Endocrine changes in late bovine pregnancy with special emphasis on fetal well-being

During late bovine pregnancy, several hormones are involved to maintain and develop a successful result with a live calf. These hormones are e.g., progesterone, high levels during the whole pregnancy period, originating from the corpus luteum, maternal adrenals and placenta. Oestrone sulphate, oestrone in its conjugated form, shows elevated levels from about mid-pregnancy until the third stage of parturition (expelling of the fetal membranes). For the onset of normal parturition and the parturition process as such, a change from progesterone to oestrone synthesis is crucial. The increasing levels of oestrone are time-related to an increased synthesis of prostaglandin F(2alpha) (reflected as elevated levels of 15-ketodihydro-PGF(2alpha)) causing prepartal luteolysis and several hormones are then involved in the labour process such as prostaglandin F(2alpha), cortisol and oxytocin. Cortisol might also be an indicator of stressful events for the dam. Levels of pregnancy associated glycoproteins (PAGs), originating from the trophoblastic binucleate cells, are increasing during the last 10 days prior to parturition. All the mentioned hormones have certain functions during pregnancy, more or less understood. However, could deviations from the expected profiles during late bovine pregnancy indicate impaired fetal well-being or be of importance for reproductive performance during the postpartum period? Abortions, stillbirths or dystocia are situations where endocrine profiles might predict the status of the calf. There are two possible approaches to study the endocrine changes in late pregnancy-to follow spontaneous cases of normal or impaired pregnancies or to experimentally disturb the gestation or induce parturition. We have in one study followed pregnant animals to depict reproductive disturbances, both animals with expected normal parturitions and animals where the sire of the calf has given rise to a high incidence of stillborn calves. The number of stillborn calves or dystocia has been small and so far it has not been possible to obtain a clear picture of the usefulness of endocrine parameters to follow fetal well being, but some of the hormonal parameters show a deviating profile. In a small group of animals with induced parturition (PGF(2alpha)), two out of three had parturition problems and one of these animals had a stillborn calf. All three animals had retained fetal membranes. It was possible to demonstrate a deviating endocrine profile in the cow having the stillborn calf in the sense of higher levels of progesterone, cortisol and 15-ketodihydro-PGF(2alpha) at the time of parturition. In both animals with dystocia the levels of oestrone sulphate after parturition were more sustained. Increasing and high levels of PAGs were only demonstrated in the animal with a normal parturition. These studies are ongoing, aiming at finding changes in endocrine profiles related to impaired pregnancies.     

Effects of twinning on gestation length, retained placenta, and dystocia

Constraints to maximal productivity from twinning in beef cattle include increased incidence of dystocia and retained placenta, longer postpartum interval, and lower conception rate. Incidence and cause(s) of the shorter gestation length and of the increased retained placenta and dystocia associated with twinning were evaluated for 3,370 single and 1,014 twin births produced in a population of cattle selected for natural twin births. Gestation length was shorter for twin than for single pregnancies (275.6 vs. 281.3 d, P<.01) and likely contributed to the higher incidence of retained placenta associated with twin births (27.9 vs. 1.9%; P<.01). Incidence of retained placenta was also higher in the spring (March-April) than in the fall (August-September) calving season (18.3 vs. 11.4%; P<.01). The higher incidence of dystocia with twins than with singles (46.9 vs. 20.6%, P<.01) was primarily due to abnormal presentation (37.0 vs. 4.5%, respectively) of one or both twin calves at parturition. First- (40.5%) and second- (22.7%) parity dams with a single birth had more (P<.01) dystocia than older dams (13.4%), whereas dystocia was not affected (P>.10) by parity with twin births. Because of the shorter gestation length and the increased incidence of retained placenta and(or) dystocia, achievement of increased productivity with twinning in cattle necessitates intensive management of twin-producing dams and their calves during the calving season. Management of the increased dystocia can be facilitated by preparturient diagnosis of twin pregnancies, enabling timely administration of obstetrical assistance to facilitate delivery of twin calves and to increase their neonatal survival.     

