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1.
The uterine effects of oxytocin, the prostaglandins dinoprost and cloprostenol as well as clenbuterol, ergometrin, xylazine and Utrorale were investigated in 8 cows during late pregnancy, parturition and early puerperium (until 4th day p. p.). Uterine motility was measured by means of pressure microsensors and electrodes which were surgically implanted 3 to 4 weeks before parturition. Hysterograms were characterized by means of pressure amplitude, frequency and duration of uterine contractions and also by electromyography. Oxytocin (2-5 IE) given intravenously always provoked strong uterine contractions until the 4th day p.p. From the prostaglandins examined during early puerperium only dinoprost (15 mg i.v.) produced uterotonic effects, while the synthetic analogue cloprostenol (0.25 mg i.v.) had a weak stimulatory activity only on day 1 p.p. Both prostaglandins were ineffective when injected intramuscularly. Clenbuterol (0.3 mg i.v.) a beta 2-mimetic compound effectively induced long lasting tocolysis during parturition, which could be abolished by oxytocin. Xylazine (10 mg i.v.) was able to significantly increase uterine motility during late gestation. Following intravenous administration of ergometrin (1 and 10 mg), bunitrolol (1-16 mg) and Utrorale (0.1-4 ml) including its compounds oleum sabinae, oleum terebinthinae, balsamum copaivale and Styrax no uterokinetic activity was recorded at any time.  相似文献   

2.
The present study was conducted to determine the difference in plasma prostaglandin F2α metabolite concentrations following oxytocin (OT) challenge between pregnant and non‐pregnant cows. Experiment 1: cows were subjected to the OT challenge test on days 12, 14 or 16 (day of estrus = day 0) with or without prior insemination and plasma 13,14‐dihydro‐15‐keto prostaglandin F2α (PGFM) concentrations were measured from ?30 to 180 min after OT injection. On day 16, the increment of plasma PGFM concentrations in response to OT injection was significantly smaller in pregnant than that in cyclic cows. On days 12 and 14, there was little OT‐induced PGFM secretion and no difference in PGFM increase between the pregnant and cyclic cows. Experiment 2: cows were inseminated on day 0 and subjected to the OT challenge test on day 16. Cows were classified into non‐pregnant/early embryonic death (NP/EED), late embryonic death (LED) and pregnant (PREG) groups. The increment of PGFM concentrations in response to OT injection was less in both PREG and LED groups than that in the NP/EED group. In conclusion, plasma PGFM secretion induced by OT is suggested as the base of pregnancy diagnosis prior to returning estrus in cows.  相似文献   

3.
The objectives were to investigate the relationships between endometrial cytology (EC) and interval from calving to first ovulation, and pregnancy in dairy cows, and that between uterine fluid and EC. On day 25 postpartum, 39 dairy cows were grouped based on EC, as having low (?8%) or high (>8%) polymorphonuclear cells (PMN), and the quantity of uterine fluid was assessed by ultrasound. The interval from calving to first ovulation was shorter in low, than in high PMN cows (32 vs. 45 d). A greater proportion of cows with uterine fluid had high PMN (64% vs. 21%), and the PMN increased from 14% to 34% as the quantity of uterine fluid increased. The mean interval from calving to ovulation was longer in primiparous cows with high PMN (49 d) compared to that of primiparous and multiparous cows with low PMN (28 and 29 d, respectively). Although the conception rate to first service at 92 d postpartum was not different between PMN groups, the cumulative pregnancy at 270 d tended to be higher in low than in high PMN (80% vs. 58%) multiparous cows. Also, cows that had uterine fluid on day 25 postpartum had a shorter interval from calving to pregnancy than those with no uterine fluid (161 vs. 208 d). In conclusion, combining transrectal ultrasonography with endometrial cytology on day 25 postpartum has diagnostic value in the assessment of uterine inflammation.  相似文献   

