Concentrations of Oestrone and Oestradiol-l 7β in the Peripheral Plasma of the Nanny Goat during the Oestrous Cycle, Gestation and Puerperium

The changes in the plasma levels of oestrone sulphate and oestradiol-17β during the oestrous cycle, gestation and puerperium in the goat are described. The oestrone sulphate concentrations remained fairly constant (250–350 pg/ml) throughout the oestrous cycle until day 20 when a sharp increase of the oestrone sulphate plasma levels occurred in pregnant goats which became significantly different at day 38 of gestation from nonpregnant values. Oestradiol-17β plasma levels were significantly lower at days 17–20 in pregnant than in nonpregnant does. Oestrone sulphate and oestradiol-17β concentrations rose until the 12th week of gestation and then declined to about 50% of the former ranges of concentrations before rising again to high values at weeks 17–20 of gestation. Increasing plasma levels of oestrone sulphate and oestradiol-17β were determined during the last ten days preceding parturition. The concentrations of oestrone sulphate returned to basal levels by the 2nd—4th day post partum whereas oestradiol-17β values reached base values 24 hours after parturition. Both oestrogen concentrations remained constant during the puerperium until day 51 post partum .     

West Nile Virus Antibody Titers and Total Immunoglobulin G Concentrations in Foals from Mares Vaccinated in Late Gestation

This study was conducted to determine whether prepartum vaccination of mares would enhance passive transfer of West Nile virus (WNV)-specific antibodies and to characterize the pattern of decline for maternally derived WNV antibodies in foals. Seventeen light horse mares were allocated to WNV or control treatments. At 30 days before expected foaling, mares were vaccinated for encephalomyelitis, tetanus, herpesvirus, and influenza. At this time, WNV mares were vaccinated with a killed WNV vaccine. Blood samples were taken from mares 30 days before expected foaling, from mares and foals within 24 hours of foaling (0 days), and from foals at 7, 30, 60, 90, 120, 150, and 180 days of age as well as 30 days after an initial (PV1) and subsequent (PV2) WNV vaccination. Serum was analyzed for titer to WNV and total immunoglobulin G (IgG). Although WNV titer did not change over time in control mares, an increase (P < .05) was observed in WNV titer for WNV mares vaccinated 30 days before expected foaling. Foals of WNV dams had greater (P < .05) WNV titers than foals of control dams. Mean WNV titers of all foals increased from 0 to 7 days and declined through 180 days of age. Total IgG of foals increased from days 0 to 7, declined from days 30 to 120, and increased from days 150 through PV2. These results suggest that vaccination of mares for WNV in late gestation has a beneficial effect on foal WNV titer.     

Involvement of Plasma Progesterone, Oestradiol-17β and Cortisol in Ovulatory Response to Gonadotropin-releasing Hormone in Dairy Cows with Cystic Follicles

The aim of the present study was to examine the plasma concentrations of progesterone, oestradiol-17beta and cortisol in the cows with cystic follicle and to examine its relationship with the ovulatory response to gonadotropin-releasing hormone (GnRH). Eighty-five post-partum Holstein-Friesian cows with cystic follicles regardless of the presence of corpus luteum were studied. Follicular size, presence of corpus luteum and occurrence of ovulation were checked by palpation per rectum. Blood collection and palpation per rectum were conducted on days 0, 7 and 14. Gonadotropin-releasing hormone was administered at day 7. Plasma concentrations of progesterone, oestradiol-17beta and cortisol were determined. Progesterone concentrations of <3.2, 3.2-4.8 and >4.8 nmol/l were defined as low, intermediate and high, respectively. Sixty-three (74.1%) of 85 cows showed low (<3.2 nmol/l =1 ng/ml) progesterone concentrations on day 0. Only 40 (47.1%) of them showed low-low pattern of progesterone at days 0 and 7. In 27 (31.8%) of them, progesterone concentration had increased by day 14. Of 22 cows having high progesterone concentration (>/=4.8 nmol/l) on day 0, corpus luteum was not detected in 18 cows (21.2%). Only in 10 cows, cystic follicle disappeared after GnRH administration. However, only one of 27 cows in which progesterone pattern was low-low-high at days 0, 7 and 14 experienced ovulation of the cystic follicle. Significantly lower oestradiol-17beta concentration was found on day 7 in cows showing a low-low-low pattern than a low-low-high pattern of progesterone (43.0 +/- 4.6 vs 55.8 +/- 2.8 pmol/l, p < 0.05). There was no significant difference in cortisol concentration on any days (days 0, 7 and 14) between cows showing a low-low-low and low-low-high pattern of progesterone. These results suggest that approximately one-fifth of cows diagnosed to have ovarian cysts possess luteal cysts and that a high oestradiol-17beta concentration at the time of GnRH administration is involved in the subsequent ovulation of the follicle, although ovulated follicle may not be cystic.     

