Ultrasonography of the bovine postpartum uterus with retained fetal membranes

Economic Impacts of Ultrasonographic Fetal Sex Determination on Hanwoo Cattle Profitability and Market Dynamics

(1) Background: The Hanwoo cattle industry, valued for its premium beef, faces economic challenges due to fluctuating market prices, rising production costs, and profitability disparities based on calf sex, with male calves fetching higher prices and creating income imbalances for breeding farms. (2) Methods: This study assessed the economic impact of ultrasonographic fetal sex determination, a technology enabling fetal sex identification between 55 and 100 days of gestation, using 107 pregnant Hanwoo cows, of which 104 were successfully assessed with a 96.1% accuracy rate across all gestational stages. (3) Results: Economic analysis revealed that farms employing this technology achieved higher profitability by adjusting prices based on calf sex, with male calves significantly enhancing asset value; however, the technology's financial benefits were influenced by market dynamics, implementation costs, and sex ratios. (4) Conclusions: These findings underscore the potential of ultrasonographic fetal sex determination to improve Hanwoo farm profitability and sustainability, provided its adoption is accompanied by careful consideration of costs and market conditions.

Effect of exogenous estradiol Benzoate on uterine blood flow in postpartum dairy cows

The objective of this study was to assess the uterine blood flow following estradiol benzoate administration in Holstein-Friesian dairy cows by trans-rectal color Doppler ultrasonography. Six healthy lactating Holstein-Friesian cows were examined daily for 10 days starting at 4 weeks postpartum. All the cows, which were clinically healthy based on vaginal mucus scoring and endometrial cytology, were examined by trans-rectal Doppler ultrasonography to measure pulsatility index (PI), resistance index (RI), time average maximum velocity (TAMAX), blood flow volume (BFV) and diameter in the uterine arteries ipsilateral and contralateral to the previously pregnant uterine horn. On the third day of the experiment, the six cows were administered 10 mg intramuscular injection of estradiol-17β (E₂).Blood samples were collected at the time of daily examination for the assessment ofE₂concentrations.The PI and RI values decreased while TAMAX, BFV and diameter of uterine arteries increased in response toE₂ administration (P < 0.05).There was a high correlation between both the ipsilateral and contralateral uterine arteries for all variables that were studied(r = 0.860, P < 0.0001, r = 0.922, P < 0.0001, r = 0.651, P < 0.0001, r = 0.879, P < 0.0001, r = 0.861, P < 0.0001 for the PI, RI, TAMAX, BFV and uterine arteries diameter, respectively).In conclusion, the greater blood concentrations ofE₂may be responsible for the greater TAMAX, BFV, increased diameters and decreased PI and RI of the uterine arteries during the puerperium in dairy cows.

Transrectal Doppler sonography of uterine blood flow during the first two weeks after parturition in Simmenthal heifers

Transrectal Doppler sonography was used to evaluate uterine blood flow during the first two weeks after parturition in six primiparous Simmental cows. The uterine blood flow was evaluated on the day of parturition (Day 0), once daily from Days 1 to 8 and then every other day until Day 14. Blood flow was quantified by determining the diameter (D), the time-averaged maximum velocity (TAMV), the pulsatility index (PI) and the blood flow volume (BFV) of the uterine arteries ipsilateral and contralateral to the formerly pregnant uterine horn. During the first four days after calving D, TAMV and BFV declined (ipsilateral: TAMV 70%, BFV 87%, contralateral: D 47%, BFV 84%; p < 0.05), while PI increased (ipsilateral 158%, contralateral 100%; p < 0.05) distinctly. Between Days 4 and 14 only the ipsilateral D (12%) and the BFV of both arteries (ipsilateral 5%, contralateral 8%) decreased (p < 0.05). Blood flow variables were very strongly correlated with each other (r > ±0.75, p < 0.05), with negative correlations with PI and positive correlations with all other investigated factors. Overall, this study revealed characteristic changes in uterine perfusion during the first two weeks after parturition in cows that were pronounced during the first four days postpartum.

