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1.
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. 相似文献
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A field study on the usefulness of milk progesterone determination to confirm estrus and pregnancy of dairy cows in the Fraser Valley area of British Columbia 
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下载免费PDF全文 Rajamahendran R Burton B Shelford J 《The Canadian veterinary journal. La revue veterinaire canadienne》1993,34(6):349-352
A field study was conducted to determine the usefulness of milk progesterone determination at the time of breeding to confirm estrus and at 21 days postbreeding to detect open cows. Twenty-seven dairy farmers collaborated in this study by providing milk samples on the day of breeding and 21 days later, together with pregnancy diagnosis data and information on herd reproductive management. Herd size ranged from 15 to 175 cows, the average being 65 milking cows. Six hundred and sixty-seven breeding-day samples and 472, 21-day samples were provided by the farmers. Analysis of milk samples for progesterone by a solid phase radioimmunoassay showed that only 32 (4.8%) of the services were performed when the cow was not in estrus (progesterone > 1 ng/mL). Of the 472, 21-day samples, 337 (71%) showed progesterone levels of > 1 ng/mL, while 135 (29%) showed progesterone levels of < 1 ng/mL. Subsequently, 243 (72%) of the cows with progesterone > 1 ng/mL and eight (6%) of the cows with progesterone < 1 ng/mL were diagnosed pregnant by transrectal palpation, giving a pregnancy rate of 53%. Progesterone concentration on the day of breeding was not associated with season or herd size. However, progesterone concentration at 21 days and pregnancy rate were associated with herd size. These results indicate that fertillzation failure and/or early embryonic mortality, rather than inaccurate detection of estrus, are the major reproductive problems encountered by the dairy farmers in British Columbia. Furthermore, progesterone values at 21 days were closely related to reproductive status and indicate the usefulness of milk progesterone assay for the early detection of open cows. 相似文献
4.
The effects of acetic acid administered at an amount of 300 to 600 g (5 to 10 mol) to the rumen of breeding cows, were investigated on ovulation, conception and progesterone levels in the blood and milk of cows with cloprostenol-induced (Oestrophan Spofa) oestrus at a dose of 500 micrograms i.m. In the group of 15 cows exposed to the acetic acid load five cows got in calf after the first insemination (33.3%), and 12 cows (80.0%) after all inseminations in 37.6 days after cloprostenol administration, with the insemination index 1.67 (Tab. I). In the control group (five cows) four cows (80.0%) got in calf after the first insemination, in total all five breeding cows got in calf in 20.6 days after cloprostenol administration, with the insemination index 1.2. In the experimental group of 15 cows a clinical examination of ovaries on day 7 after insemination revealed ovulation disorders in eight cows, that means in 53.3% of the animals (Tab. II). No ovulation disorders were observed in the control group of five cows. Progesterone levels in the blood showed high variability (Tab. III). In the group of cows administered acetic acid they were by more than a half lower (1.49; 0.67; 1.53 per ml) on days 7, 14 and 21 after insemination in comparison with the control group (3.35; 2.5; 3.38 ng per ml). The average progesterone levels in milk (Tab. IV) were 1.27 and 1.53 on day 7, 6.74 and 7.27 on day 14 and 3.52 and 11.85 ng per ml on day 21, respectively, the higher values apply to the control. It was not possible to evaluate reliably from the progesterone levels in the blood and milk if ovulation took place and if the corpus luteum was developing (Tab. V and VI). The clinical control of ovaries on days 7 and 8 after oestrus and insemination was more reliable to determine the ovulation disorders than the progesterone determination in the blood and milk of cows. 相似文献
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The reason why cows carrying the mutation of complex vertebral malformation (CVM) show poor reproductive capability although they carry only one mutant allele is still not fully understood. Monitoring the progesterone profiles during oestrous cycle and early pregnancy in carrier cows might help explain their lowered reproductive capability. Progesterone concentration was measured in 19 CVM carrier cows and 21 control cows during oestrous cycle and early pregnancy. Milk samples were collected from all cows starting on the day of artificial insemination until day 45 post‐AI. Progesterone was measured in skim milk using enzyme‐linked immunosorbent assay (ELISA). Progesterone concentration was significantly reduced on day 7 (p < 0.05) and day 9 (p < 0.01) post‐insemination in conceived CVM carrier cows when compared with that in control conceived cows. The mean progesterone concentration during early pregnancy was significantly lower (p < 0.05) in conceived cows with CVM than that of control cows in the same period. However, the mean progesterone concentration did not differ significantly (p = 0.072) in CVM cows that showed fertilization failure or embryonic death than that of control cows. Additionally, of 13 conceived control cows, eight cows (61.5%) showed normal luteal function. In contrast, of nine conceived CVM cows, only four cows (44.4%) showed normal luteal function. The conception rate was 47.4% in CVM carrier cows and 61.9% in control cows, but this difference did not reach significance. In conclusion, progesterone concentration might be lowered during early pregnancy in conceived CVM cows compared with that in control cows. 相似文献
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Shamsuddin M Bhuiyan MM Chanda PK Alam MG Galloway D 《Tropical animal health and production》2006,38(1):85-92
This study focused on the use of radioimmunoassay of progesterone in milk for the diagnosis of post-partum ovarian cyclicity
and accurate detection of oestrus and non-pregnancy in cows in the artificial insemination (AI) programme in Bangladesh. In
Investigation 1, milk samples were collected on day 0 (day of AI), day 9–13 and day 21–24 from 444 milking cows of various
breeds presented for the first post-partum insemination by 413 farmers living at 182 villages/regions in Mymensingh District
from 6 AI centres and sub-centres. Each cow was then examined three times after each AI until it stopped returning to oestrus.