Use of Luprostiol and Cloprostenol for Induction of Parturition in Pregnant Goats

Pregnant goats were induced to parturition on day 145 of pregnancy, with three different protocols: group Cl (n = 19) was injected intramuscularly (IM) with 75 μg of the prostaglandin analogue R‐Cloprostenol; group L (n = 20) was treated IM with 7.5 mg of the prostaglandin analogue Luprostiol; group L₅₀ (n = 18) was injected IM with 3.75 mg of Luprostiol (IM); in addition, Group S (Control, n = 15) was injected IM with 1 ml of saline solution. Thereafter, goats were continuously observed to record the following parameters: parturition, dystocia incidence, placental delivery and kid and maternal survival. Moreover, blood sampling was performed around kidding and plasma progesterone concentrations were analyzed. The interval from injection to parturition (mean ± SEM) was not significantly different among the experimental groups: 35.1 ± 1.5 h, 33.3 ± 0.9 h and 34.1 ± 1.8 h (groups Cl, L and L₅₀, respectively). In the control group, time to parturition was 99.4 ± 12.1 h (range: 34–166 h). All the goats expelled the foetal membranes within the first 2 h after the induction. The incidence of dystocia due to foetal posture was not significantly different between induced and control goats (21.1%, 20.0%, 22.0% and 20%, for groups Cl, L, L₅₀ and S, respectively). The percentage of live kids was practically similar between induced goats (93.9%, 94.9% and 92.1%, for groups Cl, L and L₅₀, respectively); in addition, there was a case of maternal mortality in control group (6.7%; 1/15), whereas there was no mortality in induced goats (0%; 0/57). Plasma concentrations of progesterone showed an intense drop (<2 ng/ml) at 24 h after induction. This study confirms the effectiveness of the luprostiol to induce the parturition in goats, within a narrow range (30–40 h) in most of the induced females (80.0%, 7.5 mg; 77.8%, 3.75 mg).     

OC13Induction of Parturition in Canary Goats with Luprostiol

Twenty-two pregnant goats of the Canarian breed were administered 10 mg of the prostaglandin analogue luprostiol intramuscular (IM) on day 145 of pregnancy; seventeen pregnant goats were injected IM with saline solution the same day. Twenty hours after luprostiol application, goats were continuously observed in order to record the following parameters: parturition, dystocia incidence, placental delivery and live births. Parturition was successfully induced in all goats; the mean interval to parturition (first kid delivery) was of 32.9 ± 1.0 (SEM) hours (h) and the range varied from 21 to 41 h; in addition, no significant differences (p > 0.1) were detected between nuliparous and multiparous goats (31.3 ± 1.3 h and 34.7 ± 1.2 h, respectively). In the control group, the interval from saline injection to parturition was 75.9 ± 12.5 h (mean ± SEM), showing a range between 34 and 138 h. All the goats expelled the fetal membranes in the first 6 h after the induced or natural parturition. The incidence of dystocia due to fetal maldisposition was not significantly different between induced and control goats (9.0% and 11.8%, respectively). In addition, the percentage of live kids was practically similar between both groups (90.7% and 88.0%, induced vs control goats). This study confirms the effectiveness of the luprostiol to induce the parturition in goats, showing a narrow range (30–37 h) in most of the induced females (86.3%; 19/22 goats). The administration of prostaglandin analogue is a basic tool to plan kidding, allowing a effective concentration of effort and resources at the time of parturition.     

Plasma Concentrations of 13, 14‐Dihydro‐15‐keto‐Prostaglandin F2α, Progesterone and Cortisol During Periparturient Period in Yaks (Poephagus grunniens L.)