Repeatability and Reliability of Heart Rate Variability in Healthy,Adult Pony Mares

Heart rate variability (HRV) is an important noninvasive method to quantify stress by measuring sympathetic and parasympathetic activity of the autonomic nervous system. Few studies exist on the repeatability and reliability of HRV in equids. The objectives of this study were to (1) compare the effect of different correction factors (CF) available in HRV analysis software on HRV indicator values and (2) to determine the repeatability and reliability of HRV indicators in an unrestricted (pasture) and a restricted movement (equine examination stocks) environment. Data were recorded on five consecutive days from six adult pony mares. Short-term tachograms were compared with regard to software CF by graphical and statistical (Friedman's and Wilcoxon signed rank test) comparison. The results showed that the specific CF influences the HRV indicator values. The strong CF was able to balance the elimination of artefacts without removing the variability of RR intervals and was subsequently used to determine repeatability and reliability. HRV indicators showed good repeatability over the 5 days using Friedman test (pasture, P = .162–.898; examination stocks, P = .29–.865), indicating that there were no significant differences between HRV indicator values. The reliability, represented by intraclass correlation coefficient (ICC) and coefficient of variation (CV), was poor-to-good for pasture data (ICC = 0.44–0.79; CV = 10–68.10) and examination stocks data (ICC = 0.22–0.83; CV = 16.07–62.29). Measurements obtained from the examination stocks were less reliable than those from pasture. Using normalized low-frequency and normalized high-frequency components improved reliability. Free-movement environment-based HRV recordings could ensure better reliability but may require the use of a stronger CF.     

β-endorphin immunoreactivity during anaesthesia in equidae

Objective To determine the effects of surgery, hypoxia, hypercapnia and flunixin administration on plasma β‐endorphin immunoreactivity (BEI) in anaesthetized horses. Study design Prospective crossover study. Animals Six healthy adult Welsh Mountain ponies and seven healthy adult Thoroughbreds. Methods Ponies were anaesthetized with thiopentone and halothane or with pentobarbitone and the horses with guaiphenesin, thiopentone and halothane. Ponies were anaesthetized for 2 hours and on separate occasions underwent a period of hypoxia, hypercapnia, anaesthesia only, or were given flunixin at induction. The horses were anaesthetized for 2 hours and on separate occasions underwent surgery to relocate one carotid artery subcutaneously or anaesthesia only. Plasma samples were taken pre‐anaesthesia, at 20 minute intervals during, and after anaesthesia for BEI assay using radio‐immunoassay. Analysis of variance of the concentration‐time curve was used for statistical analysis. Results Pre‐anaesthetic β‐endorphin immunoreactivity (BEI) values ranged between 5.7 and 20.4 pmol L^?1. Induction of anaesthesia caused a five to 10 fold increase in mean plasma BEI in all cases except the hypercapnia group. Halothane anaesthesia increased BEI in ponies and horses but there were no significant changes during pentobarbitone anaesthesia. The increase in BEI in the hypoxic group was greater (peak value 136.8 ± 32.2 pmol L^?1) and sustained for a longer period compared with levels in those given halothane alone or in those which became hypercapnic. There was marked individual variation in the flunixin group and changes were not significant. Surgery in the horses resulted in the highest peak values in the study (182.5 ± 153.0 pmol L^?1) but the AUC was not significantly higher than in the same animals without surgery, where the peak value was 102.9 ± 42.1 pmol L^?1. Conclusions Beta‐endorphin appeared to be a sensitive marker of an endocrine stress response but its physiological role during equine anaesthesia is unknown. Clinical relevance Unknown.     