4.
The objectives were to investigate the relationships between endometrial cytology (EC) and interval from calving to first ovulation, and pregnancy in dairy cows, and that between uterine fluid and EC. On day 25 postpartum, 39 dairy cows were grouped based on EC, as having low (⩽8%) or high (>8%) polymorphonuclear cells (PMN), and the quantity of uterine fluid was assessed by ultrasound. The interval from calving to first ovulation was shorter in low, than in high PMN cows (32 vs. 45 d). A greater proportion of cows with uterine fluid had high PMN (64% vs. 21%), and the PMN increased from 14% to 34% as the quantity of uterine fluid increased. The mean interval from calving to ovulation was longer in primiparous cows with high PMN (49 d) compared to that of primiparous and multiparous cows with low PMN (28 and 29 d, respectively). Although the conception rate to first service at 92 d postpartum was not different between PMN groups, the cumulative pregnancy at 270 d tended to be higher in low than in high PMN (80% vs. 58%) multiparous cows. Also, cows that had uterine fluid on day 25 postpartum had a shorter interval from calving to pregnancy than those with no uterine fluid (161 vs. 208 d). In conclusion, combining transrectal ultrasonography with endometrial cytology on day 25 postpartum has diagnostic value in the assessment of uterine inflammation.  相似文献   

5.
Various parenteral treatment forms of oxytocin, as often used under praxis circumstances, may act differently on contractility of the uterus during the first days of the puerperium. Various patterns of such induced uterotonic responses may lead to alterations in the emptying characteristics of the uterine lumen, thus influencing, as a late consequence, the process of involution. Therefore, this study was designed to test whether two different parenteral administration forms of oxytocin induce changes in peripheral plasma concentrations of 15-ketodihydro-prostaglandin F(2α) (PGF(2α) metabolite) in early post-partum cows. Between 13 and 15 h after uncomplicated calving, healthy dairy cows without retained foetal membranes were treated with 50 IU oxytocin, either intramuscularly (OT-IM group; n = 15) or intravenously (OT-IV group; n = 16). Saline solution was administered intramuscularly as controls (CON group; n = 15). Jugular blood samples were taken at 10-min intervals from 1 h before to 2 h after treatment. Plasma PGF(2α) metabolite levels were measured by radioimmunoassay. No significant differences in peripheral plasma PGF(2α) metabolite concentrations occurred in the OT-IM and CON groups, but mean values significantly increased in the OT-IV group, peaking at 20 min after treatment and reaching pre-treatment baseline values again at 120 min. Although the source of prostaglandins was not investigated in this study, our results suggest that exogenous oxytocin may enhance secretion of prostaglandins by the uterus during the first day after normal calving. These prostaglandins might contribute, by an endocrine or paracrine route, to the stimulation of myometrial contractility when exogenous oxytocin is given during this early post-partum stage.  相似文献   

6.
The origin and physiological significance of high pulses of prostaglandin F2α (PGF2α) in uterine venous blood that occur 2-3 days after luteolysis are not well understood. We studied the relationship between contractions of the uterus evoked by exogenous oxytocin (OT) and PGF2α concentration in uterine venous blood on day 17 of the porcine oestrous cycle. The infusion of OT into the uterine artery produced an immediate increase in the uterine intraluminal pressure (UIP) (p < 0.001) and a simultaneous elevation in PGF2α concentration in uterine venous blood (p < 0.0001). The infusion of indomethacin (IND) into the uterine artery slightly decreased PGF2α concentration in uterine venous blood, but it did not suppress uterine contraction or the rapid increase in PGF2α concentration in uterine venous blood just after OT infusion (p < 0.0001), which was lower that in gilts not treated with IND. We conclude that the spikes of PGF2α concentration in uterine venous blood occurring after OT infusion on day 17 of the porcine oestrous cycle are mainly caused by the excretion with venous blood from the remodelled uterus and that PGF2α synthesis may contribute to this. These results suggest that the high spikes in PGF2α concentration that occur 2-3 days after luteolysis in pigs, sheep, cows and mares all have a similar origin.  相似文献   

