Tierarztl Prax Ausg G Grosstiere Nutztiere 2023; 51(06): 358-366
DOI: 10.1055/a-2186-2693
Original Article

Age and treatment on the day of embryo transfer in recipient mares affect likelihood of pregnancy

Alter und Behandlung am Tag des Embryotransfers bei Empfängerstuten beeinflussen die Wahrscheinlichkeit einer Trächtigkeit
Miguel Blanco
1   Studfarm Lewitz – PS Pferdehaltung, Neustadt-Glewe, Germany
2   Unit for Reproductive Medicine – Clinic for Horses, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
,
Rob Foss
3   Equine Medical Services, Columbia, MO, USA
,
Anna Tönißen
2   Unit for Reproductive Medicine – Clinic for Horses, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
,
Karl Rohn
4   Institute for Veterinary Epidemiology, University of Veterinary Medicine Hanover, Foundation, Germany
,
Dominik Burger
5   Swiss Institute of Equine Medicine ISME, University of Berne, and Agroscope, Avenches, Switzerland
,
Harald Sieme
2   Unit for Reproductive Medicine – Clinic for Horses, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
› Author Affiliations

Abstract

Objective This retrospective evaluation of data from a large commercial embryo transfer facility aimed to determine the extent to which age and treatment on the day of embryo transfer in recipient mares influence the likelihood of pregnancy.

Material and methods Embryo recovery was carried out on days 8–10 post-ovulation using transcervical uterine flushing. Recipient mares grouped according to their age were treated once on the day of embryo transfer (Day 3–8 post ovulation) and were assigned randomly to 1 of 3 groups: Mares in Group A (n=101) received antispasmodic, antimicrobial, and anti-inflammatory drugs. Mares in Group B (n=100) received gentamicin and flunixin meglumine. Group C (control) (n=103) did not receive any treatment. Detomidine (0.008 mg/kg bwt i.v.) was administered to all recipients before transfer of the embryo. The influence of treatment and recipient´s age was calculated using binary logistic regression.

Results Day 16 post-transfer pregnancy rates were highest in Group A (74/101, 73.3a%), when compared to Group B (60/100, 60%), and Group C (57/103, 55.3b%) (a vs b, p<0.05). Pregnancy loss rates at D45 were not different between groups, A (8/74, 10.8%), B (5/60, 8.3%), and C (6/57, 10.5%), respectively (p>0.05). Pregnancy losses were increased in recipient mares 17–22 years (33.3a%) compared to younger recipient mares (2–6 years 7b%, 7–11 years 10%, 12–16 years 8b%) (a:b p<0.05). The regression model showed that the predicted probability for pregnancy after embryo transfer decreased as the age of the recipient mare increased for treated recipients in Group A (p=0.012), there was no effect of treatment and recipient´s age in Group B, and a decreased likelihood of pregnancy in recipients of advanced age (≥12 years of age) in untreated recipients (group C).

Conclusions and clinical relevance Likelihood of pregnancy increased following single administration of antispasmodic, antimicrobial, and anti-inflammatory drugs at the time of embryo transfer in recipients 2–12 years of age. Likelihood of pregnancy in recipients decreased in recipients≥12 years of age. These results, obtained under the conditions of a large commercial embryo transfer program, offer an opportunity to improve pregnancy rates in recipient mares≤12 years of age.

Zusammenfassung

Zielsetzung Mit dieser retrospektiven Auswertung der Daten einer großen kommerziellen Embryotransfereinrichtung sollte ermittelt werden, inwieweit Alter und Behandlung am Tag des Embryotransfers bei Empfängerstuten die Wahrscheinlichkeit einer Trächtigkeit beeinflussen.

Material und Methoden Die Gewinnung der Embryonen erfolgte an den Tagen 8–10 nach dem Eisprung mittels transzervikaler Gebärmutterspülung. Die Empfängerstuten, die nach ihrem Alter (2–6, 7–11, 12–16 und 17–22 Jahre) eingeteilt wurden, wurden einmal am Tag des Embryotransfers (Tag 3–8 post ovulationem) behandelt und nach dem Zufallsprinzip einer von 3 Gruppen zugeteilt: Die Empfängerstuten in Gruppe A (n=101) erhielten krampflösende, antimikrobielle und entzündungshemmende Medikamente. Die Stuten der Gruppe B (n=100) erhielten Gentamicin und Flunixin meglumine. Empfängerstuten der Gruppe C (Kontrolle) (n=103) erhielten keine Behandlung. Detomidin (0,008 mg/kg) wurde allen Empfängerstuten vor dem Embryotransfer verabreicht. Der Einfluss der Behandlung und des Alters der Empfängerstuten wurde mittels binärer logistischer Regression überprüft.

