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1.
Segwagwe BV Malmo J Macmillan KL Mansell PD 《Journal of the South African Veterinary Association》2006,77(1):33-39
The objective of this study was to compare the reproductive performance of anoestrous dairy cows treated just prior to the mating start date (MSD) with a Controlled Internal Drug Releasing Device (CIDR) which was placed intravaginaly for either 6 or 8 days, and a combination of oestradiol benzoate. Lactating dairy cows (n = 926) that had been diagnosed with anovulatory anoestrus were divided into two sub-groups. A hormonal treatment protocol that involved the use of a CIDR device containing 1.9 g of progesterone was inserted into the vagina of each cow and left intravaginally for either 6 (6-day group, n = 441) or 8 days (8-day group, n = 485). Every cow in the trial was inseminated after being detected in oestrus from Day -2 onwards (where Day 0, was a herd's MSD), using an appropriate detection aid according to the herds' preference. Cows that had been seen in oestrus and were inseminated by Day 2 were selected for re-synchrony. The standardised re-synchrony involved the re-insertion of a previously used CIDR device into the vagina of each cow on Day 14, together with an injection of 1.0 mg oestradiolbenzoate i.m. This CIDR device was removed on Day 22 and each of these cows injected with 1.0 mg oestradiol benzoate i.m. on Day 23. Each re-synchronised cow that was detected in oestrus was re-inseminated. Treatment with an 8-day CIDR increased the proportion of cows submitted for insemination within the first 3 days of the MSD, compared with the 6-day group (83.7 % vs 71.2%, respectively, P < 0.001), as well as the proportion of cows conceiving within the first 3 days of MSD (36.2% vs 27.7%, P = 0.02), but reduced both the interval from MSD to the first service (4.5 +/- 0.5 vs 6.8 +/- 0.7, P = 0.01), and the interval from MSD to conception (28.1 +/- 1.5 vs 34.0 +/- 1.8, P = 0.009). A greater percentage of the cows in the 6-day group that were not pregnant to the first insemination were submitted for a second insemination by Day 28 compared with the 8-day group (81.1% vs 68.3%, P < 0.001). Conception rates for cows submitted for this second insemination by Day 28 of the MSD were also higher in the 6-day than in the 8-day group (48.4% vs 33.9%, P = 0.009). The percentage of cows pregnant at the end of a herd's AI period of 6 weeks did not differ (57.1% vs 54.8% for 8-day and 6-day groups, respectively, P = 0.42); neither did the proportion of cows pregnant at the end of the a herd's combined AI and natural mating period of 21 weeks (81.4% vs 79.2%, for 8-day and 6-day groups respectively P = 0.36). Treatment of anovulatory anoestrous dairy cows with a combination of an 8-day CIDR and oestradiol benzoate before the MSD improved their reproductive performance by increasing the portion of cows submitted for insemination within the first 3-days of the MSD by reducing the interval from MSD to first service and by increasing the conception rate to the first insemination to collectively reduce the average interval from MSD to conception. 相似文献
2.
AIMS: To determine the reproductive performance of cows diagnosed as anoestrus prior to the planned start of mating (PSM) when they were either treated when first diagnosed, or left untreated until 16 days after the PSM. METHODS: A clinical trial was conducted during the 1996/97 and 1997/98 breeding seasons involving 823 anoestrous dairy cows in 14 herds. On Day -8 (PSM = Day 0), cows in one group (Treated) were each treated with an intravaginal device containing 1.9 g of progesterone (CIDR). The CIDR device was removed on Day -2, and on Day -1 each cow was injected intramuscularly with 1 mg oestradiol benzoate. Cows in the second group (Control) remained untreated at the time of first examination. All cows detected in oestrus after the PSM were mated by artificial insemination (AI) or a bull. Sixteen days after the PSM, all cows that had not been mated were presented for veterinary examination, and those which were still classified as anoestrus were treated with the previously described CIDR regimen. Pregnancy status and approximate date of conception were determined by palpation per rectum 10 -13 weeks after the PSM or 6 weeks after the end of the mating period. RESULTS: Treatment of anoestrous cows 8 days before the PSM significantly increased the number of cows detected in oestrus (95.0% vs 63.1%; p<0.001) and conceiving (59.5% vs 38.8%; p<0.001) during the first 21 days of mating, and reduced the interval from PSM to conception by 7.5 days (p<0.001). There was no significant difference between the conception rate of cows mated following the CIDR treatment regimen compared to cows mated at their first spontaneous oestrus after calving (52.4% vs 58.3%; p = 0.143). CONCLUSION: Diagnosis and treatment of anoestrous dairy cows prior to the start of mating significantly improves their reproductive performance under the seasonal mating conditions typical of spring-calving New Zealand dairy herds. 相似文献
3.
