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1.

Background

Application of assisted reproductive technologies in buffaloes is limited to some extent by farmers’ inability to detect oestrus because of its poor expression. The present study aimed at investigating reliability of a milk progesterone enzyme-linked immunosorbent assay (ELISA) to assess the ovarian cyclicity during post partum, oestrus and post-breeding periods in water buffaloes.

Methods

Progesterone concentrations were measured by an ELISA in milk of 23 postpartum buffaloes in relation to oestrus, pregnancy, body condition score (BCS) and milk production. Two milk samples were taken at 10 days intervals, every month starting from day 30 and continued to day 150 post partum. BCS and milk production were recorded during sample collection. Milk samples from bred buffaloes were collected at Day 0 (day of breeding), Days 10–12 and Days 22–24. Defatted milk was preserved at −80°C until analysis. Pregnancy was confirmed by palpation per rectum on Days 70–90.

Results

Seventeen buffaloes had 47 ovulatory cycles, one to four in each, 13 were detected in oestrus once (28 % oestrus detection rate). Progesterone concentration ≥1 ng/ml in one of the two 10-day-interval milk samples reflected ovulation and corpus luteum formation. The intervals between calving to first luteal activity and to first detected oestrus varied from 41 to 123 days (n = 17) and 83 to 135 (n = 13) days, respectively. Eight buffaloes were bred in the course of the study and seven were found pregnant. These buffaloes had a progesterone profile of low (<1 ng/ml), high (≥ 1 ng/ml) and high (≥ 1 ng/ml) on Day 0, Days 10–12 and Days 22–24, respectively. Buffaloes cycling later in the postpartum period had fewer missed oestruses (P < 0.05). Buffaloes with a superior BCS had a shorter calving to oestrus interval and produced more milk (P < 0.05).

Conclusions

Milk progesterone ELISA is a reliable tool for monitoring ovarian cyclicity and good BCS may be an indicator of resuming cyclicity in water buffalo.  相似文献   

2.
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).  相似文献   

3.
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   

4.
The onset of pregnancy may be associated with hormonal changes and decline in milk yield of buffaloes. To investigate this, forty lactating buffaloes from 1st to 23rd weeks post-conception were selected. The animals were assigned to three treatments: PRT, PRS, NPRT and three milk yielding groups HMY, 66 to 75 l/week, n = 12; MMY, 56 to 65 l/week, n = 16; LMY, 46 to 55 l/week, n = 12). Milk samples were collected on alternate weeks and analyzed with ultrasonic milk analyzer. EIA was used for milk progesterone concentrations. Group means were compared and correlation analysis was conducted. Progesterone concentrations increased in almost similar pattern with the advancing weeks post-conception. The high and low yielder showed greater progesterone concentrations in the supplemented than the animals on traditional ration (P < 0.001). Progesterone concentrations correlated positively with fat (%), negatively with milk yield, protein (%) and lactose (%). Decline in milk yield became drastic when progesterone concentrations rose above 6.44 ng/ml. The pregnant animals on traditional ration exhibited a sharper decline in milk yield with the increasing progesterone concentrations as compared to pregnant animals with supplemented ration. It is concluded that concentrates supplementation induced a raise in progesterone levels. Progesterone concentrations and milk yield showed an inverse relationship.  相似文献   

5.
The aim of this study was to evaluate the effect of cloprostenol administration on the blood flow of pre-ovulatory follicle (PF) and corpus luteum (CL), progesterone secretion and pregnancy outcome in buffaloes subjected to AI. The trial was performed on 75 Italian buffaloes at 182 ± 8 days in milk. Synchronized animals were randomly divided into two groups on the day of oestrus: Group T (n = 37) received a 0.524 mg intramuscular injection of cloprostenol and Group C (n = 38) received saline. Ultrasound examinations of the ovaries were performed 5 h after AI on the PF and 10 and 20 days after AI on the CL. Resistive (RI) and pulsatily index (PI) were calculated by colour-Doppler mode in each examination. Blood samples were collected on days 10, 20 and 25 after AI for progesterone assay and 25 days after AI, ultrasonography was performed to assess pregnancy, which was confirmed on day 45. Subjects pregnant on day 25 but not on day 45 were considered to have undergone late embryonic mortality (LEM). Statistical analysis was performed by anova. No differences were found in PF dimensions, CL size and blood flow on day 10 and 20 after AI between treated and control groups. Pre-ovulatory follicle area was higher in buffaloes that resulted pregnant on day 25 after AI compared to those that were non-pregnant (2.13 vs 1.66 cm in pregnant and non-pregnant buffaloes, respectively), while non-pregnant buffaloes showed higher values of RI (0.49 vs 0.30; p < 0.05) and PI (1.0 vs 0.37; p = 0.07) compared to pregnant subjects. Treatment by cloprostenol did not influence pregnancy rate both on day 25 (31/75; 41.3%) and 45 (27/75; 36.0%), progesterone levels and incidence of LEM (4/31; 12.9%). In conclusion, cloprostenol administration at the time of AI does not seem to affect PF and CL blood flow.  相似文献   

