"Stallgassen"-Progesterontest auf dem Prüfstand

Abstract: Examination of a cowside milk progesterone kit
Milk samples with high (7.1–15.0 ng/ml), intermediate (3.1–6.1 ng/ml) or low (< 1.5 ng/ml) progesterone content were analyzed for progesterone by the commercially available cowside test "Bovi-test" (Santel/Bad Segeberg). It was found that high levels of progesterone are positively recognizable. The reliability of the test at intermediate and low levels of progesterone, however, is unsatisfactory.     

Den Milchprogesteron-Schnelltest "Hygia" erprobt

Abstract: "Hygia" cowside milk progesterone kit examined Milk samples of a wide range of progesterone concentrations (< 0.6 – 50 ng/ml) were analyzed with the cowside test "Hygia" (Hartmann AG, HeidenheirnlBrenz). The test is easy to conduct and takes 10–15 min. In case of high (> 10 nglml), intermediate (2.2–9.5 ng/ml) and low (< 1.8 ng/ml) progesterone levels correct diagnoses were arrived at in 98%, 87% and 95% of all cases, respectively.     

Use of pulsatile intravenous administration of gonadotropin-releasing hormone to induce fertile estrus in bitches

The pulsatile IV administration of gonadotropin-releasing hormone (GnRH) was evaluated as a method to induce fertile estrus in 8 anestrous Beagle bitches. Bitches received 1.25 micrograms of GnRH every 90 minutes for 11 to 13 days. Gonadotropin-releasing hormone was delivered by use of an automatic pump. Reproductive history was known for all bitches, 4 of which, on the basis of 3 or 4 preceding cycles, had an interestrous interval of 219 +/- 14 days (mean +/- SEM). Estrus induction was attempted during early anestrus in 6 bitches (ie, 148 +/- 10 days since the preceding estrus) and late anestrus in 1 bitch (ie, 260 days since the preceding estrus); another bitch had not had an estrous cycle for nearly 2 years before GnRH administration. Signs of estrus were seen within 16 days after the start of GnRH administration in the bitches with regular estrous cycles (group 1, n = 7), and within 23 days in the bitch (group 2) with prolonged anestrus. All bitches were bred, and 7 of 8 (87.5%) became pregnant, with a mean litter size of 4.5 +/- 0.75. A normal hormonal response pattern was observed in group-1 bitches--a peak increase in plasma estrogen concentration of 22.3 +/- 2 pg/ml immediately before the onset of estrus. Peak plasma progesterone concentration (17.3 +/- 3 ng/ml) was observed 1 to 14 days after the onset of diestrus in the group-1 bitches that ovulated, and adequate plasma progesterone concentration was maintained throughout gestation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct radioimmunoassay of progesterone in bovine plasma using danazol (17-alpha-2,4-pregnadien-20-yno(2,3-d)isoxazol-17-ol) as a displacing agent.

The majority of progesterone in plasma is bound to cortisol-binding globulin and albumin carrier proteins. In the determination of plasma progesterone concentration by radioimmunoassay (RIA), it is necessary to remove these carrier proteins or displace the hormone from them. In the present study, we have examined the suitability of danazol (17-alpha-2,4-pregnadien-20-yno(2,3-d)isoxazol-17-ol), a synthetic steroid, to displace progesterone from plasma proteins in a direct RIA of bovine plasma. Accordingly, the progesterone content of bovine plasma samples was measured with a RIA using danazol as a displacing agent (direct RIA) and compared with results obtained with a RIA incorporating a preliminary solvent extraction step (extraction RIA). Danazol did not alter the standard curve for progesterone. Sensitivity (ED80) of the direct RIA (9.8 pg/tube) was comparable to that of the extraction RIA (10.3 pg/tube). Results for progesterone assayed in the direct RIA correlated well (r = 0.99) with the results obtained with the extraction RIA. The direct RIA was shown to be accurate; the mean recovery of known amounts of progesterone added to a sample of pooled bovine plasma was 98.5% +/- 3.29 (SEM). The direct RIA intra-assay coefficient of variation (CV) RIA for samples within the low concentration range (0.1-1.0 ng/mL), the medium concentration range (1.0-3.0 ng/mL) and the high concentration range (3.0-6.0 ng/mL) of progesterone were 8.1%, 8.3% and 7.73%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Validation of a human progesterone enzyme immunoassay (EIA) kit for use on serum of cattle in Cameroon

