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PubMed1988

[Clinical and bacteriologic studies of the frequency of mastitis during and after parturition in heifers lactating for the first time].

The udders of 100 heifers were examined for clinical changes during parturition. Of each quarter colostral samples were taken and analyzed bacteriologically. 35 heifers (13.5% of the quarters) showed clinical changes of the quarters and/or of colostral samples. 14 of these animals (4.75% of the quarters) suffered from cellulitis-like mastitis. 13 (5.25% of the quarters) had acute catarrhalic mastitis and eight heifers (3.5% of the quarters) showed acute galactophoritis. In all milk samples of animals with pathological changes of the udder or of colostrum the causing bacteria could be identified. Besides the group of 35 heifers with clinical lesions udder-pathogenic bacteria were found in samples of 24 apparently healthy animals (20.5% of the quarters) during parturition. However, these animals failed to show clinical signs of inflammation at least until the end of this study (10 days post partum). Isolated bacteria included facultative and obligate pathogenic species, 70% of which were gram-positive cocci (i.e. Streptococcus [Sc.] uberis, Sc. dysgalactiae, Sc. agalactiae, Staphylococcus aureus and other staphylococci) versus 30% of gram-negative bacteria (i.e. Escherichia [E.] coli, Klebsiella and other coliform species. In-vitro-susceptibility tests showed best effectiveness of Penicillin against Sc., Cloxacillin against staphylococci and Gentamycin and Polymyxin B against coliform bacteria. Possible pathways, leading to bacterial infection of first lactating heifers during parturition, are discussed. Pathways of infection seem to be of lesser importance for the development of apparent, sometimes severe mastitis with coliform bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Influence of a deficient supply of magnesium during the dry period on the rate of calcium mobilisation by dairy cows at parturition.

The influence of a deficient magnesium supply during the dry period on the ability of dairy cows to mobilise calcium at parturition was investigated. The daily rations pre-partum consisted of 6 kg grass hay, and 4 kg concentrates containing either 1.58 per cent magnesium (HMg) or 0.22 per cent magnesium (LMg). Nine cows of parity one to six received the LMg diet and 10 cows of parity one to seven the HMg diet. Both rations provided 1.40 times maintenance on an energy basis and contained 4 per cent potassium in the dry matter. Throughout the dry period the mean concentration of magnesium in the plasma of the LMg group was significantly lower than in the HMg group and at parturition the mean plasma concentrations were 0.65 mmol litre-1 and 1.16 mmol litre-1, respectively. After parturition two cows in the LMg group showed clinical signs of hypocalcaemia but none of the HMg group did so. Cows of the LMg group had a lower mean rate of calcium mobilisation (0.27 mmol min-1) than those of the HMg group (0.34 mmol min-1) but the difference could not be explained by differences in bone turnover as reflected by urinary hydroxyproline excretion. Such a reduced rate of calcium mobilisation may be a contributory factor in the high incidence of milk fever in some herds fed inadequate magnesium in the dry period.

Animal Feed↗
PubMed1987

[The effect of beta-carotene on thyroxine and cholesterol levels in pregnant heifers before and after parturition].

Thyroxine (T4) and cholesterol concentrations and their dynamic changes and differences were studied in 20 pregnant heifers 10 days before calving until 56 days after calving. Ten control heifers were fed the feed ration for pregnant heifers according to Czechoslovak Standard CSN 46 7070. The feed ration given to another ten (experimental) heifers was fortified with 300 mg of synthetic beta-carotene per head/day within the period of five months before insemination, during pregnancy and till the 56th day after parturition. As suggested by the regression function of straight line, no obvious differences were recorded in the dynamic changes of T4 before parturition and during the first days after parturition. T4 concentrations had a generally descending tendency in both groups, the lowest values being recorded in the 48th hour in the experimental group and the 24th hour in the control. A marked increase of T4 concentrations with the values significantly higher in the control group than in the experimental group was observed between the 21st and 35th day after calving. A medium increase of cholesterol concentrations was found in the heifers given rations fortified with beta-carotene. No significant differences in cholesterol concentrations were observed between the two groups, except in the 72nd hour and the seventh day. Significant T4: cholesterol correlations were recorded in the experimental animals in the first and second hours, on the 42nd day (P less than 0.05), and in the 72nd hour (P less than 0.001); in the control group these observations were made the seventh day before calving and in the sixth hour and on the 14th, 21st and 56th days (P less than 0.05) after calving. It is inferred from the results that beta-carotene interferes with the activity of the thyroid gland and the production of its hormones, and that the increases or decreases of the activity of this gland, caused by beta-carotene, influence the metabolism of cholesterol in the body.

