1
|
Gonçalves JD, Dias JH, Machado-Neves M, Vergani GB, Ahmadi B, Pereira Batista RIT, Souza-Fabjan JMG, Oliveira MEF, Bartlewski PM, da Fonseca JF. Transcervical uterine flushing and embryo transfer in sheep: Morphophysiological basis for approaches currently used, major challenges, potential improvements, and new directions (alas, including some old ideas). Reprod Biol 2024; 24:100920. [PMID: 38970979 DOI: 10.1016/j.repbio.2024.100920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/31/2024] [Accepted: 06/20/2024] [Indexed: 07/08/2024]
Abstract
At present, the success of non-surgical embryo recovery (NSER) and transfer (NSET) hinges upon the cervical passage of catheters, but penetration of the uterine cervix in ewes is problematic due to its anatomical structure (i.e., long and narrow cervical lumen with misaligned folds and rings). It is a major obstacle limiting the widespread application of NSER and NSET in sheep. While initial attempts to traverse the uterine cervix focused on adapting or re-designing insemination catheters, more recent studies demonstrated that cervical relaxation protocols were instrumental for transcervical penetration in the ewe. An application of such protocols more than tripled cervical penetration rates (currently at 90-95 %) in sheep of different breeds (e.g., Dorper, Lacaune, Santa Inês, crossbred, and indigenous Brazilian breeds) and ages/parity. There is now sufficient evidence to suggest that even repeatedly performed cervical passages do not adversely affect overall health and reproductive function of ewes. Despite these improvements, appropriate selection of donors and recipients remains one of the most important requirements for maintaining high success rates of NSER and NSET, respectively. Non-surgical ovine embryo recovery has gradually become a commercially viable method as even though the procedure still cannot be performed by untrained individuals, it is inexpensive, yields satisfactory results, and complies with current public expectations of animal welfare standards. This article reviews critical morphophysiological aspects of transcervical embryo flushing and transfer, and the prospect of both techniques to replace surgical methods for multiple ovulation and embryo transfer (MOET) programs in sheep. We have also discussed some potential pharmacological and technical developments in the field of non-invasive embryo recovery and deposition.
Collapse
Affiliation(s)
- Joedson Dantas Gonçalves
- Department of Pathology, Reproduction and One Health, School of Agricultural and Veterinarian Sciences, São Paulo State University, Via de acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Jenniffer Hauschildt Dias
- Department of Veterinary Medicine, Federal University of Viçosa, Av. Peter Henry Rolfs, s/n, CEP 36570-000 Viçosa, MG, Brazil
| | - Mariana Machado-Neves
- Department of Veterinary Medicine, Federal University of Viçosa, Av. Peter Henry Rolfs, s/n, CEP 36570-000 Viçosa, MG, Brazil
| | - Gabriel Brun Vergani
- Department of Pathology, Reproduction and One Health, School of Agricultural and Veterinarian Sciences, São Paulo State University, Via de acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Bahareh Ahmadi
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | | | | - Maria Emilia Franco Oliveira
- Department of Pathology, Reproduction and One Health, School of Agricultural and Veterinarian Sciences, São Paulo State University, Via de acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Pawel Mieczyslaw Bartlewski
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | |
Collapse
|
2
|
Souza-Fabjan JMG, Oliveira MEF, Guimarães MPP, Brandão FZ, Bartlewski PM, Fonseca JF. Review: Non-surgical artificial insemination and embryo recovery as safe tools for genetic preservation in small ruminants. Animal 2023; 17 Suppl 1:100787. [PMID: 37567658 DOI: 10.1016/j.animal.2023.100787] [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: 10/03/2022] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 08/13/2023] Open
Abstract