Sixty to 90 days after the last AI, the cows were examined per rectum to confirm the pregnancy. Milk progesterone data on day 21–24 contributed to a clear diagnosis with respect to non-pregnancy
in 100% cows, indicating a possible use of this progesterone assay for identifying non-pregnant cows in AI programmes. In
Investigation 2, milk progesterone was monitored two times in a month with a 10-day interval in 88 cows. The samples were
taken between 10 days after calving and the first detected oestrus, followed by two more samples 10 days apart. The proportion
of cows accurately detected in oestrus was 30%. Another 30% were stated to be in oestrus when they were not (false positive)
and 40% were not detected when they were in oestrus (false negative). The mean intervals between calving and oestrus and between
calving luteal activity were 40 to 362 days (median = 120, n = 82) and 34 to 398 (median = 111, n = 64) days, respectively. The body condition scores at calving and at the initiation of luteal activity influenced the interval
between calving and luteal activity (p < 0.05). Cows suckled twice daily initiated luteal activity earlier than their counterparts suckled several times daily (p < 0.05). Determination of progesterone in milk on day 21–24 is a good means for detecting non-pregnant cows. 相似文献
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Use of milk progesterone enzyme immunoassay for differential diagnosis of follicular cyst, luteal cyst, and cystic corpus luteum in cows 总被引：1，自引：0，他引：1
T Nakao A Sugihashi N Saga N Tsunoda K Kawata 《American journal of veterinary research》1983,44(5):888-890
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). 相似文献
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Jeanne V. Samsonova Alexander P. Osipov Sergey E. Kondakov 《Veterinary journal (London, England : 1997)》2014,199(3):471-472
A new method for milk sample collection and storage, based on a dried milk sampling technique, is proposed. The method includes application of a whole milk sample to a porous membrane followed by drying. One hundred whole milk samples (dried and liquid) taken on day 21 post insemination were analysed for progesterone by ELISA and results for both dried and liquid samples were well correlated (r = 0.911). Milk progesterone ELISA accuracy for pregnancy diagnosis in cows was 87%. 相似文献
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The incidence of low day 5 milk progesterone in dairy cows has been investigated and the efficacy of treating the problem assessed. The incidence of inadequate milk progesterone (empirically defined as <3ng/mL) in repeat breeder cows was 34% compared with 11.4% in first insemination cows. Treatment with an intravaginal progesterone device for 7 days starting from day 5 or 6 did not improve pregnancy rate. Treatment with 1500 iu human chorionic gonadotrophin (hCG) on day 5 gave an increase in pregnancy rate that was dependent on initial progesterone concentration and significant (P<0.05) in multiparous but not primiparous cows. While the incidence of inadequate day 5 progesterone was high in repeat breeder cows, it was responsive to hCG treatment, although only in multiparous and not primiparous animals. 相似文献
10.
No significant differences in plasma testosterone level were observed between cows carrying a male foetus and cows carrying a female foetus at any ten-day interval from day 35 of gestation until parturition. Reported higher abortion rates for male than for female foetuses would thus appear not to be due to effects of foetal testosterone on the maternal endocrine balance. In spite of a great individual variation in plasma testosterone values at similar stages of gestation, certain trends are evident. From the 35th to the 80th day of gestation the average concentration was 90–100 pg/ml. Later it rose and reached 200 pg/ml on the 180th day, remaining at this level until after partus. During the first day after parturition plasma testosterone fell significantly and stabilized around 120 pg/ml. 相似文献
11.