A study aimed at validating a human progesterone enzyme immunoassay kit was carried out on cattle at Bambui, Cameroon. Progesterone ELISA Kits (EH-511) were obtained from Clinpro International. Forty-one cows were selected, of which 19 were pregnant and 22 within 14 days post partum. Blood samples were analysed and progesterone levels were deduced from a curve obtained from standard absorbance values (A ₄₅₀). Results show that 95.5% of postpartum cows had progesterone levels below 1 ng/ml, with the highest level being 0.75 ng/ml. The mean level was 0.5 ± 0.26 ng/ml. The cows in the ‘pregnant group’ had progesterone levels ranging from 3.5 to 17.5 ng/ml. This kit can be used for measuring progesterone levels in cattle. Levels of 1 ng/ml for two consecutive samples or one sample at or above 3 ng/ml are an indication of the presence of corpus luteum, while cows below 1 ng/ml will be in anoestrus.     

Establishment of a Pregnancy Following Intravaginal Insemination with Epididymal Semen from a Dog Castrated due to Benign Prostatic Hyperplasia

Benign prostatic hyperplasia was diagnosed in an American Staffordshire Terrier of high breeding value presenting concurrent haematuria. Castration as a treatment was synchronized with the oestrus cycle of a bitch selected for insemination. After castration the cauda epididymis was flushed with Gent semen extender and collected spermatozoa were filtered and analysed by Hamilton Thorn computer assisted sperm analysis. A total of 7 ml semen containing 742 x 10(6) spermatozoa with 76.5% mean motility was used for insemination. Intravaginal insemination of the bitch was performed with an insemination catheter for dogs (Kruuse, Marslev, Denmark) on the day when plasma progesterone levels reached 9.9 ng/ml. Normal pregnancy without complications resulted in eight live-born puppies 63 days after insemination. This is the first report of a normal pregnancy and birth of puppies from a bitch inseminated with epididymal semen obtained from a dog affected by benign prostate hyperplasia.     

Diagnostic Efficacy of a Single Progesterone Determination to Assess Full‐Term Pregnancy in the Bitch

In clinical settings, when the reproductive history of a near‐term bitch is limited to mating dates, the possibility to accurately assess whether pregnancy is at term could be very useful in order to be able to plan a correct management of parturition or to safely perform an elective Caesarean section. The aim of this study was to assess the diagnostic efficacy of a single progesterone determination, measured by chemiluminescent immunoassay (CLIA), in predicting the occurrence of parturition on the following day. At least one blood sample was collected from 51 pre‐partum bitches during the 3 days before parturition and on day of parturition. The efficacy of progesterone as a marker of the end of pregnancy was tested using a receiver operating characteristic (ROC) analysis. Youden's index was calculated to select the optimal cut‐off value (with 95% confidence interval), aiming at maximizing the correct identification of negative events, so not to risk to diagnose as full term a bitch which is not. Progesterone concentration lower than 3.4 ng/ml correctly identified the bitches whelping the following day; however, because of the obliged prudential approach, sensitivity was low (46.88%), and 17 of 32 full‐term bitches were missed. Due to a very large individual variation, a single progesterone determination has low diagnostic efficacy, although it can represent a useful first screening.     