An attempt was made to determine plasma concentrations of, 13, 14‐dihydro‐15‐keto‐prostaglandin F_2α (PGFM), cortisol and progesterone during periparturient period in yak. Plasma PGFM level showed an increasing trend beginning day 5 prior to parturition (0.48 ± 0.14 ng/ml) and increased steeply thereafter to reach a peak level (17.16 ± 1.31 ng/ml) on the day of parturition. The levels, then, declined sharply on day 1 postpartum to reach 1.20 ± 0.40 ng/ml and thereafter declined gradually over the days to reach 0.28 ± 0.09 ng/ml on day 20 postpartum and this level was maintained with fluctuation within narrow limits thereafter till conclusion of the blood sampling on day 90 post‐calving. The plasma progesterone concentration on days 7 and 6 before parturition was high (2.10 ± 0.10 and 2.12 ± 0.10 ng/ml, respectively). The level then decreased gradually and abrupt fall was observed 1–2 days before parturition and became basal on day of parturition (0.24 ± 0.04 ng/ml). This basal level was maintained till the end of the blood sampling on day 90 postpartum. Plasma cortisol level showed an increasing trend beginning day 2 prior to parturition (2.36 ± 0.65 ng/ml) and increased steeply thereafter to reach a peak level (26.65 ± 5.28 ng/ml) on the day of parturition. The levels, then, declined gradually over the days and touched 2.36 ± 0.25 ng/ml on day 3 postpartum and this level was maintained with fluctuation within narrow limits thereafter till day 7 post‐calving.     

Common Peripartum Problems in the Mare

Reproductive problems in the perinatal period can adversely affect a mare's future fertility or, worse, may be life threatening to her or her foal. A number of abnormalities can occur, including uterine torsion, uterine artery or uterine hemorrhage, retained fetal membranes, metritis, rectovaginal injuries, and necrotic vaginitis. Because hemorrhage, retained placenta, metritis, and necrotic vaginitis can happen after a normal delivery or after dystocia, all mares should be monitored closely in the first days after parturition for signs of lethargy, depression, colic, sore feet, or anorexia. Methods for diagnosing, managing, and treating these conditions and the possible complications are discussed.     

Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.

Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity. Daily blood samples were obtained from pregnant cows, starting 15 days before the expected day of calving until eight days after parturition. Sera from 15 cows which retained fetal membranes longer than 24 hours and 15 cows which shed fetal membranes within six hours after parturition were analyzed for alkaline phosphatase and lactate dehydrogenase enzyme activities. Mean alkaline phosphatase enzyme activities ranged from 15.93 to 32.6 U/L in retained and nonretained placenta cows. There was a trend towards higher serum alkaline phosphatase activities in retained placenta cows but the differences were not significant among the groups (P greater than 0.05). Mean lactate dehydrogenase activities ranged from 307.2 to 438.86 U/L in nonretained and retained placenta cows. Lactate dehydrogenase enzyme activities in nonretained and retained placenta cows were similar (P greater than 0.05). The alkaline phosphatase and lactate dehydrogenase enzyme activities peaked at the time of parturition in both groups. However, the differences in alkaline phosphatase and lactate dehydrogenase activities on different days within non-retained and retained placenta cows were significant (P less than 0.05). Results indicate that prepartal changes in alkaline phosphatase and lactate dehydrogenase enzyme activities are not predictive of placental retention postpartum.     

Physiology and Treatment of Retained Fetal Membranes in Cattle

Retained fetal membranes (RFM) in cattle have adverse effects on fertility and production. Understanding the pathophysiology and causes of RFM is important for managing this disease. The hormonal processes that lead to normal placental separation are multifactorial and begin before parturition. A variety of risk factors, including early or induced parturition, dystocia, hormonal imbalances, and immunosuppression, can interrupt these normal processes and result in retention of the placenta. Current research does not support the efficacy of many commonly practiced treatments for RFM. Systemic administration of antibiotics can be beneficial for treating metritis after RFM, but antibiotic administration has not been shown to significantly improve future reproduction in cows with RFM. Collagenase injected into the umbilical arteries of retained placentas specifically targets the lack of placentome proteolysis and might enhance placental release. However, such therapy is costly and its benefits in terms of improving subsequent reproductive function have not been evaluated.     

