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1.
A single injection of a synthetic analogue of prostaglandin F2 alpha (fenprostalene; Syntex) on the day of calving or between days 14 and 21 after calving did not affect the calving to first service interval, the number of services per conception or the conception rate of dairy cows. In a second trial, cows calved more than 45 days were injected once weekly with prostaglandin F2 alpha (dinoprost; Upjohn) or fenprostalene until served at the first detected oestrus. The calving to first service interval and the conception rate were not affected. Following injection of either prostaglandin, the spread in the pattern of onset of oestrus and the range in the proportion of cows (75 to 98 per cent) seen in oestrus within seven days were similar. This variation in the time of onset of oestrus after the administration of prostaglandin precludes limiting oestrus detection to four or five days per week, and is a major limitation to the use of prostaglandins in breeding programmes in dairy cows. 相似文献
2.
Commercial dairy cows were given a routine injection of dinoprost tromethamine (prostaglandin F2 alpha THAM) in the early post partum period. The first service conception rate of 64 cows given a single 25 mg injection of dinoprost during the period 14 to 28 days after calving was 68 per cent, that of 64 untreated controls was 43 per cent. The difference was highly significant at the level P = 0.007. In cows with no blood progesterone and with basal progesterone concentrations at the time of treatment, indicating absence of an active corpus luteum, the mean conception rates for 30 treated and 38 control cows were 70 and 44 per cent, respectively, demonstrating that this is not a luteolytic effect. Although that implies a positive myometrial effect, the interval from calving to first service was not shortened in treated cows. 相似文献
3.
Three hundred and thirty-one dairy cows in six herds were used to study the effect of a single injection of 25 mg dinoprost, a prostaglandin F2 alpha derivative, administered eight days after calving on several indices of fertility. A detailed comparison was made between 113 treated cows and 113 control cows of the same parity, which had calved within seven days of each other on the same farm and had experienced the same degree of dystocia. In cows which had calved without assistance, the treatment reduced the mean interval between calving and first heat from 40 days to 37 days but increased the mean interval between calving and conception from 83 days to 85 days. In cows which had required assistance at calving, the treatment reduced the mean interval between calving and first heat from 44 days to 34 days and reduced the mean calving to conception interval from 86 days to 68 days. The cows which benefited most were those which had required assistance during their second, third or fourth calvings; their calving to conception intervals were shortened by 22.5 days. An average of 1.39 services was required to establish conception in the treated cows which calved unaided, with 70 per cent conceiving to the first service, compared with an average of 1.34 services per conception and a 72 per cent conception rate to first service for their untreated herdmates.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
A planned breeding regimen, using gondadotrophin-releasing hormone (GnRH), prostaglandin F2alpha, and a second dose of GnRH, followed by a fixed time insemination, was evaluated in comparison with a negative control on eight commercial dairy farms in the south of England. Fertility data were collected from the 220 cows in the planned breeding group and from 220 matched control cows inseminated at observed oestrus. The planned regimen induced visible oestrus in the vast majority of the cows, and serving the cows at this oestrus reduced the calving to conception interval by 15 days, resulting in 12 per cent more cows being pregnant by 125 days after calving, and 6 per cent more by 150 days. The results from the individual farms suggested that more benefit may be derived from using the regimen in herds with only average fertility indices. There was also evidence to suggest that the second GnRH injection was important, even in cows that came on heat and were served before the fixed time insemination. 相似文献
5.