7.
The objective of the current study was to examine cyclooxygenase (COX), cytochrome P450 1A (CYP1A) and 2C (CYP2C) activity in bovine endometrial cell cultures following exposure to oxytocin (OT), interferon‐τ (IFN), estradiol (E2) and/or progesterone (P4). Bovine endometrial epithelial cells were treated with OT, IFN, a combination of OT+IFN or control (CON) media for 24 h. For the second experiment, cells were treated with E2, P4, a combination of E2 + P4 or CON media for 24 h. Treatments were performed in triplicate, and the experiment was repeated four times (n = 12 per treatment). Treatment with OT alone increased (p < 0.01) activity of COX compared with CON; however, OT alone did not alter activity of CYP1A (p = 0.55) or CYP2C (p = 0.46) compared with CON. Activity of CYP1A and CYP2C was decreased in cells exposed to IFN (p < 0.01) or OT+IFN (p < 0.01) compared with CON. Treatment with E2 alone did not alter activity of CYP1A (p = 0.64) or CYP2C (p = 0.06) compared with CON. Activity of CYP1A and CYP2C was decreased (p < 0.01) in P4 vs CON. In summary, IFN exposure, irrespective of OT treatment, decreased the activity of CYP1A and CYP2C. Activity of CYP1A was decreased following P4 treatment alone, while that of CYP2C was decreased following both P4 and E2 + P4 treatment. The mixed function monooxygenase enzymes, CYP1A and CYP2C, have been implicated in synthesizing embryotoxic compounds; therefore, downregulation in the endometrium may be necessary during maternal recognition of pregnancy.  相似文献   

8.
The objectives of this study were as follows: (a) to assess the reproducibility of polymorphonuclear neutrophil (PMN) cell counts at five predefined endometrial sites (corpus uteri, left horn base, right horn base, left horn tip and right horn tip) and (b) to determine the agreement for the diagnosis of subclinical endometritis (SE) between the different endometrial sites. Forty milking cows between 28 and 34 days post‐partum were enrolled for endometrial sampling using cytobrush technique. Intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of PMN counts at different sites. The right horn base was found to have the greatest agreement of PMN counts with the other endometrial sites (ICC = 0.66–0.85). Twenty‐eight of 40 cows showed no signs of clinical endometritis and were used for evaluation of agreement for the diagnosis of SE, analysed by using Cohen´s kappa (κ) statistics. Agreement for SE diagnosis with PMN cut‐off ≥5% was greatest between the right horn base and the right horn tip (κ = 0.84), and with PMN cut‐off ≥18% between the right horn base and left horn tip (κ = 1.0), respectively. The results indicate that the right horn base can be regarded as suitable for cytobrush sampling. The probability to detect an animal positive for SE (PMN ≥ 5%) with a single cytobrush sampling was 51.0%; thus, a second sampling is recommended to improve the accuracy.  相似文献   

9.
An endometritis model was used to investigate the influence of degenerative endometrial changes (endometrosis) on functional parameters of uterine neutrophils in the horse. Six hours after intrauterine application of recombinant human interleukin‐8 (rhIL‐8), the uteri of 15 mares were flushed with phosphate‐buffered saline. Quantitative and qualitative flow cytometric assays were then made to determine the absolute numbers, viability, phenotype, generation of reactive oxygen species (ROS), and phagocytic activity of immigrated polymorphonuclear neutrophilic granulocytes (PMN). Recombinant hIL‐8 attracted similarly high numbers of similarly viable PMN into the uteri of mares with or without degenerative endometrial changes. Compared with blood PMN, immigrated uterine neutrophils displayed significantly upregulated expression of CD11a/CD18 (LFA‐1) on uterine PMN whereas major histocompatibility complex class I molecules were expressed at lower densities. The ability to phagocytose opsonized streptococci did not differ between uterine and blood PMN. However, uterine PMN displayed a higher capacity to generate ROS. On average, uterine PMN of mares with degenerative endometrial changes showed phenotypical and functional characteristics similar to those of mares with a histologically healthy endometrium. Therefore, degenerative endometrial changes per se did not reduce the functional capacity of equine uterine neutrophils in mares.  相似文献   