Estimated pregnancy length from ovulation to parturition in the bitch and its influencing factors: a retrospective study in 162 pregnancies

An accurate timing of parturition is very useful for managing canine parturition. It is generally accepted that parturition in bitches occurs between 64 and 66 days after the luteinizing hormone peak. In this retrospective study, we determined pregnancy length in different breeds and its influencing factors dating it from the estimated day of ovulation (EDO), defined as the day when peripheral plasma level of progesterone (P4) reaches 6 ng/ml. From January 2001 to December 2006, 162 pregnancies in 151 bitches of 53 different breeds were followed. Different parameters concerning the bitch, the litter, the type of semen and the type of reproduction were studied. The mean estimated pregnancy length in the bitch from EDO to parturition was 63.1±2.1 days. The main influencing factors for the pregnancies studied were the breed, the size of the bitch and the number of puppies within the litter.     

Milk Progesterone Profile at and after Artificial Insemination in Repeat-Breeding Cows: Effects on Conception Rate and Embryonic Death

The aim of this study was to investigate whether the skim milk progesterone concentrations at artificial insemination (AI) and day of rise of post-ovulatory progesterone concentration thereafter affect the conception and embryonic death rates in repeat-breeding cows. Milk samples were obtained from 96 repeat-breeding cows that failed to conceive to three or more AIs. The samples were taken from the cows at the day of AI and three times/week until day 45 post-AI. Skim milk was obtained after centrifugation and used for progesterone assay. The cows with a progesterone concentration more than 0.5 ng/ml at AI showed a significantly higher incidence of late embryonic death than those having a progesterone concentration<0.5 ng/ml at AI (p<0.01). As the progesterone level at insemination rose, conception rate declined. A negative correlation was shown between conception rate and skim milk progesterone level at AI. Of 56 cows showing a rise of progesterone to 1 ng/ml or more within 6 days after AI, 28 cows (50%) conceived. On the contrary, only eight of 39 cows (20.5%) conceived when the progesterone rose up to 1 ng/ml after day 6 post-AI. We concluded that increased progesterone concentration at the time of AI and delayed rise of progesterone post-AI might lead to decrease in fertility in repeat-breeding cows.     

Pregnancy diagnosis by milk progesterone on days 18, 22, and 24 postbreeding in dairy cows

Milk samples were collected from 91 dairy cows on days 18, 22, and 24 postbreeding. The progesterone values of these samples were assayed, using enzyme-immuno-assay for pregnancy diagnosis. These animals were classified by nonpregnant (low progesterone values, 5 ng/ml or less) and pregnant (high progesterone values, more than 5 ng/ml). The accuracy of diagnosis on days 18, 22, and 24 postbreeding were 56%, 78%, and 79% for pregnant cows and 90%, 93%, and 93% for nonpregnant animals. The sampling date had a significant effect on diagnostic accuracy (P less than 0.05).     

A Retrospective Analysis of 2,253 Cases Submitted for Endocrine Diagnosis of Possible Granulosa Cell Tumors in Mares

Endocrine diagnoses of granulosa cell tumors (GCTs) in the mare are frequently based upon determination of serum concentrations of inhibin, testosterone, and progesterone (GCT panel). In the present study, we examined results from 2,253 samples submitted for determination of GCT panel. In an additional subset of samples (n = 75), diagnosis of GCT was confirmed based upon surgery or necropsy. The objective of the current study was to examine the agreement between serum inhibin and testosterone concentrations in mares with serum progesterone concentrations less than or ≥1 ng/mL. Across all samples, elevations in serum inhibin or testosterone were noted in 15.2% or 17.3% of samples, respectively. For samples with progesterone <1 ng/mL, more (P = .001) samples had elevated inhibin than elevated testosterone, whereas for samples with progesterone ≥1 ng/mL, more (P < .0001) samples had elevated testosterone than elevated inhibin. For samples with progesterone <1 ng/mL, the agreement between elevated inhibin and testosterone was greater than that for samples with progesterone ≥1 ng/mL. In a subset of 53 samples with progesterone ≥1 ng/mL, 28 samples had endocrine evidence of a granulosa cell tumors based upon elevations of serum anti-Müllerian hormone, and 4 of these samples had endocrine evidence of pregnancy based upon estrone sulfate concentrations. For samples from mares with confirmed GCTs, 85% and 55% had elevated inhibin or testosterone, respectively. Based upon endocrine diagnosis, GCTs occur in mares with elevated progesterone and/or estrone sulfate, albeit at a low rate.     

