共查询到20条相似文献，搜索用时 93 毫秒
1.
K Elze H J Hagner F Schneider R K?hler K Eulenberger R Hühn G Michel A Rauwolf 《Archiv fuer experimentelle veterinaermedizin》1979,33(5):791-806
Premature parturition was induced in 115 of 121 sows (95%) that had been given injections of 150 microgram or 200 microgram of "Estrumate", a prostaglandin analogues, on the 112th and 113th days of gestation. The average time that elapsed between injection and parturition of those 115 animals was 27.2 +/- 7.7 hours, with no difference being observed between gilts, on the one hand, and old sows, on the other. The time of gestation of the treated animals was shortened with significance from 114.6 +/- 1.6 days for the controls to 113.2 +/- 0.4 days. The average duration of parturition proper was 3.7 +/- 2.2 hours, the average litter being 11.2 +/- 3.3 piglets. The total number of piglets born was 1,320, with stillbirths accounting for 4.17%. The average weight at birth, 1,330 +/- 210 g, and the weight at weaning did not differ from weight figures recorded from the controls. The courses of parturition and puerperium were in agreement with normal biological standards. The sows treated were tested for their blood counts close to full term and for their endometrial histomorphology after weaning, with no side effects of "Estrumate" treatment being established. The behaviours of progesterone, 17-beta oestradiol, and cortisol in serum of "Estrumate"-treated sows were investigated, and congruence was established between spontaneous and prostaglandin-induced parturitions, which was in agreement with international literature. The conclusion is that 150 micrograms of 'Estrumate", administered to swine, after the 11th day of gestation has very good labour-inducing effects and ensures normal physiological parturition and piglet development. 相似文献
2.
Kornmatitsuk B Königsson K Kindahl H Gustafsson H Forsberg M Madej A 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2000,47(7):395-409
Parturition was induced in 12 dairy heifers with prostaglandin (PG) F2 alpha about 2 weeks before the expected time of calving. Eight animals gave birth after two injections (group 1), three animals needed more than two injections (group 2) and one animal (cow no. 740) required one injection. All animals in groups 1 and 2 had retained foetal membranes and the time needed to induce parturition was 59 +/- 7 and 149 +/- 10 h, respectively. As cow no. 740 did not have retained foetal membranes and calved 24 h after one PGF2 alpha injection, it was excluded from the results. Udder distension and relaxation of the pelvic ligaments could predict the calving to within 12 h. Furthermore, the pre-calving drop of body temperature could predict the time of parturition to within 16 h. The total white blood cells and polymorphonuclear cells were at their highest values on the day preceding parturition whereas mononuclear cells had a tendency to increase 3 days after calving. Increased levels of haemoglobin were found at the time of parturition, whereas, plasma-calcium levels significantly decreased after parturition (P < 0.001). Progesterone levels markedly decreased after the first PGF2 alpha injection and reached 2 nmol/l at the time of parturition. Plasma levels of oestradiol-17 beta reached the peak at the time of parturition, whereas, the highest levels of the PGF2 alpha metabolite and cortisol were recorded 16 h after calving. 相似文献
3.