Supplementing treated anoestrous dairy cows with progesterone does not increase conception rates 总被引：1，自引：1，他引：0
AIM: To determine whether conception rates of anoestrous dairy cows treated with progesterone and oestradiol benzoate (ODB) could be increased by treating them with additional progesterone following insemination at the induced oestrus. METHODS: Cows which had not been detected in oestrus for at least 21 days after calving in 18 herds were confirmed anovulatory anoestrus (AA) by veterinary examination, due to the absence of a detectable corpus luteum in the ovaries. All cows were treated with intra-vaginal progesterone (CIDR insert) for 6 days and injected with 1 mg ODB 24 h after insert removal (Day 0). Only cows which were seen in oestrus on Days 0, 1 or 2 were enrolled in the trial. These cows were either treated with a second CIDR insert on Day 8, for 7 days (P4+; n=422), or remained untreated (Control; n=756). Milk progesterone concentrations were measured in a subset of enrolled cows (n=669) on Day 8 to determine the proportion of cows that ovulated following the induced oestrus. RESULTS: Conception rates to first insemination were similar in P4+ and Control cows (40.3% and 37.2%, p=0.59). Of cows which had milk progesterone concentrations measured on Day 8, 78.6% displayed oestrus and ovulated, (range: 53.8% to 94.6% among herds). Of the cows that ovulated, conception rate to first insemination was 46.8% and 43.5% in P4+ and Control cows, respectively (p=0.86). CONCLUSION: Conception rates to first insemination in AA cows treated with progesterone and ODB were not increased by progesterone supplementation using CIDR inserts following insemination. KEY WORDS: dairy cattle, postpartum anoestrus, reproduction, progesterone treatment, CIDR insert. 相似文献
4.
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
5.
Aims: To determine the reproductive performance of cows diagnosed as anoestrus prior to the planned start of mating (PSM) when they were either treated when first diagnosed, or left untreated until 16 days after the PSM. Methods: A clinical trial was conducted during the 1996/97 and 1997/98 breeding seasons involving 823 anoestrous dairy cows in 14 herds. On Day-8 (PSM = Day 0), cows in one group (Treated) were each treated with an intravaginal device containing 1.9 g of progesterone (CIDR).The CIDR device was removed on Day-2, and on Day-1 each cow was injected intramuscularly with 1 mg oestradiol benzoate. Cows in the second group (Control) remained untreated at the time of first examination. All cows detected in oestrus after the PSM were mated by artificial insemination (AI) or a bull. Sixteen days after the PSM, all cows that had not been mated were presented for veterinary examination, and those which were still classified as anoestrus were treated with the previously described CIDR regimen. Pregnancy status and approximate date of conception were determined by palpation per rectum 10-13 weeks after the PSM or 6 weeks after the end of the mating period. Results: Treatment of anoestrous cows 8 days before the PSM significantly increased the number of cows detected in oestrus (95.0% vs 63.1%;p < 0.001) and conceiving (59.5% vs 38.8%;p < 0.001) during the first 21 days of mating, and reduced the interval from PSM to conception by 7.5 days (p < 0.001). There was no significant difference between the conception rate of cows mated following the CIDR treatment regimen compared to cows mated at their first spontaneous oestrus after calving (52.4% vs 58.3%; p = 0.143). Conclusion: Diagnosis and treatment of anoestrous dairy cows prior to the start of mating significantly improves their reproductive performance under the seasonal mating conditions typical of spring-calving New Zealand dairy herds. 相似文献
6.
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
7.