Relationship between different concentrations of the plasma progesterone at the time of FSH-P treatment and the superovulatory response in Holstein dairy heifers

The aim of this study was to evaluate the influence of two different concentrations of plasma progesterone at the time of FSH-P treatment on the superovulatory response in dairy heifers. Sixteen reproductively sound Holstein heifers (13-15 months of age) were used in this study. Superovulatory treatment was commenced at mid-dioestrus (Day 10 ± 2 of the oestrous cycle) of the synchronized (using two injections of PGF2α, 11 days apart) oestrous cycles. Blood samples were collected on the day and the day after commencing FSH-P treatment and at oestrus for plasma progesterone determination. Heifers were grouped based on two levels of plasma progesterone; Group low progesterone (LP; ranging from 2 to 4.5 ng /ml; n = 7) and Group high progesterone (HP; ≥ 4.6 ng /ml; n = 8) at the beginning of FSH-P treatment (one heifer was excluded from the statistical analysis because of the abnormal progesterone level at oestrus). The superovulatory response in terms of mean numbers of palpable corpora lutea (ovulation rate) was significantly higher (p < 0.05) in group LP than group HP. Ovulation rate was negatively correlated (r = -0.51) with the progesterone concentration at the time of commencing FSH-P treatment (p < 0.05). Data suggest that varying concentrations of plasma progesterone at the time of FSH-P treatment may have a different effect on the outcome of superovulatory response in dairy heifers.     

Comparison Between Vestibular and Subcutaneous Insertion of Deslorelin Implants for Oestrus Induction in Bitches

Investigations using sustained-release deslorelin implants at various insertion sites have shown that this method consistently induces oestrus in anoestus bitches. However, fertility comparisons between implant insertion sites have not been performed. Anestrous beagle bitches received one 2.1 mg deslorelin implant beneath the vestibular mucosa (VM group; n = 6) or in the subcutaneous tissue between the shoulder blades (SubQ group; n = 8). Vestibular implants were removed when serum progesterone concentrations first exceeded 1.5 ng/ml. Vaginal cytologies and blood samples were collected daily and bitches were inseminated during oestrus. Serum progesterone and deslorelin concentrations were measured and pregnancy status was determined using ultrasonography. There were no differences between groups in the intervals between implant administration and the onset of proestrus, the time of the luteinizing hormone surge and the onset of cytologic diestrus. There were also no differences in the number of corpora lutea or foetuses. However, conception rate was significantly lower in the SubQ group. The pregnancy rate did not differ significantly between the VM and SubQ groups [4 out of 6 (66.7%) and 3 out of 8 (37.5%), respectively]. One bitch (16.7%) in the VM group and three bitches (37.5%) in the SubQ group suffered distinct, premature declines in serum progesterone concentrations starting 1–4 weeks after cytologic diestrus. Serum progesterone concentrations did not recover (premature luteal failure), resulting in abortion. Bitches with premature luteal failure in the SubQ group still had serum deslorelin concentrations >100 pg/ml 20 days after implant insertion, suggesting a possible association between prolonged deslorelin release and luteal failure.     