AIM: To determine whether mating previously anoestrous cows on their second, rather than first, oestrus post pm-turn could increase conception rates to that service. METHODS: Cows diagnosed as anovulatory anoestrus were allocated to two groups, starting treatment on Day -17 (OES2) or on Day -7 (OESI) where the date of the planned start of mating = Day 0. All cows were treated with intravaginal progesterone (CIDR device) for 6 days and an injection of 1 mg oestradiol benzoate 24 h after removal of the device. Cows in the OES2 group were also injected with prostaglandin F2alpha on Day 0. RESULTS: During the first 7 days of mating, 61.8% (207/335) and 88.2% (328/372) of cows in the OES2 and OESl groups, respectively, were inseminated on detection of oestrus (p <0.001). Oestrus without ovulation occurred in 1.5% of cows in the OES2 group and 6.2% of cows in the OESl group during this period (p <0.01). Of those cows inseminated in the first week of mating, conception rates were 54.0% in the OES2 group and 45.5% in the OESl group (p = 0.05). There was no significant difference in median interval from start of mating to conception between the two groups (24 and 22 days for OES2 and OESl, respectively, p >0.05). CONCLUSION: Mating previously anoestrous cows on their second, rather than first oestrus post partum increased conception rates to that service. However, median intervals from start of mating to conception were not altered. 相似文献
6.
F Cairoli A Mollo MC Veronesi B Renaville M Faustini M Battocchio 《Reproduction in domestic animals》2006,41(2):175-179
A short calving to conception interval is of main importance to achieve high economic efficiency in dairy cow industry. In order to reduce this interval, several hormonal treatments have been put on the market, in which cloprostenol, a synthetic analogue of prostaglandin F2alpha (PGF2alpha). The aim of this study was to compare fertility of cloprostenol-induced oestrus to that of spontaneous oestrus in dairy cows. In a group of 525 cows, 280 (treated group) were administered 0.5 mg cloprostenol i.m. after transrectal corpus luteum (CL) detection, and inseminated at detected oestrus during the following week. The other 245 cows (control group) were inseminated during spontaneous oestrus. Whey progesterone concentrations were checked at treatment and at insemination in order to remove from the study cows whose P4 levels indicate a non-functional CL, or a lack of luteolysis respectively. Moreover, cows that were not inseminated due to genital problems were also excluded from this study. Conception (59% vs 54.5%) and calving rates (93.7% vs 93%) were not significantly different between the two groups. 相似文献
7.
Plasma progesterone, oestradiol, 13,14-dihydro, 15-keto, prostaglandin F2 alpha (PGFM) and luteinising hormone were measured in daily samples from eight dairy cows for 15 days before and after spontaneous calving, and compared to patterns obtained from 15 cows during and after induction of parturition with dexamethasone +/- prostaglandin. The average (+/- sd) length of pregnancy in the control cows was 285 +/- 3.04 days compared to 264 +/- 7.4 days in the induced group. Only nine cows required prostaglandin on day 11 after dexamethasone, which resulted in all nine calving 1.7 +/- 0.3 days later. Eight of the 15 treated cows retained the fetal membranes; however, the calving to first heat interval for all treated cows was 46.7 +/- 10 days (range 30 to 66 days) and calving to conception 52.4 +/- 17 days (range 30 to 85 days) compared to 42.1 +/- 15 days (range 28 to 64 days) and 76.5 +/- 24 days (range 54 to 115 days) respectively for the eight cows which calved without induction. The pre-partum hormone profiles were similar in all cows. Hormone profiles in the post partum period were also similar in all cows, irrespective of previous history. Baseline values for progesterone and oestradiol were not reached until 4.6 +/- 1.7 days and 2.75 +/- 0.7 days post partum respectively, whereas PGFM values increased for two or three days, reaching baseline levels 8.87 +/- 2.10 days later. Five cows had secondary peaks of PGFM on days 5,6 and 7. Luteinising hormone values increased steadily after calving in all cows.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
A study was conducted to evaluate the effects of postpartum prostaglandin treatment on reproduction in 3 seasonal calving dairy herds. Recently calved lactating dairy cows were paired on herd, age, calving date and previous production index. One cow in each of the 196 pairs received a single intramuscular injection of 25 mg of the prostaglandin analogue, dinoprost, between 14 and 28 days after calving. Subsequent reproduction was monitored. Within each herd and overall, there was no significant effect of treatment on the intervals from calving to first service, mating start date to first service, calving to conception, mating start date to conception and first service to conception. Treatment also had no significant effect on 21-day submission and pregnancy rates, on the proportion of each group not pregnant at the end of mating, and on first service pregnancy rates. Responses to treatment did not vary between cows calving within 50 days of mating start date and earlier calving cows or between cows aged less than 5 years and older cows. 相似文献
9.