Artificial insemination (AI) and in vivo embryo production (or multiple ovulation and embryo transfer, MOET) programs are both instrumental in accelerating the propagation of genetically and economically superior goats and sheep. The aim of this review was to present the current gestalt of non-surgical AI and embryo recovery (NSER) procedures in small ruminants. Small body size, precluding rectal palpation, and highly limited penetrability of the uterine cervix in ewes are the major reasons for the scarce use of non-surgical assisted reproduction techniques in this species. As a result, AI and embryo recovery techniques in sheep mainly involve laparoscopy or laparotomy (LAP). In does, however, the Embrapa method of AI allows for successful intrauterine deposition of semen, resulting in pregnancy rates from 50 to 80% under field conditions (>3 000 goats inseminated) when frozen-thawed semen is used. After the administration of prostaglandin F2α (PGF2α), non-surgical (transcervical) embryo recovery is also feasible in goats, with the cervical penetration rate approaching 100%. There is a paucity of information on the efficacy of non-surgical AI using frozen semen in sheep, but the results are satisfactory with fresh, cooled, or chilled ram semen. An application of the NSER technique in ewes has greatly improved over the last decade, and cervical penetration rates of ∼90% can be achieved when a hormonal cervical dilation protocol using PGF2α, oxytocin, and/or estradiol ester (e.g., estradiol benzoate) is applied. In some genotypes of sheep, sufficient cervical dilation can be induced without estradiol ester included in the protocol. Several studies indicated that recovery of transferable quality ovine embryos using NSER is comparable to that employing a ventral midline laparotomy, and NSER is evidently a method of choice when animal welfare is concerned. Considering both the number of retrievable embryos and animal well-being, the NSER is a viable alternative for surgical procedures. With further developments, it has the makings of a primary, if not exclusive, embryo recovery technique in small ruminants worldwide.
Collapse
Affiliation(s)
- J M G Souza-Fabjan
- Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Cep 24230-340, Niterói, RJ, Brazil.
| | - M E F Oliveira
- Departamento de Patologia, Reprodução e Saúde Única, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane, s/n, Cep 14884-900 Jaboticabal, SP, Brazil
| | - M P P Guimarães
- Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Cep 24230-340, Niterói, RJ, Brazil
| | - F Z Brandão
- Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Cep 24230-340, Niterói, RJ, Brazil
| | - P M Bartlewski
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, ON N1G 2W1, Canada
| | - J F Fonseca
- Embrapa Caprinos e Ovinos, Rodovia MG 133, Km 42, Cep 36155000, Coronel Pacheco, MG, Brazil
| |
Collapse
|
3
|
Figueira LM, Alves NG, Souza-Fabjan JMG, Vergani GB, Oliveira MEF, de Lima RR, Fonseca JF. Ultrasonographic cervical evaluation: A tool to select ewes for non-surgical embryo recovery. Reprod Domest Anim 2020; 55:1638-1645. [PMID: 32959440 DOI: 10.1111/rda.13825] [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: 06/22/2020] [Accepted: 09/09/2020] [Indexed: 11/27/2022]
Abstract
This study assessed the cervical ultrasonography mapping as a tool to select donor ewes for non-surgical embryo recovery (NSER). Lacaune ewes had their cervix evaluated by ultrasonography 12 hr after induced oestrus onset (Trial 1, n = 24) or 30 min before NSER (Trial 2, n = 17). Cervical rings were longitudinally evaluated and classified by their degree of misalignment on ultrasonography (DMUS) into: DMUS-1-cervix rectilinear, DMUS-2-intermediate and DMUS-3-highly asymmetrical. For predicting cervical transposing, only DMUS-1 and DMUS-2 were considered suitable. Similar ranking was attributed to degree of misalignment on the cervical map (DMCM 1-3), established immediately before NSER, which was performed at days 6 to 7 after oestrus. In Trial 1, cervical retraction for NSER was not possible only in three ewes classified as DMUS-3 (3/14, 21.4%). No difference (p > .05) was observed in the cervical transposing rates between ewes with different DMUS (ranged from 80% to 100%). In Trial 2, DMUS-1 and DMUS-2 reached 100% of transposing, and the only DMUS-3 ewe has not been transposed. In Trial 1, the prediction performance for successful cervical transposing showed low sensitivity (45%) and no specificity due to a high incidence of false negatives (52%). However, in Trial 2, sensitivity and specificity were both 100%. The DMCM and DMUS were uncorrelated, probably due to cervical stretching required to perform NSER. In conclusion, cervical ultrasound assessment immediately before NSER was more efficient to predict the cervical transposing than at induced oestrus, allowing the classification and selection of ewes eligible for NSER.
