Effect of insemination timing on the fertilizing capacity of frozen/thawed equine spermatozoa. Academic Article uri icon


  • A breeding trial was conducted to evaluate the effect of insemination timing on the fertility of mares bred with frozen/thawed equine semen. One stallion and 60 reproductively sound, estrous-synchronized mares were included in the study. Mares were assigned to one of three groups (n = 20): 1) insemination with fresh semen every other day during estrus from detection of a 35-mm follicle until ovulation, 2) insemination with frozen/thawed semen every day during estrus from detection of a 35-mm follicle until ovulation or 3) insemination with frozen/thawed semen once, within 6 h after ovulation. Single-cycle 18-d pregnancy rates resulting from insemination with fresh semen (70%), preovulation insemination with frozen/thawed semen (60%) and postovulation insemination with frozen/thawed semen (55%) were not different (P > 0.05). Possibly, equivalent pregnancy rates could be achieved with frozen/thawed semen using either daily inseminations until ovulation occurs or frequent ovarian palpations with a single post-ovulation insemination. Further studies regarding the effect of insemination timing on stallion fertility are needed since the present investigation included only one stallion and a small number of mares.

published proceedings

  • Theriogenology

author list (cited authors)

  • Kloppe, L. H., Varner, D. D., Elmore, R. G., Bretzlaff, K. N., & Shull, J. W

citation count

  • 23

complete list of authors

  • Kloppe, LH||Varner, DD||Elmore, RG||Bretzlaff, KN||Shull, JW

publication date

  • February 1988