Use of milk progesterone enzyme immunoassay for differential diagnosis of follicular cyst, luteal cyst, and cystic corpus luteum in cows

In 160 cows with ovarian cysts as determined by rectal palpation, differentiation was made of follicular cyst, luteal cyst, and cystic corpus luteum on the basis of milk progesterone concentrations estimated by an enzyme immunoassay before and at 10 days after cows were treated with gonadotropin-releasing hormone. Cows having a progesterone concentration in skim milk less than 1.0 ng/ml were considered to have follicular cysts and those with concentrations of 1.0 ng/ml or higher were regarded as the cases of luteal cyst or cystic corpus luteum. Luteal cyst was characterized by progesterone values remaining high in the cows for 10 days after treatment, and cystic corpus luteum was characterized by a decrease in progesterone concentration after cows were treated. By the rectal palpation procedure it was impossible to differentiate luteal cyst and cystic corpus luteum from follicular cyst. The frequencies of follicular cyst, luteal cyst, and cystic corpus luteum were 65%, 19%, and 16%, respectively. Of 104 cows with follicular cysts as defined by milk progesterone assay result, 73 (70%) responded to the treatment with gonadotropin-releasing hormone, the milk progesterone concentration increasing from 0.7 +/- 0.2 ng/ml (mean +/- SD) to 1.8 +/- 1.1 ng/ml. The accuracy of rectal palpation 10 days after treatment for judgment of luteinization of follicular cyst confirmed by milk progesterone analysis was only 30% (48 cows of 160).     

奶牛发情期的奶孕酮分析

<正> 影响奶牛人工授精成功率的主要原因是对发情期能否正确判断,适时输精。据1981年联邦德国Bavarian动物健康服务机构的报告,输精时间不正确,是影响奶牛繁殖率的重要因素。由于孕酮含量在发情周期中呈规律性变化,在发情期显著下降,因此可     

Measurement of Ovine Pregnancy-Associated Glycoprotein (PAG) During Early Pregnancy in Lacaune Sheep

This study describes ovine pregnancy‐associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi‐purified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG_57+59kDa) and R805 (against ovPAG5_58+61kDa) were used respectively in RIA‐780 and RIA‐805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n = 17) than in non‐pregnant ones (n = 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA‐780 and 14 900 Ci/mmol in RIA‐805. The minimal detection limits for RIA‐780 and RIA‐805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra‐assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA‐780 and 8%, 9% and 5% for RIA‐805. The inter‐assay CV in the same samples were 13%, 12% and 7% for RIA‐780 and 13%, 11% and 5% for RIA‐805. The recovery was higher than 95% in both assays. No cross‐reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA‐780 and RIA‐805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding.     

Milk progesterone determination in buffaloes post-insemination

Milk progesterone levels were studied in 17 buffaloes between post-insemination and 30 days thereafter. Six animals were confirmed pregnant. Seven of 10 animals took greater than 24 days to return to oestrus and the pattern of change of progesterone levels indicated a steady increase from 1 ng/ml on day 2 to 20 ng/ml on day 14 post-insemination, falling subsequently to about 5 ng/ml, 2 days prior to oestrus. In pregnant buffaloes, the milk progesterone levels showed a continuous increase up to 20 days post-insemination but did not decline thereafter. In individual buffaloes returning to oestrus, a cut-off milk progesterone level of greater than 10 ng/ml was considered for pregnancy diagnosis, 20, 22 and 24 days post-insemination. The test was 60, 75 and 75% accurate for detection of pregnancy on days 20, 22 and 24 respectively and 100% for non-pregnancy diagnosis on all three days. Individual animals showed a highly variable oestrous cycle length, which has been suggested as a contributory factor for false pregnancy diagnosis by milk progesterone test in this species. Milk progesterone assay may also identify silent heats, and clinical disorders.     