Animals↗
PubMed1988

[Changes in N-acetyl-beta-glucosaminidase activity in the maternal plasma and utero-placental tissues during normal pregnancy and parturition].

In the ripening of the uterine cervix during parturition, glycosaminoglycan (GAG) in the cervical extracellular matrix has been reported to undergo drastic changes i.e. the increase in hyaluronic acid, and the decrease in dermatan sulfate and chondroitin sulfate. N-acetyl-beta-glucosaminidase (NAG; EC3.2.1.30), one of marker enzymes of lysosome, may also degrade extracellular GAG in the uterine cervix. This study is undertaken to determine if NAG plays a role in the ripening of the cervix during parturition. The maternal plasma were collected from 252 women with normal pregnancy (5-41 weeks gestation). Amnion, chorion and parietal decidua were obtained from 20 patients at more than 36 gestational weeks who had undergone cesarean section (CS) prior to labor, and from 24 who had undergone CS after the onset of labor. NAG activity in the maternal plasma gradually increased with the advance of gestation, and increased drastically after the onset of labor. The activity in the amnion and decidua, but not in the chorion, decreased significantly in the women who had undergone CS after the onset of labor compared with those who had undergone CS prior to labor. It is concluded that NAG is released into the maternal circulation from lysosomes in amnion and decidua, and it is also estimated that NAG plays a role in the ripening of the uterine cervix during parturition by degrading GAG in the cervical extracellular matrix.

Acetylglucosaminidase↗
PubMed1986

Behavior and viability of the premature neonatal foal after induced parturition.

Parturition was induced in 2 groups of mares, less than 300 (n = 49) and 300 to 320 days gestation (n = 31), by the administration of prostaglandin F2 alpha or fluprostenol and oxytocin. Foals were categorized into 4 groups according to their ability to adapt in, and survive, the neonatal period. Group A had no demonstrable coordinating reflexes, were weak from birth, and all died within 90 minutes. Group B had some righting reflexes, but had poor coordination and a weak suck reflex. They showed some improvement for about 2 hours, but all died within 9 hours. Group C foals had a good suck reflex and made attempts to stand. After 24 hours, there was a steady deterioration and death occurred within 48 hours. Group D were initially weak, but showed rapid clinical improvement with good adaptation to the environment and survived for at least 7 days. The overall survival rate for the 80 foals born was only 5%. Most group A foals had gestational ages of less than 300 days, but a few (n = 9) were delivered after 300 days and 2 up to 319 days. The youngest survivor was delivered at 318 days and the 3 other survivors were delivered at 320 days. Aspects of the hazards of prematurely induced parturition were considered to be immaturity and stress of parturition.

Animals↗
PubMed1987

Effects of calcium and magnesium intakes and feeding level during the dry period on bone resorption in dairy cows at parturition.

A study was made of the influence of low and high calcium intakes at two feeding levels (experiments 1 and 2), and of different magnesium intakes (experiment 3) during the dry period, on the cellular resorptive activity in bone of dairy cows at parturition. In experiment 1 (26 cows) the feed intake was 1.12 times maintenance and the calcium intake was either 13.0 g d-1 or 83.5 g d-1. In experiment 2 (33 cows) the feed intake was 1.9 times maintenance and the calcium intake was either 26.4 g d-1 or 87.2 g d-1. In experiment 3 the cows feed intake was 1.4 times maintenance, the calcium intake was 71 to 72 g d-1 and the magnesium intake was either 16.6 g d-1 or 71.0 g d-1. Bone biopsies were taken from the tuber coxae between three and eight hours after parturition. In experiment 1 the cellular resorptive activity in bone from older cows was higher in the cows receiving the low calcium diet. In experiment 2 the differences between the bone resorptive activities of the two groups were small. In experiment 3 the bone resorptive activity was lower in the cows with a deficient supply of magnesium. There were significant relationships in young cows, but not in older cows, between the cellular resorptive activity in bone and the rate of calcium mobilisation measured biochemically. These results suggest that in older dairy cows bone resorption makes only a minor contribution to the total rate of calcium mobilisation at parturition and is therefore of minor importance for the prevention of periparturient hypocalcaemia.

Animals↗
PubMed1986

[Studies on the relationship between reproductive phenomena and thyroid function--dynamics of the concentrations of thyroid hormones in pregnancy, parturition and puerperium].