The ability to synchronise onset of oestrus, and hence the time of breeding and calving, offers potential economic and management benefits to dairy farmers, especially in herds with seasonally concentrated calving patterns. A trial involving 2681 cows in 11 seasonal herds was conducted to evaluate the reproductive performance of lactating dairy cows following oestrus synchronisation with a combination of progesterone, oestradiol and prostaglandin. Cows were randomly assigned within herds to synchronised and control groups, balanced for age, date of calving, body condition and breed. Cows in the synchronised group were treated with an intravaginal progesterone-releasing device containing 1.9 g of progesterone and a gelatin capsule containing 10 mg of oestradiol benzoate 10 days prior to the planned start of the breeding season (Day 0). The device was removed 8 days later on Day -2 and a luteolytic dose of prostaglandin F2alpha was administered 2 days prior to removal of the progesterone-releasing device. Returns to service for cows in the synchronised group were synchronised by inserting a previously used intravaginal device during Days 16-21 after the start of the breeding season. Cows in the control group were left untreated. The percentage of cows being inseminated during the first 5 days was 89.0% for the synchronised group compared to 29.7% for the control group. Compared to cows in the control group, those in the synchronised group had a lower conception rate to the first insemination (52.9% v. 64.3%, p<0.001), a lower conception rate to the second insemination (51.8% v. 62.5%, p<0.001), a higher percentage of empty cows at the end of the breeding season (7.3% v. 5.1%, p<0.05), and more insemination services per pregnancy to artificial insemination (2.0 v. 1.6, p<0.001). There was no difference between the synchronised and control groups in the percentage of cows pregnant to artificial insemination (81.8% v. 85.5%, p>0.10). The mean day of conception from the start of the breeding season was advanced (p>0.0 1) by 1.3 days in synchronised cows (19.9 +/- 0.7 days; mean +/- SEM) compared to control cows (21.2 +/- 0.5 days). It is concluded that the oestrus synchronisation regime used in the present study caused a reduction in fertility, which reduced the potential gains from using such a programme to increase reproductive efficiency in dairy cows. 相似文献
10.
AIM: To determine if the reproductive performance of dairy cows not previously detected in oestrus but with a detectable corpus luteum before the planned start of mating (PSM), could be improved by treatment with progesterone, oestradiol benzoate (ODB) and prostaglandin F2alpha (PGF). METHODS: Cows in 18 herds which had not been detected in oestrus, but which had a detectable corpus luteum present at veterinary examination 7 days prior to the PSM (Day -7), were allocated to 1 of 2 groups. Treated cows (n=232) received an injection of 2 mg ODB and an intravaginal progesterone releasing device (CIDR insert) on Day -7, and an injection of PGF on the day of insert removal 7 days later (Treated group). The Control group (n=243) remained untreated. Cows were mated to detected oestrus from Day 0, and conception dates confirmed by manual palpation or transrectal ultrasonography. RESULTS: During the first 7 days of mating, 37.4% of Control cows and 65.9% of Treated cows were inseminated on detection of oestrus (p<0.001). Pregnancy rates for this period were 20.4% and 36.3%, respectively (p=0.001). Conception rates to first insemination, pregnancy rates after 21 days of mating and at the end of the mating period were similar between groups (p>0.1). Median interval from the PSM to conception did not differ between treatment groups (24 and 23 days for Control and Treated, respectively, p>0.1). CONCLUSION: Treating postpartum dairy cows which had not previously been detected in oestrus but which had a detectable corpus luteum, with progesterone, ODB and PGF did not significantly improve their reproductive performance compared with no hormonal intervention. KEY WORDS: dairy cattle, postpartum, anoestrous, reproduction, progesterone treatment. 相似文献
11.
