Relationship between bovine endometrial thickness and plasma progesterone and estradiol concentrations in natural and induced estrus

The objective of this study was to investigate cyclical changes in endometrial thickness in relation to progesterone (P-4) and estradiol-17 beta (E-2) concentrations during natural and induced estrus in 15 cows. In the prostaglandin (PG) F-2 alpha induced estrus group, ultrasonography (USG) at 6-h intervals was used to determine endometrial thickness 48-24 h before the PGF(2 alpha), treatment until 24 h after ovulation (ovulation = Day 0). In the natural estrus group, USG was performed every 48 h from Day 3 to Days 15-18 after the first ovulation, and then every 6 h until 24 h after ovulation. Endometrial thickness was standardized using Day 13 as a reference day. Blood was collected during every USG examination and plasma P-4 and E-2 concentrations were determined. Endometrial thickness of the induced estrus group (n = 11) was greater than that of the natural estrus group (n = 9) between 60 and 12 h before ovulation (P < 0.05). In the natural estrus group, prior to an increase in endometrial thickness, a decrease in P-4 and an increase in E-2 were detected. In the induced estrus group, based on the time of ovulation, an increase in endometrial thickness was detected at the same time of a decrease in P-4 before an increase in E-2. These results suggest that decreases in P-4 concentrations may be a cue to changes in endometrial thickness, while increases in E-2 concentrations appear to sustain and/or enhance these changes

Association of postpartum diseases occurring within 60 days after calving with productivity and reproductive performance in dairy cows in Fukuoka: A cow-level, retrospective cohort study

Peripartum disorders in dairy cows negatively influence their productivity and reproductive performance. However, only a few reports have clearly indicated the influence of such disorders on the productivity and reproductive performance at a local-area or cow-level in Japan. This study aimed to elucidate the influence of diseases occurring within 60 days after calving on subsequent productivity and reproductive performance. Accordingly, a wide-area database on dairy production was used for epidemiological analysis; subsequently, multivariable analysis was performed to investigate the association of such diseases with productivity or reproductive performance in 6,545 cows from 178 farms in Fukuoka. We used 305-day energy-corrected milk (305 ECM) as an index of productivity and conception and culling as indices of reproductive performance. With regard to causality, mixed-effects model was used for analyzing the association between disease and productivity, and Cox proportional hazard model was used for analyzing the association between disease and reproductive performance. Compared to the disease absence group, the disease presence group demonstrated significantly lower 305 ECM [−154 kg; 95% confidence interval (CI), −229 to −79] and risk of pregnancy [hazard ratio (HR), 0.85; 95% CI, 0.80–0.91] and higher risk of culling (HR, 1.36; 95% CI, 1.17–1.59). These results indicate that, in Fukuoka, dairy cows affected by diseases within 60 days after calving exhibit lower productivity and reproductive performance. Therefore, proper dairy cow management during the peripartum period to prevent diseases during early lactation may maintain or improve productivity

A transvaginal endoscopy-based technique for performing ovarian examinations in sows

For examining pig ovaries, which have complex structures, laparoscopy is a useful technique, but requires general anesthesia; therefore, it cannot be performed repeatedly within a short period of time. We report a transvaginal endoscopy-based technique for conducting ovarian examinations without general anesthesia. Sows were sedated in pig stalls. Using a colonoscope, the vaginal wall was punctured with a trocar. To avoid the trocar being caught in the broad ligament of the uterus or the connective tissue around the vagina, the trocar was inserted close to the external uterine os and between the 2:00 and 3:00 or the 9:00 and 10:00 positions (in a clockwise direction). Then, a urethroscope was inserted into the abdomen, and an examination was carried out after the ovaries had been moved towards the urethroscope camera via rectal palpation. This less invasive procedure may allow repeated examinations and will increase our understanding of ovarian dynamics in pigs

Relationship between bovine endometrial thickness and plasma progesterone and estradiol concentrations in natural and induced estrus

The objective of this study was to investigate cyclical changes in endometrial thickness in relation to progesterone (P_4) and estradiol-17β (E_2) concentrations during natural and induced estrus in 15 cows. In the prostaglandin (PG) |-induced estrus group, ultrasonography (USG) at 6-h intervals was used to determine endometrial thickness 48–24 h before the PGF_ treatment until 24 h after ovulation (ovulation = Day 0). In the natural estrus group, USG was performed every 48 h from Day 3 to Days 15–18 after the first ovulation, and then every 6 h until 24 h after ovulation. Endometrial thickness was standardized using Day 13 as a reference day. Blood was collected during every USG examination and plasma P_4 and E_2 concentrations were determined. Endometrial thickness of the induced estrus group (n = 11) was greater than that of the natural estrus group (n = 9) between 60 and 12 h before ovulation (P < 0.05). In the natural estrus group, prior to an increase in endometrial thickness, a decrease in P_4 and an increase in E_2 were detected. In the induced estrus group, based on the time of ovulation, an increase in endometrial thickness was detected at the same time of a decrease in P_4 before an increase in E_2. These results suggest that decreases in P_4 concentrations may be a cue to changes in endometrial thickness, while increases in E_2 concentrations appear to sustain and/or enhance these changes

Characterization of Reproductive Microbiota of Primiparous Cows During Early Postpartum Periods in the Presence and Absence of Endometritis

Endometritis has a major impact on fertility in postpartum dairy cows. Since previous studies showed an association between reproductive microbiota and perinatal disease, we monitored both bovine uterine and vaginal microbiota in primiparous cows to elucidate the effect of early postpartum microbiota on endometritis. Uterine and vaginal samples were collected at time points from pre-calving to 35 days postpartum (DPP), and analyzed by 16S rRNA sequencing, combined with ancillary bacterial culture. A total of seven healthy cows and seven cows diagnosed with endometritis on 35 DPP were used in the current study. The uterine and vaginal microbiota showed a maximum of 20.1% shared amplicon sequence variants (ASVs) at linked time points. 16S rRNA based analysis and traditional culture methods revealed that Trueperella showed a higher abundance in both uterus and vagina of the endometritis group compared to the healthy group on 21 DPP (U-test p < 0.05). Differential abundance analysis of the uterine microbiota showed that Enterococcus and six bacterial genera including Bifidobacterium were unique to the healthy group on the day of calving (0 DPP) and 28 DPP, respectively. In contrast, Histophilus and Mogibacteriaceae were characteristic bacteria in the vagina pre-calving in cows that later developed endometritis, suggesting that these bacteria could be valuable to predict clinical outcomes. Comparing the abundances of bacterial genera in the uterine microbiota, a negative correlation was observed between Trueperella and several bacteria including Lactobacillus. These results suggest that building an environment where there is an increase in bacteria that are generally recognized as beneficial, such as Lactobacillus, may be one possible solution to reduce the abundance of Trueperella and control endometritis