Thyroid function during pregnancy, parturition and puerperium was studied by measuring the concentration of free thyroxine (f-T4), free triiodothyronine (f-T3) and reverse triiodothyronine (r-T3) in maternal and cord sera, and simultaneously metabolism of thyroid hormones in chorionic tissues was examined. Results obtained were as follows: In cases of normal pregnancy, maternal f-T4 and f-T3 levels tend to decrease during the course of pregnancy toward parturition. Pathological pregnancies such as intra uterine growth retardation (IUGR) and toxemia (H, h) showed a tendency for maternal f-T3 to decrease and for r-T3 to increase, compared to normal cases at the same gestational age. Maternal f-T3 levels were significantly higher and r-T3 were lower than those of cord sera. Inner monodeiodination activity was found in the placenta, and T4 incubated with chorionic tissue was mainly converted to r-T3. From these findings, it was suggested that the metabolic state of pregnant women would become hypometabolic during the course of pregnancy toward parturition. Higher r-T3 and lower f-T3 levels in pathological pregnant women indicated that T4 to r-T3 conversion might be more dominant than T4 to T3 because of the maternal intensified hypometabolism. In the meanwhile, placental inner monodeiodination seems to prevent active movement of thyroid hormones from the dam to fetus.

Female↗
PubMed1985

Myometrial electrical activity during pregnancy and parturition in the pygmy goat.

To quantify the pattern of myometrial activity during gestation and parturition, one bipolar electrode was implanted on each uterine horn of four bilaterally pregnant pygmy goats between days 102 and 120 of gestation. After a recovery period, electromyographic recordings were made for at least six hours per day and continuously when parturition was judged to be imminent. During late gestation myometrial activity occurred as discrete episodes of myometrial electrical activity (EMEA) with a mean duration ranging from 6.2 +/- 2.07 to 8.3 +/- 1.60 minutes. The mean interval between two successive EMEAs ranged from 45.8 +/- 19.95 to 74.7 +/- 42.27 minutes. In three of the four goats these characteristics were not significantly different from the two uterine horns. Parturition was preceded by a prolonged period (eight to 12 hours) of myometrial quiescence. It was only from 19 to 15 hours before expulsion of the first kid that total duration of EMG activity increased. This finally resulted in the regular occurrence of bursts which occupied 25 to 30 per cent of the recording time. The results demonstrate that, as in the sheep, cow and pig, the myometrium is active during late pregnancy. It is postulated that luteolysis coincides with the prolonged period of myometrial quiescence which precedes the onset of the parturient pattern of uterine activity.

Action Potentials↗
PubMed1979

Induced parturition in swine herds.

Intramuscular injections of various levels of prostaglandin F(2alpha) were administered to 116 pregnant swine in three commercial herds and the University research unit on Day 111, 112 or 113 of gestation. Sixty-three percent of the treated animals farrowed during the working day immediately following treatment. The parturition time, birth weight, litter size, number of piglets weaned, growth of the piglets to weaning and subsequent rebreeding of the dams were comparable with the expected performance in the herds. The results indicated that prostaglandin F(2alpha) in doses ranging from 5 to 12.5 mg per animal were effective for induction of parturition in a substantial proportion of the treated animals. Successful induction of parturition could reduce the farrowing interval for batches, allow more supervision of farrowing, facilitate transfer of piglets from large to small litters and generally increase efficiency in the farrowing unit. This technique could have practical application in intensive swine production units.

Animals↗
PubMed1983

Radiographic diagnosis of canine pregnancy: onset of fetal skeletal radiopacity in relation to times of breeding, preovulatory luteinizing hormone release, and parturition.

The onset and progression of canine fetal skeletal radiopacity were studied in relation to the times of mating, the preovulatory peak in serum luteinizing hormone (LH) levels, and parturition for each of 6 pregnancies. Lateral radiographs were obtained at 2- to 3-day intervals 30 days after mating and at 1- to 2-day intervals during the period fetal skeletons became radiopaque. Radiographs were assessed as to whether fetal elements were absent, barely discernible, distinct, or obvious. Fetal skeletal elements were 1st detected 20 to 21 days before parturition (42 to 52 days after mating and 44 to 47 days after the LH peak). Radiographs of fetal skeletons, sufficiently distinct for an unequivocal diagnosis of pregnancy, were obtained 17 to 20 days before parturition (43 to 54 days after mating and 46 to 49 days after the LH peak).

Animals↗
PubMed1976

[Changes of lactic and pyramic acid levels and of the L/P index in cows and calves during parturition].