Outcome and subsequent fertility of sheep and goats undergoing cesarean section because of dystocia: 110 cases (1981-2001)

OBJECTIVE: To determine the outcome and subsequent fertility of sheep and goats undergoing a cesarean section because of dystocia. DESIGN: Retrospective study. ANIMALS: 85 sheep and 25 goats. PROCEDURE: Medical records were reviewed, and information was obtained on signalment, history, physical examination findings, anesthesia protocol, surgical technique, number of lambs or kids delivered, pre- and postoperative treatments, duration of hospitalization, and postoperative complications. Follow-up information was obtained through telephone conversations with owners. RESULTS: The proportion of sheep admitted to the veterinary teaching hospital during the study period that underwent a cesarean section (4.4%) was significantly higher than the proportion of goats that did (2.2%). Pygmy goats were overrepresented, compared with the hospital population. The most common reason for cesarean section was inadequate dilatation of the cervix. The most common surgical approach was via the left paralumbar fossa. Two hundred one lambs and kids were delivered, of which 116 were dead at delivery or died shortly afterward. Forty-two of the 65 dams with 1 or more dead fetuses had been in stage-2 labor for > 6 hours, and fetal death was significantly associated with a prolonged duration of dystocia. The most common complication following surgery was retained placenta (n = 49). Use of antimicrobials was associated with a lower rate of complications. All 16 dams that were rebred became pregnant and had no problems with dystocia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cesarean section is an effective method of resolving dystocia in sheep and goats and does not adversely affect subsequent fertility.     

Induction of parturition with aglepristone in the Majorera goat

This study assessed the efficacy of aglepristone at inducing parturition in pregnant goats. Six experimental groups were defined: group A-5 (n = 12), group A-3.3 (n = 12), group A-2.5 (n = 12) and group A-1.5 (n = 12) in which goats were injected SC once with 5.0, 3.3, 2.5 and 1.5 mg of aglepristone per kg body weight of goat, respectively, group L (n = 11), which was treated IM with 3.75 mg of luprostiol; and group Ct (n = 11), which was injected SC with 1 ml of saline solution. Different parameters associated with parturition were thereafter investigated. In addition, plasma progesterone concentrations were defined after treatments till parturition. Aglepristone effectively induced parturition in all of the goats. In the A-5, A-3.3 and A-2.5 groups, the time to parturition was around 30-34 h, and the majority of goats (97.2%, 35/36) started kidding between 25 and 40 h after the aglepristone injection. However, the goats in group A-1.5 showed a significantly (p < 0.01) higher time to parturition (mean: 46.8 h). Overall, the incidence of dystocia registered in aglepristone-induced goats (20.8%, 10/48) and luprostiol-induced goats was not different from that observed after a spontaneous parturition. The percentage of live kids was very similar between A-5, A-3.3, A.2.5 and L groups (95.7, 95.3, 95.0 and 96.3%, respectively) but was higher that observed in the control (83.4%) and A-1.5 (81.2%) groups. In addition, no maternal mortality was registered in any groups. No changes in plasma progesterone were observed during the first 24 h after treatment, and high plasma progesterone concentrations were present at kidding (6.7, 5.5, 4.5 and 3.6 ng/ml for groups A-5, A-3.3, A-2.5 and A-1.5, respectively), confirming that aglepristone does not induce parturition via luteolysis. This study demonstrates that aglepristone can be used to induce parturition in goats with satisfactory efficacy, inducing pregnancy termination without direct or immediate modifications of luteal function.     

