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López-Gatius F. Ovarian response to prostaglandin F 2α in lactating dairy cows: a clinical update. J Reprod Dev 2021; 68:104-109. [PMID: 34980770 PMCID: PMC8979807 DOI: 10.1262/jrd.2021-119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prostaglandin F2α (PGF2α) and its analogs are used to induce luteolysis in estrus synchronization programs to terminate unwanted pregnancies or to promote ovulation in certain cow subpopulations. In the past few decades, the luteolytic dose of PGF2α has remained unchanged. This review explores the clinical implications of increasing the standard dose for these applications in high-producing dairy cows. Ultrasonography may assist in selecting the most appropriate PGF2α dose and improve the results. A reference has been used for PGF2α for promoting ovulation in herds showing poor reproductive performance.
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Affiliation(s)
- Fernando López-Gatius
- Agrotecnio Centre, University of Lleida, 25198 Lleida, Spain.,Transfer in Bovine Reproduction SLu, 22300 Barbastro, Spain
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Martins JPN, Acevedo MJT, Piterini CG, Cunha TO, Pursley JR. Effect of PGF 2α treatments during early corpus luteum development on circulating progesterone concentrations and ovulation in breeding-age Holstein heifers. Theriogenology 2021; 173:12-18. [PMID: 34126407 DOI: 10.1016/j.theriogenology.2021.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/19/2022]
Abstract
The objective of this study was to test the effect of low circulating concentrations of progesterone (P4) on pre-ovulatory follicle development in heifers as part of an overarching objective to develop a model to understand this phenomenon in dairy cattle without the confounding factors of lactation. Holstein heifers between 12 and 13 mo of age were pre-synchronized to ensure all heifers were on d 6 of the estrous cycle at the start of the Ovsynch program. Only heifers with CL regression and ovulation to the following pre-treatment strategy were used in the study: 0.5 mg cloprostenol (PGF2α), 2 d later, 0.1 mg GnRH, 6 d later, GnRH (G1; 1st GnRH of Ovsynch). Heifers (n = 159) responding to pre-treatment were randomly assigned to 4 groups and completed the Ovsynch program: high P4 control (HPC), low P4 control (LPC; PGF2α 24 h after G1), PG2 (PGF2α 24 and 48 h after G1) and PG3 (PGF2α 24, 48, and 96 h after G1). Only heifers that had ovulation to G1 remained in the study. Blood samples were collected in all heifers on d 7 (n = 157) and in a subset of heifers on d 1, 2, 3, 4 (n = 82) after G1 to measure serum P4. Pre-ovulatory follicle size at G1 (13.0 ± 0.1 mm; P = 0.53) and mean serum P4 24 h after G1 (d 1; 3.62 ± 0.11 ng/mL; P = 0.46) did not differ among treatments. HPC heifers had greater (P < 0.001) mean serum P4 compared to LPC, PG2 and PG3 on d 2, 3, 4, and 7. On d 2, 3 and 4, mean serum P4 of LPC, PG2 and PG3 heifers did not differ (P > 0.10). On d 7, LPC heifers had greater (P < 0.001) serum P4 compared to PG2 and PG3 heifers. Mean ± SEM serum P4 on d 7 after G1 was 8.43 ± 0.39, 2.55 ± 0.36, 1.58 ± 0.20, and 1.21 ± 0.15 ng/mL for HPC, LPC, PG2, and PG3, respectively. Percentage of heifers with P4 < 0.50 ng/mL on d 7 was greater (P < 0.05) for LPC, PG2 and PG3 (27, 32 and 26%, respectively) compared to HPC (0%). A greater (P < 0.05) proportion of heifers ovulated before G2 in the LPC, PG2 and PG3 than in the HPC. For heifers that ovulated after G2, low serum concentrations of P4 in LPC, PG2 and PG3 induced double ovulations in 6/97 heifers after the final GnRH of Ovsynch compared to 0/33 in HPC. In summary, PGF2α treatments during early CL development reduced circulating P4 concentrations 7 d after G1 compared with both HPC and LPC. However, it did not effectively control CL and follicle function to be utilized as a model to test high vs. low serum P4 on fertility parameters in Holstein heifers.
