Relationship between rectal findings of corpus luteum and whole milk progesterone levels in postpartum dairy cows

The reliability of clinical ovarian findings was assessed as an indicator of luteal function in primiparous dairy cows. The postpartum period of 103 cows following their first parturition was studied by thrice weekly rectal palpation of ovaries and whole milk progesterone assay from 1 week after parturition to the first insemination. The relationship between milk progesterone levels and 1101 ovarian findings was compared during the follicular phases, short luteal phases and during the early, mid and late thirds of normal luteal phases. The compatibility between elevated progesterone and palpable corpus luteum was 71%, and between low progesterone and lack of corpus luteum 77%. In 10% of all rectal examinations the finding was unspecified; i.e. the clinician could not differentiate between luteal and follicular activity. During the acyclic period prior to the initiation of luteal function, the proportion of false corpus luteum findings was 11%. The corpora lutea of the short oestrous cycles were more difficult to palpate than those of normal cycles. During early dioestrus the corpus luteum was significantly more difficult to palpate than during the rest of dioestrus. The percentage of unspecified findings was highest during early dioestrus.The paper discusses the reliability of rectal examination as a method of diagnosing cyclicity and of evaluating the responsiveness of a cow to prostaglandin treatment.     

Formation of a secondary corpus luteum after ultrasound-guided follicular aspiration in cows

This paper reports the observed formation of a secondary corpus luteum (CL) in the presence of the cyclic corpus luteum, on the ovaries of a cow after ultrasound-guided follicular aspiration for oocyte recovery. The secondary structure, although smaller and lighter (4.97 g vs. 6.02 g) than the natural one, had the typical macroscopic appearance of a corpus luteum. Histological examination of the structure using electron microscopy revealed typical structural features of a natural CL. Mean tissue progesterone concentration was significantly lower in the secondary CL (31.15 +/- 3.11 compared with 58.29 +/- 6.32 micrograms/g tissue of the cyclic CL) and oestradiol-17 beta significantly higher than in the natural CL (108 +/- 11.6 compared with 74.2 +/- 7.81 pg/g tissue). P450scc and P450(17 alpha) mRNA was detected in both structures while P450arom and full-length mRNA FSH receptor were detected only in the secondary structure.     

Effect of exogenous progesterone administration on luteal sensitivity to PGF during the early development of the corpus luteum in mares and cows

The objective of this study was to determine the effect of exogenous progesterone administration at ovulation and during the early development of the CL, on its future sensitivity to a single administration of PGF2a in mares and cows. Horse Retrospective reproductive data from an equine clinic in the UK during three breeding seasons were used. Mares were divided into: control group, cycles with single ovulations; double ovulation group cycles with asynchronous double ovulations; and PRID group: cycles with single ovulations and treatment with intravaginal progesterone device (CIDR) immediately after the ovulation. All mares were treated with d‐cloprostenol (PGF) at either: (i) 88 hr; (ii) 96 hr; (iii) 104 hr; or (iv) 112 hr after the last ovulation. Cattle A total of nine non‐lactating Holstein cows were used. All cows were administered PGF14 d apart and allocated to one of two groups control group GnRH was administered 56 hr after the second PGF administration. CIDR group CIDR was inserted at the same time of GnRH administration. All cows were administered PGF at 120 hr post‐ovulation. The complete luteolysis rate of mares with double ovulation (66.7%) and those treated with exogenous progesterone (68.4%) was significantly higher than the rate of mares with single ovulation (35.6%) at 104 hr. In the cow, however, the treatment with CIDR did not increase the luteolytic response in cows treated at 120 hr post‐ovulation. In conclusion, the degree of complete luteolysis can be influenced by increasing the concentration of progesterone during the early luteal development in mares.     

Use of an enzyme immunoassay to determine concentrations of progesterone in caprine plasma and milk

Concentrations of progesterone (P4) were determined using enzyme immunoassay kits on plasma and milk samples obtained on the same days from 18 lactating dairy goats. Progesterone profiles documenting anestrus, short estrous cycles, normal estrous cycles, a prolonged follicular phase, and prolonged luteal phases were established. When plasma P4 concentrations were used as an accurate indication of the presence or absence of functional luteal tissue, milk P4 concentrations agreed with plasma determinations in 79.4% of the 465 samples tested. Milk samples could not be used to make a definitive decision because of marginal values in 11.2% of the determinations. Milk P4 concentrations were high when plasma P4 concentrations were low in 6.2% of the paired samples, especially those obtained around the time of estrus when peripheral P4 concentrations were changing rapidly. The remaining 3.2% of milk samples had low milk P4 concentrations when plasma P4 concentrations were high. Composite milk from 8 does in estrus or 8 does in the luteal phase was not consistently different from strippings in butterfat percentage or P4 concentration.     

