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Cattaneo L, Prieto C, Ojeda D, Pereira A, Frutos J, Bó GA. The use of a recombinant equine chorionic gonadotropin (reCG) in fixed-time AI programs in beef cattle. Theriogenology 2024; 227:77-83. [PMID: 39029411 DOI: 10.1016/j.theriogenology.2024.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/04/2024] [Accepted: 07/11/2024] [Indexed: 07/21/2024]
Abstract
The aim of the current study was to evaluate the effect of a novel recombinant eCG (reCG) on pregnancy rates to AI (P/AI) in suckled beef cows of different breeds that were synchronized with an estradiol/progesterone (P4)-based protocol for fixed-time AI (TAI). In experiment 1, 1244 Bos taurus suckled cows were used. On Day 0 all cows received an intravaginal P4 device (600 mg P4) and 2 mg of estradiol benzoate. On Day 7, devices were removed, and all cows received 0.150 mg of D-cloprostenol plus 1 mg of estradiol cypionate and were randomly divided to receive 140 IU or 105 IU of reCG or no reCG treatment (controls) at that time. Cows were tail painted for estrus detection and those in estrus by 48 h after P4 device removal were inseminated; whereas those not showing estrus were also inseminated and received GnRH at the same time. In experiment 2, 818 Bos taurus x Bos indicus crossbred suckled cows received the same FTAI protocol used in Experiment 1. Cows were randomly divided at the time of P4 device removal into 4 groups to receive 140 IU, 105 IU or 84 IU of reCG or no reCG treatment. In experiment 3, 345 Bos indicus suckled cows were submitted to the same FTAI protocol as those in previous experiments and were randomly divided into three groups to receive 140 IU or 105 IU of reCG, or 300 IU of serum derived eCG (PMSG). In Experiment 1, estrus rate and P/AI was greater (P < 0.05) in cows treated with reCG (79.9 and 53.5 %, 76.9 and 52.3 % for the 105 UI and 140 UI reCG groups, respectively) than those in the control group (69.9 and 44.4 %, respectively). In Experiment 2, cows treated with reCG tended (P < 0.1) to achieve a greater P/AI than control cows (38.6 %, 37.1 %, 36.2 % and 28.2 % for those receiving 84 IU, 105 IU,140 IU of reCG, and those in the control group); but when P/AI of all cows treated with reCG was contrasted to that of control cows, the difference was significant (P < 0.01). In Experiment 3, P/AI in cows treated with 84 IU of reCG (54 %) did not differ from that of cows treated with serum derived eCG (59 %) but both were greater (P < 0.05) than cows treated with 105 UI of reCG (41 %). In conclusion, treatment with reCG improved fertility in suckled Bos taurus and Bos taurus x Bos indicus beef cows. In suckled Bos indicus cows, although treatment with reCG and serum derived eCG were comparable, the higher dosage of reCG was detrimental to their P/AI.
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Affiliation(s)
- Luciano Cattaneo
- Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Esperanza, Santa Fe, Argentina; CEVA-ZOOVET S.A., Santa Fe, Argentina
| | - Claudio Prieto
- CEVA-Biotecnofe S.A., Santa Fe, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Centro Biotecnológico del Litoral, Laboratorio de Desarrollo Biotecnológico, Ciudad Santa Fe, Argentina
| | | | | | | | - Gabriel A Bó
- Instituto de Reproducción Animal Córdoba (IRAC), Córdoba, Argentina; Instituto A.P. de Ciencias Básicas y Aplicadas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa del Rosario, Córdoba, Argentina.