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Affiliation(s)
- João Paulo N Martins
- Department of Animal Science, Michigan State University, East Lansing, MI, 48824, USA
| | - Melisa J T Acevedo
- Department of Animal Science, Michigan State University, East Lansing, MI, 48824, USA
| | - Christian G Piterini
- Department of Animal Science, Michigan State University, East Lansing, MI, 48824, USA
| | - Thiago O Cunha
- Department of Animal Science, Michigan State University, East Lansing, MI, 48824, USA
| | - J Richard Pursley
- Department of Animal Science, Michigan State University, East Lansing, MI, 48824, USA.
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López-Gatius F. Presence of multiple corpora lutea affects the luteolytic response to prostaglandin F 2α in lactating dairy cows. J Reprod Dev 2021; 67:135-139. [PMID: 33583915 PMCID: PMC8075729 DOI: 10.1262/jrd.2020-144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Since the 1970s, luteolytic doses used for synchronizing estrus in dairy cattle have remained unchanged. This study aimed to evaluate the dose-response effect
of prostaglandin F2α (PGF2α), which is used for synchronizing estrus, and subsequent fertility in cows with two or more corpora lutea
(CL). The study population consisted of 1,683 cows with a single CL (1CL), 501 cows with multiple CL receiving a single dose of PGF2α (2CL1), and 252
cows with multiple CL receiving a 1.5 × PGF2α dose (2CL1.5). Cows with a single CL (n = 1,245) showed estrus significantly (P < 0.01) earlier
(3.01 ± 1.23 days; mean ± SD) than cows with multiple CL (n = 287; 3.33 ± 1.69 days). Using 1CL cows as reference, the odds ratio (OR) for the estrus response
in 2CL1 cows was 0.13 (P < 0.0001), whereas the ORs for estrus response and pregnancy of 2CL1.5 cows were 1.8 (P = 0.0001) and 1.7 (P = 0.001), respectively.
Based on the results for only the 2CL1 cows, the OR for the estrus response was 0.7 (P = 0.01) for cows producing ≥ 45 kg of milk at treatment, compared to the
remaining cows producing < 45 kg of milk. Our results showed that the presence of multiple CL reduced the estrus response to that induced by a single
PGF2α dose and milk production was inversely associated with this response, whereas an increased PGF2α dose improved the estrus
response. Therefore, an increase in the standard PGF2α dose is recommended.
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Affiliation(s)
- Fernando López-Gatius
- Agrotecnio Centre; University of Lleida, 25198 Lleida, Spain.,Transfer in Bovine Reproduction SLu, 22300 Barbastro, Spain
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LÓpez-Gatius F. Clinical prospects proposing an increase in the luteolytic dose of prostaglandin F 2α in dairy cattle. J Reprod Dev 2020; 67:1-3. [PMID: 33162429 PMCID: PMC7902216 DOI: 10.1262/jrd.2020-101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Over the past few decades, the luteolytic dose of prostaglandin F2α (PGF2α) and its analogs, used to synchronize estrus for fixed-time insemination in dairy cattle, have remained unchanged. Given the beneficial effects of PGF2α on a young corpus luteum and on multiple ovulations in a fixed-time insemination protocol, and its therapeutic abortive effects on multiple ovulations in pregnant cows, we propose the use of a double PGF2α dose or two PGF2α treatments 24 hours apart. Ultrasonography procedures serve to identify luteal structures and may therefore help to determine the best PGF2α dose to improve the fertility of high-producing dairy cows.
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Affiliation(s)
- Fernando LÓpez-Gatius
- Transfer in Bovine Reproduction SLu, 22300 Barbastro, Spain.,Agrotecnio Centre, University of Lleida, 25198 Lleida, Spain
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Liu TC, Ho CT, Li KP, Chang CC, Chan JPW. Human chorionic gonadotropin (hCG)-induced ovulation occurs later but with equal occurrence in lactating dairy cows: comparing hCG and gonadotropin-releasing hormone protocols. J Reprod Dev 2019; 65:507-514. [PMID: 31619595 PMCID: PMC6923156 DOI: 10.1262/jrd.2019-037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 09/17/2019] [Indexed: 12/18/2022] Open
Abstract
This study assessed the effects of two hormones, human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH), on ovulatory responses during different diestrous stages in lactating dairy cows. Estrous cycles of 21 cows were synchronized and were enrolled in stage 1 of the experiment. The cows were treated with a prostaglandin (PG) F2α analog either 9 to 10 days [mid-diestrus (MD) group] or 5.5 to 6.5 days [early-diestrus (ED) group] after synchronized ovulation (day 0 = first PGF2α administration). On day 2, the cows were administrated 250 μg GnRH or 3000 IU hCG. Ovulation was determined every 2 h from 24 to 36 h after GnRH or hCG administration, and then every 4 h up to 72 h until ovulation. Cows in stage 2 were administered these treatments in the reverse order. The results indicated that average ovulation times in cows treated with GnRH in the MD group (GnRH-MD group) and cows treated with GnRH in the ED group (GnRH-ED group) were 30.0 ± 1.0 h and 28.8 ± 0.4 h, respectively. However, ovulation times for cows treated with hCG in the MD group (hCG-MD group) and cows treated with hCG in the ED group (hCG-ED group) were 35.8 ± 4.6 h and 32.8 ± 2.2 h, respectively, and ovulation occurred significantly later in the hCG-treated groups than in the GnRH-treated groups. In summary, we found that hCG-induced ovulation occurred later than GnRH-induced ovulation regardless of different diestrous peroids; however, the two treatments did not differ in terms of percentage of ovulation.
