Follicular dynamics and oestrous detection in Thai postpartum swamp buffaloes (Bubalus bubalis).

This study characterized follicular activity and oestrous behaviour from 5 to 9 days post-calving up to the 4th ovulation postpartum (pp) in 16 multiparous (range 2-7 parities) Thai swamp buffalo cows (Bubalus bubalis), aged 4-12 years and weighing from 432 to 676 kg. Ovarian follicular activity was examined by transrectal ultrasonography (TUS) every morning. Oestrous detection was performed twice daily by direct personal observation of behaviour and for presence of clear cervical mucus discharge and indirectly by video camera recording during 21 h/day. A follicular wave-like pattern was present before the 1st ovulation leading to short oestrous cycles. Growth rates and maximum diameters of the ovulatory follicles did not differ between the 1st and 4th ovulations. However, growth rate for non-ovulatory dominant follicles (DF) before the 1st ovulation was lower than for the ovulatory follicle (p<0.05). In addition, the diameter of all ovulatory follicles (14.3 ± 0.46 mm, n=39) was significantly larger (p < 0.01) than those of the preceding last but one non-ovulatory DF (10.8 ± 0.20 mm, n = 5), but similar to the last preceding non-ovulatory DF diameter (12.92 ± 0.96 mm, n = 14). Short oestrous cycles were most common between the 1st and 2nd ovulations (93.75%, 15/16 cows, 10.2 ± 0.38 days) decreasing in prevalence thereafter (50%, 3/6 buffaloes, 12.0 ± 1.53 days). Oestrous signs were relatively vague around the 1st ovulation pp to become more easily detectable thereafter. This study suggests that properly fed swamp buffaloes could be mated successfully within 2 months pp, at their 2nd spontaneous ovulation, provided oestrous detection is at least performed daily at 06:00-08:00 hour.

Cervical ripening and parturition in cows are driven by a cascade of pro-inflammatory cytokines.

The final stages of cervical ripening and parturition resemble an inflammatory process. Although the role of cytokines in both spontaneous and experimentally induced parturitions has been described in several small laboratory animals and humans, the involvement of pro-inflammatory and regulatory cytokines in physiologic parturition in cows has not been determined. In this study, the cytokine expression profiles were assessed in bovine cervical tissue at several stages of pregnancy and at parturition. Serial biopsy samples of the cervix were obtained from 10 cows on day 185 and day 275 of pregnancy (which was on average 5.4 days before parturition) and at parturition. Messenger RNA expression levels of interleukin (IL)-1beta, IL-6, IL-8, IL-10 and tumour necrosis factor (TNF)alpha were determined using real-time polymerase chain reaction and the number of neutrophils and eosinophils was estimated by Luna and Sirius Red staining. At parturition, IL-8 expression had increased 430-fold (p < 0.001) when compared with that of the day 185 of pregnancy, large numbers of neutrophils had invaded the cervix while eosinophils remained scarce, IL-1beta had increased eightfold (p < 0.05) and IL-6 had not changed significantly. Additionally, IL-10 was increased by 10-fold (p < 0.001) and TNFalpha decreased by 57% (p < 0.05) when compared with that of the day 185 of pregnancy. The large increase in expression of IL-8, enabling the influx of neutrophils, is indicative of its important role in the final stage of cervical ripening and at parturition. As previous studies have shown that neutrophils excrete matrix metalloproteinases (MMP), this might contribute to softening of the cervix. In contrast, the only slightly increased levels of IL-1, steady concentrations of IL-6 and decreased TNFalpha, the potential consequences of increased IL-10 expression, indicate that final cervical of cows in ripening at term parturition is an inflammatory process influenced by regulatory cytokines.

Smooth muscle cells of the bovine cervical stroma may have a secretory, rather than a contractile function during parturition.