Collapse
Affiliation(s)
- Lucas Machado Figueira
- Universidade Federal de Lavras, Lavras, Brazil.,Universidade Federal Fluminense, Niterói, Brazil
| | | | | | | | - Maria Emilia Franco Oliveira
- Universidade Estadual Paulista "Júlio de Mesquita Filho", Jaboticabal, Brazil.,Embrapa Caprinos e Ovinos, Coronel Pacheco, Brazil
| | | | | |
Collapse
|
4
|
Padilha-Nakaghi LC, Uscategui RAR, Oliveira MEF, Nociti RP, Macente BI, Coutinho LN, Nakaghi EYO, Motta GA, Santos VJC, Maciel GS, Mariano RSG, Barros FFPC, Primo FL, Tedesco AC, Vicente WRR. Local α1-adrenergic blockers: An alternative for sheep cervix dilation? Anim Reprod Sci 2020; 222:106609. [PMID: 33002660 DOI: 10.1016/j.anireprosci.2020.106609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 11/29/2022]
Abstract
To facilitate transcervical artificial insemination in sheep, the effects of local treatment with α1-adrenergic receptor antagonists on cervix dilation and hemodynamics were evaluated. Ewes (n = 7) were subjected to oestrous synchronisation every 40 days and assigned to treatments in a Latin square experimental design (seven animals × seven periods) with a factorial treatment arrangement (A × B), Factors A (prazosin or tamsulosin) and B (1, 2, or 4 mg/animal). Ewes of the six treatment groups (P1, P2, P4, T1, T2, and T4) were administered α1-adrenergic receptor antagonists while those of the control group (CG) were administered only α1-adrenergic antagonist carrier agent. Distance that the transcervical catheter penetrated without cervical resistance, mean arterial pressure, and uterine artery dopplerfluxometry were evaluated before and after 30 min, 1, 2, 4, 8, and 10 h of treatment. Catheter penetration distance was greater in ewes of the T4 and P4 groups (P < 0.01), with there being a positive correlation between dose and distance (r = 0.243). The penetration distance was similar (P = 0.84) for treated groups, with the greatest penetration occurring 2, 4, and 6 h after treatment (P < 0.01). The passage into the uterine lumen was greater (P = 0.013) in ewes of the P4 (17.9 %) and T4 (19.6 %) groups. There were no effects on blood pressure or uterine blood flow (P> 0.05). These preliminary results indicate there are benefits of treatment with 4 mg/animal of tamsulosin or prazosin in catheter passage through the sheep cervix 2-6 h after administration without hemodynamic effects.
Collapse
Affiliation(s)
- Luciana C Padilha-Nakaghi
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil.
| | - Ricardo A R Uscategui
- Instituto de Ciências Agrarias, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Unaí, MG, Brazil
| | - Maria Emilia F Oliveira
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Ricardo P Nociti
- Departamento de Medicina Veterinária-ZMV, Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), Universidade de São Paulo (USP), SP, Brazil
| | - Beatrice I Macente
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Leandro N Coutinho
- Instituto da Saúde e Produção Animal (ISPA), Universidade Federal Rural da Amazônia (UFRA), Belém, PA, Brazil
| | - Eduardo Y O Nakaghi
- Coordenadoria de Defesa Agropecuária do Estado de São Paulo (CDA/SSA-SP), Jaboticabal, SP, Brazil
| | - Guilherme A Motta
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Victor J C Santos
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Giovanna S Maciel
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Renata S G Mariano
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| | - Felipe F P C Barros
- Departamento de Medicina e Cirurgia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - Fernando L Primo
- Departamento de Engenharia de Bioprocessos e Biotecnologia, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista (UNESP), Araraquara, SP, Brazil
| | - Antonio C Tedesco
- Departamento de Química, Laboratório de Fotobiologia e Fotomedicina, Centro de Nanotecnologia e Engenharia Tecidual, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de SãoPaulo (USP), Ribeirão Preto, SP, Brazil
| | - Wilter R R Vicente
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Cep 14884-900, Jaboticabal, SP, Brazil
| |
Collapse
|
5
|
Dos Santos VMB, Pinto PHN, Balaro MFA, Santos JDR, Taira AR, do Espirito Santo CG, Gonçalves FM, da Fonseca JF, Brandão FZ. Use of oxytocin to attain cervical dilation for transcervical embryo transfer in sheep. Reprod Domest Anim 2020; 55:1446-1454. [PMID: 32757343 DOI: 10.1111/rda.13795] [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: 03/10/2020] [Revised: 07/13/2020] [Accepted: 07/30/2020] [Indexed: 11/30/2022]
Abstract
