• 1.

    Cuervo-Arango J, Claes AN, Stout TA. A retrospective comparison of the efficiency of different assisted reproductive techniques in the horse, emphasizing the impact of maternal age. Theriogenology. 2019;132:3644.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 2.

    Velez IC, Arnold C, Jacobson CC, et al. Effects of repeated transvaginal aspiration of immature follicles on mare health and ovarian status. Equine Vet J Suppl. 2012;(43):7883.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Choi YH, Velez IC, Macías-Garcia B, Riera FL, Ballard CS, Hinrichs K. Effect of clinically-related factors on in vitro blastocyst development after equine ICSI. Theriogenology. 2016;85(7):12891296.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Meintjes M, Bellow MS, Paul JB, et al. Transvaginal ultrasound-guided oocyte retrieval from cyclic and pregnant horse and pony mares for in vitro fertilization. Biol Reprod. 1995;52(Monograph series 1):281292.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Cuervo-Arango J, Claes AN, Stout TAE. Mare and stallion effects on blastocyst production in a commercial equine ovum pick-up-intracytoplasmic sperm injection program. Reprod Fertil Dev. 2019;31:18941903.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Duchamp G, Bézard J, Palmer E. Oocyte yield and the consequences of puncture of all follicles larger than 8 millimetres in mares. Biol Reprod. 1995;52(Monograph series 1):233241.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Jacobson CC, Choi YH, Hayden SS, Hinrichs K. Recovery of mare oocytes on a fixed biweekly schedule, and resulting blastocyst formation after intracytoplasmic sperm injection. Theriogenology. 2010;73(8):11161126.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Vernunft A, Alm H, Tuchscherer A, Kanitz W, Hinrichs K, Torner H. Chromatin and cytoplasmic characteristics of equine oocytes recovered by transvaginal ultrasound-guided follicle aspiration are influenced by the developmental stage of their follicle of origin. Theriogenology. 2013;80(1):19.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Metcalf E, Masterson K, Battaglia D, Beck R. Comparison of maturation, cleavage and blastocyst rates in equine oocytes recovered by transvaginal aspiration from estrogen-subordinate follicles versus non-estrogen-subordinate follicles. Clin Theriogenol. 2017;9(3):449.

    • Search Google Scholar
    • Export Citation
  • 10.

    Hinrichs K, Williams KA. Relationships among oocyte-cumulus morphology, follicular atresia, initial chromatin configuration, and oocyte meiotic competence in the horse. Biol Reprod. 1997;57(2):377384.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Hinrichs K, Schmidt AL. Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season. Biol Reprod. 2000;62(5):14021408.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Hinrichs K, Choi YH, Love LB, Varner DD, Love CC, Walckenaer. Chromatin configuration within the germinal vesicle of horse oocytes: changes post mortem and relationship to meiotic and developmental competence. Biol Reprod. 2005;72(5):11421150.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Riera FL, Roldan JE, Gomez J, Hinrichs K. Factors affecting the efficiency of foal production in a commercial oocyte transfer program. Theriogenology. 2016;85(6):10531062.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Salgado RM, Brom-de-Luna JG, Resende HL, Canesin HS, Hinrichs K. Lower blastocyst quality after conventional vs. Piezo ICSI in the horse reflects delayed sperm component remodeling and oocyte activation. J Assist Reprod Genet. 2018;35(5):825840.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Canesin HS, Ortiz I, Rocha Filho AN, Salgado RM, Brom-de-Luna JG, Hinrichs K. Effect of warming method on embryo quality in a simplified equine embryo vitrification system. Theriogenology. 2020;151:151158.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Hawley LR, Enders AC, Hinrichs K. Comparison of equine and bovine oocyte-cumulus morphology within the ovarian follicle. Biol Reprod. 1995;52(Monograph series 1):243252.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Kanitz W, Becker F, Alm H, Torner H. Ultrasound-guided follicular aspiration in mares. Biol Reprod. 1995;52(Monograph series 1):225231.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Brück I, Bézard J, Baltsen M, et al. Effect of administering a crude equine gonadotrophin preparation to mares on follicular development, oocyte recovery rate and oocyte maturation in vivo. J Reprod Fertil. 2000;118(2):351360.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Ginther O, Beg MA, Gastal M, Gastal EL. Follicle dynamics and selection in mares. Anim Reprod. 2004;1(1):4563.

  • 20.