The bovine cervix contains a large amount of smooth muscle cells distributed over an outer muscular layer and within a stromal layer. The stromal layer exhibits no electromyographic (EMG) activity at parturition. This leads to the question whether the stromal smooth muscle cells of the bovine cervix are prepared to contract with parturition, or whether they have another function. To this end, cervical biopsies were repeatedly taken from 10 pregnant cows at day-185 and -275 of gestation, at spontaneous, uncomplicated calving and at 30 days after calving. The smooth muscle bundles of the stroma were immunohistochemically analysed (n = 5) with regard to their integrity and cellular density, and the degree of staining for connexin-43, smooth muscle actin alpha (SMA), desmin and vimentin. Additionally, the mRNA expression for connexin-43, SMA, desmin and vimentin was determined with RT-PCR (n = 5). The smooth muscle tissue was arranged in bundles, also at parturition. However, the cellular density of these bundles and the SMA mRNA expression were decreased at parturition. Additionally, the SMA staining and connexin-43 expression and staining remained constant during pregnancy and at parturition. This might indicate that stromal smooth muscle cells are not prepared to contract with parturition, in contrast to the myometrial smooth muscle cells. The smooth muscle cells, stained for SMA, also expressed vimentin, and the proportion of co-expression was increased at day-275 of pregnancy. This suggests that the stromal smooth muscle cells predominantly have a secretory function in cows.

Ultrasonic cervimetry to study the dilatation of the caudal cervix of the cow at parturition.

The objective of this study was to investigate the temporal changes in dilatation of the caudal cervix during induced calvings (n = 5). We used ultrasound cervimetry, allowing the continuous recording of the distance between a transmitting and receiving ultrasound crystal, which were implanted opposite to each other on the caudal rim of the cervix. We started recording between 19 and 21 h after injecting a prostaglandin analogue (PG) on day 272 of gestation. A fluid-filled catheter had been introduced transcervically between the fetal membranes and the uterine wall for measurements of intra-uterine pressure (IUP). While the characteristics of calving varied widely between the five animals, it appeared possible to divide the process of dilatation into four phases. During the latent phase, which lasted until 25-43 h after PG, no net gain in dilatation occurred. We found an acceleration phase (4.3-6.8 h), in which the dilatation rate speeds up (0.49-0.84 cm/h) in three of the cows. During the phase of maximum slope (lasting 0.5-4.8 h), we measured an even higher rate (1.47-8.48 cm/h), decreasing again during the deceleration phase (rate 0.24-2.28 cm/h) in four cows. The quality of the IUP measurements precluded us from continuously investigating the relationship between cervical dilatation and uterine contractions. However, short term simultaneous recordings revealed that the cervical opening changed momentarily in the absence of IUP during the latent phase, while during the phase of maximum slope, temporary changes of dilatation coincided with uterine contractions. We concluded that the method of ultrasound cervimetry used in this study provides a valuable way to study the process of cervical dilatation in parturient cows in vivo.

Fetal heart rate patterns and the influence of myometrial activity during the last month of gestation in cows.

Five cows in the last month of gestation, provided with uterine electrodes and in which catheters had been chronically installed in the fetal aorta, were used to study patterns of fetal heart rate (FHR) and the influence of periods of myometrial electrical activity during gestation (contractures) on FHR. The FHR was calculated by counting the number of blood pressure pulses on the tracings during alternate periods of 12 seconds. Three 1-hour recordings without contractures and 10 recordings during the time of a contracture were randomly selected for each cow. The calculated data points were plotted on a graph to display FHR patterns. In 41 periods associated with single contractures, FHR data points were taken every 72 seconds. Changes in absolute and relative FHR in these periods were determined to analyze a possible effect of contractures on FHR. Three types of variation in FHR patterns could be distinguished: a short-term, low-amplitude variation of basal FHR; a second type in which the duration was < 4 minutes and the amplitude was > or = 15 beats/min; and prolonged periods with increased or decreased FHR values (> 4 minutes and > or = 15 beats/min). The relationship between these types of variation and fetal activity states remains to be established for cows. During the 60 hours of recordings that were analyzed, a period of several minutes during which FHR values were extremely high (> 180 beats/min) was found 3 times. There were no significant differences in absolute or relative FHR before, during, or after a contracture.

Fertility, production and culling following cesarean section in dairy cattle.

A population-based historical cohort study design was used to investigate the effects of a cesarean section on calf mortality, fertility, milk production and culling on 35 Dutch dairy farms. The data were collected during a routine herd health and production control program. Cows undergoing a cesarean section had a higher calf mortality rate, a longer interval from first service to conception and a smaller risk for retained placenta than control cows, those with spontaneous deliveries and those with dystocias. Cumulative milk production at 100 days was lower and the risk of being culled was higher for cows with cesarean sections than for the control cows.

Synchronised calvings after withdrawal of norgestomet implants from cows treated near term with prostaglandin.