Accuracy of rectal palpation and of a rapid milk progesterone enzyme-immunoassay for determining the presence of a functional corpus luteum in subestrous dairy cows

The accuracy of rectal palpation and of a rapid milk progesterone enzymeimmunoassay (EIA) for determining the presence of a functional corpus luteum (CL) in subestrous dairy cows was investigated, using the results of a radioimmunoassay (RIA) for progesterone in skimmed milk as the “gold standard”. The ovaries and uterus of each of 359 subestrous cows from 32 dairy herds were palpated per rectum, the presence or absence of a functional CL was predicted, and a milk sample was collected for analysis by both the rapid EIA and the RIA.

The nine clinicians participating in the study had a combined sensitivity of 82.6% and specificity of 52.6%, compared to the EIA which had a sensitivity of 90.3% and a specificity of 84.2% for predicting the presence of functional luteal tissue.

It was concluded that the technique of rectal palpation was inaccurate at assessing the functional (progesterone-secreting) status of ovarian structures. In addition, a qualitative EIA was as sensitive and more specific than rectal palpation in predicting the presence of a functional CL in the subestrous cow.

     

The milk progesterone test as an aid to the diagnosis of cystic ovaries in dairy cows

Two field trials were carried out by five experienced veterinary surgeons to evaluate the milk progesterone test as an aid to the differential diagnosis of cystic ovaries in dairy cows. Of 200 cystic cows, 71 per cent were diagnosed clinically as follicular and 29 per cent as luteal cases; 80 per cent of the cases occurred in the six winter months November to April. The progesterone assay indicated that the diagnosis was correct in 84 per cent of the follicular cases but only 54 per cent of the luteal cases. Seventy-four per cent of the confirmed cystic cases responded to treatment within two weeks according to milk progesterone tests and there were no significant treatment differences. Overall, 80 per cent of the cows became pregnant on average 38 days after treatment having received an average of 1.70 inseminations each. Milk yield data in the first trial indicated that the cystic cows were not significantly higher yielders than their herd-mates.     

雌二醇与孕酮奶样纸片酶免法的建立及应用

乳汁雌二醇(E2)与孕酮(P4)含量是判断母牛卵巢机能状态的重要指标。本试验建立了E2与P4奶样纸片酶免法,P4检测灵敏度达到2.1 pg,回收率91%,板内和板间变异系数分别为5.3%(n=8)和10.4%(n=10);E2检测灵敏度达到1.7 pg,回收率89%,板内和板间变异系数分别为4.8%(n=7)和9.6%(n=10)。将该方法用于测定定时排卵程序中母牛乳汁E2与P4含量,结果表明所建立的方法简便实用,排卵程序中母牛乳汁E2、P4变化规律与理论分析相符,可以用来判定母牛发情、妊娠及卵巢功能。     

Detection of a corpus luteum in apparently anoestrous cows by manual palpation, transrectal ultrasonography and plasma progesterone concentration

AIMS: To determine the level of agreement between transrectal ultrasonography, manual palpation and measurement of progesterone in the detection of corpora lutea in post-partum cows. To evaluate the reproductive performance of cows not detected in oestrus prior to mating, but detected with a corpus luteum at the start of mating. METHODS: Cows from seven herds which were not detected in oestrus were examined between 5 and 7 days before the herd's planned start of mating. Ovaries were examined by palpation and ultrasonography in 160 cows and plasma progesterone concentrations were also measured in 103 cows. Insemination dates and pregnancy data were recorded in 159 cows not detected in oestrus but having a corpus luteum and 1405 cycling herd mates. RESULTS: The level of agreement between ultrasonography and measurement of progesterone (kappa = 0.74) was higher than with manual palpation (kappa = 0.67) although it was significant for both techniques (p <0.001). Cows which were not detected in oestrus, but detected with a corpus luteum had a longer interval to first service (12 v. 10 days, p <0.05) and conception (19 v. 15 days, p = 0.01) than cycling herd mates and had a higher empty rate (9.7% v. 3.8%, p <0.001). CONCLUSIONS: These data indicate that ultrasonography may provide a better diagnostic tool for examining cows not detected in oestrus than manual palpation or measurement of progesterone concentration. Cows not detected in oestrus but having a corpus luteum were shown to have significantly poorer reproductive performance than cycling herd mates.     