McDougall S 《New Zealand veterinary journal》2003,51(3):117-124
AIMS: To determine if resynchrony, using a progesterone (P4) / oestradiol benzoate (ODB) regime, of previously treated, anovulatory anoestrous (AA) cows would increase the probability of oestrus, conception and pregnancy compared to no resynchrony. Additionally, the effect of prostaglandin F2alpha (PG) treatment of cows not detected in oestrus, but in which a corpus luteum (CL) was palpable transrectally (NDO/CL+), was compared with no treatment. METHODS: Cows not detected in oestrus by 1 week before the start of the seasonal breeding programme were categorised as AA or NDO/CL+, based on absence or presence of a palpable CL, respectively. All AA cows were treated with an intravaginal device containing 1.36 g P4 (CIDR-B) for a period of 6 days, and with 1 mg ODB by intramuscular (I/M) injection 1 day after the device was removed (Day 0). Half the AA cows that were detected in oestrus between Days 0 and 3 were randomly assigned to be resynchronised by reinsertion of a clean used CIDR-B device on Day 15, for a period of 6 days, followed by an I/M injection of 0.5 mg ODB, 1 day after the device was removed (resynchrony, RS), while the other half were not resynchronised (no-RS). NDO/CL+ cows were alternately assigned to be either treated with 25 mg of the PG, dinoprost tromethamine, on Day 0 or left as untreated controls (Con). RESULTS: Resynchrony increased the percentage of cows detected in oestrus between Days 14 and 28 (212/282 = 75.2% vs 155/285 = 54.4%, for RS vs no-RS, respectively; p<0.001), but had no effect on conception rate to a service within the first 3 days of the mating period (146/397 = 36.8% vs 148/399= 37.1%, for RS vs no-RS cows, respectively; p>0.9), or to a service between Days 14 and 28 (84/159 = 52.8% vs 114/217 = 52.5%, for RS vs no-RS cows, respectively; p>0.9). Resynchrony increased the Day 28 pregnancy rate (264/432 = 61.1% vs 237/435 = 54.5%, for RS vs no-RS cows, respectively; p=0.03), but had no effect on the Day 56 or final pregnancy rates (p>0.1).Prostaglandin treatment of NDO/CL+ cows did not affect the percentage of cows detected in oestrus by Day 7 (43/106 = 40.6% vs 51/101 = 50.5%, for Con vs PG, respectively; p=0.15), or Day 28 (92/106 = 86.8% vs 91/101 = 90.1%, for Con vs PG, respectively; p>0.4). Treatment did not affect the Day 28 pregnancy rate (55/103 = 53.4% vs 54/98 = 55.1%, for Con vs PG, respectively; p>0.9), the Day 56 pregnancy rate (81/103 = 78.6% vs 74/98 = 75.5%, for Con vs PG, respectively; p>0.6), or the final pregnancy rate (98/103 = 95.1% vs 89/97 = 91.8%, for Con vs PG, respectively; p>0.3). CONCLUSIONS: Resynchrony of AA cows treated using the present protocol increased the proportion of non-pregnant cows detected in oestrus between Days 14 and 28 and increased the Day 28 pregnancy rate. This resynchrony protocol may be useful for increasing the proportion of the herd pregnant in the first month of the breeding programme, especially in herds that have a history of a low proportion of non-pregnant cows detected in oestrus between Days 14 and 28. There was no benefit in treating NDO/CL+ cows with PG compared to no treatment. KEYWORDS: Dairy cows, anoestrus, treatment, resynchrony, prostaglandin, progesterone, oestradiol benzoate. 相似文献
8.
AIM: To evaluate the efficacy of a programme using oestradiol benzoate, progesterone and the prostaglandin-F2 (PG) analogue, cloprostenol, to synchronise oestrus and ovulation in dairy cows, compared with a programme using a gonadotropinreleasing hormone (GnRH) agonist, buserelin, and cloprostenol. METHODS: Twenty non-lactating dairy cows, at random stages of the oestrus cycle, were randomly assigned to 1 of 2 treatments. In Treatment 1 ( OPPG; n=10), cows were injected with 2 mg oestradiol benzoate intramuscularly (IM) plus 200 mg progesterone subcutaneously (SC) on Day 0, followed by 500 microg cloprostenol IM on Day 9 and 1 mg oestradiol benzoate on Day 10. In Treatment 2 (GPG; n=10), cows were injected with 10 microg buserelin IM on Day 0, 500 microg cloprostenol IM on Day 7 and 10 microg buserelin on Day 9. The ovaries of all cows were examined by ultrasonography, using an 8 MHz probe, from 5 days before the initial treatment until ovulation. Cows were observed for oestrus 3 times daily for 7 days after cloprostenol treatment. Blood samples were collected daily for determination of progesterone, and 6-hourly for 36 h after the second oestradiol or buserelin injection for the determination of follicle stimulating hormone (FSH) and luteinising hormone (LH) concentrations. RESULTS: The percentage of cows observed in oestrus was higher in the OPPG group than in the GPG group (100% vs 55.6%, p=0.018). Treatment with either short-acting progesterone plus oestradiol benzoate or buserelin was followed by atresia or ovulation of the dominant follicle. Emergence of a new follicular wave occurred earlier (p>0.001) in the GPG group (2.2+/-0.2 days) than in the OPPG group (3.6+/-0.2 days). There was no significant difference between treatment groups in the variation of time of follicular wave emergence or size of the largest follicles at either the time of initial treatment (10.8+/-1.4 mm vs 11.1+/-0.8 mm), cloprostenol treatment (13.8+/-0.7 mm vs 14.0+/-1.3 mm) or of ovulation (15.4+/-0.7 mm vs 17.6+/-1.1 mm; p=0.10). The LH surge occurred sooner after the second injection of buserelin (4.0+/-1.0 h) than after the second injection of oestradiol benzoate (22.8+/-1.2 h; p>0.001). The interval between the second injection of oestradiol benzoate or buserelin and ovulation did not differ significantly between treatment groups (1.7+/-0.3 days vs 1.6+/-0.2 days; p=0.69). CONCLUSIONS: The use of short-term progesterone treatment, combined with oestradiol benzoate for follicular wave synchronisation, and cloprostenol to cause lysis of residual luteal tissue, is a promising alternative to established methods of oestrus synchronisation in cows. 相似文献
9.