Adrenocorticotropic hormone-induced secretion of cortisol in goats is inhibited by androgen

In a previous study, it was found that there are sex differences in goats with respect to the levels of cortisol secretion induced by transportation stress. We also found that treatment of castrated male goats with dihydrotestosterone (DHT) suppressed the increase in plasma cortisol concentration following transportation, but did not suppress the secretion of adrenocorticotropic hormone (ACTH). This suggests that androgen might block ACTH ‐ induced cortisol secretion. In order to examine this hypothesis, the effects of androgen on ACTH‐induced cortisol secretion in goats were investigated. First, castrated male goats were treated with testosterone (T), DHT or cholesterol (cho) for 21–25 days. Cho was used as a control for T and DHT treatment. Then, plasma cortisol concentrations were compared among the hormonal treatments after ACTH injection. Subsequently, the distribution of androgen receptors in the caprine adrenal gland was investigated. There were no differences in the basal cortisol concentrations among the hormonal treatments. However, plasma cortisol concentrations after ACTH injection were significantly lower in T ‐ and DHT ‐ treated goats than in cho ‐ treated goats. Androgen receptors were present in 60% of the cells in the zonae fasciculata and reticularis of the adrenal cortex, the regions that secrete glucocorticoids. These results suggest that androgen may act directly on the adrenal cortex to suppress cortisol secretion induced by ACTH.     

Effects of twinning on postpartum reproductive performance in cattle selected for twin births

The effects of twinning, dystocia, retained placenta, and body weight on postpartum reproduction were evaluated for 3,370 single and 1,014 twin births. Females were bred by AI for 40 d followed by 20 or 30 d of natural service with equal numbers bred and calved in spring and fall. Percentage of dams cyclic by the end of the AI period was lower (P<.05) for dams birthing and nursing a single calf (92.4%) than for dams birthing twins and nursing zero (98.7%) or two (94.7%) calves. Whereas the interval from parturition to first estrus was shorter (P<.01) for dams birthing and nursing a single (56.9 d) than for dams birthing twins and nursing one (68.5 d) or two (69.6 d) calves, length of the interval was further reduced by dystocia in nonlactating dams of either twins or singles (type of birth x dystocia, P<.05). Ensuing pregnancy rates were also affected by type of birth and dystocia. Without dystocia, dams birthing and nursing a single calf had a higher pregnancy rate (79.2%) than dams birthing twins and nursing one (61.7%) or two (66.3%) calves, whereas the lower ensuing pregnancy rates associated with dystocia in dams of singles (71.9%) resulted in similar rates among dams of singles and twins with dystocia (type of birth x dystocia; P<.01). Having a retained placenta resulted in a lower incidence of (93.5 vs. 96.4%, with vs. without; P<.05) and a longer interval to (64.7 vs. 59.2 d; P<.01) estrus while reducing subsequent pregnancy rates (X = 9.6%) in 3 of the 7 yr evaluated (retained placenta x year, P<.01). Because all parous females were bred during the same calendrical period, the shorter gestation length for twin calves (275.6 vs. 281.3 d) resulted in a longer interval from parturition to conception for twin births, whereas means for conception date differed by only 2 d between dams of twins and singles. Furthermore, a reduction (P<.01) in the interval to conception occurred with dystocia in dams of singles (89.3 vs. 85.0 d, without vs. with dystocia) and of twins nursed by zero (116.9 vs. 83.5 d), one (100.2 vs. 92.8 d), or two (96.1 vs. 97.2 d) calves. Another detriment to fertility was the higher incidence of fetal mortality or abortions associated with twin vs. single pregnancies (12.4 vs. 3.5%; P<.01). However, despite the lower conception rates for dams of twins, the increased prolificacy provides an opportunity to increase total beef production with a twinning technology.     

The Cow in Endocrine Focus Before and After Calving

During the period 1 month before and 1 month after parturition in the cow, several events take place. The dam has to be prepared for the impending parturition and the uterus and ovaries must return to a certain stage to be prepared for a new pregnancy. Most of these processes are due to or reflected in endocrine changes. A special interest is of course the status of the foetus --"foetal well being". The processes could either be considered as normal in a clinical perspective or as impaired (dystocia, small calves, stillbirth, retained foetal membranes, etc.). The main question for this presentation is if normal and impaired performance could be mirrored in endocrine parameters. Many studies have been performed to follow endocrine changes during the periparturient period in the cow. The following parameters have been shown to be the most important and seem to be the most suitable for an endocrine supervision: Endocrine parameter: progesterone; parameter of: corpus luteum, maternal adrenals, placenta. Endocrine parameter: prostaglandin (PG) metabolite; parameter of: placenta, uterus, inflammation. Endocrine parameter: cortisol; parameter of: regulator of prostaglandin synthesis, stress. Endocrine parameter: free oestrogens; parameter of: placenta, ovaries. Endocrine parameter: oestrone sulphate; parameter of: placenta, calf weight. Endocrine parameter: pregnancy-associated glycoproteins (PAG); parameter of: placenta.     