10.
In six horses, a 0.05% solution of chlorhexidine diacetate was used to lavage one tarsocrural joint; the contralateral control joint was lavaged with lactated Ringer's solution. Horses were evaluated daily for lameness. Synovial fluid samples were collected on days 1, 4, and 8 for determination of protein concentration, total and differential leukocyte counts, and mucin clot formation. After death on day 8, synovium and osteochondral samples were collected from the tarsocrural joints for examination of morphology and proteoglycan staining. Lavage with chlorhexidine solution caused lameness that was reduced but still evident at day 8. Synovial protein concentration was significantly increased by chlorhexidine lavage; the greatest increase occurred on day 1. Joint lavage increased synovial leukocyte counts on day 1, primarily by increasing polymorphonuclear (PMN) cell counts. Although total synovial leukocyte counts returned to normal by day 4, PMN cell counts remained elevated through day 8; PMN cell counts for chlorhexidine-lavaged joints were typically twice that of control joints. Chlorhexidine lavage caused synovial ulceration, inflammation, and abundant fibrin accumulation. Consistent differences in proteoglycan staining were not detected between control and chlorhexidine-lavaged joints. Joint lavage with 0.05% chlorhexidine diacetate, the lowest known bactericidal concentration, is not recommended for equine joints.  相似文献   

11.
Objective-To determine whether parenteral l-alanyl-l-glutamine (Ala-Gln) administration modulated phagocytic responses of polymorphonuclear neutrophilic leukocytes (PMNs) from dogs undergoing high-dose methylprednisolone sodium succinate (MPSS) treatment. Animals-15 healthy Beagles. Procedures-Dogs were randomly assigned to 3 treatment groups (n = 5/group): 38-hour IV infusion of saline (0.9% NaCl) solution (control group), saline solution with 8.5% amino acids (2.3 g/kg/d), or saline solution with 8.5% amino acids (1.8 g/kg/d) and 20% l-alanyl-l-glutamine (Ala-Gln; 0.5 g/kg/d). High-dose MPSS treatment was initiated at the same time that IV infusions began, such that a total dose of 85 mg of MPSS/kg was administered through multiple IV injections over a 26-hour period. The infusions were maintained until 12 hours after the last MPSS injection. Blood samples collected before MPSS injections began and 2, 12, and 24 hours after injections ceased were used to evaluate PMN function. Results-MPSS injections resulted in an increase in the total number of circulating leukocytes and increases in neutrophil and monocyte counts but did not affect lymphocyte, eosinophil, or basophil counts. Lymphocyte counts in the Ala-Gln group were higher than in the control group 12 hours after MPSS injections finished. Relative to preinfusion values, phagocytic capacity, oxidative burst activity, and filamentous actin polymerization of PMNs were suppressed in all dogs except those that received Ala-Gln. Conclusions and Clinical Relevance-Parenteral Ala-Gln administration in dogs resulted in an increase in PMN phagocytic responses that were suppressed by high-dose MPSS treatment.  相似文献   