6.
<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  相似文献   

7.
奶牛早孕诊断乳汁孕酮临界值的确定   总被引：3，自引：0，他引：3  
随机选择健康荷斯坦母牛６３头，其中发情周期牛５头，配后１８－２４天牛３０头和通过直接确定的怀孕牛２８头，按程序采集末乳乳样。用放射免疫测定法（ＲＬＡ）测定乳汁孕酮（ＭＰ４）浓度。以发情第３天ＭＰ４浓度加上２倍标准差为未孕临界值的土限，以配后１８－２４天怀孕牛ＭＰ４浓度的平均值减去１倍标准差为怀孕临界值的下限。结果表明，奶牛ＭＰ４早孕诊断临界值为：≥７．１９ｎｇ／ｍｌ为怀孕，〈４．７２ｎｇ／ｍｌ为未  相似文献   

8.
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   

9.
The aims of this study were to verify the efficacy of delayed hormonal treatments performed on day 25 post‐insemination on pregnancy rate at 45 and 70 days in buffalo. The trial was performed on 385 buffaloes synchronized by the Ovsynch/TAI protocol and submitted to artificial insemination (AI). Twenty‐five days after AI, pregnant animals were assigned to four treatments: (1) GnRH agonist (n = 52), 12 μg of buserelin acetate; (2) hCG (n = 51), 1500 IU of human chorionic gonadotrophin; (3) Progesterone (n = 47), 341 mg of P4 intramuscular (im) every 4 days for three times; (4) Control (n = 54), treatment with physiological saline (0.9% NaCl). Milk samples were collected on days 10, 20 and 25 after AI in all buffaloes to determine progesterone concentration in whey by radioimmunoassay method. Statistical analysis was performed by anova . Pregnancy rate on day 25 after AI was 52.9%, but declined to 41.8% by day 45, indicating an embryonic mortality (EM) of 21%. If only control group is considered, the incidence of EM was 38.9%. Pregnant buffaloes had higher (p < 0.01) progesterone concentrations on day 20 and 25 after AI than both non‐pregnant buffaloes and buffaloes that showed EM. The treatments on day 25 increased (p < 0.01) pregnancy rate, although in buffaloes with a low whey progesterone concentration on day 20 and 25 after AI (n = 22); all treatments were ineffective to reduce EM.  相似文献   

10.
SUMMARY Of 87 Dorset ewes injected at 20 to 60 days of pregnancy with either 125 μg or 250 μg of the prostaglandin F2α analogue, cloprostenol, 72 (83%) were detected in oestrus by teaser rams within 7 days. A total of 60 ewes mated with fertile rams 14 to 28 days after treatment and 36 of these (60%) subsequently lambed. Thirty-eight ewes mated with fertile rams 29 to 56 days after treatment and 30 of these (79%) subsequently lambed. The difference in fertility between the 2 periods was not significant.
Six additional ewes which did not respond to the cloprostenol lambed normally within 6 weeks. They were more than 100 days pregnant when treated.
In ewes which first exhibited oestrus by 7 days of treatment, plasma progesterone concentrations fell from near 4 ng/ml to 0.6 ng/ml within 48 h of treatment. In ewes not detected in oestrus progesterone concentrations did not decrease to similar low levels (1.4 ng/ml; t-test p < 0.005). Concentrations in the 6 ewes treated near 100 days of pregnancy dropped from 7.4 to 4.4 ng/ml over 48 h. Overall, the progesterone concentrations indicated that 92% of ewes treated at 20 to 60 days of pregnancy experienced rapid luteolysis in response to the cloprostenol.
There were no differences between the 2 doses of cloprostenol in the responses or subsequent fertility of the ewes.  相似文献   