A comparative study on behavioral,physiological, and adrenal changes in buffaloes during the first stage of labor with normal and difficult parturition

The present study was primarily carried out to trace the behavioral, physiological, and adrenal changes during the first stage of labor in cases of dystocia, either in parturient buffalo heifers or cows, and their clinical significance. Of the 118 investigated buffalo herds, 40 cows (dystocia = 20 and eutocia = 20) and 40 heifers (dystocia = 20 and eutocia = 20) were used in this study. Cows approaching actual birth were transferred to a calving box with straw bedding. Behavior of the studied animals was recorded from the time that the animal was moved to the calving box until the emergence of the fetal limbs in the vulval lips. If no progress in parturition was observed within two hours after the rupture of fetal sacs (end of the first stage), these cases were considered as suffering dystocia. As the fetal limbs emerged from the birth canal, animals were examined clinically to determine their average pulse and respiratory rates as well as body temperature. Blood samples were collected to determine the cow/heifers cortisol level. Results of the present study indicated that dystocia was accompanied by disturbed physiological status and cortisol levels. Practical monitoring system of parturient animals, through observing behavioral, physiological, and adrenal aspects during calving, should be regarded to expect dystocia and provide help for the animal in the appropriate time.     

15-ketodihydro-PGF2 alpha, progesterone and cortisol profiles in heifers after induction of parturition by injection of dexamethasone.

In order to study rapid changes in 15-ketodihydro-PGF2 alpha, cortisol and progesterone in the period preceding parturition in cattle, pre-term parturition was induced in 4 late pregnant heifers. Parturitions were induced by 2 intramuscular injections of 20 mg dexamethasone with a 24-h interval. The first injection was made on days 254, 258, 264 and 265 in gestation, respectively. Twenty-four h before the first injection an intravenous polyurethane cannula was inserted. Blood samples were collected at least every hour until 12 h after parturition and during the second stage of labour at least 6 times per hour. Plasma was analysed for 15-ketodihydro-PGF2 alpha and progesterone by radioimmunoassays, and for cortisol by an ELISA. The average time from injection to parturition was 7.7 (6.6-8.9) days (mean (range)). Two of the heifers had retained foetal membranes (RFM). At the start of the experiment the levels of PGF2 alpha metabolite were low (< 300 pmol/L) and increased slowly to levels between 1000 and 2000 pmol/L at one day before parturition. During the last day, however, the levels increased rapidly and the highest levels (> 10,000 pmol/L) were reached at the time of delivery. No pulsatile release was seen. Immediately after foetal expulsion the PG-metabolite levels decreased rapidly in all animals. In the 2 animals with RFM, however, this decline ceased within a few h. The PG-metabolite levels in these animals then started to increase and reached levels as high as during parturition. Luteolysis occurred between 1.6 and 0.4 days before parturition in all animals. The cortisol profile showed a distinct peak at the time of parturition in the RFM heifers. This peak was absent in the non-RFM heifers. This study shows that the PGF2 alpha release at prepartal luteolysis and parturition is not pulsatile in cattle and that cortisol profiles in heifers with retained foetal membranes might differ from the profiles in non-RFM heifers at the time of parturition.     

Effects of gonadotrophin releasing hormone on reproductive performance of dairy cows with retained placenta.

