Impact of Probing the Reproductive Tract During Early Pregnancy on Fertility of Beef Cows

Abstract

This short communication reports the impact of endometrial biopsies, uterine flushings and follicular fluid aspiration procedures at day 6 post artificial insemination (AI) on pregnancy rates. In Experiment 1, cows were timed AI (TAI) and assigned to the following treatment groups: control (n = 37), uterine flushing (n = 35) and endometrial biopsy (n = 38). On day 30 post AI, pregnancy rates were 40.5%, 33% and 28.5%, respectively (p > 0.1). Pregnancy rate on day 60 was lower (p < 0.004) in flushed cows than in the controls. In Experiment 2, oestrus was detected and cows were assigned to flushing (n = 32) or biopsy (n = 33) treatments 6 days after AI, which resulted in pregnancy rates of 31% and 36%, respectively (p > 0.1). In Experiment 3, cows were, 6 days after TAI, randomly assigned to the following treatments: control (n = 84) or aspiration of the largest follicle (n = 73). Pregnancy rates on day 30 post AI were 63.5% for the control group and 53% for the aspirated group (p > 0.1). In conclusion, uterine flushing and endometrial biopsy negatively affect pregnancy rates, but neither procedure can be considered to be incompatible with pregnancy maintenance. Follicular aspiration during pregnancy does not interact with pregnancy success. The amount and quality of samples obtained are compatible with the use of cellular and molecular analysis of uterine variables from cows that failed or succeeded on maintaining pregnancy.

Endometrial biopsy in Bos indicus beef heifers

“…Another advantage of using the circular cup forceps was the small sample of endometrial tissue recovered. The tissue recovered with this instrument was 2.5 mm which was smaller than those obtained using larger alligator-jaw devices (0.4 × 0.8 cm; Figure 1) (Mann & Lamming, 1994) (Pugliesi et al, 2014). Hence, the use of a small-fragment biopsy device is ideal for minimizing tissue damage and increasing the likelihood of rapid healing after injury.…”

63 Effect of Endometrial Biopsy on Uterine Health of Tropically Adapted Beef Cattle

“…In a prospective cohort study, Pugliesi et al (2014) evaluated the effect of collecting EB 6 days after timed artificial insemination, from the horn contralateral to the CL on pregnancy rates at Day 30 and 60. Uterine tissue was collected using the Hauptner and Eppendorfer device.…”

Effect of endometrial biopsy on uterine health in tropically adapted beef cattle

“…Thus, the presence of cytokines and inflammatory factors within the uterine fluid the day of transfer may have a deleterious effect on embryo development (Hill and Gilbert, 2008). Although Pugliesi et al (2014) collected endometrial biopsies using the Hauptner device six days after insemination from the horn contralateral to the CL accompanied by a simultaneous injection of broad spectrum antibiotics and COX inhibitors, they found lower pregnancy rates at Day 30 in biopsied heifers than non-biopsied heifers. This suggests that even when collecting a biopsy from the contralateral horn, there is still a chance that triggering an inflammatory response could compromise embryo development.…”

“…In a prospective cohort study, Pugliesi et al (2014) evaluated the effect of uterine flushing 6 days after timed artificial insemination on pregnancy rates at Day 30 and 60. The uterine fluid was collected after infusion of 20 ml PBS, from the horn contralateral to the CL from multiparous B.…”

“…In a recent study, Pugliesi et al, (2014) scanned the uterus after EB and found an increase in endometrial vascular perfusion at 6 h that returned to normal 24 h later. This acute increase in uterine blood flow may reflect a transitory inflammatory reaction in uterine horns after the biopsy procedure.…”