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Samir H, El-Sherbiny HR, Ahmed AE, Ahmad Sindi R, Al Syaad KM, Abdelnaby EA. Administration of Estradiol Benzoate Enhances Ovarian and Uterine Hemodynamics in Postpartum Dairy Buffaloes. Animals (Basel) 2023; 13:2340. [PMID: 37508117 PMCID: PMC10376374 DOI: 10.3390/ani13142340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 07/30/2023] Open
Abstract
The postpartum (PP) period is a crucial stage for the resumption of reproductive performance and ovarian cyclicity in dairy buffaloes. The present study aimed, for the first time, to assess the effect of the administration of estradiol benzoate (EB) on ovarian and uterine hemodynamics in PP dairy buffaloes. Eight pluriparous acyclic domestic buffaloes were enrolled in the present experiment and received a dose of 10 mg of estradiol benzoate (EB) intramuscularly 4 weeks after parturition. All animals were examined two times before EB administration (days -3, and -1) and on the day of EB administration (day 0), followed by examinations on days 1, 3, 5, 7, and 9 post-EB administration. The middle uterine artery (MUA) and ovarian artery (OA) blood flow patterns were assessed using a color Doppler ultrasound device. The reproductive parameters were (1) the cross-sectional diameters (cm) of the OA and MUA, (2) cranial uterine horn thickness (UHT; cm), and (3) hemodynamic changes within the MUA on both the ipsi- and contra-lateral sides of the previous pregnant horn and within the OA corresponding to the ovarian tissues. The examined blood flow parameters were the pulsatility index (PI), resistance index (RI), peak systolic/end-diastolic ratio (S/D), time-averaged maximum velocity (TAV; cm/s), uterine blood flow rate (BFR; bpm), and uterine blood flow volume (BFV; mL/min). Concomitantly, blood samples were collected from the coccygeal vein, and the sera were stored at -18 °C for use in estradiol (E2-17β) and nitric oxide (NO) assays. The results revealed increases in both OA and MUA cross-sectional diameter (cm) on the ipsi-lateral and contra-lateral (p < 0.05) sides within 24 h until day 9 post-treatment. The values of the RI and PI of blood flow within the OA and MUA on the ipsi-lateral and contra-lateral sides of the previous pregnancy were obviously lower (p < 0.05) at 24 h after the administration of EB, and then, started to gradually elevate, reaching the pre-treatment values on day 9 after EB administration. Both the BFR and BFV in the OA and MUA significantly increased from 24 h to 72 h after EB administration on both the ipsi-lateral and contra-lateral sides (p < 0.05); then, their values started to decrease to reach the pretreatment value on day 9 after EB administration. Both E2 and NO concentrations significantly increased (p < 0.05) from 24 h until day 3 after EB injection and then started to decline after that, reaching the pre-treatment value on day 9. In conclusion, the administration of EB enhances the ovarian and uterine blood flow concomitantly with increased levels of NO in PP dairy buffaloes.
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Affiliation(s)
- Haney Samir
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Hossam R El-Sherbiny
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Ahmed Ezzat Ahmed
- Biology Department, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Ramya Ahmad Sindi
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah Al-Mukarramah 24382, Saudi Arabia
| | - Khalid M Al Syaad
- Biology Department, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Elshymaa A Abdelnaby
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
- Department of Clinical Sciences, College of Veterinary Medicine, King Faisal University, Alahsa 31982, Saudi Arabia
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Horn EJ, Read CC, Edwards JL, Schrick FN, Rhinehart JD, Payton RR, Campagna SR, Klabnik JL, Clark HM, Myer PR, McLean KJ, Moorey SE. Preovulatory follicular fluid and serum metabolome profiles in lactating beef cows with thin, moderate, and obese body condition. J Anim Sci 2022; 100:skac152. [PMID: 35772755 PMCID: PMC9246665 DOI: 10.1093/jas/skac152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/25/2022] [Indexed: 12/20/2022] Open
Abstract