12.
The role of oxytocin (OT) in the regulation of prostaglandin F2 alpha (PGF2 alpha) secretion during luteolysis in gilts was studied using a highly specific OT antagonist (CAP-581). In Experiment 1 gilts on Days 14 to 19 of the oestrous cycle in Latin square design were used, to determine the dose and time of application of OT and CAP. In Group I (n = 6) gilts were treated intravenously with saline or with 10, 20 and 30 IU of OT. Concentrations of the main PGF2 alpha metabolite i.e. 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were measured in blood samples as uterine response to the treatment. Twenty IU of OT was the most effective to stimulate PGFM release and this dose was used after CAP treatment in gilts of Groups II, III and IV. Gilts of Group II (n = 3) were injected into the uterine horns (UH) with saline (5 ml/horn) or CAP (2 mg, 3 mg and 4 mg; half dose/horn) and OT was injected (i.v.) 30 min thereafter. Any of the CAP doses given into the UH affected PGFM plasma concentrations stimulated by OT. In Group III (n = 4) gilts were infused (i.v.) for 30 min with CAP (9 mg, 14 mg and 18 mg/gilt) followed by 20 IU of OT. All doses of CAP effectively inhibited OT-stimulated PGF2 alpha release, therefore 9 mg was selected for the further studies. Gilts of Group IV (n = 4) received OT 4, 6 and 8 h after CAP to define how long CAP blocks the OT receptors. Concentrations of PGFM increased after any of this period of time. Thus, we concluded that 9 mg of CAP infused every 4 h will effectively block OT receptors. In Experiment 2, gilts (n = 4) received CAP as a 30-min infusion every 4 h on Days 12-20 of the oestrous cycle. Control gilts (n = 3) were infused with saline. CAP infusions diminished the height of PGFM peaks (P < 0.05). Frequency of the PGFM (P < 0.057) and OT (P < 0.082) peaks only tended to be lower in the CAP-treated gilts. Peripheral plasma concentrations of progesterone (P4) and oestradiol-17 beta (E2) and the time of luteolysis initiation as measured by the decrease of P4 concentration were the same in CAP- and saline-treated gilts. The macroscopic studies of the ovaries in gilts revealed lack of differences between groups. We conclude that OT is involved in the secretion of luteolytic PGF2 alpha peaks but its role is limited to controlling their height and frequency. Blocking of OT receptors did not prevent luteolysis in sows.  相似文献   

13.
Background: Laminar inflammation is one of the earliest events in equine laminitis. Calprotectin (CP), a Damage-Associated Molecular Pattern protein, is overexpressed in inflammatory conditions of human skin.
Hypothesis: CP is overexpressed in the laminar epidermis of horses with black walnut extract (BWE)-induced laminitis.
Animals: Twenty adult horses.
Methods: Experimental study. Horses were allocated to one of 4 groups. BWE was administered to horses in 3 groups, which were sampled 1.5, 3, and 12 hours (LAM) later. CP was visualized by immunohistochemistry. Laminar leukocyte counts and intensity of laminar epithelial staining were scored for all animals and statistically analyzed.
Results: Laminar epidermal CP signal was significantly increased ( P = .02) at the LAM time point, compared with other groups. Rare leukocytes were detected in laminae with CP staining in CON group, but there were marked increases in number of leukocytes in BWE-treated groups ( P = .003). Sequential hematoxylin and eosin staining demonstrated that the majority of CP-positive leukocytes were perivascular polymorphonuclear neutrophils (PMN) at each of the developmental time points. CP-positive PMN and mononuclear cells were detected in perivascular locations and close to the epidermal basement membrane in the LAM group.
Conclusions and Clinical Importance: CP expression in the laminar epidermis occurs after extravasation of leukocytes, indicating that leukocyte emigration might be an initiating factor in laminar epithelial stress and inflammation in BWE-induced laminitis. These results indicate a possible role of CP in laminitis pathophysiology and laminar failure.  相似文献   

14.
Spontaneous and drug-induced uterine motility (UM) was recorded in 5 nonanesthetized bitches for 2 to 4 days. Catheter-tip pressure transducers were surgically implanted in 1 uterine horn, tunneled subcutaneously to exit from the skin over the dorsal lumbar area, and protected by a bandage. On the day after implantation, spontaneous UM was recorded in the awake bitch. Effects of IV prostaglandin (PG) F2 alpha (5 micrograms/kg of body weight) and oxytocin (0.05 USP U/kg) and IM PGF2 alpha (25 micrograms/kg) were measured. Estradiol (1 to 25 micrograms/kg) was administered and the study was repeated 24 hours later. In awake bitches, spontaneous UM was 190% greater than UM in anesthetized bitches. Uterine motility was increased by more than 100% after IV PGF2 alpha or oxytocin and by 52% after IM PGF2 alpha. Estradiol abolished spontaneous UM, but did not affect drug-induced responses. Seemingly, spontaneous and drug-induced UM can be documented in the nonanesthetized bitch.  相似文献   