During the course of parturition seven high pregnant sows, crossbreds of the Large White and Landrace breeds, and their 69 piglets being born, were studied for the changes of the total and separate free amino acids in the blood plasma in relation to the time of duration of the parturition, to the sequence of piglets being born in the litter, and to the birth weight of the piglets. The concentration of the total free amino acids in blood plasma is 2.44 +/- 0.182 mmol.l-1 just before parturition; after the birth of the last piglet it decreases insignificantly to 2.17 +/- 0.190 mmol.l-1. The concentration of the total free amino acids in the blood plasma of newborn piglets is always significantly higher than in their mothers (p less than 0.001) and is 4.24 +/- 0.109 mmol.l-1. The rank of each piglet in the sequence of births in litter has no influence on the level of plasma concentration of the total free amino acids amino acidaemia was 4.03 +/- 0.268 mmol.l-1 in the piglets born first and insignificantly changed to 3.99 +/- 0.445 mmol.l-1 of blood plasma in the last piglets born in the litter. The time factor of parturition is also statistically insignificant. However, the differences in the free "amino acids" concentration in the blood plasma between the piglets with the lowest weight and the piglets with a weight of up to 1200 and 1500 g are statistically significant (p less than 0.02). Alanine (0.43 +/- 0.052 mmol.l-1) and glycine (0.43 +/- 0.063 mmol.l-1) constitute the largest proportions of all the 17 amino acids studied in the blood plasma in the high pregnant sows before parturition. The tyrosine concentration in piglets at birth is remarkably high (1.44 +/- 0.035 mmol.l-1); it represent 34 per cent of the total amino acidaemia. Tyrosine, histidine and lysine concentration in the blood plasma is statistically highly significantly higher (p less than 0.001) in newborn piglets than in their mothers. The phenomenon of 6-times higher tyrosinaemia in piglets, compared with the sows is discussed in connection with the weight at birth and with the data on the function and concentration of thyroid hormones in piglets during the first days of their lives. 相似文献
4.
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. 相似文献
5.
A R Peters 《The Veterinary record》1989,124(14):371-373
This study was designed to evaluate the effects of exogenous prostaglandin F2 alpha (PGF2 alpha) on hormone secretion in cows without a corpus luteum. Blood samples were taken from 10 Friesian dairy cows at frequent intervals from a jugular vein and the caudal vena cava starting between nine and 20 days after parturition. PGF2 alpha (25 mg dinoprost) was injected intramuscularly into five cows after the first eight hours of sampling. Plasma concentrations of 13,14-dihydro 15-keto PGF2 alpha (PGFM) increased rapidly but had returned to baseline by 14 hours after injection. There was no significant effect of the treatment on the time taken by the cows to resume ovarian cycles, and it had no consistent effect on plasma luteinising hormone (LH) patterns; however the amplitude of pulses of LH was temporarily suppressed in two cows and the frequency of pulses of LH was immediately increased in one cow. Treatment with PGF2 alpha had no significant effect on the concentration of oestradiol in blood from the vena cava. It is concluded that any enhancement of the reproductive performance of cows treated with PGF2 alpha after parturition is not due to a direct effect on pituitary-ovarian function. 相似文献
6.
K K?nigsson K Kask H Gustafsson H Kindahl N Parvizi 《Acta veterinaria Scandinavica》2001,42(1):151-159
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. 相似文献
7.
Oestrus synchronisation, fertility and kidding behaviour were studied in 44 Black Bengal goats. They were divided into six experimental groups: group 1, control; group 2, progesterone; group 3, progesterone, pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG); group 4, prostaglandin F2 alpha (PGF2 alpha); group 5, PGF2 alpha, PMSG and HCG; group 6, PMSG and HCG. There was 100 per cent synchronisation of oestrus in the groups treated with progesterone, progesterone with PMSG and HCG, and prostaglandin with PMSG and HCG. In the other two treated groups the synchronisation was between 66 and 75 per cent. In the control group only 50 per cent of the animals came into oestrus during the period of observation. The duration of oestrus varied between 19 and 24 hours except in group 5 where it was 40.87 hours. Animals came on heat between 95 and 137 hours after treatment except in group 5 where the interval was only 18.87 hours. A maximum fertility of 75 per cent was observed in group 4 while the kidding percentage was greatest in group 2. There appeared to be no beneficial effect of superovulation on the number of kids produced. Gestation length was similar in all the groups. 相似文献
8.
Ninety-one to 100 per cent of pregnant sows injected with 0.25, 0.5 or 1 mg of fenprostalene on days 112, 113 or 114 of gestation began to farrow within 30 hours of treatment, the majority during working hours on the day after injection. Induction of farrowing had no significant effect on the piglets' viability, the litter weight or the subsequent sow or litter performance. Treatment of sows with fenprostalene and oxytocin on day 114 of pregnancy resulted in a reduction in duration of farrowing compared with fenprostalene alone. 相似文献
9.