OBJECTIVE: To compare the use of gonadotrophin releasing hormone (GnRH) and oestradiol benzoate (ODB) administered following a synchronised pro-oestrus on reproductive performance of lactating dairy cows and the submission rates of non-pregnant cows following resynchronisation. DESIGN: Cohort study. PROCEDURE: Lactating Holstein cows enrolled in a controlled breeding program were first treated with an intravaginal progesterone releasing insert (IVP4) for 8 days, 2.0 mg of ODB intramuscular (i.m.) at device insertion (Day 0), an analogue of PGF2alpha at device removal and either 1.0 mg of ODB i.m., 24 h after device removal (ODB group, n = 242), or 0.25 mg of a GnRH agonist (GnRH group, n = 152) injected i.m. approximately 34 h after device removal. Every cow was artificially inseminated between 49 and 56 h after removal of its insert (Day 10). Cows detected in oestrus 1 day after artificial insemination (AI) that were not detected in oestrus on the previous day were re-inseminated on that day. All cows treated on Day 0 were resynchronised for reinsemination by insertion of a used IVP4 device on Day 23. Oestradiol benzoate at a dose of 1.0 mg was administered i.m. at the time of device insertion. Inserts were removed 8 days later (Day 31) and 1.0 mg of ODB was injected i.m. 24 h later. Those cows detected in oestrus between Days 31 and 35 were artificially inseminated. On Day 46 these cows were resynchronised for a third round of AI by insertion of an IVP4 device, used previously to synchronise cows for the first and second rounds of AI, and administration of 1.0 mg of ODB i.m.. Eight days later inserts were removed. Cows detected in oestrus between Days 54 and 58 were artificially inseminated. Bulls were run with the herd between rounds of AI and removed after 21 weeks of mating. RESULTS: Treatment with ODB or GnRH at the first synchronised pro-oestrus did not significantly alter the reproductive performance over three rounds of AI or over a 21-week breeding period. Treatment also did not alter submission rates at the second round of AI or the proportion of non-pregnant and non-return cows ('phantom' cows) detected and did not result in significant differences in concentrations of progesterone in plasma 10 and 18 days after removal of inserts at the first round of AI. Treatment with GnRH reduced the proportion of cows detected in oestrus at the first round of AI (36.2 vs 97.5%; P < 0.001). CONCLUSION: Administration of GnRH compared to ODB at a synchronised pro-oestrus results in similar reproductive performance. Treatment with GnRH reduced the proportion of cows detected in oestrus following treatment. This may offer advantages to the way AI is managed by enabling insemination at a fixed-time and removing the need for the detection of oestrus. 相似文献
10.
AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oestrus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based synchrony programmes. METHODS: Scientific papers written in the English language between 1989 and 2002 that investigated the effects of treatment programmes including CIDR devices on reproductive performance in dairy heifers or lactating dairy cows were identified using a computerised literature search. The criteria for inclusion incorporated evidence that treatment allocation was completely randomised; the population studied was lactating dairy cows; and that data were available on submission, conception and pregnancy rates and their associated measures of variability. Reproductive outcomes from 25 synchrony trials (total n=11,058 cows) were analysed. Summary measures of the effect of treatment on reproductive outcome were assessed using fixed- and random-effects Bayesian meta-analysis models. RESULTS: Treatment programmes including a CIDR device increased the risk of submission in cycling cows (predicted Bayesian RR=2.86, 95% credible interval=1.46-5.67). Compared with controls, synchrony programmes including CIDR devices in cycling dairy cows had no effect on the risk of conception to first service post-treatment (predicted Bayesian RR=1.00, 95% credible interval=0.80-1.24). Compared with controls, synchrony programmes including CIDR devices had no effect on the risk of pregnancy throughout the mating period (predicted Bayesian RR=1.02, 95% credible interval=0.89-1.17). In anoestrous cows, CIDR treatment had no effect on the risk of conception to first service post-treatment and no effect on the risk of pregnancy throughout the mating period, compared with anoestrous, untreated controls (predicted Bayesian RR=0.91 and 0.97, respectively; 95% credible interval=0.68-1.26 and 0.59-1.60, respectively). CONCLUSION: The results of this meta-analysis showed that synchrony programmes using CIDR devices combined with other hormones reliably enhanced submission rates in lactating dairy cows. The relatively small number of trials with data suitable for analysis and the heterogeneity of results at the individual trial level limited our ability to confirm either a beneficial or deleterious effect of treatment on conception or pregnancy rates. Further randomised, controlled trials to evaluate the effectiveness of this form of reproductive therapy in commercial dairy farms are needed. 相似文献
11.