Extremes in body condition reduce fertility and overall productivity in beef cattle herds, due in part to altered systemic metabolic conditions that influence the intrafollicular and uterine environment. Follicular fluid and serum metabolome profiles are influenced by body composition in women and dairy cattle; however, such information is lacking in beef cattle. We hypothesized that body condition score (BCS)-related alterations in the metabolome of preovulatory follicular fluid and serum may influence oocyte maturation while impacting the oviductal or uterine environment. Therefore, we performed a study with the objective to determine the relationship between BCS and the metabolome of follicular fluid and serum in lactating beef cattle. We synchronized the development of a preovulatory follicle in 130 cows of varying BCS. We collected blood and performed transvaginal follicle aspirations to collect follicular fluid from the preovulatory follicle ~18 h after gonadotropin-releasing hormone administration to stimulate the preovulatory gonadotropin surge. We then selected follicular fluid and serum samples from cows with BCS 4 (Thin; n = 14), BCS 6 (Moderate; n = 18), or BCS >8 (Obese; n = 14) for ultra-high performance liquid chromatography-high resolution mass spectrometry. We identified differences in the follicular fluid or serum of thin, moderate, and obese animals based on multiple linear regression. MetaboAnalyst 5.0 was used for enrichment analysis of significant metabolites. We identified 38 metabolites in follicular fluid and 49 metabolites in serum. There were no significant differences in follicular fluid metabolite content among BCS classifications. There were 5, 22, and 1 serum metabolites differentially abundant between thin-obese, moderate-thin, and moderate-obese classifications, respectively (false discovery rate [FDR] < 0.10). These metabolites were enriched in multiple processes including "arginine biosynthesis," "arginine/proline metabolism," and "D-glutamine/D-glutamate metabolism" (FDR < 0.04). Pathways enriched with serum metabolites associated with BCS indicate potentially increased reactive oxygen species (ROS) in serum of thin cows. ROS crossing the blood follicular barrier may negatively impact the oocyte during oocyte maturation and contribute to the reduced pregnancy rates observed in thin beef cows.
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Affiliation(s)
- Emma J Horn
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Casey C Read
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - J Lannett Edwards
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - F Neal Schrick
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Justin D Rhinehart
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Rebecca R Payton
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Shawn R Campagna
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA
| | - Jessica L Klabnik
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Hannah M Clark
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Phillip R Myer
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Kyle J McLean
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Sarah E Moorey
- Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA
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Dysart LM, Messman RD, Crouse AA, Lemley CO, Larson JE. Effects of administration of exogenous estradiol benzoate on follicular, luteal, and uterine hemodynamics in beef cows. Anim Reprod Sci 2021; 232:106817. [PMID: 34329917 DOI: 10.1016/j.anireprosci.2021.106817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 10/20/2022]
Abstract
Objectives of these two experiments were to determine if exogenous estradiol benzoate (EB) affects follicular, luteal, and uterine hemodynamics. In both experiments, 77 estrous-synchronized beef cows were assigned to one of two treatments: 1) Control (CON) or, 2) an injection of 1 mg EB the day before expected estrus (Day 0; Experiment 1) or on the day of estrus (Day 1; Experiment 2). There was transfer of an embryo (Day 7) into cows that expressed estrus. In Experiment 1, estradiol concentrations in circulation at Day 0 were greater in EB-treated cows (P = 0.003); however, concentrations of progesterone were only greater (P = 0.03) at Day 21 in cows of the EB-treated compared to those in the CON group. The follicular and luteal blood perfusion was similar, however, treatment with EB resulted in a greater uterine blood perfusion. In Experiment 2, treatment with EB did not affect size or blood perfusion of the corpus luteum (CL) on Day 7, 14, and 21. Only on Day 21, however, did pregnant cows have a larger CL than non-pregnant cows (P = 0.02). Blood perfusion to the CL was greater (P < 0.05) in all cows on Day 21 compared to 7 or 14 and those determined to be pregnant on Day 35 tended (P = 0.06) to have greater CL blood perfusion only on Day 21 compared to non-pregnant cows. In conclusion, EB treatment resulted in a greater blood perfusion of the uterus, and only affected the CL on Day 21 in Experiment 2.