NC Friggens M Bjerring C Ridder S Højsgaard T Larsen 《Reproduction in domestic animals》2008,43(S2):113-121
This study tested a model for predicting reproductive status from in-line milk progesterone `measurements. The model is that of Friggens and Chagunda [Theriogenology 64 (2005) 155]. Milk progesterone measurements (n = 55 036) representing 578 lactations from 380 cows were used to test the model. Two types of known oestrus were identified: (1) confirmed oestrus (at which insemination resulted in a confirmed pregnancy, n = 121) and (2) ratified oestrus (where the shape of the progesterone profile matched that of the average progesterone profile of a confirmed oestrus, n = 679). The model detected 99.2% of the confirmed oestruses. This included a number of cases (n = 16) where the smoothed progesterone did not decrease below 4 ng/ml. These cows had significantly greater concentrations of progesterone, both minimum and average, suggesting that between cow variation exists in the absolute level of the progesterone profile. Using ratified oestruses, model sensitivity was 93.3% and specificity was 93.7% for detection of oestrus. Examination of false positives showed that they were largely associated with low concentrations of progesterone, fluctuating around the 4 ng/ml threshold. The distribution of time from insemination until the model detected pregnancy failure had a median of 22 days post-insemination. In this test, the model was run using limited inputs, the potential benefits of including additional non-progesterone information were not evaluated. Despite this, the model performed at least as well as other oestrus detection systems. 相似文献
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Comparison of 2 enzyme immunoassays and a radioimmunoassay for measurement of progesterone concentrations in bovine plasma, skim milk, and whole milk 总被引：1，自引：0，他引：1 下载免费PDF全文
下载免费PDF全文 Marcos G. Colazo Divakar J. Ambrose John P. Kastelic Julie A. Small 《Canadian journal of veterinary research》2008,72(1):32-36
The objective of this study was to compare 2 enzyme immunoassays (EIAs) with a radioimmunoassay (RIA) as to sensitivity and accuracy in the measurement of the progesterone (P4) concentration in bovine plasma, skim milk, and whole milk. The 72 samples from 24 lactating dairy cows expected to have either a high P4 concentration (cows in diestrus or pregnant) or a low P4 concentration (cows in estrus or anestrus) were analyzed by RIA, solid-phase EIA (SPEIA), which included a solvent extraction step, or direct EIA (DEIA) without solvent extraction. The overall mean concentrations of P4 did not differ (P < 0.4) among the assays. However, for the cows that were in diestrus or pregnant, the mean P4 concentrations (and standard error) were higher (P < 0.03), regardless of sample type, with RIA than with SPEIA, at 7.3 (0.7) and 6.1 (0.6) ng/mL, respectively. When only the high-P4 samples analyzed by RIA were compared, the mean P4 concentration was higher (P < 0.001) in whole milk than in skim milk, at 9.8 (1.0) and 4.1 (0.7) ng/mL, respectively. Although the mean P4 concentrations in the low-P4 samples did not differ (P < 0.80) among assays, the proportions of cows with a P4 concentration > or = 1 ng/mL were 3%, 14%, and 44% for RIA, SPEIA, and DEIA, respectively (P < 0.01; DEIA > SPEIA > RIA). 相似文献
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A trial based on progesterone radioimmunoassay of milk samples is described. Samples from 2274 cows in 14 herds were collected on the day of insemination and 7, 23 and 30 days later, unless a return to service occurred before the designated sample date. Two additional samples were collected from cows which returned to service more than 35 days after the first service, one on the day of the return and another seven days later. All six samples from these cows were assayed for progesterone concentration. Late returns, defined as returns to oestrus 36 or more days after mating, occurred in 8.6% of the cows. Milk progesterone assay results indicate that of these apparently late-returning cows, 55.9% suffered a loss of the conceptus, 22.1% had not been detected in oestrus around 21 days after first insemination, 11.8% were in anoestrus at insemination, 5.6% conceived to the insemination and were pregnant when thought to have had a late return, 2.6% were in prooestrus or dioestrus at insemination and 2.1% went into anoestrus after an oestrus insemination. The average prevalence of late returns after the 35th day (8.6%) and the estimated incidence of losses of concepta (4.8%) are lower than those reported in comparable studies elsewhere. Although many of the late-return cows were mated again and conceived, this syndrome nevertheless contributes significantly to the wastage rate, at least in New Zealand dairy herds with their strictly seasonal calving pattern. The implications of these findings are discussed and recommendations for their prevention are made where appropriate. 相似文献