The levels of lactic acid, pyruvic acid and L/P index were studied during parturition in cows and calves. The results demonstrate various values of the metabolites studied in dependence on the length of parturient activity and on the way of finishing the parturition. The level of lactic acid increases with protracted parturient activity and that of puruvic acid decreases. Anesthesia applied at the traditional caesarean section hinders the course of fixed acids, which is reflected in the values of the L/P index. An excessive accumulation of fixed acids in mother's organism at the protracted parturition unfavorably influences the metabolism of fetus by means of the fetoplacental bed. Anesthesia does not affect the levels of the metabolites studied in calves. The values of the L/P index are in the same proportion as the levels of lactic and pyruvic acids are.

Animals↗
PubMed1994

Corticotrophin-releasing hormone, proenkephalin A and oxytocin mRNA's in the paraventricular nucleus during pregnancy and parturition in the rat.

Since stress and opioids affect oxytocin secretion we investigated the involvement of corticotrophin-releasing hormone (CRH) and enkephalin on the regulation of oxytocin production during pregnancy and parturition by measuring CRH, proenkephalin A (PENK) and oxytocin mRNA's in the paraventricular nucleus (PVN) using quantitative in situ hybridisation. On day 21 of pregnancy and during parturition CRH mRNA content and the number of parvocellular neurones expressing CRH were significantly decreased but neither PENK nor oxytocin mRNA was altered. The suppression of the CRH gene in late pregnancy and parturition may lead to the previously reported reduction in stress responses during lactation.

Animals↗
PubMed1995

Oxytocin and the timing of parturition. Influence of oxytocin receptor gene expression, oxytocin secretion, and oxytocin-induced prostaglandin F2 alpha and E2 release.

Oxytocin receptor (OTR) gene expression was studied in various tissues of the reproductive tract of pregnant cows and compared with ligand binding activity. Myometrium, intercaruncular endometrium, caruncular endometrium, cotyledons and fetal membranes, as well as the uterine cervix of pregnant cows expressed the bovine OTR gene. Receptor concentrations, measured by ligand binding to crude microsomal pellets, were comparable to OTR mRNA signal strength in all instances indicating that the receptor protein formation is probably regulated at the transcriptional level. During bovine pregnancy OTR gene expression was initiated at different times depending on the tissue. The expression of the gene for OT peptide was not found in any of the bovine uterine tissues but was found in the corpora lutea at term and during parturition and then at relatively low levels. Therefore endogenous OT is derived almost exclusively from the pituitary during bovine pregnancy. OT secretion occurred in a pulsatile manner during pregnancy; a significant increase in pulse amplitude was observed during the last days before delivery and a large surge was associated with active labor and delivery. We postulate that the temporal order of OTR gene expression in the uterine and intrauterine tissues is a factor in the synchronization of the events that eventually lead to the onset of parturition. Because OT receptor mediates different actions in different tissues OT has multiple functions in the mechanism of parturition. The peptide initiates and maintains myometrial contractions, it stimulates release of PGF2 alpha from the endometrium and fetal membranes and, as demonstrated in this study, OT induces PGE2 release from cervical tissues in an OTR dependent manner. We conclude that in pregnant cows, OT participates both in the events that prepare the reproductive tract for birth and initiate the birth process.

Animals↗
PubMed1996

[Effect of dihydroetorphini hydrochloride on mice parturition].

OBJECTIVE: To determine the effect of dihydroetorphini hydrochloride (DHE) on parturition of mice. METHODS: 180 pregnant mice were divided equally into 6 groups. DHE was administered intramuscularly (i.m.) to mice group A, B and C at the dose levels of 1, 2 and 4 micrograms/kg respectively. Morphine hydrochloride 200 micrograms/kg (hypodermic) was given to group D and procaine hydrochloride 1000 micrograms/kg i.m. for group E, while for group F as control distilled water was given. Each preparation was given to the pregnant mice 3 times, i.e. 18 hours before the date of confinement, during labor and 2 hours postpartum. RESULTS: No effects on mice parturition were found in group A, B, E, and F. The percentage of cyanosis in newborn mice of group C and D was 13.8% and 22.8% respectively, which was significantly higher than that (7.4%) in group F. CONCLUSION: DHE is safer than morphine and procaine for analgesia during labor, and no adverse effects of DHE at dose levels of 1 microgram/kg and 2 micrograms/kg were observed on mice parturition.

Abdominal Pain↗
PubMed2004

Mechanisms responsible for parturition; the use of experimental models.