The aim of the following investigation was to study the effect of beta-carotin serum concentrations on reproductive performance in dairy cows. Blood samples were collected from 201 cows 3 to 4 weeks antepartum, 1 to 2 weeks postpartum and at the time of insemination. Concentrations of beta-carotin in blood serum were determined via HPLC. The incidence of retained placental fetal membranes, endometritis, ovarian cysts as well as the beginning of the oestrous cycle and various measures of fertility such as first service conception rate, pregnancy index, interval from calving to first insemination, interval from calving to conception, interval from first insemination to conception and expected calving interval were recorded and analysed. The beta-carotin serum concentrations were not related to the incidence of retained placental fetal membranes, endometritis, ovarian cysts or the onset of cyclicity post partum. Cows with lower beta-carotin concentrations partially seemed to have a reduced reproductive performance than cows with higher beta-carotin concentrations. Overall, our results suggest only a minor relationship between the beta-carotin serum concentration and fertility in dairy cows. 相似文献
12.
Jemmeson A 《Australian veterinary journal》2000,78(2):108-111
OBJECTIVE: To compare oestrus synchronisation using two treatments of gonadotropin-releasing hormone (GnRH) and one of prostaglandin F2 alpha (PG) with a double prostaglandin synchronisation protocol under southern Australian conditions. DESIGN: A clinical trial. PROCEDURE: Eight hundred and forty, seasonally calving, lactating dairy cows within nine herds in the Tallangatta district of northeast Victoria were randomly allocated to treatment and control groups. The treatment (GnRH) group received gonadotropin-releasing hormone followed by prostaglandin F2 alpha and then a second treatment with gonadotropin-releasing hormone. These cows were inseminated at a fixed time after the second gonadotropin-releasing hormone treatment. Cows in the control (PG) group received two injections of prostaglandin F2 alpha, 14 days apart, and were inseminated according to detected oestrus. RESULTS: The effect of GnRH treatment on first service conception rate (CRS1) and 30 day pregnancy rate (PR30) varied between herd (P < 0.001 and P < 0.02, respectively). A significant difference in CRS1 between treatment (GnRH) and control (PG) groups existed in pooled data from eight of the nine herds (38.1% vs 65.9%, P < 0.001). A significant difference also existed in PR30 between treatment (GnRH) and control (PG) groups in pooled data from eight of the nine herds (64.1% vs 72.4%, P = 0.03). Pregnancy rates after 56 days of mating for both groups were not significantly different (79.8% vs 84.1%, P = 0.13 for treatment (GnRH) and control (PG) groups, respectively). Submission rates (proportion of cows submitted for insemination) for the treatment (GnRH) groups were 100%. There was significant variation in submission rates in the control (PG) groups. CONCLUSION: The GnRH protocol may be of benefit in herds where a poor response to the double prostaglandin program is anticipated. However, in the majority of herds in this trial, the double prostaglandin program achieved better results with fewer inseminations. 相似文献
13.
Tenhagen BA Drillich M Heuwieser W 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2000,47(10):577-584
The effect of two insemination policies after synchronization of oestrus on reproductive performance in two groups of cows was investigated. Oestrus was synchronized by two treatments with prostaglandin F2 alpha (PGF2 alpha) at a 14-day interval. Cows in Group 1 (n = 234) were inseminated twice on appointment 66 and 90 h after the second treatment. Cows in Group 2 (n = 222) were intensively watched for signs of oestrus after the synchronization protocol and inseminated on observed oestrus. Cows with abnormal discharge after synchronization were excluded from breeding and inseminated later during the study period. Service rate within 1 week after synchronization was higher in Group 1 than in Group 2 (89.3 versus 67.1%). Conception rates on first service did not differ between groups (33.2 versus 30.0%). Days to first service and days open were shorter in Group 1 (P < 0.05). The number of cows culled for infertility did not differ between the groups. Endometritis 14-20 days post-partum decreased the percentage of cows pregnant at the end of the study period in both groups but did not have a significant effect on conception rates and days open. It is concluded that additional inseminations required in the timed artificial insemination protocol were economically justified by the reduction in days open in comparison with insemination on observed oestrus after synchronization. 相似文献
14.
