Response of lactating dairy cows with or without purulent vaginal discharge to gonadotropin-releasing hormone and prostaglandin F2α1,2

Abstract

Purulent vaginal discharge (PVD) is a common uterine disease in dairy cattle that has negative effects on reproductive performance. Reproductive management programs that synchronize ovulation use gonadotropin-releasing hormone (GnRH) to induce ovulation and prostaglandin F2α (PGF2α) to induce luteolysis. The objectives of this study were to evaluate ovarian response to treatment with GnRH and the odds of bearing a corpus luteum or being inseminated in dairy cows with or without PVD. Another objective was to determine the hazard of insemination after administration of PGF2α in dairy cows with or without PVD. Primiparous (n = 291) and multiparous (n = 402) cows were evaluated for PVD using a Metricheck device at 46 ± 3 and 35 ± 3 days in milk (DIM) (study day 0), respectively. On study day 14, primiparous (n = 107) and multiparous (n = 197) cows were treated with GnRH and subsequent ovulation was recorded. Primiparous (n = 178) and multiparous (n = 368) cows not inseminated by study day 21 were administered PGF2α and response to PGF2α treatment was determined by detection of estrus. Furthermore, cows were categorized by the presence of a CL or being inseminated by study days 14, 21, and 35. Overall prevalence of PVD was 28.5% and 13.4% for primiparous and multiparous cows, respectively. Projected 305-d milk yield was less (P < 0.01) in PVD+ multiparous cows compared with PVD- multiparous cows, however, no (P = 0.26) difference was detected between primiparous PVD+ and PVD- cows. Ovulatory response to GnRH treatment was 51.8% and 47.8% for primiparous and multiparous cows, respectively. Primiparous PVD- cows tended (P = 0.06) to be less likely to ovulate to GnRH than primiparous PVD+ cows, whereas multiparous PVD+ cows were less (P = 0.04) likely to ovulate to GnRH than PVD- multiparous cows. The odds of bearing a corpus luteum or being inseminated by study days 14, 21, or 35 was not associated with PVD in primiparous cows. In contrast, the odds of bearing a corpus luteum or being inseminated by study days 14 and 21 was (P ≤ 0.03) associated with PVD in multiparous cows, but not (P = 0.11) on study day 35. Hazard of insemination after PGF2α was not (P ≥ 0.38) associated with PVD in primiparous or multiparous cows. Purulent vaginal discharge is associated with response to treatment with GnRH in dairy cattle. Purulent vaginal discharge might negatively affect reproductive management programs that use GnRH to induce ovulation.

The vaginal and uterine blood flow changes during the ovsynch program and its impact on the pregnancy rates in Holstein dairy cows

“…Ovsynch protocols are important for increasing the use of AI with semen from bulls with desired genetic with respect to milk production daughters, but AI does not improve fertility in dairy cattle as conception rates (CR) for AI services after Ovsynch are similar to those for cows inseminated after observed natural estrus [ 4 , 7 ]. New protocols, such as Presynch-Ovsynch and Double-Ovsynch, have been developed to improve the timing of insemination and fertility following AI at a timed AI (TAI) [ 8 – 10 ].…”

The Impact of Different Estrus Synchronization Programs on Postpartum Holstein Dairy Cow Reproductive Performance

“…The detection of estrus is the most critical aspect affecting the reproductive success of artificial insemination programs, because peak estrus activity generally occurs at night, and determining the real commencement of standing estrus without 24 hours observation might be challenging [21]. At least two times per day, early in the morning and late in the evening, are required for optimal heat detection [22]. Induction of ovulation in heifers and cows with cyclic ovarian function utilizing prostaglandins or their analogs via luteolysis; ovulation will occur 2-5 days after treatment; effective observation of cyclicity and detection will power the conception rate [23] [24].…”