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Eleven multiparous Quarter Horse and Thoroughbred mares were used to determine the plasma concentrations of progesterone and prolactin during early pregnancy and to examine the relationship of plasma progesterone and prolactin to pregnancy loss prior to d 45 of gestation. Plasma samples were collected at two day intervals beginning on d 14 of pregnancy (d 0 = ovulation) and countinued to d 80. Ovulation and pregnancy status were determined by ultrasonography. Four mares experienced pregnancy loss between d 28 and 44 and plasma samples were collected for 10 days beyond the detected loss. Seven mares had successful pregnancies (Term group).Plasma progesterone concentrations peaked by d 28 in the Term group, with individual peak values ranging from 14.9 to 31.9 ng/ml. Values then declined until d 36, followed by a rise until d 80. Prior to d 45 of gestation 5 of the 7 mares had a peak in excess of 15 ng/ml and 3 of these had brief periods, ranging fron 1 to 8 days when progesterone dropped to less than 2 ng/ml. The other 2 mares had peak plasma progesterone concentrations of less than 7 ng/ml, but maintained concentrations in excess of 2 ng/ml during this period.Within the mares experiencing pregnancy loss, 2 mares had a decline in plasma progesterone concentrations prior to pregnancy loss, while the other 2 had typical progesterone patterns beyond the detected loss. Differences in individual patterns of plasma progesterone concentration were observed in both groups (P<.01).Plasma prolactin concentrations ranged from less than .32 to 4.58 ng/ml in the Term group and from .31 to 1.9 ng/ml in the mares experiencing pregnancy loss. Differences in the individual patterns of prolactin secretion were observed in both groups (P<.01).A correlation between progesterone and prolactin was observed in the Term group between day 14 and 37 (P<.01, r2=.88). 相似文献
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OBJECTIVE: To determine if failure to detect oestrus in cows treated to resynchronise oestrus leads to fewer cows being inseminated than are truly in oestrus. PROCEDURE: Cows in three herds were enrolled in a controlled breeding program that involved synchronisation of oestrus for a first round of artificial insemination (AI) followed by resynchronisation for a second round of AI. Just before oestrus was expected at the second round of AI, aids for the detection of oestrus were fitted, which included pedometers, radiotelemetric transmitters (HeatWatch), tail-paint and heatmount detectors. Milk samples were collected at the second round of AI (day 33, herds A and B; day 35, herd C of the treatment program) and were used in combination with pregnancy testing to determine the number of cows that were in oestrus (milk progesterone < 2.0 ng/mL) and cows that were not in oestrus (milk progesterone > 2.0 ng/mL or pregnant at second round of AI) at the time samples were collected. RESULTS: The mean sensitivity of detection of oestrus at the resynchronised oestrus was 92.5% and did not differ significantly between herds (P = 0.19). A total of 75% (60/80) of cows that were retrospectively determined to be not pregnant at the time of the second round of AI were classified as having high (> or = 2.0 ng/mL) concentrations of progesterone in milk at that time. Pregnancy testing of cows about 35 days after AI suggested that early pregnancy loss also contributed to a reduction in submission rates at the resynchronised oestrus. CONCLUSION: Failure to submit cows for insemination at a resynchronised oestrus was mainly due to cows not being in oestrus rather than due to a failure to detect oestrus. 相似文献
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I. García-Ispierto F. López-Gatius S. Almería J. Yániz P. Santolaria B. Serrano G. Bech-Sàbat C. Nogareda J. Sulon N.M. de Sousa J.F. Beckers 《Domestic animal endocrinology》2009
The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, Neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (PAG-1), progesterone and cortisol. Pregnancy was diagnosed by trans-rectal ultrasonography on Day 40 post-insemination and by palpation per rectum on Days 90, 120, 150, 180 and 210 or until abortion in aborting cows. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The study population was comprised of 73 non-aborting (54 Neospora-seropositive cows) and 20 aborting cows (all Neospora-seropositive) cows. In non-aborting cows, GLM repeated measures of analysis of variance revealed that lactation number and days in milk had no effect on plasma prolactin concentrations throughout gestation, whereas high plasma prolactin concentrations were significantly associated with high plasma levels of cortisol and PAG-1, with Neospora-seropositivity, positive photoperiod (increasing day length), twin pregnancy, and with low plasma progesterone concentrations. An interaction among plasma prolactin, plasma cortisol and milk production was observed in that plasma prolactin concentrations differed significantly throughout gestation and were highest in high-producing cows with high cortisol levels. In Neospora-seropositive non-aborting versus aborting cows, mean prolactin concentrations failed to differ on Days 40, 90, 120, 150 and 180 of pregnancy, whereas prolactin values were significantly lower (P = 0.03) in aborting animals on Day 210 of pregnancy. Our results indicate that a positive photoperiod and Neospora-infection lead to increased plasma prolactin concentrations throughout gestation. Reduced prolactin concentrations detected in Neospora-seropositive aborting cows compared to non-aborting animals suggests a protective effect of prolactin in N. caninum infection. 相似文献
17.