11.
The present study investigated the changes of serum progesterone (P4) and its faecal metabolites in pregnant and non-pregnant cows (Expt 1) and the feasibilty of using faecal P4 metabolites for early screening of open cows post-insemination (Expt 2). In Expt 1, seven crossbred Holstein-Friesian (HF) cows were studied. Serum and faecal samples were collected once daily from the day of artificial insemination (AI) until 25 days after AI. In Expt 2, 27 crossbred HF inseminated cows were employed. Serum and faecal samples were obtained on the day of AI (day 0) and on days 19-22 post-insemination. Enzyme immunoassay measurements of serum P4 and faecal P4 metabolites were established. The low detection limit of the assay was 0.01 ng/ml and the amount of P4, resulting in a 50% reduction in the initial binding value, was 1.07 ng/ml. The intra- and inter-assay coefficients of variation were <8% and <14%, respectively. A positive correlation between the levels of serum P4 and faecal P4 metabolites was found in every single cow (r = 0.73-0.88, p < 0.001) and pooled data (r = 0.78, p < 0.001). The estimated value of faecal P4 metabolites at 100 ng/g of faeces was equal to the serum P4 levels of 1 ng/ml. The accuracies of pregnancy and non-pregnancy diagnosis based on the analyses of faecal P4 metabolites between day 0 and days 19-22 post-insemination, were 67% and 100%, respectively. In conclusion, the measurement of faecal P4 metabolites can be a potentially alternative method for early screening of open cows post-insemination with the same accuracy and precision, as measured by serum P4 assay.  相似文献   

12.
A new and rapid enzyme-amplified immunoassay (AELIA) has been developed for the measurement of progesterone in milk. The AELIA system is a non-isotopic method that gives results within 35 minutes. Milk progesterone concentrations measured in 10 cows sampled daily at various stages of the reproductive cycle were very similar to those recorded by a validated radioimmunoassay. The results show that the speed and sensitivity of the AELIA system would make it possible to diagnose pregnancy rapidly at about 24 days after insemination, to predict the onset of behavioural oestrus from decreasing progesterone values during the third week after a preceding oestrus, and to obtain a daily record of milk progesterone levels in animals treated for infertility of ovarian origin.  相似文献   

13.
Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F2 α (Lutalyse®) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 ± 0.92 ng/ml) until day 41 (27.27 ± 6.74 ng/ml), remaining high (20.71 ± 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51–4.80 ng/ml) than in non-pregnant buffaloes (0.28–1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28.  相似文献   

14.
Sixtyfour mares were examined 3 and 6 weeks after mating. Progesterone was measured in 22 mares 3 weeks after mating in order to see if this could be of any help in the oestrous diagnosis. None of the pregnant mares had plasma progesterone below 2 ng/ml. Pregnant mares that did not show oestrus had higher levels of plasma progesterone than pregnant mares showing signs of oestrus 3 weeks after mating. Clinical findings in pregnant and nonpregnant mares 3 weeks after mating is compared, and oestrus in pregnant mares is discussed.  相似文献   

15.
Three hundred and sixty inseminated Holstein cows were monitored in a controlled trial for low milk progesterone concentration 21-23 days post-breeding. Information about low progesterone cows was given to herdsmen for the experimental group only. Of the cows in the experimental group with milk progesterone of less than or equal to 4.5 ng/ml, 56.0% were inseminated within 2 days of monitoring compared to 28.8% of the control animals. Of the cows reaching the 42-day rectal pregnancy diagnosis, 13.7% and 43.6% were negative for the experimental and the control groups respectively. Inter-service intervals were 34.5 +/- 14.5 days and 44.3 +/- 17.7 days for the experimental and control groups respectively. Pregnancy rates were the same for 264 cows served on routine progesterone monitoring and for 318 cows bred on behavioural oestrus when matched to farm and day of breeding. A gain of US $32.5 (an equivalent of 85 l milk) per lactation for a cow in the monitored herd was established using the data in a model of a 250-cow herd with a total pregnancy goal of 82.4%.  相似文献   