    Ginther OJ, Beg MA, Donadeu FX, Bergfelt DR. Mechanism of follicle deviation in monovular farm species. Anim Reprod Sci. 2003;78(3-4):239257.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Ginther OJ, Gastal EL, Gastal MO, Bergfelt DR, Baerwald AR, Pierson RA. Comparative study of the dynamics of follicular waves in mares and women. Biol Reprod. 2004;71:11951201.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Foss R, Ortis H, Hinrichs K. Effect of potential oocyte transport protocols on blastocyst rates after intracytoplasmic sperm injection in the horse. Equine Vet J Suppl. 2013;(45):3943.

    • Crossref
    • Search Google Scholar
    • Export Citation

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Effect of day of estrus cycle at time of transvaginal follicle aspiration for oocyte recovery on rates of in vitro maturation and blastocyst production after intracytoplasmic sperm injection

Stephanie R. WalbornnRood and Riddle Equine Hospital, Lexington, KY

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Matheus FelixDepartment of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA

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Maria R. SchnobrichRood and Riddle Equine Hospital, Lexington, KY

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Etta A. BradecampRood and Riddle Equine Hospital, Lexington, KY

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Charlie F. ScogginRood and Riddle Equine Hospital, Lexington, KY

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Darko StefanovskiDepartment of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA

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Katrin HinrichsDepartment of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA

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Abstract

OBJECTIVE

To determine the effect of stage of estrus cycle (day after ovulation) at the time of transvaginal ultrasound-guided follicle aspiration (TVA) on parameters related to the success of in vitro equine embryo production.

ANIMALS

14 healthy mares were used; 11 completed the study and were included for analysis.

PROCEDURES

Mares underwent TVA of all follicles ≥ 5 mm diameter at each of 3 timepoints: 7 days after ovulation, 14 days after ovulation, and S-DSF (subordinate to a dominant stimulated follicle), during estrus at 24 hours after gonadotropin administration. The 3 treatments were assigned to each mare in random order; mares underwent follicle growth and ovulation between treatments. Recovered oocytes were matured in vitro, subjected to intracytoplasmic sperm injection (ICSI), and cultured to the blastocyst stage in vitro.

RESULTS

Total follicle numbers differed significantly between individual mares but did not differ between treatments. The number of follicles of different sizes significantly (P < 0.05) differed between treatments, with mares in the Day 7 treatment having more follicles 5 to 9 mm in diameter and fewer follicles 20 to 24 mm in diameter than mares in the other 2 treatments. After in vitro maturation culture, there were significantly more mature oocytes in the S-DSF treatment than in the other 2 treatments. There were no differences in blastocyst rate after ICSI among treatment groups.

CLINICAL RELEVANCE

Timing of TVA for aspiration of S-DSFs may increase the number of mature oocytes available for ICSI. Understanding of the effects of timing of TVA will help veterinarians to maximize the efficiency of this procedure.

Abstract

OBJECTIVE

To determine the effect of stage of estrus cycle (day after ovulation) at the time of transvaginal ultrasound-guided follicle aspiration (TVA) on parameters related to the success of in vitro equine embryo production.

ANIMALS

14 healthy mares were used; 11 completed the study and were included for analysis.

PROCEDURES

Mares underwent TVA of all follicles ≥ 5 mm diameter at each of 3 timepoints: 7 days after ovulation, 14 days after ovulation, and S-DSF (subordinate to a dominant stimulated follicle), during estrus at 24 hours after gonadotropin administration. The 3 treatments were assigned to each mare in random order; mares underwent follicle growth and ovulation between treatments. Recovered oocytes were matured in vitro, subjected to intracytoplasmic sperm injection (ICSI), and cultured to the blastocyst stage in vitro.

RESULTS

Total follicle numbers differed significantly between individual mares but did not differ between treatments. The number of follicles of different sizes significantly (P < 0.05) differed between treatments, with mares in the Day 7 treatment having more follicles 5 to 9 mm in diameter and fewer follicles 20 to 24 mm in diameter than mares in the other 2 treatments. After in vitro maturation culture, there were significantly more mature oocytes in the S-DSF treatment than in the other 2 treatments. There were no differences in blastocyst rate after ICSI among treatment groups.

CLINICAL RELEVANCE

Timing of TVA for aspiration of S-DSFs may increase the number of mature oocytes available for ICSI. Understanding of the effects of timing of TVA will help veterinarians to maximize the efficiency of this procedure.

Contributor Notes

Corresponding author: Dr. Hinrichs (katrinh@vet.upenn.edu)