In modern high-yielding dairy herds fertility is of major economic importance. In order to gain maximum profit, calving intervals should not exceed 365 days. The achievement of a 365-day calving interval requires an early resumption of ovarian activity, an excellent oestrus detection, and a high first-service conception rate. Especially the inability to detect oestrus and to mate the cows by 60 to 80 days after calving is a common problem among dairy farmers nowadays. In this article a review is given about the occurrence, causes, treatment and prevention of post-partum anoestrus in dairy cows. 相似文献
15.
THE EFFECT OF VARIATIONS IN THE INTERVAL BETWEEN CALVING AND FIRST SERVICE ON THE REPRODUCTIVE PERFORMANCE OF NORMAL DAIRY COWS 总被引：3，自引：0，他引：3
SUMMARY Reproductive records from 8 commercial dairy herds in a herd health scheme were examined to determine the effect of the calving to first service interval on breeding performance. A reduction in the first service conception rate was observed in cows bred within 60 days of calving. Early breeding did not appear to have any adverse effect on subsequent reproductive performance. A linear relationship between days to first service and intercalving interval was demonstrated. A 1-day reduction in the interval to first service reduced the intercalving interval by 0.86 of a day. This paper shows that a reduction in calving to service intervals to achieve annual calving produces high economic gains. 相似文献
16.
Four autumn-calving dairy herds were selected to investigate the effect of an injection of prostaglandin in the period 14 to 28 days (mean 22 days) after calving on subsequent fertility. The cows were selected on the basis of having a condition likely to affect their fertility, including assisted calving, endometritis, retained fetal membranes, milk fever, cows with five or more lactations, cows having twins, or a combination of any of these conditions. They were assigned to treatment or control groups and paired as closely as possible on the basis of their condition and date of calving. Milk progesterone concentrations were measured on the day of treatment and then three and 10 days later. The trial ran for four months and involved 90 treated and 90 control cows. The combined data from all the animals in the trial failed to show any difference between the calving to conception interval, the first service conception rate or the numbers of services per conception of the treated and control groups. A Student's paired t test for groups of cows with a particular condition, both within individual herds and in all the herds, failed to show any significant effect of treatment (P greater than 0.05). Milk progesterone data showed that the presence of a corpus luteum did not influence the outcome of prostaglandin treatment. There was no evidence for excessive failure of luteolysis. It was concluded that there was no benefit in a routine injection of prostaglandin to dairy cows in the period 14 to 28 days after calving when re-breeding commenced more than 70 days after calving. 相似文献
17.
Y R el-Baghdady E S Fattouh K I el-Ekhnawy M M Ayoub L H Bedeir 《The British veterinary journal》1990,146(6):577-581
A study was conducted on 40 buffalo-cows, assigned randomly, immediately after calving into three groups: group I (n = 10) injected with saline and taken as control; group II (n = 15) received 25 mg PGF2 alpha/animal (Lutalyse); group III (n = 15) received 25 mg PGF2 alpha + 25 i.u. oxytocin/animal (Syntocinon), single i.m. dose. Oxytocin and/or PGF2 alpha significantly (P less than 0.01) shortened the interval from calving to first service (38.33 and 31.53 days for groups II and III respectively, versus 91.60 days for controls). The treatment reduced the service period (38.29 and 35.87 days for groups II and III respectively, versus 45.40 days for controls). Concomitantly a significant (P less than 0.01) decrease in the open-days post partum was achieved (76.62 and 67.40 days for groups II and III respectively, versus 137.00 days for controls). In addition, the treated buffaloes needed significantly (P less than 0.01) fewer services per conception (1.67 and 1.20 S/C for groups II and III respectively) than the untreated ones (2.70 S/C), besides a substantial improvement (P less than 0.01) in their conception rate either at 60 or 85 days post partum. Significantly improved (P less than 0.05) results were obtained in the oxytocin and PGF2 alpha treated animals, than in those receiving PGF2 alpha alone for all the previous parameters, except for the service period. Buffaloes therefore seemed to respond better to such treatment than dairy cows. 相似文献
18.