Kim UH Suh GH Hur TY Kang SJ Kang HG Park SB Kim HS Kim IH 《The Journal of reproduction and development》2007,53(3):639-645
This study compared two types of controlled internal drug release (CIDR)-based timed artificial insemination (TAI) protocol for treatment of repeat breeder dairy cows. In the first trial of the experiment, 55 repeat breeder cows were randomly assigned to the following two treatments. (1) In the EB group, a CIDR device was inserted into the cows, and then the cows were administered an injection of 1 mg estradiol benzoate (EB) plus 50 mg progesterone (P4; Day 0). On Day 7, they were given an injection of PGF(2alpha) and the CIDR device was removed. The cows were given an injection of 1 mg EB on Day 8 and were subjected to TAI 30 h later (n=27). (2) In the gonadotrophin releasing hormone (GnRH) group, a CIDR device was inserted into the cows, and then the cows were administered an injection of 250 microg gonadorelin (GnRH; Day 0). On Day 7, they were given an injection of PGF(2alpha) and the CIDR device was removed. The cows were given an injection of 250 microg GnRH on Day 9 and were subjected to TAI 17 h later (n=28). In the second trial, 41 repeat breeder cows that were confirmed as not pregnant in the first trial were randomly assigned to the same two treatments used in the first trial (an EB group of 20 cows and a GnRH group of 21 cows). The ovaries of 15 cows from each group were examined by transrectal ultrasonography in order to observe the changes in ovarian structures, and blood samples were collected for analysis of serum P4 concentrations. The pregnancy rates following TAI in the first (18.5 vs. 32.1%) and second (40.0 vs. 38.1%) trials and the combined rates (27.7 vs. 34.7%) did not differ between the EB and GnRH groups. The proportions of cows with follicular wave emergence within 7 days did not differ between the EB (12/15) and GnRH groups (13/15). The interval to wave emergence was shorter (P<0.01) in the GnRH group than in the EB group, but there was no difference in the mean diameters of dominant follicles on Day 7 between the groups. Moreover, the proportions of cows with synchronized ovulation following a second EB or GnRH treatment did not differ between the groups. In conclusion, treatment with either EB or GnRH in a CIDR-based TAI protocol results in synchronous follicular wave emergence, follicular development, synchronous ovulation, and similar pregnancy rates for TAI in repeat breeder cows. 相似文献
12.
Recent Developments in Oestrous Synchronization of Postpartum Dairy Cows with and without Ovarian Disorders 总被引：1，自引：0，他引：1
This report reviews the most recent developments in prostaglandin‐based oestrous synchronization programmes for postpartum dairy cows and addresses the efficiency of controlled breeding protocols based on such developments for cows with abnormal ovarian conditions. A double prostaglandin protocol applied 11–14 days apart seems to be capable of bringing most cows to oestrus. Because of varying oestrus onset times, improved conception rates are obtained following artificial insemination (AI) at detected oestrus rather than fixed‐time AI in prostaglandin‐treated cows. The administration of oestradiol or human chorionic gonadotrophin, or both these hormones, after prostaglandin treatment, improves the synchrony of oestrus yet does not enhance the conception rate. Progesterone‐based treatments for oestrous synchronization are considered the most appropriate for non‐cyclic or anoestrous postpartum dairy cows; prostaglandin alone being ineffective because of the absence of a mature corpus luteum in these cows. Improved oestrus synchrony and fertility rate have been reported using short‐term progesterone treatment regimes (7–9 days) with or without oestradiol benzoate combined with the use of a luteolytic agent given 1 day before, or at the time of, progesterone withdrawal. The ovulation synchronization (Ovsynch) protocol, based on the use of gonadotrophin releasing hormone and prostaglandin, was developed to coordinate follicular recruitment, CL regression and the time of ovulation. This protocol allows fixed time insemination and has proved effective in improving reproductive management in postpartum dairy cows. However, timed AI following Ovsynch seems to have no beneficial effects in heifers, because of an inconsistent follicle wave pattern, and in anoestrous cows, given their lack of prostaglandin responsive CL. To date, there are several prostaglandin based, fixed‐time insemination oestrous synchronization protocols for use in early postpartum dairy cows with ovarian disorders such as ovarian cysts and acyclicity. 相似文献
13.
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
14.