Validation of pressure measurements and electromyographic results for the uterus of cattle during the early postpartum period

OBJECTIVE

To evaluate methods for on-farm measurements of uterine contractility in postpartum dairy cows by comparing data simultaneously recorded by use of 2 intrauterine pressure (IUP) devices and quantified electromyographic (EMG) signals.

ANIMALS

5 cows during the first 48 hours after parturition.

PROCEDURE

2 EMG electrodes were implanted on the surface of the gravid uterine horn. Parturition was induced by injection of a prostaglandin F2alpha analogue at day 274 of gestation. An open-tip catheter and pressure microtransducer were transcervically inserted and affixed to a caruncle immediately after calving. Changes in IUP were recorded concurrent with EMG recordings during 2-hour periods at 2, 6, 12, 18, 24, 36, and 48 hours after parturition. Novel acquisition and analysis software programs were used with a digital data-filtering capability for evaluation of IUP and EMG signals.

RESULTS

The method for intrauterine fixation of the 2 pressure measurement instruments was effective and allowed easy, externally guided removal of the devices 48 hours after parturition. There was a high correlation between the data obtained by the 2 pressure measuring systems. Good correlation was also found between pressure data obtained by the open-tip catheter system and EMG signals. Although the quantified IUP and EMG signals were highly comparable, synchronization was not always evident during visual inspection of these signals.

CONCLUSIONS AND CLINICAL RELEVANCE

The open-tip IUP catheter system with a special fixation method is suitable for use in on-farm studies. It will enable investigators to record natural and pharmacologically influenced uterine contractility in early postpartum dairy cows.

Assessment of early postpartum reproductive performance in two high producing Estonian dairy herds

Early postpartum (6 weeks) ovarian activity, hormonal profiles, uterine involution, uterine infections, serum electrolytes, glucose, milk acetoacetate and blood urea nitrogen (BUN) levels were studied in 2 Estonian high producing dairy herd with annual milk production of 7688 (Farm A) and 9425 (Farm B). From each farm 10 cows, with normal calving performance were used. Blood samples for the hormonal (PGF_2α-metabolite, progesterone) analyses were withdrawn. On day 25 PP blood serum samples were taken for the evaluation of metabolic/electrolyte status. On the same day estimation of milk acetoacetate values was done. The ultrasound (US) was started on day 7 PP and was performed every 3^rd day until the end of experiment. Uterine content, follicular activity and sizes of the largest follicle and corpus luteum were monitored and measured. Vaginal discharge and uterine tone were recorded during the rectal palpation. Each animal in the study was sampled for bacteriological examination using endometrial biopsies once a week. Two types of PGF_2α-metabolite patterns were detected: elevated levels during 14 days PP, then decline to the basal level and then a second small elevation at the time of final elimination of the bacteria from the uterus; or elevated levels during first 7 days PP, then decline to the basal level and a second small elevation before the final elimination of bacteria. Endometritis was diagnosed in 5 cows in farm A and in 3 cows in farm B respectively. In farm A, 5 cows out of 10 ovulated during experimental period and in 1 cow cystic ovaries were found. In farm B, 3 cows out of 10 ovulated. In 3 cows cystic ovaries were found. Altogether 40% of cows had their first ovulation during the experimental period. Three cows in farm A and 5 cows in farm B were totally bacteria negative during the experimental period. The most frequent bacteria found were A. pyogenes, Streptococcus spp., E. coli., F. necrophorum and Bacteroides spp. The highest incidence of bacteriological species was found during the first 3 weeks in both farms. All animals were free from bacteria after 5^th week PP in farm A and after 4^th week in farm B respectively. Serum electrolytes and glucose levels were found to be within the reference limits for the cows in both farms. No significant difference was found between farms (p > 0.05). Low phosphorus levels were found in both farms. Significant difference (p < 0.05) was found in BUN levels between farms. In both farms milk acetoacetate values were staying within the reference range given for the used test (<100 μmol/l). The uterine involution and bacterial elimination in the investigated cows could consider as normal but more profound metabolic studies could be needed to find reasons for later resumption of ovarian activity. Some recommendations to changing feeding regimes and strategies should also be given.