15.
The effect of dietary selenium (Se) deficiency on the generation of neutrophil chemotactic factors from goat polymorphonuclear leukocytes (PMN) was studied. Polymorphonuclear leukocytes were isolated from 2 groups of crossbred goats. One group (n = 3) was fed a diet deficient in Se; the other (n = 3) was fed a diet adequate in Se. The PMN from each goat were stimulated with calcium ionophore A23187 and supernatants were collected. Each supernatant was immediately assayed for its ability to elicit neutrophil chemotaxis (NCT) and neutrophil chemokinesis by the Boyden chamber technique and neutrophil chemiluminescence (NCL) by the luminol-dependent chemiluminescence assay. Measurements from each group were compared, using the Student's t test. There was no significant difference (P greater than 0.01) in neutrophil chemokinesis elicited by supernatants derived from stimulated PMN from the 2 groups. However, supernatants derived from PMN of goats fed the Se-deficient diet had a significantly decreased capacity (P less than 0.01) to stimulate NCT and NCL. In vitro incubation of PMN with Se before ionophore treatment produced supernatants with increased NCL stimulation (P less than 0.05), but none with increased NCT stimulation (P greater than 0.05). However, both activities were restored after goats fed the Se-deficient diet (P less than 0.01) were given Se subcutaneously. Seemingly, dietary Se deficiency is associated with depressed PMN generation of factors that stimulate NCT and NCL. In contrast to NCL factors, synthesis of factors stimulating NCT probably was not associated directly with PMN glutathione peroxidase concentration.  相似文献   

16.
The effect of an intra-luteal injection of the 5-lipoxygenase (5-LO) inhibitor BWA4C (2 mg in 50 μ1 dmso) on the secretion of oxytocin (OT) from the corpus luteum in response to a close-arterial infusion of prostaglandin (PG)-F2α (5 ng mint) was examined in anaesthetised sheep. Within 30 minutes of administration both basal (pre-infusion) and PGF2α stimulated OT release into the posterior vena cava were significantly (P<0·01) reduced. These results are consistent with the proposition that 5-LO products of arachidonic acid may modulate OT secretion from the ovine corpus luteum.  相似文献   

17.
The study evaluated, in early post‐partum anoestrous Nelore cows, if the increase in plasma oestradiol (E2) concentrations in the pre‐ovulatory period and/or progesterone priming (P4 priming) preceding ovulation, induced by hormonal treatment, reduces the endogenous release of prostaglandin PGF2αand prevents premature lysis of the corpus luteum (CL). Nelore cows were subjected to temporary calf removal for 48 h and divided into two groups: GPE/eCG group (n = 10) and GPG/eCG group (n = 10). Animals of the GPE/eCG group were treated with a GnRH agonist. Seven days later, they received 400 IU of eCG, immediately after PGF2α treatment, and on day 0, 1.0 mg of oestradiol benzoate (EB). Cows of the GPG/eCG group were similarly treated as those of the GPE/eCG group, except that EB was replaced with a second dose of GnRH. All animals were challenged with oxytocin (OT) 9, 12, 15 and 18 days after EB or GnRH administration and blood samples were collected before and 30 min after OT. Irrespective of the treatments, a decline in P4 concentration on day 18 was observed for cows without P4 priming. However, animals exposed to P4 priming, treated with EB maintained high P4 concentrations (8.8 ± 1.2 ng/ml), whereas there was a decline in P4 on day 18 (2.1 ± 1.0 ng/ml) for cows that received GnRH to induce ovulation (p < 0.01). Production of 13,14‐dihydro‐15‐keto prostaglandin F2α (PGFM) in response to OT increased between days 9 and 18 (p < 0.01), and this increase tended to be more evident in animals not exposed to P4 priming (p < 0.06). In conclusion, the increase in E2 during the pre‐ovulatory period was not effective in inhibiting PGFM release, which was lower in P4‐primed than in non‐primed animals. Treatment with EB promoted the maintenance of elevated P4 concentrations 18 days after ovulation in P4‐primed animals, indicating a possible beneficial effect of hormone protocols containing EB in animals with P4 priming.  相似文献   