To investigate whether calving could be controlled by the withdrawal of progestogen implants from cows treated near term with prostaglandin three cows (group 1) received an intramuscular injection of 5 mg flumethasone on day 270 of pregnancy, and four cows (group 2) and three cows (group 3) received implants containing 3 mg norgestomet in both ears on day 262 of gestation and were treated with a prostaglandin F2 alpha analogue on day 264. On day 270 the implants were removed and at the same time the cows of group 3 were treated with 5 mg flumethasone. Jugular blood samples were taken daily to estimate progesterone concentrations in the plasma. Luteolysis was achieved by the injection of prostaglandin, as judged by the decrease in plasma progesterone concentration in the cows of groups 2 and 3 on day 264. Pregnancy was maintained in these cows until after the removal of the norgestomet implants. The interval from the removal of the implants and, or, the injection of flumethasone on day 270 until the onset of second stage labour ranged from 36 to 47 hours and the mean intervals for the three groups were not significantly different. In all the cows except one from group 3 the dilatation of the cervix and vagina and the softening of the pelvic ligaments appeared normal at calving. It is concluded that calving near term can be synchronised by a progestogen in the absence of a corpus luteum.

Flumethason-induced calving is preceded by a period of myometrial inhibition during luteolysis.

The temporal relationship among changes of the concentrations of the 13,14-dihydro-15-keto metabolite of prostaglandin F2 alpha (PGFM), estrone (E1) and estrone sulphate (E1S) in maternal arterial plasma (MP) and amniotic fluid (AF), the prepartum progesterone (P4) decline in MP, and the evolution of uterine electromyographic (EMG) activity was investigated in 6 cows. Calving was induced by a single i.m. injection of 5 mg flumethason on Day 270 of gestation. The period under investigation was subdivided into four consecutive periods: Period 1 covered the last 2 days before flumethason treatment; Period 2 (mean +/- SEM duration: 16.1 +/- 2.5 h), Period 3 (8.8 +/- 1.1 h), and Period 4 (13.0 +/- 1.5 h) together included the interval between injection and the onset of the expulsive stage of induced parturition. Each was defined by its pattern of uterine EMG activity. During Periods 1 and 2, this activity occurred in long episodes (2-20 min; contractures) at a similar mean (+/- SEM) frequency (0.51 +/- 0.14/h and 0.42 +/- 0.07/h, respectively). No significant differences in hormonal concentrations in MP and AF between these two periods were detected. During Period 3, contractures nearly disappeared (freq: 0.09 +/- 0.05/h), and in MP mean P4 levels were significantly lower and PGFM levels were significantly higher than before. Mean PGFM concentrations in AF were not significantly changed during Period 3. Finally, during Period 4, EMG activity reappeared and a parturient EMG pattern gradually evolved in the presence of a further significant decline of P4 levels and significant increase of PGFM concentrations in MP.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotocography in cows: A method for monitoring calves during delivery.

Fetal ECG-electrodes and an intrauterine catheter were inserted into 15 Holstein-Friesian cows during their first stage of labor to make a cardiotocogram. Simultaneously, fetal heart rate and intrauterine pressure were recorded until completion of fetal expulsion. Immediatly post partum the viability of the calf was assessed by clinical evaluation and measurements of blood pH, base excess (BE) and pCO(2). Fetal heart rate patterns and their changes were evaluated according to standards used in human medicine. Basal fetal heart rate (90 to 120) in 10 calves gradually increased towards the end of parturition, with a marked loss of variability. Decelerations, coinciding with periods of increased intrauterine pressure, occurred in all cows. When decelerations occurred beyond the end of a contraction the calf was born in a poor condition. Accelerations were only recorded in two cows. Many of the fetal heart rate changes observed were similar to those which in human cardiotocography are considered to be signs of fetal distress. Further investigation is needed to establish the predictive value of fetal heart rate patterns in cows, which would be a welcome addition to improved fetal diagnostics during parturition.

Physiological aspects of pregnancy and parturition in dogs.

During late pregnancy (greater than 50 days) the pattern of uterine electrical activity is characterized by episodes of activity lasting 3-10 min and recurring at a low frequency (maximum 2.5/h). During the last 7 days before delivery there is a progressive qualitative change in activity which is correlated with the decrease in plasma progesterone concentration. Together with significant quantitative changes in uterine activity which occur during the last 24 h before parturition and after the sharp fall in progesterone concentration this suggests that progesterone plays a crucial role in the process of parturition in the bitch. Experiments with a calcium-channel antagonist have demonstrated the important role of Ca2+ ions in uterine contractility in dogs, but further investigations will be necessary to illustrate the clinical significance of hypocalcaemia in relation to primary uterine inertia. By marking all fetuses in utero before term by means of a radio-opaque substance, it was demonstrated that, when one or more pups were left in each uterine horn after birth of a pup, 78.2% of the pups were expelled from the contralateral horn. Assessment of the blood gas and acid-base status in spontaneously born puppies indicated that the initial state of acidosis is more severe than in several other domestic species. A mild to severe combined respiratory-metabolic acidosis occurs in almost every newborn puppy.

