treatment and the impact of aCL on reproductive performance are not consistent. In our previous study, we confirmed that administering GnRH between 7-14 days after artificial insemination (AI) can increase the number of aCL and improve reproductive performance in repeat-breeder dairy cows [1]. According to the results of Doležel et al, [17], inducing aCL through gonadorelin administration was found to be more efficient in cows treated on day 5 following insemination, as compared to cows treated on days 6 or 7.…”

“…However, we recommend implementing this therapy 7-14 days after AI in repeat breeder dairy cows. It is conclusive, can be done once a week, and has a significant economic impact on the dairy farm [1].…”

Gonadotropin-Releasing Hormone (GnRH) and Its Agonists in Bovine Reproduction II: Diverse Applications during Insemination, Post-Insemination, Pregnancy, and Postpartum Periods

“…It has been found that GnRH administration during the diestrous phase (5–7 days post AI) can increase the proportion of cows with an additional CL, which enhances embryo survival [ 54 ]. Similar results were observed when GnRH was administered between the 7th and 14th days after AI in dairy cows [ 55 ] and lactating buffaloes [ 56 ]. Previous research suggested that GnRH administration on day 12 of the previous cycle improves ovulation and conception rates compared to the control group, and it significantly increases P 4 concentrations in pregnant cows on day 22 [ 57 ].…”

Current Insights in the Repeat Breeder Cow Syndrome

“…A double dose (250 µg) increased the pregnancy rate and suggested that it could improve embryo survival. There is evidence that the administration of GnRH agonists in RBCs between 7 and 14 days after AI stimulates the development of a second CL and promotes embryo survival, resulting in a significant increase in pregnancy rate (11 percentage points compared to the control group) [ 120 ].…”