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Affiliation(s)
- Lacey M Dysart
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Riley D Messman
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Abigail A Crouse
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Caleb O Lemley
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA
| | - Jamie E Larson
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
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Ciernia LA, Perry GA, Smith MF, Rich JJ, Northrop EJ, Perkins SD, Green JA, Zezeski AL, Geary TW. Effect of estradiol preceding and progesterone subsequent to ovulation on proportion of postpartum beef cows pregnant. Anim Reprod Sci 2021; 227:106723. [PMID: 33621845 DOI: 10.1016/j.anireprosci.2021.106723] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 11/29/2022]
Abstract
Two experiments were conducted to examine the effect of plasma concentrations of 17β-estradiol (E2) preceding and progesterone (P4) subsequent to ovulation on proportions of beef cows pregnant following embryo transfer. Timing of ovulation (d 0) among postpartum cows was synchronized and cows that expressed estrus were removed from each study. In Experiment 1, plasma E2 concentration on d 0 was used to classify cows (n = 353) into Low, Medium, and High E2 groups. Pregnancy rate for cows with Low, Medium, or High E2 concentrations were different (P < 0.05). In Experiment 2, there were multiple administrations of PGF2α to evaluate the independent effects of Low or High E2 before ovulation and Low or Normal (no treatment) P4 after ovulation on proportions of cows pregnant. Treatment groups in Experiment 2, therefore, were: Low E2-Low P4 (LL; n = 71), Low E2-Normal P4 (LN; n = 69), High E2-Low P4 (HL; n = 74), and High E2-Normal P4 (HN; n = 73). Concentrations of P4 on d 7 subsequent to ovulation were less (P < 0.05) in cows of the HL compared to HN, and in LL compared to LN groups. Concentrations of E2 on d -2, 0, and change in E2 (d -2 to d 0) had a positive effect (P < 0.008) on pregnancy rates. In summary, relatively greater E2 concentrations preceding ovulation; and relatively greater P4 concentrations subsequent to ovulation combined with lesser E2 concentrations preceding ovulation had a positive effect on proportions of postpartum cows pregnant.
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Affiliation(s)
| | - G A Perry
- South Dakota State University, Brookings, SD, USA
| | - M F Smith
- University of Missouri, Columbia, MO, USA
| | - J J Rich
- South Dakota State University, Brookings, SD, USA
| | - E J Northrop
- South Dakota State University, Brookings, SD, USA
| | - S D Perkins
- South Dakota State University, Brookings, SD, USA
| | - J A Green
- University of Missouri, Columbia, MO, USA
| | - A L Zezeski
- USDA-ARS, Fort Keogh Livestock and Range Research Lab, Miles City, MT, USA
| | - T W Geary
- USDA-ARS, Fort Keogh Livestock and Range Research Lab, Miles City, MT, USA.
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Cedeño AV, Cuervo R, Tríbulo A, Tríbulo R, Andrada S, Mapletoft R, Menchaca A, Bó GA. Effect of expression of estrus and treatment with GnRH on pregnancies per AI in beef cattle synchronized with an estradiol/progesterone-based protocol. Theriogenology 2020; 161:294-300. [PMID: 33370598 DOI: 10.1016/j.theriogenology.2020.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Three experiments evaluated the effects of expression of estrus and gonadotropin releasing hormone (GnRH) treatment on pregnancies per AI (P/AI) in beef cattle that were treated with an estradiol/progesterone (P4)-based protocol for fixed-time artificial insemination (FTAI). In Experiment 1, 20 non-lactating beef cows were treated with 2 mg estradiol benzoate (EB) and an intravaginal device containing 0.5 g of P4. Seven days later, P4 devices were removed and all cows received prostaglandin F2 alpha (PGF2α) and 0.5 mg estradiol cypionate (ECP). Estrus was detected using tail paint and cows that did not show estrus by 48 h after P4 device removal were randomized to receive GnRH or no treatment. Ovulation, as determined by ultrasonography, occurred earlier in cows that showed estrus (68.0 ± 2.5 h) than in cows that did not (82.0 ± 2.1 h, P < 0.05). Furthermore, cows that received GnRH ovulated earlier (78.0 ± 2.6 h) than those that did not (86.0 ± 2.0, P < 0.05). Experiment 2 determined whether expression of estrus and the administration of GnRH to animals that did not show estrus increased P/AI. Non-lactating beef cows and heifers (n = 1356) were treated as in Experiment 1 (P4 device removal, PGF2α and ECP administration on Day 7) or extended until Day 8. All animals in estrus by 48 h after P4 device removal were inseminated and those not showing estrus received GnRH or no treatment and were FTAI 8 h