In a clinical trial involving 123 cats and 88 dogs, the efficacy of tablets containing nitenpyram against natural flea infestations was investigated. The animals were selected from the routine cases of nine veterinary clinics in the UK and 143 were treated with the tablets and 68 control animals were treated with placebo tablets. Each animal was maintained in an individual cage. The time when the first fleas fell off each animal was recorded between 30 minutes and five hours after treatment, and six hours after treatment the numbers of live, moribund or dead fleas on each animal were determined, and the flea survival rate was calculated. The drug's efficacy was assessed by comparing the mean survival rates of fleas on the treated and control animals. Fleas started to fall from the animals 30 minutes after treatment and two hours after treatment some fleas had detached from 81 per cent of the treated animals. After six hours the efficacy of the drug reached 96.7 per cent on dogs and 95.2 per cent on cats, and 85.9 per cent of the fleas were found off the treated animals, compared with 1.8 per cent in the controls. No adverse drug reactions were recorded during the trial. 相似文献
10.
Analogues of prostaglandin F2 alpha are widely used in the United Kingdom to induce parturition in sows. A disadvantage is that sows are induced to farrow in advance of expected delivery dates. An alternative might be to maintain gestation by the application of a progestogen. Farrowing might then be initiated on the withdrawal of the progestogen. The use of an orally active progestogen (allyl-trenbolone) in an attempt to control the time of parturition in sows is described. In experiment 1, 20 large white cross landrace sows were allocated at random to one of two treatments. Treated sows were fed 16 mg/day of allyl-trenbolone from day 111 of gestation to day 118 of gestation. The farrowing performance of these sows was compared with that of control sows which farrowed naturally. Treated sows farrowed significantly (P less than 0.01) later than the control sows (118.2 and 116.1 days respectively). For treated sows the interval from progestogen withdrawal to farrowing was 29.6 +/- 4.8 hours. The number of stillbirths for treated and control sows respectively was 2.1 and 0.4 per litter. Treatment had no effect either on the birth weight of piglets or on their weaning weight at six weeks old. There was a tendency for more treated sows to show subsequent reproductive malfunction. In a second experiment, under commercial conditions, 81 sows and 12 gilts were allocated to one of four treatments. Treatment A animals were untreated controls.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
11.
Studies were conducted with 66 gilts with synchronised ovulation, all kept in five separate experimental groups (I-V). Each of the animals received 75 mg Dexamethason (DXMS) per die over three consecutive days of pregnancy. Treatment of Groups I through V was started in this order on the 101st, 103rd, 105th, 107th or 109th days of pregnancy. The average intervals that elapsed between the last DXMS injection and onset of parturition were, in the same order, 174, 167, 133, 94 or 74 hours. Births were concentrated on two consecutive days in Group V. DXMS had no significant effect on the average duration and course of parturitions. The lowest average litter and piglet birth weights were recorded from those DXMS groups with shortest pregnancy. No significant mean differences in piglet weight were any longer established between the groups on the tenth day of age. 相似文献
12.
S Kühne E Kolb G Gründel K Nestler C Schineff U Schmidt 《Archiv fuer experimentelle veterinaermedizin》1989,43(2):261-277
Blood samples were collected from 22 calves in three weight classes (A: 29.3 +/- 0.5 kg, B: 36.0 +/- 1.3 kg, C: 42.7 +/- 3.7 kg), 1-3 minutes after parturition and prior to uptake of foremilk as well as 24-26 hours after parturition. Other blood samples were collected from 45 calves, 5-60 minutes after parturition, and from their mothers, 3-5 or 5-60 minutes from calving. Haematocrit and haemoglobin in the blood of the calves, immediately after parturition, were higher the values recorded from adult cattle. Major differences were found to exist between individual calves regarding total protein of blood plasma. Protein levels in 14 calves were below 50 g/l, within 24-26 hours from parturition. Free fatty acids in blood plasma of calves were lower than those in cattle, 1-3 minutes from parturition, and were higher, 5-60 minutes from parturition. Glucose levels in Group C were higher than those in A and B, 1-3 minutes postpartum. Lactate in Group C was higher than that in B. An account is also given of blood plasma levels of Ca, Pa, Mg, Na, K, Cu, and Zn. 相似文献
13.