18.
The postpartum uterine bacteriology, histology, resumption of ovarian activity and polymorphonuclear granulocyte (PMN) number and function in 18 Swedish dairy cows were studied. Cows were milked either 2x (n = 9) or 3x per day (n = 9). Endometrial biopsy samples for bacteriological and histological investigations were collected during 8 weeks postpartum, starting within one week after calving. Milk samples for progesterone determination were collected twice a week until the cows had shown normal reproductive cyclicity. Blood samples for granulocyte function (phagocytic capacity and total number) were collected from each animal on the same days as when the biopsies were obtained. All animals in both groups were free from bacteria at the latest after 6 weeks post-partum and there was no difference regarding bacterial elimination and bacterial species between milking groups. No difference regarding uterine histology between milking groups was seen. In both groups, 8 cows had normal to slight infiltration of leukocytes in the endometrium at the end of sample collection. No changes in granulocyte function could be seen in the 2 milking groups. Resumption of ovarian activity was detected on day 45.6 +/- 9.3 (mean +/- SD) postpartum in the 2x milking group and 36.6 +/- 9.0 (mean +/- SD) post-partum in the 3x milking group (p = 0.05). Based on our findings, an increased milking frequency from 2 to 3 times a day did not influence the uterine function postpartum.  相似文献   

19.
Nine multiparous cyclic sows with permanent jugular catheters were introduced to a boar at day 10 (n = 9) or 11 (n = 5) after ovulation to study the effect on oxytocin (OT) release. If it occurs, the release of OT might play a role in embryo migration which occurs around this time, by stimulating uterine contractions. Blood samples were taken before introduction of the boar and at 2-min intervals up to 10 min after boar introduction. On average, OT levels after boar introduction were not higher than before. In only three out of the 14 occasions of boar introduction, a rise in OT level was observed that was higher than two times the standard deviation above base level. However, even on these occasions OT levels were far below the range normally observed during other events where exogenous stimuli cause OT release, such as boar introduction during estrus and suckling during lactation. We conclude that boar contact around day 10 of the estrous cycle does not induce a biologically significant OT release in sows.  相似文献   

20.
The present study was conducted on 50 recently calved Iraqi Buffalo cows. Depending on the kind of parturition, buffalo cows were divided into two main groups, the first group had normal unassisted parturition (NP) (26 animals) and the second group with certain periparturent complications (PPC) (24 animals). After 24 h of parturition, these two groups were further subdivided into two groups as cows expel their foetal membranes in <24 h postpartum and referred as non‐retained placenta (NRP) while cows that did not expel their foetal membrane after 24 h referred as retained placenta (RP). Sampling for bacteriology, uterine discharge for polymorphonuclear cells per cent and blood samples for polymorphonuclear neutrophil (PMN) and the enzyme creatine kinase activity were performed at 6, 24 and 48 h postpartum. In PPC group, the most prevalent bacteria after 6 h of calving were Escherichia coli, β‐haemolytic Streptococci and Lactobacillus acidophilus. Total bacterial isolates in the uterus of buffaloes with RP in PPC group after 24 and 48 h were 129 and 183 respectively. Among the isolates, Archanobacterium pyogenes, Fusobacterium necrophorum, Prevotella melaninogenicus and Staphylococcus aureus were the most prevalent isolates after 48 h of RP buffaloes in PPC group. Polymorphonuclear neutrophil were significantly (p < 0.01) increased in the uterine discharge than in blood in buffaloes with RP in both PPC and NP groups. In conclusion, uterine contamination occurs as a result of postpartum ascending contamination by non‐specific environmental organisms. The presence of Lactobacillus sp. in the uterus indicated a healthy uterus. Peripartum complications followed by retention of foetal membranes with the dominance of E. coli in the uterine lumen might favour the colonization of other bacteria including facultative anaerobic and strictly anaerobic in the uterine wall of buffaloes.  相似文献   

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