The effects of gonadotrophin releasing hormone (GnRH) on the reproductive performance of dairy cows with retained placenta were studied. Three hundred and seventy-eight cows diagnosed as having retained placenta received intramuscular injections of either 2 mL sterile water or 200 micrograms of GnRH in 2 mL sterile water between day 8 and day 14 postpartum. Rectal palpation was performed at the time of treatment and ten to 20 days after treatment in order to determine the rate of uterine involution. Thereafter, monthly rectal examinations were carried out until insemination. Pregnancy diagnosis was made by rectal palpation at 40 days or more after breeding. Using the entire experimental population, there were no significant differences between GnRH-treated and control cows for the rate of uterine involution, the occurrence of reproductive problems, the interval from parturition to first observed estrus, the interval from parturition to first insemination, the interval from parturition to conception, the number of services per conception, the total number of services per cow regardless of conception and the incidence of culling for infertility. When the data for herds in which breeding began earlier in the postpartum period (herds having a mean less than or equal to 80 days from parturition to first service for retained placenta cows) were considered, the GnRH treatment resulted in a significantly shorter (p less than or equal to 0.01) calving to conception interval as compared to control cows. Also, there was a significant reduction (p less than or equal to 0.05) in the total number of services per cow regardless of conception and a significant reduction in the interval from parturition to first service.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of oxytocin on placental retention following dystocia

A double blind randomised clinical trial was performed to assess the effects of oxytocin on the duration of placental retention following dystocia. If the placenta remained attached to the uterus immediately following assisted delivery of a calf, and was not expelled in the period taken to complete the protocol, an intramuscular injection of either 3 ml (60 USP units) of oxytocin or 3 ml of 0.9 per cent physiological saline was given to the cow. Each farmer was asked to observe the cow to determine the time of placental expulsion. In 55 cases available for analysis there was no significant difference between the treatment and control groups for percentage of placental retention at days 1, 2 or 3 post partum.     

Serum Progesterone Concentrations and Blood Neutrophil Alkaline Phosphatase Activity in Cows Following Normal and Abnormal Parturition

Serum progesterone concentrations and alkaline phosphatase (ALP) activity of blood neutrophils were determined in 3 groups of cows (n = 5 each) on days 1 and 2 and then at 3-day intervals up to 32 days post-partum. Group I cows had a normal delivery, Group II cows had dexamethasone-induced parturition and Group III cows were subjected to a caesarian section. All cows in Group III and 2 cows in Group II retained their fetal membranes. Mean serum progesterone concentrations declined the second day after calving (to < 0.67 ng/ml) and remained at low levels (< 0.54 ng/ml) throughout the observation period, except for the values in Group III, which were elevated on day 16 (0.94 ng/ml), declined again on day 26 (0.46 ng/ml) and peaked (1.05 ng/ml) on day 32 portpartum. Significant (P < 0.01) differences were found between serum progesterone concentrations on day 1 and on each of the other sampling days in Groups I and III. Day X parturition group interaction was significant (P < 0.05) for the progesterone concentrations. No significant differences were found between the overall means of ALP activity of blood neutrophils in the 3 parturition groups nor between days of the experiment. No significant correlation was found between serum progesterone concentrations and ALP activity values of blood PMN during the first 32 days post-partum. Inhalt: Serum Progesteron Konzentrat und Aktivität der alkalischen Phosphatase in neutrophilen Blutzellen bei Küken mit normalem und abnormalen Geburtsverlauf Serum-Progesteronkonzentrationen und alkalische Phosphatase- (ALP) Aktivität von neutrophilen Granulozysten, nach der Abkalbung am Tag 1 und 2 und dann im Abstand von 3 Tagen bis zum 32. Tag p.p. bei Kühen untersucht, die in drei Untersuchungsgruppen (n = 5) eingeteilt waren. Gruppe I kalbte normal ab, in Gruppe II wurde die Geburt durch Dexamethason eingeleitet, und Kälber der Gruppe III wurden via Kaiserschnitt gewonnen. Alle Tiere der Gruppe III und 2 Kühe der Gruppe II wiesen Nachgeburtsverhaltungen auf Der mittlere Serum-Progesterongehalt sank am 2. Tag p.p. auf < 0,67 ng/ml ab und blieb auf niederigem Niveau (< 0,54 ng/ml) während der gesamten Untersuchungs-periode. Lediglich in Gruppe III, mit erhöhten Werten (0,94 ng/ml) an Tag 16 p.p., sanken die Werte wieder an Tag 26 p.p. (0,46 ng/ml) und erreichten einen Maximalwert an Tag 32 p.p. mit 1,05 ng/ml. Signifikante (P 0,01) Unterschiede in der Serum-Progesteronkonrentration wurden zwischen Tag 1 p.p. und allen anderen Untersuchungstagen in den Gruppen I und III gefunden. Interaktionen zwischen den Gruppen für Tag X waren signifikant (P 0,05). Keine signifikanten Unterschiede wurden für den Gesamtmittelwert der ALP-Aktivität in den neutrophilen Granulorysten zwischen den Gruppen und im Vergleich der Untersuchungstage gefunden. Es wurden auch keine signifikanten Korrelationen zwischen den Serum-Progesteronkonzentrationen und der ALP-Aktivität der PMN während der ersten 32 Tage p.p. nachgewiesen.     