蒙古利亚矮种母马垂体促性腺激素的血清含量与妊娠状态和年龄的相关性

选用 10匹 4～ 16岁怀孕和 2 2匹 0 5～ 17岁非怀孕的蒙古利亚矮种母马 ,采用放射免疫法分别测定了其血清中FSH和LH的浓度。其结果显示 ,妊娠母马的血清FSH和LH含量分别为 0 3 0 83mIU /ml± 0 1611mIU/ml和 0 65 67mIU /ml± 0 40 61mIU/ml,显著低于非妊娠母马的 2 40 5 9mIU/ml± 0 64 46mIU /ml和 2 3 85 5mIU /ml± 0 3 5 2 9mIU/ml(P <0 0 5 ) ;此外 ,3～ 8岁组、10～ 14岁组和 15岁以上组非妊娠母马血清FSH和LH含量分别为 2 44 0 0mIU /ml±0 780 0mIU /ml、2 40 0 0mIU/ml± 1 3 0 78mIU /ml、5 3 75 0mIU/ml± 0 885 0mIU /ml和 1 840 0mIU/ml± 0 80 0 0mIU /ml、2 5 92 9mIU/ml± 0 5 93 0mIU/ml、3 975 0mIU /ml± 0 485 0mIU/ml。以上结果表明 ,在妊娠阶段 ,母马血清中的FSH和LH显著降低 ,而繁殖季节的非妊娠母马血清FSH和LH的浓度却随着母马的老年化而呈现增加的趋势。     

Effect of Oestrous Synchronization with Estradiol 17β and Progesterone on Follicular Wave Dynamics in Dairy Heifers