持久黄体性不孕奶牛用复方缩宫素乳剂处理后血清中孕酮和雌二醇水平的变化

选择患持久黄体的不孕奶牛14头进行复方缩宫素乳剂的临床治疗试验,并利用放射免疫方法对部分患牛治疗前后血清孕酮（P     

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).     

Supra-basal progesterone concentrations during the follicular phase are associated with development of cystic follicles in dairy cows

The objective of this study was to test the hypothesis that supra-basal concentrations of progesterone during the follicular phase are associated with the development of follicular cysts. Twenty-five non-lactating dairy cows were used in the study, which was performed over five identical replicate trials. Luteolysis was induced during the mid-luteal phase. Transrectal ultrasonography was performed daily to determine the occurrence/timing of ovulation. Plasma samples were collected for progesterone, oestradiol and luteinizing hormone (LH) analysis. Three cows failed to ovulate (cystic anovulatory) but did ovulate in a subsequent replicate (cystic ovulatory). Eight cows from the appropriate replicates were used as control cows (normal group). Follicular growth patterns and plasma oestradiol concentrations were similar between the three groups. However, the plasma progesterone concentrations during the follicular phase were twofold higher in the cystic anovulatory group (P < 0.01). Furthermore, no LH surge was detected in these animals. While LH pulse amplitude was similar between groups, LH pulse frequency in the cystic anovulatory group was attenuated (P < 0.05). In conclusion, the formation of follicular cysts were preceded by elevated plasma progesterone concentrations and the suppression of the LH surge.     

检测奶牛乳汁孕酮的免疫生物传感器优化

为了完善已建立的孕酮免疫生物传感器的检测性能,本试验应用碳化二亚胺法将11α-羟基孕酮半琥珀酸和OVA制备成孕酮完全抗原,其浓度达0.6 mg/m L。在此基础上建立了以乳汁为基质的孕酮生物传感器的标准曲线(y=-4.9461x+8.7982,R2=0.993 2),进一步确立了检测乳汁孕酮的线性范围为0.31 ng/m L~50ng/m L,检测限为0.31 ng/m L,灵敏度为0.15 ng/m L,而且孕酮与皮质酮、皮质醇、雄烯二酮的免疫交叉反应较低,表明特异性较好。批内、批间变异系数分别为7.7%和7.5%,回收率为95.8%~115.7%,生物传感器稳定性在4℃保存4 d。该优化的奶牛乳汁孕酮免疫生物传感器的性能参数符合规定的标准,为检测妊娠、乏情和繁殖障碍疾病的奶牛乳汁孕酮含量提供了工具。     

Direct enzyme immunoassay of progesterone in bovine plasma

The present study was undertaken to develop a novel, practical and simple procedure for enzyme immunoassay (EIA) of plasma progesterone in cows. Diluted plasma was heated for 70°C for 30 min and applied directly to wells of a microtitre plate without extraction. Then plasma was incubated with antiprogesterone antibody and horseradish peroxidase‐labeled progesterone. The sensitivity of the assay was estimated as 4.4 pg/mL (0.11 pg/well). The intra‐assay and interassay coefficients of variation were 5.7–19.1% and 6.6–19.3%, respectively. When 0.3, 1 and 3 ng of progesterone were added to plasma, the recovery rates ranged between 79.9 and 108.4%. Only 4 h were needed to complete an assay to measure progesterone concentration. To apply the present direct EIA, progesterone concentration in plasma was assayed in crossbred cows used for the embryo transfer program. During insertion of controlled‐internal drug release (CIDR), progesterone concentrations were kept at a high level, although the removal of CIDR with treatment of dinoprost trometamine reduced progesterone concentration drastically. These results suggest that the present direct EIA is a practical and suitable method for measuring the plasma concentration of progesterone.     