G D Dial G W Almond H D Hilley R R Repasky J Hagan 《American journal of veterinary research》1987,48(6):966-970
The influence of dose of oxytocin and the interval between prostaglandin (PG) F2 alpha and oxytocin administration on the synchrony of farrowing, the prevalence of intrapartum complications, and the number of pigs dying perinatally was investigated. In study 1, sows were given 10 mg of PGF2 alpha IM on day 112, 113, or 114 of gestation or were not treated. Twenty hours after PGF2 alpha administration, sows were given 0, 5, 10, 20, or 30 USP U of oxytocin IM. Sows treated with PGF2 alpha or PGF2 alpha plus oxytocin had a shorter interval to farrowing than sows not treated or treated with oxytocin alone. Treatment with PGF2 alpha plus 30 U of oxytocin induced the most rapid onset and the greatest synchrony of farrowing, with the mean onset occurring 2.1 +/- 0.4 hours after oxytocin vs greater than 8 hours for all other treatments. Sows treated with 5 or 10 U of oxytocin had a delayed onset and a less synchronous farrowing, compared with sows treated with 0 or 20 U. Day of PGF2 alpha treatment influenced (P less than 0.05) the interval from oxytocin to onset of farrowing. As day during gestation decreased, there was a corresponding decrease in the interval between oxytocin administration and farrowing. Number of interventions to remove retained pigs was not influenced (P greater than 0.05) by day of PGF2 alpha administration. All sows treated with PGF2 alpha followed by oxytocin had a higher rate of manual interventions, compared with that in sows given PGF2 alpha but not oxytocin.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
14.
Braun U Dumelin J Siegwart N Bleul U Hässig M 《Schweizer Archiv für Tierheilkunde》2007,149(6):259-264
The goal of this study was to determine whether oral administration of sodium phosphate in conjunction with intravenous calcium is more efficaceous than intravenous calcium alone for the treatment of parturient paresis. Thirty cows with parturient paresis were examined and treated by the same veterinarian. The cows were divided randomly into two groups of 15 cows each. Cows in group A received 500 ml of a 40 per cent calcium borogluconate solution containing 15.65 g calcium gluconate and borogluconate, with a supplement of 6 per cent magnesium hypophosphite (9.85 g magnesium hypophosphite) intravenously over a period of approximately 15 min. Cows in group B received the same treatment as well as 350 g of monobasic sodium phosphate (70 g inorganic phosphate, NaH2PO4 2 H2O, Streuli) dissolved in 0.5 litres of distilled water orally via a stomach tube. After treatment, the heart rate, respiratory rate, rectal temperature, superficial body temperature, rumen motility, appetite and defecation of the cows were monitored every hour for eight h. The cows' attempts to rise and their ability to stand were also noted. Initially, the results of clinical examination and serum electrolyte analyses did not differ between the two groups of cows.Within one hour of treatment, stupor was not observed in any of the cows. The general demeanour after treatment did not differ significantly between the two groups. In both groups, the average rectal temperature increased within two hours of the initiation of treatment, from 38.0 +/- 0.95 degrees C to 38.5 +/- 0.40 degrees C. There was no significant difference in the recovery rate between the groups. Of the 30 cows, 22 (73.3 per cent) stood within eight hours of treatment (10 cows from group A and 12 cows from group B). The type of treatment did not affect the time required to stand: cows in group A stood within 47.3 +/- 44 minutes and cows in group B stood within 24.2 +/- 32 minutes after the start of treatment. Our findings do not support the hypothesis that oral treatment with 350 g of sodium phosphate together with intravenous infusion of calcium in cows with parturient paresis results in an improved outcome, even though all the cows had hypophosphataemia as well as hypocalcaemia. 相似文献
15.