In this review, our knowledge, gleaned from a range of species, of what determines gestation length, how fetal maturation and birth are synchronized and how the uterotonic mechanisms are activated at birth are discussed. Accumulated data indicate that fetal glucocorticoids are involved in, but do not necessarily play a causative role in, the initiation of parturition in eutherian mammals generally. Present observations are consistent with a complex, positive regulatory interaction between estrogens, prostaglandins and oxytocin and are consistent with a role for prostaglandins as the final, common effector in myometrial activation. We are, however, left with the possibility that the initial mechanism for the timing of birth is encoded in the fetal genome and is closely linked to, and activated when, certain prerequisite developmental events have occurred in the fetus. Our understanding of these events in the sheep have led to its extensive use as an experimental model for the study of human clinical correlates of fetal maturation and development and the control of the initiation of parturition.

Animals↗
PubMed2005

Non-invasive faecal steroid monitoring of ovarian and adrenal activity in farmed blue fox (Alopex lagopus) females during late pregnancy, parturition and lactation onset.

In the semi-domesticated blue fox, handling stress may influence reproductive performance and increase perinatal pup loss. Ovarian and adrenal steroids were analysed in faecal samples collected from mid-gestation through the first week of lactation in 40 female blue foxes to characterize hormone patterns during this important reproductive period. Daily faecal samples were collected from 40 foxes during 30 pregnancies, one late abortion and nine bred-matched non-pregnancies. Mean concentrations of faecal progestagens over the 10 days before birth were significantly higher in pregnant compared to non-pregnant females (51+/-1.50 microg/g versus 36+/-3.72 microg/g, respectively; P < 0.01). From 10 to 3 days before whelping, total faecal oestrogen concentrations also were higher (P < 0.01) in pregnant (1082+/-41.69 ng/g) than non-pregnant (628+/-72.43 ng/g) foxes, before declining to non-pregnant values (402+/-24.88 ng/g) after parturition. Overall mean faecal corticoid concentrations from 3 to 20 days before whelping differed between pregnant and non-pregnant foxes (128+/-3.11 ng/g versus 103+/-5.86 ng/g, respectively; P < 0.01). Furthermore, in pregnant foxes, corticoid excretion increased further from 2 days before to 3 days after whelping (216+/-13.71 ng/g; P < 0.01). Thereafter, corticoid concentrations were similar between pregnant and non-pregnant females (P > 0.05). In sum, the faecal steroid hormone patterns for oestrogens and progestagens were similar to those previously obtained by analyses of fox serum hormones, with both steroids being higher in pregnant than non-pregnant foxes at the end of gestation. The elevation in corticoid concentrations in pregnant females suggests that adrenal activation is involved in the initiation of parturition in the blue fox. Thus, faecal steroid analyses can be used to monitor ovarian activity during pregnancy and pseudopregnancy in farmed blue fox females.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Maternal posture during parturition].

Human parturition is a painful and sometimes dangerous physiologic process, which has been managed all over the time through mobilisation and various maternal vertical postures. Three hundred years ago, Mauriceau, a French obstetrician, imposed a semi-recumbent position for the second stage of labor, which became largely adopted in western countries. For three decades, spontaneous positions for parturition have been encouraged, based on anatomophysiologic considerations. There is now sufficient data from randomised trials for recommending maternal mobility during labor and various vertical positions for delivery. Yet, the third stage is sometimes more hemorrhagic and should be managed through preventive measures.

Adult↗
PubMed2005

New insights into the molecular endocrinology of parturition.

The signals that lead to the initiation of parturition have remained a mystery. We postulate that in humans and other mammals, uterine quiescence is maintained by increased progesterone receptor (PR) transcriptional activity, and spontaneous labor is initiated or facilitated by a concerted series of biochemical events that negatively impact PR function. In recent studies, we have obtained compelling evidence to suggest that the fetus signals the initiation of labor by secretion into amniotic fluid of major lung surfactant protein, SP-A. SP-A expression is developmentally regulated in fetal lung and is secreted into amniotic fluid in high concentrations near term (after 17 days postcoitum [dpc] in the mouse). We found that injection of exogenous SP-A into mouse amniotic fluid at 15 dpc caused preterm labor. SP-A activated amniotic fluid macrophages in vitro to express nuclear factor kappaB (NF-kappaB) and interleukin-1beta (IL-1beta). These macrophages, which are of fetal origin, migrate to the pregnant uterus causing an inflammatory response and increased uterine NF-kappaB activity. We suggest that the increase in NF-kappaB within the maternal uterus both directly increases expression of genes that promote uterine contractility and negatively impacts the capacity of the PR to maintain uterine quiescence, contributing to the onset of labor. Our findings, therefore, indicate that SP-A secreted into amniotic fluid by the maturing fetal lung serves as a hormone of parturition.

Amniotic Fluid↗