Influence of puerperal uterine infection on uterine involution and postpartum ovarian activity in dairy cows

This article presents the results of a clinical trial designed to study the effect of puerperal uterine infection on uterine involution and on ovarian activity in dairy cows, monitored twice weekly from parturition until the sixth week postpartum (wpp). Infection significantly retarded uterine involution assessed by the uterine body diameter and a score of intrauterine fluid volume (IUFV). By the sixth wpp, cows with normal puerperium (controls) and cows that showed mild puerperal endometritis had similar uterine body diameter and IUFV, indicating spontaneous recovery within the postpartum voluntary waiting period. However, in cows with severe puerperal endometritis, although uterine body diameter had regressed to pregravid size, IUFV remained significantly higher than in control and mild endometritis cows, indicating that chronic endometritis was established. The IUFV score was positively and significantly correlated with uterine swab bacterial growth density and allowed diagnosis of endometritis after the third wpp. Cows with mild or severe endometritis had a significantly higher prevalence and persistence of pathogenic bacteria (Escherichia coli, Actinomyces pyogenes, Gram-negative anaerobes - GNA) than controls. Actinomyces pyogenes was associated to GNA in 74% of isolations. Ovarian activity measured by ultrasound scanning of the ovaries and plasma progesterone (P4) concentrations was more abnormal (prolonged anoestrus, prolonged luteal phases and ovarian cysts) in cows with severe endometritis than in controls.

Effect of tetracosactid on post partum cyclicity in cows after induction of parturition with PGF2 alpha

Parturition and retention of fetal membranes were induced with PGF2 alpha in 3 primiparous dairy cows. Starting on day 12 post partum (PP) the cows were treated with 500 micrograms i.m. of ACTH-analogue (tetracosactid) every 6 h for 6 times. Changes in plasma concentrations of cortisol, progesterone and 15-ketodihydro-PGF2 alpha were evaluated immediately after treatment. The effects on the resumption of ovarian activity were evaluated by clinical and ultrasound examinations and by progesterone and 15-ketodihydro-PGF2 alpha analyses for 56 days after parturition. Treatment was able to induce a statistically significant (p < 0.01) similar increase in cortisol and progesterone after both the 1st and the 6th injections, in all cows. No changes in 15-ketodihydro-PGF2 alpha concentrations were seen after any of the injections of ACTH-analogue. The first corpus luteum (CL) was seen on day 18 PP (cow A), and 28 (cow B) and in both cases it was followed by a normal ovarian cyclicity. No CL was observed during the whole period of study in cow C. Progesterone profiles confirmed these clinical and ultrasonographic findings. The steroid output, especially progesterone, induced by the ACTH-analogue might be a stimulus for the onset of ovarian cyclicity, since 2 of the 3 animals ovulated earlier than expected. These findings point to the fact that interference with the stress system might have a positive effect on ovarian cyclicity. The different pattern of response does however demand further studies.

Induction of parturition with prostaglandin f2 alpha as a possible model to study impaired reproductive performance in the dairy cow