An experiment was designed to evaluate the effects of estradiol‐17β (E17β) on follicular wave dynamics and ovulatory response in Holstein heifers receiving either a progestogen ear‐implant (Crestar^®; Intervet International b.v. Boxmeer, The Netherlands) or an intravaginal progesterone‐releasing device [controlled internal drug release‐bovine device (Eazibreed, CIDR‐B^®; Bodinco BV, Alkmaar, The Netherlands)]. For comparison, another group of heifers was also synchronized using Crestar plus an injection of estradiol valerate (EV) and norgestomet as recommended by the pharmaceutical company. Twenty 20–22‐month‐old cycling Holstein heifers were allocated to one of the following treatment groups at random stages of the oestrous cycle: (I) simultaneous insertion of Crestar and intramuscular injection of 3 mg norgestomet and 5 mg EV (Crestar 9 + EV 9); (II) simultaneous insertion of Crestar and intramuscular injection of 5 mg E17β (Crestar 9 + E17β 9); (III) insertion of Crestar followed 2 days later by intramuscular injection of 5 mg E17β (Crestar 9 + E17β 7); or (IV) insertion of CIDR‐B device followed 2 days later by intramuscular injection of 5 mg E17β (CIDR 9 + E17β 7). The CIDR‐B or Crestar implants were removed after 9 days and all heifers received 500 μg Cloprostenol (Estrumate^®, Pitman‐Moore Nederland BV, Houten, The Netherlands). Ovarian ultrasonographic examinations were performed once daily during the synchronization period using a B‐mode scanner equipped with a 7.5 MHz linear‐array transrectal transducer. In addition, heifers were scanned every 12 h after implant/device withdrawal until 3 days after ovulation in order to monitor follicular activity, detect ovulation and subsequent early luteal formation. Detection of oestrus was performed every 6 h for 4 days after device/implant removal. Oestrus was observed 24–32 h before ovulation in all heifers. The mean hours interval from treatment withdrawal to ovulation was not significantly different (84.0 ± 16.5, 77.6 ± 4.1, 73.6 ± 4.1 and 64.0 ± 4.4 h for treatments I, II, III and IV, respectively; p > 0.1). However, the variance for heifers treated with EV + norgestomet was significantly larger (Levene’s Test; p < 0.01) than those treated with E17β. All E17β treatments resulted in dominant follicle suppression and a new wave emerged 4.1 days after treatment compared with 6.6 days for the EV + norgestomet treatment (p < 0.05). The time from emergence of the new ovulatory wave to ovulation was longer for the new wave that emerged after E17β treatment (9.2 ± 0.3 days) than after EV + norgestomet treatment (6.9 ± 0.4 days; p < 0.05). The results of this study suggest that the four treatments used were effective in inducing synchronous behavioural oestrus and ovulation. However, a higher degree of oestrus and ovulation synchrony was observed in heifers treated with E17β than in heifers treated with EV + norgestomet. Synchronization treatments with exogenous E17β or EV + norgestomet at the time of progestin device insertion (Crestar or CIDR‐B) or 2 days later in heifers can regulate a different emergence pattern of ovarian follicular development in randomly cyclic heifers. The E17β was effective in inducing follicular suppression and resulted in the consistent emergence of a new follicular wave.     

The Effect of Piglet Expulsion in the Sow on Plasma Cortisol, Adrenocorticotropic Hormone and β-endorphin

Contents
Previous studies have shown an increase in plasma cortisol in gilts over farrowing irrespective of environment suggesting that factor(s) associated with parturition itself cause physiological stress. Factors involved in mediating the hypathalomo–pituitary–adrenal (HPA) axis at parturition are not well understood. This study examines the effect of piglet expulsion on the pituitary–adrenal axis by measurement of plasma cortisol, adrenocorticotropic hormone (ACTH) and β-endorphin. The effect of farrowing environment in modulating the acute response to piglet expulsion is also investigated. Twelve second parity sows, with indwelling jugular catheters, were moved into either a farrowing crate or a straw-bedded pen 5 days before their expected parturition date (EPD). Blood samples were taken from each sow during a prefarrowing baseline period and then rapid samples (2.5 mins) were taken for 10 min following the birth of two piglets. No effect of environment was found on any of the hormonal variables which reinforces the hypothesis that the physiological stress seen in parturient pigs is due to some intrinsic factor of parturition. Plasma cortisol, ACTH and β-endorphin did not change significantly in the period following piglet expulsion suggesting that individual piglet expulsions do not play a major role in 'parturition stress'. There was however, an increase in plasma cortisol, ACTH and β-endorphin in response to increasing piglet number which is consistent with previous studies of general farrowing in which cortisol increased as farrowing progressed. Therefore this study reinforces the hypothesis that physiological stress increases with ongoing parturition although this does not appear to be a result of piglet expulsion. The potential role of other factors which may be involved in causing 'parturition stress' should be investigated.     