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Affiliation(s)
- Tsung-Ching Liu
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chia-Tang Ho
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Kuang-Po Li
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chao-Chin Chang
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Jacky Peng-Wen Chan
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
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Veronese A, Marques O, Moreira R, Belli AL, Bilby TR, Chebel RC. Estrous characteristics and reproductive outcomes of Holstein heifers treated with 2 prostaglandin formulations and detected in estrus by an automated estrous detection or mounting device. J Dairy Sci 2019; 102:6649-6659. [PMID: 31030926 DOI: 10.3168/jds.2018-15957] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/11/2019] [Indexed: 11/19/2022]
Abstract
Dinoprost tromethamine (DIN), a molecule similar to endogenous PGF2α, has a half-life of approximately 9 min. Cloprostenol sodium (CLO), a synthetic analog of PGF2α, has a half-life of approximately 3 h. We hypothesized that treatment of Holstein heifers with CLO would improve estrous detection rate, estrous characteristics, service rate, and overall reproductive performance compared with DIN. Currently in the United States, heifers are largely inseminated based on signs of estrus, which is detected visually or with the aid of mounting detection devices (MD). Automated estrous detection devices (AED) are becoming more accessible to producers, but it is not clear whether they present advantages in the reproductive management of heifers. Therefore, we hypothesized that the use of an AED would improve service and pregnancy rates compared with detection of estrus with the aid of a MD. Holstein heifers (n = 1,019) were enrolled in the experiment at 10 to 11 mo of age, when they were fitted with a Heatime HR LD System (SCR Ltd., Netanya, Israel). At 12 mo of age, we paired heifers according to estrous cycle phase and randomly assigned them to treatments in a 2 × 2 design: PGF2α formulation (CLO vs. DIN) and estrous detection treatment (AED vs. MD). Heifers in the AED treatment were detected in estrus only by the Heatime HR LD System, whereas heifers in the MD treatment were detected in estrus only by the Kamar Heatmount Detector (Kamar Products Inc., Zionsville, IN). Treatments with the same PGF2α formulations were repeated 14 d after the first treatment if heifers had not been detected in estrus. A sub-group of heifers had blood sampled on the day of PGF2α treatment and within 24 h of onset of estrus to determine progesterone and estradiol concentrations. Treatment with CLO reduced the progesterone concentration within 24 h of onset of estrus compared with DIN (0.04 ± 0.01 vs. 0.11 ± 0.01 ng/mL). Among heifers in mid diestrus on the day of PGF2α treatment, CLO reduced the interval to estrus compared with DIN (72.0 ± 2.2 vs. 82.4 ± 2.4 h). Prostaglandin F2α formulation and estrous detection treatment did not affect pregnancy to the first service. The interval between the first and second services tended to be reduced for the AED treatment compared with the MD treatment (24.4 ± 0.5 vs. 25.7 ± 0.6 d). Prostaglandin F2α formulation and estrous detection treatment did not affect the hazard of pregnancy. Although CLO treatment may shorten the interval to estrus in heifers at mid diestrus compared with DIN, PGF2α formulation did not affect reproductive performance. In the current experiment, no advantages in reproductive performance were observed when estrous detection was based on an AED compared with a MD.
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Affiliation(s)
- Anderson Veronese
- Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610
| | - Odinei Marques
- Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610
| | - Rafael Moreira
- Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610
| | - Anna L Belli
- Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610
| | | | - Ricardo C Chebel
- Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610; Department of Animal Sciences, University of Florida, Gainesville 32610.