Changes in blood levels of progesterone, triiodothyronine and thyroxine and the results of quantitative histological analysis of the placentoma and corpus luteum in cows after prolonged labor

Changes in the cell structure of the placentoma and the corpus luteum were subjected to quantitative histological investigation, parallel with the examination of the concentrations of progesterone (P4), triiodotyronine (T3) and tyroxin (T4) during parturition (Oth hour) and two and six hours after parturition. The hormone concentrations were determined by the RIA method. The results of the quantitative histological analysis of the placentomae and the corpus luteum suggest that when the placenta is retained there is a significantly higher number of maintained epithelial cells in the placentoma crypts and a higher number of unchanged small, dark and large, light lutein serraetion cells in the biopsy of the corpus luteum during the period under investigation. The morphological finding significantly correlates with higher concentrations of P4 in the blood of the cows with retained placenta, as compared with those whose placenta was not retained. It can be derived from the pattern of changes in T3 and T4 concentrations, compared with P4 and with the histological finding, that there is a functional relationship between the placentoma, corpus luteum, and the thyroid gland.     

Effects of GnRH or progesterone treatment on day 5 post-AI on plasma progesterone, luteal blood flow and leucocyte counts during the luteal phase in dairy cows

This study was designed to test the effects of progesterone or GnRH treatment on day 5 post-AI on fertility and luteal function in dairy cows and heifers. Five days after AI, 32 animals were randomly assigned to a control, intravaginal progesterone for 14 days progesterone releasing intravaginal device (PRID) or GnRH treatment group. On days 5, 7, 12, 14, 17 and 19 post-AI, each animal underwent colour Doppler ultrasonography of the corpus luteum and blood samples were collected for cell counts and plasma progesterone determination. Through general linear model repeated measures analysis of variance, significant effects were observed of treatment, parity, inseminating bull, reduced vascularization of the CL and pregnancy on plasma progesterone concentrations, whereas mean plasma progesterone and time luteal phase day, and treatment and plasma progesterone concentration on day 5 post-AI were found to, respectively, affect neutrophil and lymphocyte counts throughout the luteal phase. Moreover, two binary logistic regression analyses were performed. Based on the odds ratio, the likelihood of pregnancy by days 26-32 post-AI was 23.4 times higher in animals with high mean progesterone levels throughout the study period, compared with animals with low mean progesterone. The likelihood of reduced CL vascularization was 14 times higher in animals treated with PRID, compared with control and GnRH-treated animals. In conclusion, our results indicate that treatment on day 5 post-AI with PRID reduced subsequent CL vascularization, whereas GnRH treatment increased plasma progesterone concentrations on day 12 post-AI, although an effect was identified of the inseminating bull on plasma progesterone levels. Pregnant animals showed higher mean plasma progesterone concentrations than in nonpregnant ones and heifers higher than in lactating cows, whereas blood cell counts differed depending on the treatment and on the mean plasma progesterone concentration on day 5 post-AI.     

Age‐related changes in the bovine corpus luteum function and progesterone secretion

Decreased fertility associated with maternal ageing is a well‐known critical problem, and progesterone (P4) concentration decreases during the menopause transition in women. The corpus luteum (CL) secretes P4, thereby supporting the implantation and maintenance of pregnancy. It is proposed that a bovine model is suitable for studying age‐associated decline of fertility in women because the physiology of cows is similar to that of women and cows have a greater longevity compared with other animal models. Thus, we investigated the age‐dependent qualitative changes and inflammatory responses in the bovine CL. In vivo experiment: Cows were divided into three groups, namely, young (mean age: 34.8 months), middle (80.1 months) and aged (188.9 months). Blood samples were collected on days 7 and 12 during the estrous cycle. In vitro experiments: Cows were divided into young (mean age: 27.6 months) and aged (183.1 months). The CL tissues of these groups were collected from a local slaughterhouse and used for tissue culture experiments. An in vivo experiment, plasma P4 concentration in aged cows was significantly lower than that in young cows, whereas no difference was found regarding the area of CL. An in vitro examination in the bovine CL tissues showed that the luteal P4 concentration, P4 secretion, and mRNA expression of StAR and 3β‐HSD were lower in aged cows compared with young cows, especially in the early luteal phase. However, no differences were detected in the mRNA expression of inflammation‐ and senescence‐related factors and inflammatory responses to lipopolysaccharides between the CL tissues from young and aged cows, indicating that an age‐dependent increase in inflammation is not involved in the luteal function. P4 production and secretion from the bovine CL diminish in old cows, especially during the early luteal phase, suggesting that senescence may affect the luteal function in cows.