Kingston DJ 《New Zealand veterinary journal》1982,30(5):53-55
A review is presented of the roles of prostaglandins in swine reproduction. PGE and PGF are both produced in the ovary. PGE is thought to mediate steroidogenic activity of L.H. on the development of the granulosa cells leading to increased progesterone production in the preovulatory phase of the oestrus cycle. PGF2 acts on the theca cells leading to increased oestradiol and oestrus manifestation. The PG blocker indomethacin prevents oocyte rupture, but not maturation. The L.H. surges in the follicular phase stimulate ovarian PG production which initiates oestrus and ovulation. The uterus produces PGF2alpha. Disorders leading to abortion usually result in excess PGF2alpha production at the endometrium leading to luteolysis. With normal gestation circulatory progesterone levels fall during the last two weeks of pregnancy associated with increased circulatory foetal corticoid levels. The foetal corticoids are thought to trigger endometrial PGF2alpha levels leading to luteolysis and parturition. The use of exogenous PGF2alpha for induction of oestrus and abortion, parturition, semen collection and resolution of anoestrus is reviewed. 相似文献
16.
Pharmacokinetics of ceftazidime in sheep and its penetration into tissue and peritoneal fluids 总被引：1，自引：0，他引：1
Serum, tissue and peritoneal fluid concentrations of ceftazidime were studied in ewes after intravenous, intramuscular and subcutaneous administration at 50 mg kg-1 bodyweight. Tissue and peritoneal cages were implanted in the animals studied. After intravenous bolus administration, the mean serum concentration versus time profile was best described by a two-compartment open model. The distribution rate constant (alpha) was 3.5 +/- 1.1 h-1 and the half-life (t 1/2 alpha) 0.22 +/- 0.09 hour. The elimination rate constant (beta) was 0.43 +/- 0.04 h-1 and half-life (t 1/2 beta) 1.6 +/- 0.2 hours. The area under the curve was 275.7 +/- 84.0 micrograms.ml-1 h. The volume of distribution as steady state was 356.1 +/- 208.0 ml kg-1. The penetration ratio into tissue fluid was 62.6 +/- 15.1 per cent and into peritoneal fluid 61.1 +/- 16.5 per cent. After intramuscular injection, the elimination half-life was 1.7 +/- 0.2 hours, the area under the curve was 228.7 +/- 43.3 micrograms.ml-1 h. and the elimination rate constant was 0.42 +/- 0.05 h-1. The penetration ratio into tissue fluid was 68.5 +/- 37.3 per cent and into peritoneal fluid 73.3 +/- 34.4 per cent. After subcutaneous injection, the elimination half-life was 1.8 +/- 0.5 hours, the area under the curve was 231.8 +/- 65.6 micrograms.ml-1 h. and the elimination constant was 0.41 +/- 0.10 h-1. The penetration ratio into tissue fluid was 47.2 +/- 3.5 per cent and into peritoneal fluid 58.1 +/- 15.6 per cent.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
17.
Prostaglandin (PG) levels in milk and plasma samples from mastitic cows were determined by radioimmunoassay and compared with erythrocyte glutathione peroxidase (GSH-Px) and other relevant parameters in milk and blood. The overall levels of PGE2, PGF2 alpha and thromboxane B2 (TXB2) in milk were two to four times higher than in blood plasma both in healthy and diseased animals (P less than 0.01). In mastitic milk the PG levels were 24 to 55 per cent and in blood plasma 41 to 95 per cent higher than in healthy animals. The changes were significant and largest for the PGF2 alpha values. In milk, the PG concentrations correlated with the markedly elevated cell count (r = 0.49 to 0.57), and TXB2 values also correlated with milk yield. In blood, PGE2 and PGF2 alpha correlated positively with serum albumin, and PGE2 also correlated with glutathione (GSH). PGE2 and PGF2 alpha correlated negatively with GSH-Px and gamma-glutamyl transferase. The substantial decline in GSH-Px in mastitic animals (P less than 0.01) may be related to changes in lipid peroxidation and PG formation. The possible implications of these findings in the treatment of mastitis are discussed. 相似文献
18.