Skim milk progesterone in pregnant cows from insemination throughout lactation

The skim milk progesterone profile was assessed by radioimmunoassay, without extraction, from the day of insemination (day 0) until the cows were dried off on day 225 of gestation. A total of 418 samples were collected from 154 pregnant Holstein cows. The daily variation in skim milk progesterone was recorded from day 1 until day 45 of pregnancy to detect the commencement of progesterone secretion from the corpus luteum after insemination. Subsequent determinations were made every 2 weeks from day 46 until lactation ceased. On the day of artificial insemination and for the first 2 days after insemination, all the cows had a basal progesterone concentration <0.1 ng/ml. A rise in progesterone (0.2±0.1 ng/ml) was first detected on the third day after insemination. The progesterone values then increased significantly (p<0.001) until day 15.The values then remained nearly constant (2.5–3.5 ng/ml) until day 106 of pregnancy, when they began to decline. Between days 120 and 180 of gestation, progesterone was significantly decreased (2.2–2.9 ng/ml) before it rose again to the previous plateau (3.5–3.9 ng/ml) around day 180. The progesterone concentration then remained at the higher level until the animals were dried off.Abbreviations AI artificial insemination - RIA radioimmunoassay     

Nutritionally induced relationships between insulin levels during the weaning-to-ovulation interval and reproductive characteristics in multiparous sows: II. Luteal development, progesterone and conceptus development and uniformity

Insulin‐stimulating sow diets before mating improve piglet uniformity. We studied effects of nutritionally induced differences in insulin levels during the weaning‐to‐ovulation interval (WOI) on luteal development, progesterone secretion and pre‐implantation conceptus development and uniformity (d10). To create insulin contrasts, 32 multiparous sows were fed either a dextrose plus lactose containing diet (each 150 g/day) at 4 h intervals (DL treatment) or an isocalorically control diet (containing soybean oil) at 12 h intervals (CTRL treatment) during the WOI. After ovulation, all sows received a standard gestation diet at 12 h intervals. Ovulation rate, plasma progesterone levels, pregnancy rate and embryo survival did not differ between treatments. CTRL sows had a higher total luteal weight (11.2 vs 9.7 g; p = 0.03) than DL sows. Conceptus diameter at d10 of pregnancy tended to be larger in CTRL sows (diameter: 7.1 vs 6.4 mm; p = 0.07). Conceptus uniformity was not influenced by treatment. Insulin area under the curve (AUC) and mean insulin during the WOI were positively related with mean progesterone (β values were 0.78 (ng/ml)/1000 μU and 0.14 (ng/ml)/(μU/ml) for AUC and mean, respectively; p < 0.05) and maximal progesterone (β values were 1.46 (ng/ml)/1000 μU and 0.27 (ng/ml)/(μU/ml) for AUC and mean, respectively; p < 0.05) levels during the first 10 days of pregnancy, but not with conceptus development and uniformity. In conclusion, high insulin levels during the WOI seem to be beneficial for progesterone secretion in sows, probably mediated through beneficial effects of insulin on follicle development.     

Concentrations of progesterone and luteinizing hormone in the serum of diestrous bitches before and after hysterectomy

Blood was collected from 6 adult bitches (3 pregnant and 3 nonpregnant) daily for 59 days after the onset of diestrus, and serum progesterone concentrations were determined. The bitches were hysterectomized at various times during diestrus [diestrus day (DD) 5, 15, or 25] to determine whether the uterus has a role in maintaining luteal function in the pregnant or nonpregnant bitch. Concentrations of serum luteinizing hormone (LH) were also measured to determine whether LH concentrations decrease when luteal function abates (experiment 1). All 6 bitches in experiment 1 had progesterone concentrations greater than 1.0 ng/ml during the 2-month period, indicating that neither the pregnant nor nonpregnant uterus was necessary for maintaining luteal function in the bitch. Concentrations of LH appeared to increase in the serum of 5 of the 6 bitches when progesterone concentrations were declining, indicating that cessation of luteal function does not appear to result from a lack of LH. Blood was collected from the 6 bitches used in experiment 1 twice weekly during the 2nd diestrus after hysterectomy (experiment 2) to determine whether alterations in luteal function that might be observed during experiment 1 were due to some aspect of the surgical procedure, rather than to absence of a uterus. Progesterone concentrations in the serum were lower (P less than 0.05) during the 10 days after surgery in the 2 bitches hysterectomized on DD 5 than in the 4 bitches remaining intact during this period (experiment 1).(ABSTRACT TRUNCATED AT 250 WORDS)