Ando T Kamimura S Hamana K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(12):1497-1502
Estrous synchronization using a Controlled Internal Drug Releasing device (CIDR) in combination with GnRH or estradiol benzoate (EB) treatment was investigated in Japanese black cows characterized with initial ovarian conditions. A total of 142 cows were allocated to one of four treatments: insertion of CIDR for eight days (Group A: n=34), CIDR with 100 microg of GnRH on d 0 (Group B: n=54, d 0=CIDR insertion), CIDR with GnRH on d 0 and 1 mg of EB on d 10 (Group C: n=20) or CIDR with 2 mg of EB on d 0 and 1 mg of EB on d 9 (Group D: n=34). All cows received 25 mg of PGF(2alpha) on d 7 and blood was collected for progesterone (P4) analysis on d 0, 8, and 21. AI was performed at estrus, but in Group D timed AI was set following a day of EB treatment. Estrus was induced in 141/142 cows, and the majority of which occurred on d 10 and 11 (98 cows, 34 cows). GnRH treatment induced more intermediate ovulation than EB treatment in cows with CL on d 0 (19.0% vs. 0%). Ovulation after CIDR removal was significantly higher in cows with CL on d 0 compared to those without CL (87.0% vs. 71.4%). Group B showed higher conception rates than those combined with Groups C and D where EB was injected after CIDR removal (51.1% vs. 38.9%). Conception had no correlation with either CL existence on d 0 or intermediate ovulation on d 8. P4 concentrations on d 8 were significantly lower compared to those on d 0 or d 21. On d 21 in cows without intermediate ovulation, Group A showed significantly lower P4 concentrations than the other 3 groups. The data suggests that CIDR insertion with PGF(2alpha) treatment is an effective method for estrous synchronization irrespective of initial ovarian conditions, and GnRH treatment at CIDR insertion induces intermediate ovulation and improves the conception rate in Japanese black cows. 相似文献
15.
McDougall S 《New Zealand veterinary journal》2001,49(5):187-194
AIMS: (a) To compare the reproductive performance of anovulatory anoestrous (AA) postpartum dairy cows following treatment with 1 of 2 progesterone (P4) and oestradiol benzoate (ODB)-based treatment regimens; (b) To determine whether resynchronisation of cows initially treated for AA would improve reproductive performance and; (c) to determine whether cows not detected in oestrus but with a corpus luteum (CL) present (NDO/CL+), treated with P4 and ODB, would conceive earlier than untreated controls. METHODS: Cows (n=1386) from 11 herds, that had not been detected in oestrus before the start of the seasonal mating period (PSM) and in which a CL was not detected were diagnosed AA, blocked by age (2 or >2 years old), then randomly assigned to be treated with an intravaginal P4-releasing device for either 6 (6-Day group) or 8 days (8-Day group). Cows in the 8-Day group were injected intramuscularly (IM) with 2 mg ODB at device insertion and all cows were injected with 1 mg ODB 24 h after device removal (Day 0). Cows detected in oestrus from Days 0-3 were subsequently assigned to be either resynchronised or left as untreated controls. Resynchronised cows had a used P4-releasing device reinserted on Day 14 for 8 days and were injected with 1 mg ODB at device reinsertion and again 24 h after device removal. NDO/CL+ cows were assigned to be either treated the same as the 8-Day group or left as untreated controls. All cows were inseminated on detection of oestrus and pregnancy tested approximately 10 weeks after the PSM and again 6-8 weeks after the end of the mating period. RESULTS: For AA cows, the 14-day submission rate was similar between 6-Day and 8-Day groups (p0.1). However, the pregnancy rate by Day 14 was higher for the 8-Day than the 6Day group (43.0% vs 35.2%; p=0.006). Resynchrony treatment decreased the 14-day pregnancy rate compared with untreated controls (35.2% vs 42.5%; p=0.026). The resynchrony treatment increased the submission rate between Days 14-28 for non-pregnant cows compared with untreated controls (80.6% vs 57.4%; p=0.049). However, conception rate to resynchronised heats was lower than for cows that returned to oestrus naturally (56.6% vs 67.9%; p=0.025). Neither initial treatment type nor resynchrony treatment increased the 28-day pregnancy rate (p>0.1). There were no differences between treatment groups in the final non-pregnant rate (4.5% vs 4.6%; p>0.1). Treated NDO/CL+ cows had a higher 14-day submission rate (88.1% vs 49.4%; p>0.001), higher 14-day and 28-day pregnancy rates (42.9% vs 20.7%, p>0.001 and; 56.0% vs 42.5%, p=0.094, respectively) and conceived earlier (21 vs 36 days from PSM to median day of conception; p>0.05), than untreated NDO/CL+ cows. CONCLUSIONS: The 8-Day, ODB-P4-ODB treatment regimen resulted in a higher pregnancy rate by 14 days but not 28 days than the 6-Day, P4-ODB treatment. The resynchrony treatment increased the proportion of non-pregnant cows inseminated on days 14-28, but did not increase the 28-day pregnancy rate or final pregnancy rate. Treatment of NDO/CL+ cows with the 8-Day, ODB-P4-ODB treatment improved reproductive performance compared with no treatment. 相似文献
16.