Changes in Blood Glucose,Plasma Non-esterified Fatty Acids and Insulin in Pregnant and Non-pregnant Goats

The blood glucose and the plasma non-esterified fatty acids (NEFA) and insulin concentrations were estimated in jugular blood samples from 18 Alpine×Beetal and Sannen×Beetal goats during pregnancy and compared with samples from non-pregnant goats and from goats during the periparturient period. The blood glucose levels in the pregnant goats rose to a peak of about 60±1.36 mg/ml at 42–56 days and then declined to about 46±2.37 mg/ml at 112–126 days. In non-pregnant goats, the blood glucose levels were significantly (p<0.01) higher than in pregnant goats, except between days 42 and 70 (59±1.36 mg/ml). On the day of kidding, the levels declined significantly (p<0.01), increasing again thereafter. The plasma NEFA concentrations were significantly higher in pregnant than in non-pregnant goats from days 56 to 126. The NEFA concentration increased on the day of kidding, followed by a transient fall by day 3. The plasma insulin concentration was usually higher in pregnant than in non-pregnant goats, except between days 56 and 70 and from day 126 onwards. The insulin concentration fell late in pregnancy, but there was a transient increase 2 days after parturition. The blood glucose and plasma NEFA concentrations can be used as indices of nutritional status during pregnancy in goats.     

Breed-related plasma disposition of ivermectin following subcutaneous administration in Kilis and Damascus goats

Many factors related with drug and animals affect the plasma disposition of endectocides including ivermectin (IVM). The aim of the present study was to investigate the breed differences in pharmacokinetics of IVM in goats following subcutaneous administration. Two different goat breeds (Kilis and Damascus goats) were allocated into two treatment groups with respect to breed. The injectable formulation of IVM was administered subcutaneously at a dose rate of 0.2 mg/kg bodyweight. Blood samples were collected before treatment and at various times between 1 h and 40 days after treatment and the plasma samples were analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The results indicated that the plasma disposition of IVM was substantially affected by breed differences following subcutaneous administration in goats. The last detectable plasma concentration (t_last) of IVM was significantly later in Kilis goats (38.33 days) compared with Damascus goats (22.50 days). Although, there were no significant differences on C_max (10.83 ng/ml vs. 10.15 ng/ml) and t_max (2.75 days vs. 2.33 days) values; the area under the concentration–time curve-AUC (110.26 ng.d/ml vs. 73.38 ng.d/ml) the terminal half-life-t_1/2λz (5.65 days vs. 3.81 days) and the mean plasma residence time-MRT (9.31 days vs. 6.35 days) were significantly different in Kilis goats compared with Damascus goats, respectively. The breed-related difference observed on the plasma disposition of IVM between Kilis and Damascus goats could be attributable to different excretion pattern or specific anatomical and/or physiological characteristics such as body fat composition of each breed.