Accuracy of pregnancy diagnosis and prediction of foetal numbers in sheep with linear-array real-time ultrasound scanning.

Pregnancy diagnosis was carried out in sheep by means of transabdominal linear-array real-time ultrasound scanning. Animals were restrained standing, and the transducer was placed on the hairless area of the ventral abdominal wall just in front of the udder. Of a total of 818 tests, 724 were performed between days 29 and 89 of pregnancy, 598 animals subsequently lambed and 126 were non-lambing animals. Only 8 of these tests were wrong: 3 false positive and 5 false negative diagnoses. Sensitivity, specificity, positive- and negative predictive values for these tests were 99.2%, 97.6%, 99.5%, and 96% respectively. There was evidence to indicate that the three false positive tests were caused by foetal mortality or unobserved abortions that took place after testing. Only 2 of the 5 false negative tests were carried out after day 39 of gestation. Counting of foetal numbers (1, 2 or 3) was performed in only some animals (n = 210) between days 45 and 77 of gestation. Three groups of animals (A: 89 ewes; B: 27 PMSG-treated ewes; C: 94 ewes) were analyzed separately. Overall accuracy of all predictions was 83.1%, 37.0% and 78.7% for the 3 groups respectively. Animals in group B produced only 3 or more lambs. Sensitivity of the countings of singles, twins and triplets or more were 90.4%, 90.4% and 50% respectively for the animals from group A and 91.9%, 86% and 21.4% for the animals from group C.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in oestradiol, progesterone and testosterone concentrations in follicular fluid and in the micromorphology of preovulatory bovine follicles relative to the peak of luteinizing hormone.

Preovulatory bovine follicles (n = 58) were collected at different times after the onset of standing oestrus when cows would allow mounting until shortly before ovulation, which occurred 24 +/- 1.4 h after the peak level of LH in the peripheral blood. Non-atretic antral follicles (n = 71) of 3-20 mm were also collected from cows during the luteal phase of the oestrous cycle. The follicular fluid was aspirated for the radioimmunoassay of oestradiol-17 beta, progesterone and testosterone. The follicular wall was examined micromorphologically. Follicular fluid steroid levels were compared in 2-h periods relative to the LH peak. The development of the preovulatory follicles from onset of oestrus to ovulation can be divided into four phases. Phase 0 (after onset of oestrus but before LH surge) was characterized by a high level of oestradiol (6.05 mumol/l); the levels of progesterone and testosterone were lower (0.387 and 0.165 mumol/l respectively) but higher than in non-atretic luteal follicles of similar size. The theca interna (TI) was wider and the membrana granulosa (MG) cells were larger than those of non-atretic antral follicles. During phase 1 (0-6 h after the LH peak) oestradiol remained constant but at a lower level, progesterone increased (0.727 mumol/l) and testosterone was higher from 0 to 2h after the LH peak (0.241 mumol/l). The TI was 40% wider, whereas the size of the MG cells remained the same. In phase 2 (6-20 h after the LH peak) the level of oestradiol dropped rapidly during the period from 6 to 10 h, that of progesterone decreased to the same level as in phase 0 and that of testosterone was low (0.031 mumol/l). The width of the TI decreased to that of preovulatory follicles in phase 0 and the MG cells were slightly larger. In phase 3 (20 h after the LH peak until ovulation) the level of oestradiol decreased further (0.461 mumol/l) and that of testosterone remained low. Progesterone increased to the highest levels observed (1.51 mumol/l), however, and this coincided with a 39% increase in the size of the MG cells, whereas the width of the TI remained the same as in the preceding phases 0 and 2. In phase 3 the basement membrane began to disintegrate and phagocytic cells could be observed. This points to a simultaneous functional and morphological luteinization. It is suggested that these changes in follicular steroid levels and micromorphology are regulated by the preovulatory LH peak.