Kawate N Sakase M Seo Y Fukushima M Noda M Takeda K Ueno S Inaba T Kida K Tamada H Sawada T 《The Journal of reproduction and development》2006,52(1):81-89
We examined the relations between plasma insulin-like growth factor (IGF) -I concentrations during treatment with CIDR-based or Ovsynch protocol for timed AI and conception and plasma steroid concentrations in early postpartum Japanese Black beef cows. Cows in the control group (Ovsynch; n = 21) underwent Ovsynch protocol (GnRH analogue on Day 0, PGF(2alpha) analogue on Day 7, and GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch+CIDR group (n = 22) received Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the further treatment group (EB+CIDR+GnRH; n = 22) received 2 mg of estradiol benzoate (EB) on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. Plasma IGF-I concentrations were determined on Days -7, 0, 7, 9 and 17. Conception rates were improved in the CIDR-combined groups (both CIDR-treated groups were combined) relative to Ovsynch group (P < 0.05) for cows with low IGF-I concentrations (<1,000 ng/ml) on Days -7, 0, and 7, but improved conception rate produced by the CIDR-based protocols did not occur in cows with a high IGF-I concentration (> or =1,000 ng/ml). Plasma estradiol-17beta concentrations increased from Day 0 to 7 (P < 0.05) and were unchanged from Day 7 to 9 in the Ovsynch group with low IGF-I concentrations on Day 0, while they were unchanged from Day 0 to 7 and increased from Day 7 to 9 (P < 0.05) in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group. Plasma progesterone concentrations in the Ovsynch group with low IGF-I concentrations on Day 0 were higher on Day 14 than in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group (P < 0.05). In conclusion, CIDR-based protocols may improve conception relative to Ovsynch in early postpartum beef cows with lower plasma IGF-I concentrations at the start of the protocols. This improvement is probably due to prevention of premature increases of estradiol-17beta and progesterone concentrations, which occurred in cows with low IGF-I concentrations treated with Ovsynch, by the CIDR treatment. 相似文献
17.
R Kasimanickam JB Hall JF Currin B Inman JS Rudolph WD Whittier 《Reproduction in domestic animals》2010,45(3):487-492
Crossbred cows (n = 1073) from five locations had oestrous cycles synchronized with 100 μg of GnRH IM and insertion of controlled internal drug release device (CIDR) on Day 0 followed by 25 mg of PGF2α IM and CIDR removal on Day 7. Kamar® patches were placed on all cows at CIDR removal. Cows were observed three times daily for oestrus after PGF2α administration. In the Ovsynch‐CIDR group, cows detected in oestrus (n = 193) within 48 h after PGF2α were inseminated using the AM–PM rule. Among these cows, 80 received and 113 did not receive a second GnRH at 48 h after PGF2α. Cows (n = 345) not detected in oestrus received a second GnRH at 48 h after PGF2α on Day 9, and fixed‐time AI 16 h after the GnRH on Day 10. In the CO‐Synch‐CIDR group, cows detected in oestrus (n = 224) within 48 h after PGF2α were inseminated using the AM–PM rule. Among these cows, 79 received and 145 did not receive a second GnRH at 64 h after PGF2α. Cows (n = 311) not detected in oestrus received a second GnRH on Day 10 at the time of AI, 64 h after PGF2α. The AI pregnancy rates were not different between the Ovsynch‐CIDR and CO‐Synch‐CIDR groups (p = 0.48). There were no differences in the AI pregnancy rates for cows inseminated at a fixed time (p = 0.26) or at detected oestrus (p = 0.79) between the treatment groups. Among cows inseminated in oestrus, there were no differences in the AI pregnancy rates between cows that received or did not receive the second GnRH (p = 0.47). In conclusion, acceptable AI pregnancy rates can be achieved with or without inclusion of oestrus detection in the Ovsynch‐CIDR and CO‐Synch‐CIDR protocols. Among cows detected in oestrus, cows that received a second GnRH yielded similar pregnancy rates when compared with cows that did not receive the second GnRH. 相似文献
18.