Parturitions were induced in five cows, 2 weeks before term using prostaglandin (PG) F(2alpha). Two i.m. injections were performed with an interval of 24 h. All cows calved within 5 days (average 2.7 days) after the first injection of PGF(2alpha). Out of five cows, four had retained fetal membranes (RFM). Each animal was sampled for bacteriological examination using uterine biopsies twice a week during 42 days postpartum (PP). Jugular vein blood samples were withdrawn for PGF(2alpha)-metabolite and progesterone analyses five times per day during the first week PP and eight times per 24 h during the 2nd and 3rd weeks PP. From the 4th week, the sampling interval was reduced back to five times per day. From the 5th week PP, the sampling was reduced to two times per day and sampling was terminated after day 46 PP. Only morning samples were used for progesterone analyses. From day 10 PP, ultrasonography (US) was performed every 3rd day until day 39 PP for detection of ovarian activity and follicular dynamics. The highest incidence of bacteriological species was found during the first 3 weeks PP. After the 5th week of collection, all animals were free from bacteria. The species of bacteria found were Arcanobacterium (Actinomyces) pyogenes, Escherichia coli, alpha-hemolytic streptococcae and Pasteurella multocida. Immediately after parturition, very high levels of the PG-metabolite were seen in all animals, with a sharp decrease to line of significance around days 9-12 PP. Small increases above the line of significance were detected up to day 27 PP in cows with RFM, and after that time the levels were considered to be at baseline. Low levels of progesterone were seen in four animals during the whole experimental time. In one animal, an increase was seen on day 43 PP, which was maintained until the end of the experimental period on day 46 PP. Based on US, follicular waves were detected in all animals during the experimental period. In three animals, three non-ovulatory follicular waves were detected and in two animals, four non-ovulatory follicular waves were detected during 39 days of ultrasound sessions. Based on progesterone levels, only one animal was considered to have ovulated around day 40 PP. Results from the present study indicate that reproductive performance of cows after PG-induced parturitions differs from those of spontaneous cases of RFM. Differences regarding the resumption of ovarian activity were also observed between previous studies of dexamethasone-induced parturitions and the present study.

Bacteriological and histological investigation of the postpartum bovine uterus in two Estonian dairy herds

Postpartum uterine infections, endometrial histology and resumption of ovarian activity in cows were studied in 2 Estonian dairy herds with different herd sizes, milk yields and management systems. Ten cows at Farm A and 5 cows at Farm B were studied in the experiment. All cows in the study had normal calving performance. Endometrial biopsies for bacteriological and histological examinations were collected once a week starting on the second week postpartum and continuing for 7 weeks postpartum. Milk progesterone samples were collected twice a week during the whole study period. In both herds, the uterine flora contained mainly facultative anaerobic bacteria (Streptococcus spp., E. coli, Staphylococcus spp., Proteus vulgaris). Among obligate anaerobic bacteria only Bacteroides spp. were found. After 7 weeks of collection at farm A, a bacterial uterine flora still persisted in 2 of the cows. At farm B, on the other hand, bacterial elimination was complete after 6 weeks. Presence of inflammatory cells in uterine histology specimens remained higher at the end of collection and resumption of ovarian activity was delayed at farm A. After 7 weeks postpartum, only 6 of the 10 cows at farm A had resumed ovarian cyclicity, while at farm B the first oestrous cycle had occurred in all cows. The study showed that differences regarding uterine infections and their clearance occurred between farms and, despite these differences, cows with normal calving performance will effectively recover without any treatment.

Intrauterine bacterial findings and hormonal profiles in post-partum cows with normal puerperium

The post-partum intrauterine bacterial flora, prostaglandin release, uterine involution and resumption of ovarian activity were studied in 9 Swedish dairy cows during the first 8-week period. Uterine involution was monitored by transrectal examinations of the reproductive tract 3 times weekly. Bacteriological examination was performed from twice weekly uterine biopsies. The main PGF2 alpha metabolite (15-ketodihydro-PGF2 alpha) was monitored from twice daily blood plasma samples, while morning samples were used for progesterone determinations. The cows were assigned to 2 groups: Group I (n = 7) with an uncomplicated puerperal period and Group II (n = 2) with signs of intrauterine infections. A total of 143 biopsies were collected, of which 129 (90.2%) were found to be bacteriologically negative. Thirteen (9.1%) of the remaining 14 biopsies were bacteriologically positive, while one (0.7%) was probably a contamination on a single occasion. The 13 bacteriologically positive biopsies belonged to the Group II cows from which 31 isolates contained 6 different genera of facultative and obligate anaerobic bacteria. Actinomyces pyogenes along with Bacteroides sp. and Fusobacterium necrophorum were found to predominate in a mixed flora. The bacteria were rapidly eliminated and disappeared completely from the uteri towards the end of the third week post-partum. The average number of days required for completion of uterine involution was 21.8 +/- 3.0 for all animals. The plasma levels of the PGF2 alpha metabolite were significantly elevated for the first 12-18, and 18 and 27 days in Group I and Group II, respectively. There was no significant relationship between the duration of PGF2 alpha release and the time required for completion of uterine involution (p > 0.05). Progesterone analysis showed resumption of ovarian activity and subsequent ovulation in 4 of the 9 cows 44-55 days post-partum. Thus, intrauterine infections are not commonly seen in cows with normal calving and comparison between the duration of PGF2 alpha release and the time required for completion of uterine involution showed insignificant correlation. However, the longer duration of PGF2 alpha release recorded in the 2 cows with intrauterine infections are related to the increased frequency of infections.