Ergebnisse Am 16. Tag nach dem Transfer waren die Trächtigkeitsraten in Gruppe A (74/101, 73,3a %) am höchsten im Vergleich zu Gruppe B (60/100, 60%) und Gruppe C (57/103, 55,3b %) (a vs. b, p<0,05). Die Trächtigkeitsverlustraten an Tag 45 unterschieden sich nicht zwischen den Gruppen A (8/74, 10.8%), B (5/60, 8.3%) und C (6/57, 10.5%) (p>0,05). Trächtigkeitsverluste waren bei Empfängerstuten im Alter von 17–22 Jahren (33,3a %) im Vergleich zu jüngeren Empfängerstuten (2–6 Jahre 7b %, 7–11 Jahre 10%, 12–16 Jahre 8b %) erhöht (a:b p<0,05). Das Regressionsmodell zeigte, dass die vorhergesagte Wahrscheinlichkeit einer Trächtigkeit nach dem Embryotransfer bei behandelten Empfängerinnen in Gruppe A mit zunehmendem Alter der Empfängerstute abnahm (p=0,012), dass es in Gruppe B keinen Effekt der Behandlung und des Alters der Empfängerstuten gab und dass die Wahrscheinlichkeit einer Trächtigkeit bei Empfängerstuten im fortgeschrittenen Alter (≥12 Jahre) bei unbehandelten Empfängerstuten (Gruppe C, Kontrolle) abnahm.

Schlussfolgerungen und klinische Relevanz Die Wahrscheinlichkeit einer Trächtigkeit stieg nach einmaliger Verabreichung von krampflösenden, antimikrobiellen und entzündungshemmenden Medikamenten zum Zeitpunkt des Embryotransfers bei Empfängerstuten im Alter von 2–12 Jahren. Die Wahrscheinlichkeit einer Trächtigkeit nahm bei Empfängerstuten im Alter von≥12 Jahren ab. Diese unter den Bedingungen eines großen kommerziellen Embryotransferprogramms ermittelten Ergebnisse bieten eine Möglichkeit, die Trächtigkeitsraten bei Empfängerstuten≤12 Jahren zu verbessern.



Publication History

Received: 21 April 2023

Article published online:
06 December 2023

© 2023. Thieme. All rights reserved.