Myometrial electrical activity throughout the entire course of pregnancy in the ewe.

Bipolar electrodes were implanted into the myometrium of three cycling ewes. Natural mating took place 35, 47 and 91 days after surgery, and all three animals became pregnant. Two of them were slaughtered 18 and 40 days after mating, the third delivered twin lambs 144 days after mating. The uterine electrical activity was recorded during pregnancy and parturition. From the 3rd until the 27th day after mating the uterus appeared to be quiescent. From the 5th wk of pregnancy until induction of parturition on day 141, electrical activity was observed to occur in episodes of 5--10 min, with a frequency of 1--3 per 2 h. The episodes are separated by periods of inactivity. The amplitudes of the electrical discharges increased gradually during pregnancy, although the plasma progesterone levels increased also. It is concluded that (1) the implanted electrodes did not interfere with normal reproductive processes such as conception, maternal recognition of pregnancy, implantation and fetal development: (2) a distinct pattern of electrical activity can be detected as early as the 5th wk of pregnancy.

In-vivo myometrial electrical activity in the cyclic mare.

Uterine electromyography was performed by means of chronically implanted surface electrodes in 3 Pony mares during spontaneous oestrous cycles and following luteolysis induced by a prostaglandin analogue (fluprostenol). Three distinct patterns were recognized during the oestrous cycle. (1) During oestrus well defined phases of activity with closely grouped high-amplitude spikes were separated by long periods (10-45 min) of complete inactivity. (2) During dioestrus more diffuse phases of activity with low-amplitude spikes were separated by variable periods of relative inactivity. (3) During luteolysis, short and frequently occurring phases of activity were propagated between the two electrodes on one uterine horn; a similar pattern also occurred between 1 and 3 h after injection of fluprostenol. Peripheral plasma progesterone, but not total inconjugated oestrogen, concentrations were closely related to characteristics of the myographic activity during the cycle. Insemination during oestrus and injection of fluprostenol during dioestrus caused a marked and prolonged increase in myometrial electrical activity. Almost any non-specific environmental stimulus, including entry by palpation of the genital tract per rectum and vaginoscopic examination, but these were of brief duration and the normal resting pattern of activity was quickly re-established after completion of the manipulations.

Uterine position and presentation of minipig-fetuses and their order and presentation at birth.

Uterine position and presentation of fetuses in 17 minipigs during pregnancy were compared with their order and presentation at birth. Fetuses from 1 or both uterine horns were marked between day 80 and day 105 of gestation by 1 or more transuterine injections of either a 2.5% solution of dianil blue (3 animals) or a radiopaque substance (14 animals). Roentgenograms of the newborn pigs, which were ear-notched immediately after birth, enabled making individual identification. Pigs seemed to be delivered randomly from the 2 uterine horns. They either followed a neighbor from the same horn (n = 42) or followed a pig from the contralateral horn (n = 52). Only in 3 dams did 1 uterine horn become empty before delivery from the other horn started. In 4 dams, 1 pig passed its neighbor from the same horn, thereby being born earlier than expected. Moreover, passing of pigs could have occurred and gone undetected in those dams from which the pigs of only 1 horn were marked. This passing might have taken place within the uterine body. From 18 of 95 pigs (19%) , the presentation at birth differed from the one observed at laparotomy.

[Vaginitis in the bitch (author's transl)]. / Vaginitis bij de teef.

During a period of two and a half years (2 1/2), sixty-two patients wre submitted to the Department of Veterinary Obstetrics and Gynaecology, where a diagnosis of vaginitis was established. These patients often were young large dogs. Most of the females showed a vaginal discharge, although some bitches were only very attrative to males. There were no complaints concerning the general physical condition of the patients. On clinical examination, the vulva was found to be swollen. Exudation was also frequently observed, externally (vaginoscopy). Ninety per cent of the patients showed normal haemograms. On bacteriological examination, streptococci, E. coli and pasteurellae were often isolated. As a rule the bitches were treated locally (deeply intravaginal), the choice of the drug depending on the results of bacteriological examination. Another bacteriological examination was made after treatment. An inquiry was made into the results of treatment in these sixty-two dogs, wherever possible. On the other hand, the prognosis in those bitches in which bacteriological examination is negative at the time of discharge from the department is likely to be better than it is in those in which bacteriological examination is still positive at that time. The extent to which vaginitis may influence fertility is not known at the time of writing. The differential diagnosis of vaginitis and endometritis may present difficulties.