Prostaglandin F2 alpha metabolite and progesterone profiles in post-partum cows with retained foetal membranes

Post-partum prostaglandin release and resumption of cyclical ovarian activities were studied in 11 Swedish dairy cows with retained foetal membranes (RFM), leaving the RFM untreated. The main PGF2 alpha metabolite, 15-ketodihydro-PGF2 alpha, was measured in blood plasma collected twice daily during the first 50-60 days after delivery. Progesterone was monitored from all morning samples to evaluate the resumption of ovarian activity. The plasma levels of 15-ketodihydro-PGF2 alpha were arbitrarily considered to be significantly elevated between 6-24 days when they exceeded the mean basal value + 2 standard deviations. Comparison between this duration in days of the post-partum PGF2 alpha release and the time required for the completion of uterine involution, placental shedding and last day of post-partum clinical signs showed no significant relations. However, prior to a final decrease below a line of significance of 233-590 pmol/l, pronounced sustained and pulsatile release of PGF2 alpha occurred in relation to the increased frequency of the bacteriological findings. These additional periods of PGF2 alpha release were described as the "total" duration of post-partum release, and were found to be positively correlated with the time required for uterine involution from the stand point of rectal palpation (p < 0.05), while a tendency towards a positive relationship existed for the last day post-partum of clinical signs (p = 0.11). Progesterone analysis revealed resumption of ovarian activity and the first ovulation occurred between 19-29 days in 70% of the cows. The levels of the PGF2 alpha metabolite were again high at the time of luteolysis, thus terminating the luteal phase in the ovulating animals. Thus, it is seen that non-removal of the RFM or the resultant intrauterine infection do not prolong the duration of the immediate post-partum release of PGF2 alpha as compared to normal animals. However, a second release is associated with the increased frequency of uterine infections, indicating that PGF2 alpha may play a role for the early elimination of the infections.

Intrauterine bacterial findings in postpartum cows with retained fetal membranes

Eleven Swedish postpartum cows with retained fetal membranes (RFM) were studied to determine the intrauterine bacterial flora. Bacteriological examination was performed from twice weekly uterine biopsies. A total of 161 biopsies were collected during the first 8 weeks postpartum of which 82 (50.9%) were found with bacterial growth. Seventy-one of the 82 bacteria-positive biopsies (86.6%) showed mixed infections whereas the remaining 11 (13.4%) were pure cultures. Generally, a total of 322 isolates belonging to 12 different genera of bacteria, 6 facultative and 6 obligate anaerobic pathogens were identified. Mixed infections were most frequent for Actinomyces pyogenes together with obligate anaerobic bacteria, especially Bacteroides levii/spp. and Fusobacterium necrophorum. All of the studied cows had an infection that involved the first two genera of bacteria, whereas F. necrophorum was found in 8 of the 11 animals. The present work suggests that a possible pathogenic synergism between A. pyogenes and the two main Gram-negative anaerobes might have caused early endometritis and/or persistent infection.