The aim of this work was to determine whether a cervical dilation protocol (CDP) composed of only oxytocin can be used to perform transcervical (non-surgical) embryo transfer in sheep (NSET) without affecting the viability of the corpus luteum (CL). Likewise, we evaluated whether a cervical transposing test with a Hegar dilator (CT Hegar test), performed at oestrous time, could be used to screen ewes for NSET (greater or lower chances to transpose the cervix). For that, oestrous and ovulation synchronization was performed in 25 Santa Inês ewes to induce the dioestrous condition. Animals went through the following CDP in a crossover design: E + OX, oestradiol benzoate (100 µg intravenously [IV]) and oxytocin (100 IU IV); OX, oxytocin (100 IU IV); and SAL, saline solution (IV). Using a Hegar dilator, cervical transposing attempts were performed at oestrous (D0) and dioestrous time (D8). The viability of the CL (morphology, luteal blood flow and progesterone values) was evaluated by ultrasonography (colour Doppler and B-mode) and by serum progesterone measurement from D7 to D13. The cervical transposing rate was lower for the SAL group (64%; 16/25; p < .05) and did not differ between the E + OX (88%; 22/25, p > .05) and OX (84%; 21/25, p > .05) groups. No treatment affected the CL viability. The CT Hegar test showed a high sensitivity (85.7%-93.3%), satisfactory accuracy (72%-84%), low false-negative rate (6.7%-14.6%), but high false-positive rate (46%-66.7%). In conclusion, a CDP protocol composed exclusively of oxytocin can lead to good cervical transposing rates and does not affect the viability of the CL. In addition, a screening test (CT Hegar) performed at oestrus can identify ewes for which cervical transposing will likely not occur at NSET.
Collapse
Affiliation(s)
| | | | | | - Juliana D R Santos
- Faculdade de Veterinária, Universidade Federal Fluminense, Niterói, Brazil
| | - Augusto R Taira
- Faculdade de Veterinária, Universidade Federal Fluminense, Niterói, Brazil
| | | | | | | | - Felipe Z Brandão
- Faculdade de Veterinária, Universidade Federal Fluminense, Niterói, Brazil
| |
Collapse
|
6
|
Santos JDR, Ungerfeld R, Balaro MFA, Souza-Fabjan JMG, Cosentino IO, Brair VL, Souza CVD, Pinto PHN, Bade ALC, Fonseca JFD, Brandão FZ. Transcervical vs. laparotomy embryo collection in ewes: The effectiveness and welfare implications of each technique. Theriogenology 2020; 153:112-121. [PMID: 32450469 DOI: 10.1016/j.theriogenology.2020.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/27/2020] [Accepted: 05/02/2020] [Indexed: 11/25/2022]
Abstract
This study assessed animal welfare in ewes subjected to transcervical (TC) or laparotomy (LP) embryo collection, and the efficiency of these two techniques. Santa Inês ewes (n = 57) received a protocol for estrus synchronization and superovulation. Cervical dilation protocol was initiated 12 h before embryo collection in all ewes. Depending on the success of cervical passage, the embryos were collected from ewes by either TC or LP. Records were made of physiological (rectal temperature (RT) and heart rate (HR)), endocrine (cortisol concentration), biochemical (glycaemia, total proteins, globulin and albumin concentrations), and behavioral variables. Data were recorded before fasting (BF) and sedation (BS), during (DC) and immediately after embryo collection (IAC), and 1 h (1hAC), 3 h (3hAC), 6 h (6hAC), 12 h (12hAC), 24 h (24hAC), and 48 h (48hAC) after embryo collection. The LP and TC procedures were applied to 22 and 35 ewes (with 100.0% and 94.3% of procedures being successful, respectively). The use of LP took longer than TC (P = 0.007) but was less effective in the recovery of uterine fluid and structures (P = 0.0002 and P = 0.0180, respectively), with no difference in the number of viable embryos recovered per animal. The TC procedure induced a greater RT at DC (P = 0.002) and IAC moments (P < 0.0001). The heart rate was greater in TC than LP in IAC (P = 0.036). On the other hand, HR was greater with LP at 12hAC (P = 0.033) and 24hAC (P = 0.002). There was no interaction between the procedures and time on total proteins, albumin, or globulin concentrations. The TC procedure induced greater glycaemia than LP in IAC (P < 0.0001). LP induced greater serum cortisol concentration than TC at DC, IAC, 1hAC (P = 0.0004; P = 0.0006; P = 0.036, respectively), even though it was greater in the TC than the LP procedure at 3hAC (P = 0.008). In conclusion, the TC embryo collection was more effective than the traditional LP procedure. Although both embryo collection procedures affected ewes' welfare, the TC procedure is probably less stressor than the LP.