16.
The primary aim of the present study was to establish whether the treatment with a GnRH agonist on Day 5 after AI may result in the formation of an accessory corpus luteum, greater progesterone secretion, and the increased likelihood of pregnancy success in buffaloes. The study was conducted during a period of increasing daylight length when progesterone secretion is suppressed and embryonic mortality is relatively high in buffaloes. In Experiment 1, treatment with a GnRH agonist (buserelin, 12 μg) on Day 5 after AI induced acute increases in circulating concentrations of LH, FSH and oestradiol-17β. Pregnant buffaloes (n = 14) at Day 40 following AI showed an increase (P < 0.01) in milk whey progesterone concentration between Day 5 (310 ± 55 pg/ml) and Day 15 (424 ± 50 pg/ml). The non-pregnant buffaloes (n = 7) showed a decrease (P < 0.01) in progesterone level from Day 5 (410 ± 87 pg/ml) to Day 15 (188 ± 30 pg/ml) following AI. In Experiment 2, the treatment with buserelin (12 μg) on Day 5 after AI induced ovulation in 62% of the buffaloes (31/50) and these buffaloes showed a progressive increase in milk whey progesterone concentration on Day 10, 15 and 20 of pregnancy. Buffaloes that did not ovulate, recorded a relatively constant milk whey progesterone level from Day 10 to Day 20 following AI. Milk whey progesterone concentrations increased after the administration of the GnRH agonist in 97% of the pregnant buffaloes and 68% of the non-pregnant buffaloes. The diameter of the largest follicle in buffaloes that ovulated (ovulated n = 31) (8.9 ± 0.04 mm; range 4.2 – 13.0 mm) did not differ significantly from the diameter of the largest follicle in buffaloes that did not ovulate (not ovulate n = 19) (8.7 ± 0.04 mm; range: 4.0 – 12.0 mm). The latter observation suggested that notional ovulatory size follicles in buffaloes are heterogeneous with respect to stage of follicle maturation and capacity to respond to plasma LH. The present study showed that treatment with a GnRH agonist on Day 5 following AI provides a strategy to increase progesterone secretion and the likelihood of pregnancy in buffaloes mated during periods of increasing daylight length.  相似文献   

17.
The lowest value for plasma protein bound iodine (PBI) (3.47 g%) in 20 freshly calved Murrah buffaloes was observed on day 1 postpartum. The values then increased consistently up to day 36 and were almost constant thereafter. The plasma progesterone concentrations were lower in animals with relatively low PBI from day 22 to 57 postpartum, except on day 36. The mean values ± SE (ng/ml) in the high and low PBI groups were 0.93±0.09 and 0.72±0.15. The correlation coefficient between PBI and progesterone was 0.80 (p<0.01). Relatively poor reproductive efficiency, in terms of a higher initiation of follicular development interval, postpartum oestrus interval, service period and number of services for conception, was observed in animals in the low PBI group.  相似文献   

18.
A group of 13 cows were dosed orally nine or 10 days after a normal oestrous cycle; six animals received colostrum, five animals received milk containing varying amounts of oestrone sulphate, and two cows were given milk containing a low level of oestrone sulphate. Measurements of milk progesterone levels after dosing showed that colostrum had an apparent luteolytic effect, milk containing oestrone sulphate at a level of 2000 pg/ml had a less marked effect on milk progesterone and those animals receiving milk showed no reduction in milk progesterone. These results show that there is a physiological basis for the practice of inducing overt oestrus in cows showing no visible oestrus, by dosing them with colostrum.  相似文献   

19.
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   

20.
Single blood samples from 106 pregnant and seven non-pregnant Karan Swiss cows and 104 pregnant and nine non-pregnant Murrah buffaloes were measured for oestrone and oestrone sulphate hormones by radioimmunoassay. Mean plasma oestrone level was below detection limit (less than 2.5 pg/ml) in non-pregnant and 1 month pregnant cows and buffaloes. In cows the mean oestrone level fluctuated narrowly between 10.25 and 26.65 pg/ml between the second and eight months of pregnancy, followed by a steep rise in the ninth and especially in the tenth month (151.24 pg/ml). In buffaloes mean oestrone concentrations were lower and fluctuated between 14.81 and 23.56 pg/ml during the second to ninth months of pregnancy, rising sharply in the tenth month to a peak of 47.37 pg/ml. Mean oestrone sulphate levels were below detection limit (less than 16 pg/ml) during non-pregnancy, first and second months of pregnancy in cows, increasing sharply thereafter to a peak of 6401.38 pg/ml in the tenth month of pregnancy. In buffaloes, low mean levels of oestrone sulphate were recorded in the non-pregnant and up to the fourth month of pregnancy with the levels rising sharply thereafter to a peak of 6559.82 pg/ml in the tenth month. The hormone levels were not significantly different in the two species (P greater than 0.01). The possibility of using oestrone sulphate measurement as a test of pregnancy confirmation has been indicated for both species.  相似文献   

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