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  • References

  • 1 Oguri N, Tsutsumi Y. Non-surgical recovery of equine eggs, and an attempt at non-surgical egg transfer in horses. J Reprod Fertil 1972; 31: 187-195 10.1530/jrf.0.0310187
  • 2 Allen WR, Rowson LEA. Transfer of ova between horses and donkeys. Proc Am Ass Equine Practnrs 1972; 7: 484-487
  • 3 Oguri N, Tsutsumi Y. Non-surgical egg transfer in mares. J Reprod Fertil 1974; 41: 313-320 1530/jrf.0.0410313
  • 4 Squires EL. Current Reproductive Technologies Impacting Equine Embryo Production. J Eq Vet Sci 2020; 89: 102981 10.1016/j.jevs.2020.102981
  • 5 Marinone AI, Losinno L, Fumuso E. et al. The effect of mare`s age on multiple ovulation rate, embryo recovery, post-transfer pregnancy rate, and interovulatory interval in a commercial embryo transfer program in Argentina. Anim Reprod Sci 2015; 158: 53-59 10.1016/j.anireprosci.2015.04.007
  • 6 Squires EL, McCue PM, Vanderwall D. The current status of equine embryo transfer. Theriogenology 1999; 51: 91-104 10.1016/S0093-691X(98)00234-9
  • 7 Carnevale EM, Ramirez RJ, Squires EL. et al. Factors affecting Pregnancy rates and early embryonic death after equine embryo transfer. Theriogenology 2000; 54: 965-979 10.1016/s0093-691x(00)00405-2
  • 8 Cuervo-Arango J, Claes AN, Ruijter-Villani M. et al. Likelihood of pregnancy after embryo transfer is reduced in recipient mares with a short preceding estrus. Eq Vet J 2017; 50: 386-390 10.1111/evj.12739
  • 9 Squires EL, Garcia RH, Ginther OJ. Factors affecting success of equine embryo transfer. Eq Vet J 1985; 17: 92-95 10.1111/j.2042-3306.1985.tb04604.x
  • 10 Ricketts SW, Alonso S. The effect of age and parity on the development of equine chronic endometrial disease. Eq Vet J 1991; 23: 189-192 10.1111/j.2042-3306.1991.tb02752.x
  • 11 Foss R, Wirth N, Schiltz P. et al. Nonsurgical embryo transfer in a private practice (1998). Proc Am Ass Equine Practnrs 1999; 45: 210-212
  • 12 McCue PM, Squires EL. 2015 Equine Embryo Transfer. Teton New Media, Jackson, WI, USA.
  • 13 Stout TAE. Equine embryo transfer: review of developing potential. Eq Vet J 2006; 38: 467-478 10.2746/042516406778400529
  • 14 Koblischke P, Kindahl H, Budik S. et al. Embryo transfer induces a subclinical endometritis in recipient mares which can be prevented by treatment with non-steroid anti-inflammatory drugs. Theriogenology 2008; 70: 1147-1158 10.1016/j.theriogenology.2008.06.037
  • 15 Scenna FN, Hockett ME, Towns TM. et al. Influence of a prostaglandin synthesis inhibitor administered at embryo transfer on pregnancy rates of recipient cows. Prostaglandins & other Lipid Mediat 2005; 78: 38-45 10.1016/j.prostaglandins.2005.02.003
  • 16 Koblischke P, Budik S, Müller J. et al. Practical Experience with Treatment of Recipient Mares with a Non-Steroidal Anti-Inflammatory Drug in an Equine Embryo Transfer Programme. Reprod Dom Anim 2010; 45: 1039-1041 10.1111/j.1439-0531.2009.01486
  • 17 Pinto MR, Miragaya MH, Burns P. et al. Strategies for increasing reproductive efficiency in a commercial embryo transfer program with high performance donor mares under training. Journal of Eq Vet Sci 2017; 54: 93-97 10.1016/j.jevs.2016.09.004
  • 18 Coutinho AE, Chapman KE. The anti-inflammatory and immunosuppressive effects of glucocorticoids, recent developments and mechanistic insights. Mol Cell Endocrinol 2011; 335: 2-13 10.1016/j.mce.2010.04.005
  • 19 Bucca S, Carli A, Buckley T. et al. The use of dexamethasone administered to mares at breeding time in the modulation of persistent mating induced endometritis. Theriogenology 2008; 70: 1093-1100 10.1016/j.theriogenology.2008.06.029
  • 20 Weems CW, Weems YS, Randel RD. Prostaglandins and reproduction in female farm animals. Vet J 2006; 171: 206-228 10.1016/j.tvjl.2004.11.014
  • 21 Higgins AJ, Lees P. The acute inflammatory process, arachidonic acid metabolism and the mode of action of anti-inflammatory drugs. Eq Vet J 1984; 16: 163-175 10.1111/j.2042-3306.1984.tb01893.
  • 22 Szóstek-Mioduchowska AZ, Shiotani H, Yamamoto Y. et al. Effects of cortisol on prostaglandin F2α secretion and expression of genes involved in the arachidonic acid metabolic pathway in equine endometrium - In vitro study. Theriogenology 2021; 173: 221-229 10.1016/j.theriogenology.2021.08.009.
  • 23 Mc Ewan BS, Biron CA, Brunson KW. et al. The role of adrenocorticoids as modulators of immune function in health and disease: neural, endocrine and immune interactions. Brain Res Rev 2011; 23: 79-133 10.1016/s0165-0173(96)00012-4
  • 24 Steinman A, Isoherranen N, Ashoach O. et al. Pharmacokinetics of gentamicin C1, C1a and C2 in horses after single intravenous dose. Eq Vet J 2002; 34: 615-618 10.2746/042516402776180160
  • 25 Panzani D, Crisci A, Rota A. et al. Effect of day of transfer and treatment administration on the recipient on pregnancy rates after equine embryo transfer. Vet Res Commun 2009; 33: 113-116 10.1007/s11259-009-9303-7
  • 26 Schatzmann U, Jossfck H, Stauffer JL. et al. Effects of alpha 2-agonists on intrauterine pressure and sedation in horses: comparison between detomidine, romifidine and xylazine. Zentralbl Veterinaermed A 1994; 41: 523-529 10.1111/j.1439-0442.1994.tb00120.x.
  • 27 Fehervari Z. Antibiotics-immune system interactions. Nat Immunol 2018; 19: 99 10.1038/s41590-017-0041-7
  • 28 McCue PM, Ferris RA, Lindholm AR. et al. Embryo recovery procedures and collection success: results of 492 embryo-flush attempts. Proc Am Ass Equine Practnrs 2010; 56: 318-321
  • 29 Sánchez R, Gomes I, Ramos H. et al. Use of deep uterine low dose insemination of frozen and cooled stallion semen in a commercial embryo transfer program. Havemeyer Foundation Monograph 2005; 14: 103-104