later (i.e., at 56 h). P/AI were greater (P < 0.01) in animals that were observed in estrus by 48 h (56.4%) than in those that did not show estrus (46.5%). Likewise, animals that did not show estrus but were treated with GnRH had greater P/AI (53.8%, P < 0.04) than those that did not receive GnRH (37.9%). Experiment 3 was designed to determine the effect of delaying GnRH treatment to the time of FTAI (at 56 h) in cows not showing estrus by 48 h after P4 device removal. Suckled beef cows (n = 969) were treated as in Experiment 1, except that all cows also received 400 IU of eCG at the time of P4 device removal on Day 7. Cows that showed estrus by 48 h or 56 h had greater P/AI (62.3%, P < 0.05) than those did not show estrus (51.5%). Furthermore, when cows that did not show estrus by 48 h were analyzed separately, P/AI were greater (P < 0.05) in those that received GnRH at 48 h and were FTAI by 56 h (64.9%) than in those that received GnRH concurrent with FTAI by 56 h after device removal (54.6%). In summary, expression of estrus was associated with earlier ovulations and resulted in greater P/AI in cows and heifers treated with an estradiol/P4-based protocol for FTAI. Furthermore, GnRH treatment in animals that did not show estrus hastened the time of ovulation and increased P/AI.
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Affiliation(s)
- Andrés V Cedeño
- Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, 5145, Córdoba, Argentina; Maestría en Reproducción Bovina, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Argentina; Laboratorio de Biotecnología de La Reproducción Animal, Medicina Veterinaria, Escuela Superior Politécnica Agropecuaria de Manabí Manuel Félix López (ESPAM-MFL) Bolívar, Manabí, Ecuador
| | - Rodrigo Cuervo
- Maestría en Reproducción Bovina, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Argentina; Instituto de Ciencias Básicas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa Del Rosario, Córdoba, Argentina
| | - Andrés Tríbulo
- Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, 5145, Córdoba, Argentina
| | - Ricardo Tríbulo
- Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, 5145, Córdoba, Argentina
| | - Salvador Andrada
- Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, 5145, Córdoba, Argentina
| | - Reuben Mapletoft
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Alejo Menchaca
- Instituto de Reproducción Animal de Uruguay, IRAUy, Montevideo, Uruguay
| | - Gabriel A Bó
- Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, 5145, Córdoba, Argentina; Maestría en Reproducción Bovina, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Argentina; Instituto de Ciencias Básicas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa Del Rosario, Córdoba, Argentina.
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Núñez-Olivera R, Cuadro F, Menchaca A. Is prostaglandin F2α administration at the beginning of a progesterone and estradiol-based treatment for FTAI an effective strategy in Bos taurus heifers? Anim Reprod Sci 2019; 210:106201. [PMID: 31635780 DOI: 10.1016/j.anireprosci.2019.106201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/15/2019] [Accepted: 10/03/2019] [Indexed: 11/30/2022]
Abstract
The objective was to evaluate effects of prostaglandin (PG) F2α administration at the beginning of a progesterone and estradiol-based treatment period on ovarian response and pregnancy rate (P/AI) in Bos taurus beef heifers. Heifers were treated with 500 μg of cloprostenol administered: a) in two half-doses (250 μg) at the time of progesterone device insertion and removal (two-PG), or b) in a single dose at the time of device removal (one-PG). In the two-PG group, administration of PG at device insertion resulted in lesser serum progesterone concentrations during the 7-d treatment period (P < 0.05). Additionally, diameter of the follicle from which ovulation occurred was greater, and ovulation occurred earlier in the two-PG compared with one-PG group (P < 0.05). Fixed-time artificial insemination (FTAI) was performed in 3479 heifers with two times for FTAI (48 compared with 54 h from device removal). There was no effect on P/AI percentage for the PG treatment or the time of FTAI. The FTAI at 54 h resulted in a greater P/AI percentage in the one-PG than two-PG group (70.5%, 253/359 and 63.5%, 254/400, respectively; P < 0.05). There were no differences between PG treatments when FTAI was performed at 48 h after device removal. In conclusion, the administration of PG at the time of intravaginal progesterone device insertion results in lesser progesterone concentrations, and an increased size of the follicle from which ovulation occurs, and the time of ovulation is earlier after device removal. The pregnancy rate was not affected by the PG administration at the time of device insertion.