β-adrenergic responsiveness in stress-sensitive and stress-resistant pigs

This study investigated whether enhanced metabolic responsiveness to beta-adrenergic stimulation might explain the liability of the stress-sensitive pig to develop an acidosis during stressful situations. Blood lactate, pH, PCO2 and heart rate response to an intravenous infusion of isoprenaline were examined in three lines of pentobarbitone anaesthetized, atropinized pigs. The lines were Pietrain X Hampshire which had been selected over eight generations for a positive reaction to the halothane test (stress-sensitive); Pietrain X Hampshire which had been selected over eight generations for no reaction to the halothane test (stress-resistant) and British Landrace which had been selected over four generations for a positive halothane reaction (stress-sensitive). The metabolic responses to isoprenaline were greater in the stress-sensitive Pietrain X Hampshire line than the stress-resistant line. The stress-sensitive Landrace pigs, however, had smaller changes in pH and PCO2 in response to isoprenaline than the stress-resistant Pietrain X Hampshire pigs. This inconsistent trend across the three lines led to the conclusion that enhanced beta-adrenergic responsiveness was not the likely cause of stress sensitivity.     

Controlled release of estradiol-17β and bisphenol A from a silicone tube for long-term administration in mice

Silicone tubes filled with estradiol‐17β (E2) or the xenestrogen, bisphenol A (BPA) were covered with a polyethylene tube and implanted into mice subcutaneously. The releasing patterns from the tube in vivo were obtained from the volume of estrogen remaining in the tube by measurement with high performance lipid chromatography. E2 in glycerol was released in a few days from a silicone tube, which was not covered with a polyethylene tube (Type A). However, E2 in sesame oil was released very slowly from the silicone tube covered with a polyethylene tube (Type B) and approximately 10% of E2 remained in the tube at 56 days after implantation into the mice. The mean linear regression equation for E2 was Y = 70.967 ? 1.2271X (R² = 0.9268) and the quadratic regression equation was Y = 77.97 ? 2.2773X + 0.0194 × 2 (R² = 0.9864). The remainder rate curves of E2 and BPA were not significantly different throughout the experimental period of 56 days. The Type B tube in the present experiment might be useful for long‐term administration of estrogens.     

Cystic Degeneration in Porcine Ovaries - Second Communication: Concentrations of Progesterone, Estradiol-17β, and Testosterone in Cystic Fluid and Plasma; Interpretation of the Results

Contents: The content of progesterone, estradiol-17β, and testosterone of plasma and cystic fluid was determined in 79 sows with ovarian cysts. The average progesterone concentration of sows with dark corpora lutea (CL) was higher than of sows with pale or absent CL (39.4 vs. 8.7 vs. 8.0 ng/ml plasma; p < 0.001; and 7512 vs. 3644 vs. 2723 ng/ml cystic fluid, respectively; p < 0.001). The cystic fluid of animals with oligocystic ovaries (10 cystslanimal) had a significant higher progesterone concentration in comparison to potycystic animals (7200 vs. 3682 ng/ml; p < 0.001). Testosterone and estradwl-17β levels in plasma and in cystic fluid of polycystic animals were significantly higher in comparison to oligocystic animals (Plasma-Testosterone: p < 0.01; Plasma-Estradwl: p < 0.05; Cyst-Testosterone: p < 0.01; Cyst-Estradiol: p < 0.001). In oligocystic ovaries testosterone in cysts exceeded the estradiol-17β levels, whereas in polycystic ovaries the situation was vice versa (p < 0.001).
It is suggested that cystic ovarian degeneration in the sow is not exclusively a gradually progressing process, rather then a complex syndrome with three components, were characterized by a separate course of development (oligocystic, polycystic. oligo-polycystic syndrome).     

Measurement of histological changes in the cervix of ewes after prolonged exposure to oestrogenic clover or oestradiol-17β

Morphometric methods were used to measure abnormalities in histological architecture of the endocervix in ewes with infertility after prolonged exposure to oestrogenic clover pastures. Similar measurements were made on the cervix of ewes exposed to oestradiol-17 beta for 6 months. In both cases the changes in histological appearance were essentially similar, and were most easily measured by counting the number of cervical crypts. Ewes treated with either phyto-oestrogens or oestradiol also had significantly wider cervical folds, greater areas of lamina propria, and more cervical glands. The results provide a basis for measuring the severity of permanent oestrogenic change in different flocks or after different experimental treatments.