Subscribe to RSS
DOI: 10.1055/a-0803-1211
Increase of pregnancy rate after multiple periovulatory inseminations in mares
Steigerung der Trächtigkeitsrate von Stuten durch mehrfache periovulatorische BesamungenPublication History
05/08/2018
08/08/2018
Publication Date:
26 February 2019 (online)
![](https://www.thieme-connect.de/media/10.1055-s-00034912/201901/lookinside/thumbnails/10-1055-a-0803-1211-1.jpg)
Abstract
Objective There exist differences in the reproductive behavior of stallions and mares under free-running and domestic in-hand breeding conditions. Contrary to artificial insemination programs, a stallion mates a mare multiple times per estrus under natural conditions. The objective of this study was to determine if multiple periovulatory artificial inseminations (MI), four times in two different time intervals instead of two, would result in increased pregnancy outcome or higher incidences of breeding induced endometritis.
Material and methods Eighty-two estrous mares were allocated randomly to one of three experimental groups. They were administered intramuscular deslorelin (1.25 mg) to induce ovulation, and 24 hours later, they were inseminated either twice (group DI), four times in relatively short intervals (group MISI) or four times in relatively long intervals (MILI), after division of one commercial insemination dose (either frozen-thawed or chilled-warmed semen) into two or four portions, respectively. Uterine sampling for bacteriological and cytological analysis was conducted directly before the first insemination and 24 hours after the last insemination.
Results Mares of the MI groups showed a higher pregnancy rate with frozen-thawed semen than mares of the DI group. There was no difference in bacteriological and cytological results between the three groups. In addition, mares of the MISI group showed less intrauterine fluid accumulation 24 hours after the last insemination than mares of the DI and MILI groups.
Conclusion and clinical relevance We suggest that multiple periovulatory inseminations with frozen-thawed semen in a close time frame to ovulation lead to an increase of pregnancy results per cycle, and that they do not lead to impaired inflammatory reactions of the uterus in healthy fertile mares.
Zusammenfassung
Gegenstand und Ziel Zwischen freilebenden und unter domestizierten Bedingungen gehaltenen Hengsten und Stuten bestehen deutliche Unterschiede im Reproduktionsverhalten. Im Gegensatz zum Prozedere bei der künstlichen Besamung paart sich der Hengst in der Natur während eines Zyklus mehrmals mit der Stute. Ziel dieser Studie war zu bestimmen, ob vierfache Besamungen in verschiedenen Zeitabständen zur Ovulation, im Gegensatz zu zweifachen, in einer höheren Trächtigkeitsrate resultieren und ob solche Mehrfachbesamungen eine erhöhte Inzidenz von belegungsinduzierter Endometritis nach sich ziehen.
Material und Methoden Insgesamt 82 zyklische Stuten verschiedener Rassen wurden nach dem Zufallsprinzip einer von drei Behandlungsgruppen zugeteilt. Danach wurden sie im Rahmen einer standardisierten Untersuchung und 24 Stunden nach einer Ovulationsinduktion mittels 1,25 mg Deslorelin intramuskulär zweimal (Gruppe DI) oder viermal (Gruppe MI) mit entweder Kühl- oder Gefriersperma besamt, wobei die Besamungen in der Gruppe MI in Kurzzeit- (Gruppe MISI) oder Langzeit-Intervallen (Gruppe MILI) erfolgten. Hierzu wurde jeweils eine Besamungsdosis in zwei bzw. vier Portionen aufgeteilt. Direkt vor der ersten Besamung sowie 24 Stunden nach der letzten Besamung wurden eine bakteriologische und eine zytologische Untersuchung durchgeführt.
Ergebnisse Stuten der MI-Gruppe wiesen bei Verwendung von Gefriersperma eine signifikant höhere Trächtigkeitsrate pro Zyklus auf als Stuten der DI-Gruppe. Die bakteriologischen und zytologischen Befunde differierten zwischen den drei Gruppen nicht signifikant. In der MISI-Gruppe wiesen signifikant weniger Stuten Flüssigkeit im Uterus auf als in der MILI- und DI-Gruppe.