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Liu TC, Chiang CF, Ho CT, Chan JPW. Effect of GnRH on ovulatory response after luteolysis induced by two low doses of PGF2α in lactating dairy cows. Theriogenology 2017; 105:45-50. [PMID: 28923705 DOI: 10.1016/j.theriogenology.2017.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 11/19/2022]
Abstract
This study investigated the effect of gonadotropin-releasing hormone (GnRH) on ovulatory response after complete luteolysis induced by two low doses of prostaglandin (PG)F2α in lactating dairy cows. Cows (n = 18) ranging between 45 and 65 days in milk were recruited for synchronization by a modified Ovsynch-48 protocol (GnRH-7 days-375 μg PGF2α-1 day-250 μg of PGF2α-1 day-GnRH) over a total of 23 estrous cycles. Synchronized cows (n = 16) were randomly assigned to GnRH and Saline groups in stage 1 of the experiment after 9-10 days of ovulation in synchronization. On days 0 and 1 (day 0 = first PGF2α administration), cows were treated with 375 and 250 μg PGF2α, respectively. On day 2, cows in the GnRH and Saline groups were administered 250 μg GnRH or 2.5 mL of 0.9% saline, respectively. Serum progesterone (P4) levels were measured and changes in the corpus luteum (CL) were ultrasonically monitored daily from day 0-3 to assess complete luteolysis. Preovulatory follicle diameter and ovulatory response were evaluated by ultrasonography. In stage 2, cows were treated in a manner converse to that in stage 1. The synchronization rate was 69.6% (16/23). In stages 1 and 2, cows showed complete luteolysis with P4 concentration <1 ng/mL or remaining CL area <50%. Average ovulation time was 29.3 ± 0.5 h, which mostly occurred between 28 and 30 h after GnRH injection. However, all cows in the Saline group ovulated later than 36 h post-injection, with an average time of 52.7 ± 8.6 h. There was no difference in preovulatory follicle diameter between the two groups (16.8 ± 0.5 and 17.3 ± 0.5 mm for GnRH and saline groups, respectively). Although ovulation rate was not correlated with treatment, the rate within 48 h of GnRH injection (93.3%) tended to be higher compared with that in the Saline group (60.0%). Thus, GnRH administration increased ovulation rate following complete luteolysis induced by two low doses of PGF2α. These results indicate that this simple protocol for dairy cows is an effective alternative to timed artificial insemination programs in the field.
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Affiliation(s)
- Tsung-Ching Liu
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chen-Fei Chiang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chia-Tang Ho
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Jacky Peng-Wen Chan
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan.
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Garcia-Muñoz A, Valldecabres-Torres X, Newcombe JR, Cuervo-Arango J, Garcia-Rosello E. Effect of exogenous progesterone administration on luteal sensitivity to PGF during the early development of the corpus luteum in mares and cows. Reprod Domest Anim 2017; 52:1074-1080. [DOI: 10.1111/rda.13029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/14/2017] [Indexed: 11/28/2022]
Affiliation(s)
- A Garcia-Muñoz
- Departamento de Producción y Sanidad Animal; Facultad de Veterinaria (Grupo de Investigación Fisiopatología de la Reproducción); Universidad CEU Cardenal Herrera; Valencia Spain
| | | | - JR Newcombe
- Warren House Farm; Equine Fertility Clinic; Brownhills West Midlands UK
| | - J Cuervo-Arango
- Department of Equine Sciences; Faculty of Veterinary Medicine; Utrecht University; Utrecht The Netherlands
| | - E Garcia-Rosello
- Departamento de Medicina y Cirugía Animal; Facultad de Veterinaria (Grupo de Investigación Fisiopatología de la Reproducción); Universidad CEU Cardenal Herrera; Valencia Spain
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Viana J, Vargas M, Siqueira L, Camargo L, Figueiredo A, Fernandes C, Palhao M. Efficacy of induction of luteolysis in superovulated cows is dependent on time of prostaglandin F2alpha analog treatment: effects on plasma progesterone and luteinizing hormone profiles. Theriogenology 2016; 86:934-939. [DOI: 10.1016/j.theriogenology.2016.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 12/23/2015] [Accepted: 03/11/2016] [Indexed: 11/25/2022]
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Ferraz Junior MVC, Pires AV, Biehl MV, Santos MH, Polizel DM, Nepomuceno DD, Sartori R, Barreto Filho JB, Gonçalves JRS, Day ML. Luteolysis in Bos indicus cows on Days 5 and 7 of estrous cycle with varying doses of PGF2α. Theriogenology 2016; 86:1268-74. [DOI: 10.1016/j.theriogenology.2016.04.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 04/14/2016] [Accepted: 04/18/2016] [Indexed: 10/21/2022]