孕酮固相放免法的建立及其应用初探 总被引：2，自引：0，他引：2
利用孕酮 (Progesterone ,P4 )单克隆抗体 ,建立P4 自包被固相放免分析法 (Self -coatingRadioim munoassay,Sc -RIA)。其灵敏度为 0 .0 6nmol/L ,回收率达 95 .73 %批内CV6.8% ,,批间CV9.3 %。对 5头正常健康未孕奶牛的一个发情周期的奶样进行检测 ,检测范围在 0 .0 9～ 2 1 .3 7nmol/L ;同时对 2 0头配种奶牛进行早期妊娠诊断 ,妊娠诊断准确率达 89.4 7% ,未孕诊断准确率达 1 0 0 %。 相似文献
18.
Progesterone concentrations have been measured in defatted milk of British Friesian cows of four herds during the oestrus cycles (other than short cycles) immediately before artificial insemination (AI) at oestrus and immediately after AI (in non-pregnant cows), and during early pregnancy. Differences in mean progesterone concentrations between herds were significant (P less than 0.05) on all days within the day 10-18 period after AI, both in pregnant and in non-pregnant, inseminated cows but were not significant between pregnant and non-pregnant cows within herds until day 17 or 18. It is concluded that up to this time (that of luteolysis in non-pregnant cows) undefined factors, variable among herds, can have a much greater influence on the rate of progesterone secretion by corpora lutea and consequent progesterone concentration in plasma and milk than does the presence of conceptuses. Maximum mean progesterone concentration reached during early pregnancy in two herds did not differ significantly; it was reached in the 11-15-day period in one herd but not until 46-50 days in the second. Mean progesterone concentration declined after day 90. 相似文献
19.
Oestrone sulphate concentrations were measured by radioimmunoassay in milk samples obtained weekly during pregnancy from Jersey and Friesian cows, with each breed grazed at two different stocking rates. Mean milk yields differed significantly (P<0.05) between the four herds, while mean percentage milk fat and protein values differed significantly (P<0.05) between the two breeds. In all four herds, oestrone sulphate concentrations in milk rose progressively during pregnancy from a mean value of approximately 80-100 pg/ml at 60-80 days of pregnancy to a plateau value of approximately 1 ng/ml at 181-200 days. In non-pregnant cows, oestrone sulphate concentrations in milk ranged from non-detectable to 110 pg/ml, with a mean +/- s.e.m. value of 59 +/- 4 pg/ml. There was considerable variation in milk oestrone sulphate concentrations between cows in each herd, and oestrone sulphate concentrations could also fluctuate markedly within cows from week to week. Despite this variation, the concentration of oestrone sulphate in 98% of milk samples obtained after 120 days of pregnancy was greater than the highest concentration found in milk from non-pregnant cows. Measurement of oestrone sulphate concentrations in milk samples taken at least 120 days after mating or insemination may provide an alternative, non-invasive means of determining or confirming pregnancy in New Zealand dairy cows. 相似文献
20.
Cervical secretion was collected from 99 dairy cows of the Black Pied Lowland breed at an age of 24 to 109 months with a minimum performance of 4000 kg of milk annually in spontaneous oestrus 42 days post partum at the minimum. It was demonstrated by the radioimmunological determination of progesterone in skim milk that from all the breeding cows (n = 99) the oestral secretion was collected during an optimum insemination time (x = 0.19 ng.ml-1 progesterone). Of the statistical set of 99 cows, 55 (i.e. 56.57%) got in calf and 43 (i.e. 43.43%) remained barren. As found, the conception results were not influenced by the rank of the insemination after parturition and the conception capacity of the cows was not influenced by the length of time from parturition to the respective inseminations. It was demonstrated in our investigation that the conception capacity of the cows increases as the time of sperm survival prolongs in the cervical secretion in vitro. The highest conception capacity (80%) was recorded in the cows whose cervical secretion was free of spermiotoxic action. In such cases the motility of the spermatozoa in the oestral mucus was maintained at a temperature of 38 degrees C for longer than 300 minutes. On the other hand, it was demonstrated that the conception capacity of the cows declines with shortening time of sperm survival in the cervical mucus. 相似文献