An experiment was conducted to examine the effect of progesterone (P(4)) and oestradiol benzoate (ODB) on fertility of repeat-breeder lactating dairy cows during summer. One hundred repeat-breeder lactating dairy cows were randomly allocated to four groups (Tr1, Tr2, Tr3 and C) in a study conducted at a private dairy farm. All cows were injected with 2 mg ODB (day 0), which were at random stages of their oestrous cycles. Cows in Tr1, Tr2 and Tr3 were administered with intravaginal progesterone-releasing devices (controlled internal drug-releasing, CIDR) at the time of ODB injection for 7 days and those in group C were untreated and served as controls. Following CIDR removal, all cows were given an intramuscular injection of 25 mg Prostaglandin (PGF(2 alpha)). Twenty-four hours after the PGF(2 alpha) injection, cows in Tr1, Tr2 and C groups were injected with 1 mg ODB. Cows in Tr3 group were injected with 10 microg gonadotropin-releasing hormone (GnRH) agonist 48 h after CIDR removal. Artificial insemination was performed between 24 and 30 h following the second ODB injection for cows in Tr1 group and at the time of GnRH injection for cows in Tr3 group. Cows in Tr2 and C groups were inseminated at detected oestrus. Plasma P(4) and oestradiol 17beta (E(2)) concentrations were determined for all cows daily from day 0 to day 9. Plasma concentrations of P(4) and E(2) among cows of groups Tr1, Tr2 and Tr3 were increased and reached maximum values within 48 h following administration and were greater (p < 0.001) than those of group C cows. The proportion of cows detected in oestrus based on P4 concentration on day 9 was 88%, 72%, 88% and 60% in groups Tr1, Tr2, Tr3 and C, respectively. Oestrous detection rate differed (p < 0.01) significantly between time-inseminated groups (Tr1 and Tr3) and those inseminated at observed oestrous (Tr2 and C) groups. Pregnancy rates based on ultrasonography performed on day 28 were 52%, 56%, 60% and 40%, and those based on rectal palpation on day 45 were 32%, 44%, 36% and 28% for Tr1, Tr2, Tr3 and C cows (p > 0.1), respectively. Whereas pregnancy rates for cows with four or more previous services in all groups (54.55%) were higher (p < 0.03) than those for cows with three previous services (29.49%). In pregnant cows, mean days from calving to the day of insemination were higher (p < 0.01) among cows with four or more previous services (204 +/- 8.0 days) than those with three previous services (157 +/- 6.0 days). Results indicate that treatment with a combination of ODB and CIDR in repeat-breeder dairy cows causes elevation in plasma concentrations of E(2) and P(4). Oestrous detection rate was better in cows that were primed with P(4) than those without P(4) priming. Cows with four or more previous services had significantly higher pregnancy rates than those with three previous services. 相似文献
19.
The objective of this study was to compare oestrus expression and fertility rate in used and new controlled internal drug releasing (CIDR) device treated anoestrous buffaloes. Furthermore, to determine the timing of ovulation, and fertility rate in estradiol benzoate (EB) and GnRH-administered CIDR-treated anoestrous Nili-Ravi buffaloes. In experiment 1, buffaloes received either a used CIDR (UCIDR, n = 35) or a new CIDR (NCIDR, n = 36) for 7 day and PGF2α on day 6. Oestrous expression was similar (p > 0.05) between UCIDR (88.5%) and NCIDR (96.6%) buffaloes. The pregnancy rate did not differ (p > 0.05) because of treatment (37.1% in UCIDR vs 36.6% in NCIDR). In experiment 2, buffaloes (n = 55) received CIDR device for 7 days and PGF2α, on day 6 and randomly assigned into three treatment groups: (i) CIDR-EB (n = 17) received EB on day 8, (ii) CIDR-GnRH (n = 18) received GnRH on day 9 and (iii) control (n = 20) received no further treatment. Mean interval from CIDR removal to ovulation in CIDR-EB, CIDR-GnRH and CIDR group were 61.3 ± 0.8, 64.9 ± 1.8 and 65.1 ± 16.7 h, respectively. However, the buffaloes in the CIDR-EB and CIDR-GnRH group had lesser variability in the timing of ovulation compared to control. The pregnancy rate of both CIDR-EB group (58%) and CIDR-GnRH group (61%) were tended to be higher (p < 0.1) than control (30%). In conclusion, compared to NCIDR devices, previously UCIDR devices are equally effective to induce oestrus in anoestrous buffaloes resulting optimal pregnancy rate. Administration of EB and GnRH after CIDR removal results in tighter synchrony (less variability) and improved fertility in anoestrous buffaloes. CIDR based synchronization regimens have great potential in fertility improvement in anoestrous buffaloes. 相似文献
20.
Sakase M Kawate N Nakagawa C Fukushima M Noda M Takeda K Ueno S Inaba T Kida K Tamada H Sawada T 《Veterinary journal (London, England : 1997)》2007,173(3):691-693
Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha). 相似文献