In a large Croatian commercial unit, 1204 of parity 2-7 late pregnant sows were from January till Mai 2002 randomly assigned to four farrowing groups and treated as follows: Group one (n = 302 sows) received a single perivulvar injection of 175 g cloprostenol at day 113 of pregnancy. The remaining animals have received a treatment as group one and were additionally treated with 10 IU of oxytocin intramuscularly 6 hours after prostaglandin application (Group two, n = 311), or with 10 IU of oxytocin 6 and 12 hours later (Group three, n = 291), or 10 IU of oxytocin 6, 12 and 18 hours later (Group four, n = 300). Onset of farrowing, duration of parturition, total born litter size and stillbirth rate were evaluated. Except total born litter size, combined oxytocin + cloprostenol treated sows revealed significantly (p < 0.01) better results as the only with cloprostenol treated ones. Multiple oxytocin application increased the predictability of farrowing. The application of multiple oxytocin injections following prostaglandin partusinduction are recommended for batch farrowing of sows in large production units. 相似文献
19.
The Duration of Farrowing in Relation to the Reproductive Performance of Yorkshire Sows 总被引：2，自引：1，他引：1 
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下载免费PDF全文 D. W. Friend H. M. Cunningham J. W. G. Nicholson 《Canadian journal of veterinary research》1962,26(6):127-130
Records for 212 attended farrowings by 38 Yorkshire sows were examined. Eighty per cent of the farrowings were less than six hours, 18 per cent between six and 12 hours and two per cent between 12 and 17 hours duration. There appeared to be no marked relationship between the duration of farrowing and the size of litter.
In spite of a higher stillbirth rate in males, there were more male (52.3 per cent) than female piglets born alive. As the time taken to farrow increased from within 1-3 hours to more than eight hours, the percentage of stillborn piglets and the percentage of litters with stillbirths increased to 10.5 from 2.4 and to 61.1 from 18.2 per cent respectively.
Twenty-nine per cent of the litters were farrowed on the 114th day of gestation. As the gestation period lengthened to 117 days or more, from 113 days or less, there were corresponding increases in the duration of farrowing and the incidence of stillbirths, and a decrease in litter size.
A need to investigate the use of hormones to control parturition in sows was suggested.
相似文献20.
Three cross-bred cows calved in March and April and were followed until day 62 after parturition. Each animal was suckled by 2 calves ad libitum. All calves were removed from the cows on day 55 after parturition. Blood was collected 3 times per day from the jugular vein by venipuncture. On 4 occasions after parturition--i.e. days 7-8, 21-22, 35-36 and 49-50, the cows were bled through a jugular venous catheter every 30 min during the 24 h. The plasma samples were analyzed for the content of 15-keto-13,14-dihydro-PGF2 alpha (main PGF2 alpha metabolite), LH, prolactin, cortisol and progesterone by radioimmunoassay methods. The concentration of PGF2 alpha increased from 280 to 730 pmol/l within the last 4 days before parturition. The highest geometric mean was 3106 pmol/l on the day of parturition. Thereafter a steady decrease of PGF2 alpha metabolite concentration was seen until day 21 when it reached plateau at 148 pmol/l. In all cows plasma LH concentrations increased significantly (P < 0.05) from about 1.6 micrograms/l on days 7-8 to 2.4 micrograms/l on days 21-22 post partum. The frequency of LH pulses showed no tendency to increase as the postpartum period progressed and averaged 6.5 pulses/24 h. Mean plasma LH concentrations increased from 2.1 micrograms/l 2 days before weaning to 3.2 micrograms/l 2 days after weaning (P < 0.05). LH peaks occurred less frequently in association with prolactin and cortisol peaks than in their absence. A partial positive correlation between PGF2 alpha metabolite and cortisol (r = 0.30) was found on days 7-8 post partum. Correlation between prolactin and cortisol on days 7-8 and 21-22 post partum was also positive (r = 0.20 and r = 0.27, respectively). There was a negative correlation between LH and cortisol on days 7-8 (r = -0.27) and days 49-50 (r = -0.21) post partum. The first and short progesterone increase observed after weaning was terminated in conjunction with PGF2 alpha metabolite peaks. 相似文献