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López-Gatius F, López-Helguera I, De Rensis F, Garcia-Ispierto I. Effects of different five-day progesterone-based synchronization protocols on the estrous response and follicular/luteal dynamics in dairy cows. J Reprod Dev 2015. [PMID: 26211922 PMCID: PMC4623153 DOI: 10.1262/jrd.2015-053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study compared the responses shown by lactating dairy cows to four different P4-based protocols for AI at estrus. Cows with no estrous signs 96 h after progesterone intravaginal device (PRID) removal were subjected to fixed-time AI (FTAI), and their data were also included in the study. In Experiment I, follicular/luteal and endometrial dynamics were assessed every 12 h from the beginning of treatment until AI. The estrous response was examined in Experiment II, and fertility was assessed in both experiments. The protocols consisted of a PRID fitted for five days, along with the administration of different combinations of gonadotropin releasing hormone (GnRH), equine chorionic gonadotropin and a single or double dose (24 h apart) of prostaglandin F2α. In Experiment I (40 cows), animals receiving GnRH at the start of treatment showed a significantly higher ovulation rate during the PRID insertion period while estrus was delayed. In Experiment II (351 cows), according to the odds ratios, cows showing luteal activity at the time of treatment were less likely to show estrus than cows with no signs of luteal activity. Treatment affected the estrous response and the interval from PRID removal to estrus but did not affect conception rates 28-34 days post AI. Primiparous cows displayed a better estrous response than multiparous cows. Our findings reveal acceptable results of 5-day P4-based protocols for AI at estrus in high-producing dairy cows. Time from treatment to estrus emerged as a good guide for FTAI after a 5-day P4-based synchronization protocol.
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Valldecabres-Torres X, Larrosa-Morales P, Cuervo-Arango J. The effect of dose and type of cloprostenol on the luteolytic response of dairy cattle during the Ovsynch protocol under different oestrous cycle and physiological characteristics. Reprod Domest Anim 2013; 48:874-80. [PMID: 23691976 DOI: 10.1111/rda.12178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/08/2013] [Indexed: 11/27/2022]
Abstract
The objective of this study was to characterize the effect of dose and type of cloprostenol (CLO) on the luteolytic response of dairy cattle during the Ovsynch protocol under different oestrus cycle and physiological characteristics. Twelve non-lactating dairy cows and 111 lactating dairy cows were used in three experiments. In Experiment I, cows were synchronized so that they had only a 5.5- to 6-day-old corpus luteum (CL) at the time of the prostaglandin F2α (PGF2α ) treatment of Ovsynch. In Experiment II, cows were synchronized so that they had at least a CL of approximately 14 days old at the time of PGF2α treatment and an accessory CL if they had responded to the first GnRH of Ovsynch. Furthermore, in each experiment, cows received either a standard or a double dose of d-CLO as the luteolytic treatment. In Experiment III, lactating cows were blocked by parity and assigned to one of three luteolytic treatments during Ovsynch: 500 μg d,l-CLO, 150 or 300 μg of d-CLO. In Experiment I, the dose of d-CLO had an effect (p = 0.08) on the percentage of cows with full luteolysis, but not in Experiment II (p > 0.1). More cows in Experiment II had full luteolysis than did cows of Experiment I (87% vs 58%, respectively; p = 0.007). In Experiment III, 87.1%, 84.4% and 86.2% lactating dairy cows had full luteolysis and 37.8%, 36.8% and 36.1% of cows became pregnant after treatment with 500 μg d,l-CLO, 150 or 300 μg of d-CLO, respectively (p > 0.05).
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Affiliation(s)
- X Valldecabres-Torres
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Moncada, Spain
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Valldecabres-Torres X, García-Muñoz A, García-Roselló E, Cuervo-Arango J. Use of a split or single prostaglandin F2α treatment in a 6-day synchronization protocol for nonlactating dairy cows. J Dairy Sci 2013; 96:1647-52. [DOI: 10.3168/jds.2012-6083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 11/09/2012] [Indexed: 11/19/2022]
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