Schlussfolgerung und klinische Relevanz Die Ergebnisse der Studie deuten darauf hin, dass multiple periovulatorische Besamungen mit Gefriersperma zu einer Erhöhung der Trächtigkeitsrate führen und es dabei bei gesunden, fertilen Stuten nach der Besamung zu keiner Zunahme von Entzündungsreaktionen und mikrobieller Kontamination des Uterus kommt.
-
References
- 1 Allen WE, Pycock JF. Cyclical accumulation of uterine fluid in mares with lowered resistance to endometritis. Vet Rec 1988; 122: 489-490
- 2 Andersson M. Sexual Selection. Princeton: Princeton University Press; 1994
- 3 Barbacini S. Management of mares for frozen semen. In: Proceedings of the 14th International Congress on Animal Reproduction; Stockholm, Sweden: 2000: 308
- 4 Barbacini S, Loomis P, Squires EL. The effect of sperm number and frequency of insemination on pregnancy rates of mares inseminated with frozen-thawed spermatozoa. Anim Reprod Sci 2005; 89: 199
- 5 Crowell-Davis SL. Sexual behavior of mares. Horm Behav 2007; 52: 12-17
- 6 Fiala SM, Pimentel CA, Mattos AL. et al. Effect of sperm numbers and concentration on sperm transport and uterine inflammatory response in the mare. Theriogenology 2007; 67: 556-562
- 7 Freitas CC, Tarouco G, Möller G. et al. Sexual behaviour of Criollo stallions on pasture. Anim Reprod Sci 2006; 94: 42-45
- 8 Jeannerat E, Janett F, Sieme H. et al. Quality of seminal fluids varies with type of stimulus at ejaculation. Sci Rep 2017; 7: 44339
- 9 Jennions MD, Petrie M. Why do females mate multiply? A review of the genetic benefits. Biol Rev Camb Philos Soc 2000; 75 (01) 21-64
- 10 Katila T. Onset and duration of uterine inflammatory response of mares after insemination with fresh semen. Biology of Reproduction Monograph Series 1995; 1: 515-517
- 11 Katila T. Post-mating inflammatory responses of the uterus. Reprod Domest Anim 2012; 47 (Suppl. 05) 31-41
- 12 Kloppe LH, Varner DD, Elmore RG. et al. Effect of insemination timing on the fertilizing capacity of frozen/thawed equine spermatozoa. Theriogenology 1988; 29: 429-439
- 13 Kotilainen T, Huhtinen M, Katila T. Sperm-induced leukocytosis in the equine uterus. Theriogenology 1994; 41: 629-636
- 14 LeBlanc MM, Neuwirth L, Asbury AC. et al. Scintigraphic measurement of uterine clearance in normal mares and mares with recurrent endometritis. Equine Vet J 1994; 26: 109-113
- 15 LeBlanc MM. When to refer an infertile mare to a theriogenologist. Theriogenology 2008; 70: 421-429
- 16 Leemans B, Gadella BM, Stout TAE. et al. The role of oviductal cells in activating stallion spermatozoa. J Equine Vet Sci 2016; 43: 49-55
- 17 Lewis N, Morganti M, Collingwood F. et al. Utilization of one dose postovulatory breeding with frozen thawed semen at a commercial artificial insemination centre: Pregnancy rates and postbreeding uterine fluid accumulation in comparison to insemination with chilled or fresh semen. J Equine Vet Sci 2015; 35: 882-887
- 18 Linklater WL, Cameron EZ, Minot EO. et al. Stallion harassment and the mating system of horses. Anim Behav 1999; 58: 295-306
- 19 Loomis PR, Squires EL. Frozen semen management in equine breeding programs. Theriogenology 2005; 64: 480-491