Tenhagen BA Birkelbach E Heuwieser W 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2000,47(4):213-220
Reproductive management programmes based on strategic use of prostaglandin F2 alpha (PGF2 alpha) to induce and synchronize oestrus in post-partum dairy cows are widespread. Repeated shortening of the oestrous cycle during early lactation in high-yielding dairy cows, however, could impair corpus luteum function and thus decrease fertility. The objective of this study was to analyse the effect of repeated treatments with the prostaglandin F2 alpha analogue D (+) cloprostenol sodium on progesterone concentrations indicative of a functional corpus luteum in post-partum dairy cows. Furthermore, the influence of milk production, parity and endometritis on progesterone concentrations under these circumstances were studied. Eighty-four cows of a commercial dairy operation were treated three to four times with D (+) cloprostenol sodium (Preloban; Hoechst Roussel Vet, Wiesbaden, Germany) at 14-day intervals, starting 22-28 days post-partum. Blood samples were collected prior to treatment 1 (sample 1) and 14 days after treatments 1, 2 and 3 (samples 2-4) and serum progesterone (P4) levels were determined. The percentage of cows with P4 levels < 1 ng/ml decreased from 51% in sample 1 to 23% in samples 3 and 4. More primiparous cows had low P4 levels 14 days after the second treatment than older cows (P < 0.05). Cows with low progesterone levels in sample 3 or 4 had lower protein contents in milk on the second milk test day post-partum and in their cumulative milk yield of the first 100 days of lactation. Clinical endometritis at post-partum examination did not influence progesterone levels after treatment with PGF2 alpha. Repeated application of PGF2 alpha (more than twice) in the post-partum period does not influence serum progesterone levels 14 days after treatment. Failure to develop luteal tissue after treatment contributed to the conception failures after first service. 相似文献
19.
Macmillan KL 《New Zealand veterinary journal》1983,31(7):110-113
A re-evaluation of results from ten trials conducted in commercial dairy herds between 1974 and 1981 in which lactating dairy cows were injected once or twice with either of two forms of prostaglandin F2alpha (PGF) showed that: the variation in the post-injection interval to oestrus was influenced by the stage of the oestrous cycle at which treatment was administered; this variation was sufficient to reduce pregnancy rates to set-time inseminations; an accurate aid for oestrus detection, such as tail painting, should be used routinely with PGF; if PGF-treated cows were detected in oestrus before being inseminated, the pregnancy rates to first insemination were usually 10% higher than in untreated herd mates. The results show that PGF systems in dairy herds should not be used as au alternative to accurate oestrus detection. These systems can be used to condense the breeding programme and increase pregnancy rates to first insemination. The exploitation of this fertility effect justifies the reassessment of PGF usage in New Zealand dairy herds. 相似文献
20.
Three trials were completed to compare different regimes for the use of an analogue of prostaglandin F2 alpha(“Estrumate”: ICI) in the breeding management of herds of lactating dairy cows with seasonally concentrated calving patterns. The first regime involved two injections of ‘Estrumate’ 11 days apart, followed by insemination, either at 72h and 96h after the second injection, or at the first observed oestrus. Every cow had calved at least 40 days before the first injection. The second regime involved a single ‘Estrumate’ injection given to every cow not inseminated during the first seven days of the breeding programme. Treated cows were inseminated when observed in oestrus within 48h of injection, or at 72h and again at 96h. The third regime utilised the technique of tail-painting during the pre-mating period to identify groups of cycling cows which were subsequently givena single injection of “Estrumate” and inseminated 72h lateror at a subsequent behavioural oestrus. All regimes significantly altered the conception pattern from that obtained in untreated herd-mates. The variable incidence of post-partum anoestrus, genuine short oestrous cycles and the degree of precision in oestrus synchronisation in lactating dairy cows resulted in many animals being unnecessarily injected and/or inseminated. The third regime overcame most of these problems and could have application in many largeherds. The identification of cycling animals and insemination at detected oestrus are important components of programmes using prostaglandins for the purpose of oestrus synchronisation in lactating cows in seasonal dairy herds. 相似文献