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Affiliation(s)
- Richard Núñez-Olivera
- Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Montevideo, Uruguay; Programa de Posgrado de la Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | - Federico Cuadro
- Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Montevideo, Uruguay; Programa de Posgrado de la Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | - Alejo Menchaca
- Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Montevideo, Uruguay; Programa de Posgrado de la Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay.
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Cox JF, Navarrete F, Carrasco A, Dorado J, Saravia F. Effect of bST administration on plasma concentrations of IGF-I and follicular dynamics and ovulation during the interovulatory cycle of sheep and goats. Theriogenology 2018; 123:159-166. [PMID: 30308392 DOI: 10.1016/j.theriogenology.2018.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 12/29/2022]
Abstract
This study used a comparative approach to gather clinical information to assess the effect of bovine somatotropin (bST) on follicular dynamics and ovulation in sheep and goats during an interovulatory cycle. The performance of general markers of ovarian function and specific features of follicular dynamics obtained by daily ultrasonography (US) were used to assess the hypothesis that bST, associated with supraphysiological levels of IGF-I, was able to disrupt the follicular dynamics and ovulation in Highlander ewes and Saanen goats. In Exp 1, 15 ewes and 14 goats were estrous-synchronized (P4-6 days + PGFα d-6) and then allocated to a bST-treated group (50 and 100 mg, Lactotropin®; n = 5 females each) and to an untreated control group (5 ewes and 4 goats) to assess the activity of bST through plasma IGF-I (RIA). In Exp 2, 12 animals from each species were synchronized. At day 6, they were divided into a bST-group (100 mg in sheep and 50 mg in goats, n = 6 each) and an untreated control group (n = 6 each). Starting at day 6 and up to 22 days after ovulation in sheep and 25 days in goats, each female was subjected to daily US (10 mHz probe) to assess follicular and luteal (CL) dynamics and ovulation. This included assessments of both general ovarian features and specific follicular wave features. Our results showed that bST increased plasma IGF-I by day 3 (p < 0.01) when compared to the control group. Moreover, these concentrations were maintained for at least 10 days in sheep and 10 days in goats before returning to pre-treatment concentrations. Increases in IGF-I after bST doses were similar in terms of a daily and total amount (P > 0.10). Results from Exp.2 indicate that in sheep, bST administration had a subtle inhibitory effect on follicular function. However, bST in goats had a stronger influence, extending the interovulatory cycle (P = 0,034), increasing the number of follicular waves during the period (P = 0.003), and reducing the functional potential of large follicles as measured by their lower follicular diameter (P = 0.02), duration of the follicle waves (P = 0.02), and persistence of follicles after reaching their maximum diameters (P = 0.04). In addition, untreated sheep and goats shared common patterns of terminal follicular development and ovulations characterized by overlapping between follicular waves and ovulations of follicles from different waves, features not seen in cattle.
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Affiliation(s)
- J F Cox
- Department of Animal Science, Faculty of Veterinary Sciences, Universidad de Concepción, Avda. Vicente Méndez 595, Chillán, Chile.
| | - F Navarrete
- Department of Animal Science, Faculty of Veterinary Sciences, Universidad de Concepción, Avda. Vicente Méndez 595, Chillán, Chile
| | - A Carrasco
- Department of Animal Science, Faculty of Veterinary Sciences, Universidad de Concepción, Avda. Vicente Méndez 595, Chillán, Chile
| | - J Dorado
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universidad de Córdoba, Spain
| | - F Saravia
- Department of Animal Science, Faculty of Veterinary Sciences, Universidad de Concepción, Avda. Vicente Méndez 595, Chillán, Chile
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