Collapse
Affiliation(s)
- Juliana Dantas Rodrigues Santos
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil.
| | - Rodolfo Ungerfeld
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de la República, Lasplaces 11 1550, Montevideo, 11600, Uruguay
| | - Mário Felipe Alvarez Balaro
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | | | - Isabel Oliveira Cosentino
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | - Viviane Lopes Brair
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | - Clara Vieira de Souza
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | - Pedro Henrique Nicolau Pinto
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | - Ana Luiza Cunha Bade
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil
| | | | - Felipe Zandonadi Brandão
- Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Niterói, Rio de Janeiro, 24230-340, Brazil.
| |
Collapse
|
7
|
Prellwitz L, Zambrini FN, Guimarães JD, de Sousa MAP, Oliveira MEF, Garcia AR, Esteves SN, Bartlewski PM, Souza-Fabjan JMG, Fonseca JF. Comparison of the intravenous and intravaginal route of oxytocin administration for cervical dilation protocol and non-surgical embryo recovery in oestrous-induced Santa Inês ewes. Reprod Domest Anim 2019; 54:1230-1235. [PMID: 31243815 DOI: 10.1111/rda.13499] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/21/2019] [Indexed: 11/30/2022]
Abstract
This study compared the effects of intravaginal and intravenous routes of oxytocin (OT) administration in 46 oestrous-induced Santa Inês ewes (6-day treatment with progestin-releasing intravaginal sponges and a single injection of 200 IU of eCG at the time of sponge removal) that underwent transcervical embryo recovery 6-7 days after oestrous onset and mating. All ewes received 37.5 μg of d-cloprostenol via latero-vulvar route, and 1 mg of oestradiol benzoate i.m. 16 hr before and 50 IU of OT 20 min before non-surgical embryo recovery (NSER), with OT being administered intravenously (n = 21) or intravaginally (n = 21). An overall oestrous response was 95.6% (44/46), and adequate cervical retraction could be accomplished in 78.6% (33/42) of ewes. The percentage of successful NSER procedures was 57% (24/42) or 72.7% (24/33) of animals with sufficient cervical retraction. The duration of NSER procedure averaged 28 min (range: 17-40 min) and ~96% of flushing fluid could be recovered (range: 85%-100%). Out of 18 ewes that could not undergo NSER, 12 (66.6%) presented various anatomical barriers, whilst the other 33.4% did not present these barriers and still could not be traversed. Excluding the ewes with those anatomical features, the overall success rate of NSER was 80% (24/30). The route of OT administration had no effect on NSER efficiency or the ease with which transcervical embryo flushing was performed. Both routes of OT administration can be used for cervical dilation protocol. Discarding ewes with anatomical features precluding cervical penetration is highly recommended to increase the efficacy of NSER in sheep.
Collapse
Affiliation(s)
- Lucia Prellwitz
- Faculdade de Veterinária, Universidade Federal Fluminense, Niterói-RJ, Brazil
| | | | | | | | | | | | | | - Pawel Mieczyslaw Bartlewski
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph-ON, Ontario, Canada
| | | | | |
Collapse
|