- 20 Madill S, Troedsson MHT, Alexander SL. et al. Simultaneous recording of pituitary oxytocin secretion and myometrial activity in oestrous mares exposed to various breeding stimuli. J Reprod Fertil Suppl 2000; 56: 351-361
- 21 Mc Donnell S. Reproductive behavior of stallions and mares: comparison of free-running and domestic in-hand breeding. Anim Reprod Sci 2000; 60–61: 211-219
- 22 Nielsen JM. Endometritis in the mare: a diagnostic study comparing cultures from swab and biopsy. Theriogenology 2005; 64: 510-518
- 23 Nikolakopoulos E, Kindahl H, Gilbert CL. et al. Release of oxytocin and prostaglandin F2 alpha around teasing, natural service and associated events in the mare. Anim Reprod Sci 2000; 63: 89-99
- 24 Parker GA, Pizzari T. Sperm competition and ejaculate economics. Biol Rev Camb Philos Soc 2010; 85: 897-934
- 25 Rebordao MR, Carneiro C, Alexandre-Pires G. et al. Neutrophil extracellular traps formation by bacteria causing endometritis in the mare. J Reprod Immunol 2014; 106: 41-49
- 26 Reger HP, Bruemmer JE, Squires EL. et al. Effects of timing and placement of cryopreserved semen on fertility of mares. Equine Vet Educ 2003; 15: 128-136
- 27 Sieme H, Schäfer T, Stout TAE. et al. The effects of different insemination regimes on fertility in mares. Theriogenology 2003; 60: 1153-1164
- 28 Squires EL, Brubaker JK, McCue PM. et al. Effect of sperm number and frequency of insemination on fertility of mares inseminated with cooled semen. Theriogenology 1998; 49: 743-749
- 29 Squires EL, Barbacini S, Matthews P. et al. Retrospective study of factors affecting fertility of fresh, cooled and frozen semen. Equine Vet Educ 2006; 18: 96-99
- 30 Steinbjörnsson B, Kristjansson H. Sexual behaviour and fertility in Icelandic herds. Pferdeheilk 1999; 15: 481-490
- 31 Suarez SS, Pacey AA. Sperm transport in the female reproductive tract. Hum Reprod Update 2006; 12: 23-37
- 32 Taverne MA, van der Weyden GC, Fontijne P. et al. In-vivo myometrial electrical activity in the cyclic mare. J Reprod Fertil 1979; 56: 521-532
- 33 Troedsson MHT. Uterine clearance and resistance to persistent endometritis in the mare. Theriogenology 1999; 52: 461-471
- 34 Troedsson MHT, Loset K, Alghamdi AM. et al. Interaction between equine semen and the endometrium: the inflammatory response to semen. Anim Reprod Sci 2001; 68: 273-278
- 35 Varner DD. Odyssey of the spermatozoon. Asian J Andro 2015; 17: 522-528
- 36 Vidament M, Dupere AM, Julienne P. et al. Equine frozen semen: freezability and fertility field results. Theriogenology 1997; 48: 907-917
- 37 Voss JL, Squires EL, Pickett BW. et al. Effect of number and frequency of inseminations on fertility of mares. J Reprod Fertil Suppl 1982; 32: 53-57
- 38 Waelchli RO, Corboz L, Doebeli M. Streptomycin-resistant Escherichia coli as a marker of vulvovestibular contamination of endometrial culture swabs in the mare. Can J Vet Res 1992; 56: 308-312
- 39 Watson ED, Nikolakopoulos E, Gilbert C. et al. Oxytocin in the semen and gonads of the stallion. Theriogenology 1999; 51: 855-865
- 40 Zent WW, Troedsson MHT. Postbreeding uterine fluid accumulation in a normal population of thoroughbred mares: a field study. Proc Am Assoc Equine Pract 1998; 44: 64-65