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A Breeder's Journal

Results of Timed Insemination Protocol

"A Breeder's Journal," is a record documenting the results during the 2003 breeding season, using the (then new) Timed Insemination Protocol on four mares. 

This protocol persuaded my veterinarian of over 20 years, Dr. Terry Richards of Colville, Washington, to inseminate my mares with frozen semen. In the past I took my mares out of town for insemination, because he did not want to commit to the every-six-hours checks necessary with other protocols. Since this method can be timed so that insemination will occur during "decent" hours, veterinarians like Dr. Richards, can inseminate with frozen semen, without having to check mares throughout the night. Reports on this method reveal that the conception rate is the same as with the post-ovulation method. 

This was Dr. Richard's first season using frozen semen. He is experienced and successful with fresh-cooled and live cover breeding. As we proceed, I will provide as much detail as possible, so that interested persons can decide if this protocol might work for them, and what the costs are in comparison to other protocols. Though this protocol calls for two doses, which sounds expensive, it is hoped that the added cost for semen will be offset by the reduction of ultrasounds, palpations and after-hours office charges. In the case of doses of eight 0.5 ml straws containing 100 million sperm of good post-thaw motility per straw, four straws can be inseminated at 24 and 40 hours post-ovulating agent, for a total of one full dose (8 straws) per cycle.

All three mares below were palpated again on 7/18, and all remain pregnant, for a 100% conception rate! All three mares conceived on their first cycle. One mare experienced an early embryonic death, but was bred a second cycle and conceived again.

Timed Insemination Protocol:

  • Examine mare once daily until a 35 mm pre-ovulatory follicle is present.
  • Administer hCG or GnRH.
  • Inseminate with one dose at 24 hours post-ovulating agent. 
  • Inseminate with one dose at 40 hours post ovulating agent. 


Bubble Dancer--1995 TB

  • First foal in 2002, re-bred live-cover on 30-day heat. Teased in-foal, but returned to season after 60 days. Not rebred. 
  • 3/11 to 4/0 transitional heat
  • 4/25--in heat
  • 4/26--ultrasound showed 7 small, equal follicles on one ovary. Speculum exam revealed slight inflammatory look. Lavage performed--fluid clear. Cytology smear was good, with no indication of bacteria or white blood cells. Inflammatory appearance might indicate that mare is taking some air, and since she lost a pregnancy last season, she will be caslicked after second insemination. 
  • 4/28--one 29mm follicle, and six small follicles, which have neither progressed nor regressed.
  • 4/30--39mm follicle (no others progressing) at 8:30 a.m. At 4:00 p.m. ovulplant inserted.
  • 5/1--43mm follicle. Inseminated with four straws (400 million sperm at 80% motility) at 4:00 p.m.
  • 5/2--8:30 a.m., mare had ovulated. Inseminated with remaining half-dose of semen. Caslick surgery performed. 
  • 5/3--Lavaged due to uterine fluid present. 
  • 5/23, 7/14--Pregnant. 

Crystal Gallo--1995 TB

  • Has had three foals in a row, through 2002. Her second and third foals were from frozen semen. Was not rebred in 2002 due to a regressive follicle and the lateness of the season. 
  • 3/11 to 3/31 transitional heat. 
  • 4/16--in heat
  • 4/18--ultrasounded, 30mm follicle, uterus looked good, speculum exam good, cytology smear taken to check for white blood cells and bacteria.
  • 4/20--ultrasounded 37mm follicle. Dr. Richards chose not to inject the ovulation-inducing hormone, because even though the follicle was over 35mm, it was still very hard.
  • 4/21--ultrasounded 47mm, i.v. HcG injection given at 8:30 a.m.
  • 4/22--49mm, ultrasounded, inseminated with four 0.5 straws (approx. 400 million sperm with 50% post-thaw motility) at 9:30 a.m. Mare was checked again at 4:15 p.m., had ovulated, and was inseminated with another four straws. If she had not ovulated, she would have been inseminated near midnight (40 hours from the ovulatory agent injection). Note that we skipped a day of checking the mare early in the cycle. Mare stayed overnight at clinic, so she could be check for post-insemination inflammation/fluid the next morning. There was none, so the mare did not receive a uterine lavage.
  • 5/10--ultrasound showed deteriorating vessicle, indicating pregnancy and early embryonic death. Mare will be re-inseminated.
  • 5/14--lavaged and injected with prostaglandin.
  • 5/21--ultrasounded, 33 mm follicle. 
  • 5/22--29 mm follicle regressing. Back to teasing!
  • 5/28--ultrasounded 29 mm follicle
  • 5/29--25 mm
  • 6/2 through 6/13--Regumate (progesterone)
  • 6/14--Lutalyse (prostaglandin)
  • 6/16--in heat
  • 6/17--32 mm follicle
  • 6/19--Ovuplant
  • 6/20--inseminated with four 0.5 ml straws containing 400 million sperm
  • 6/21--inseminated with four 0.5 ml straws
  • 7/14--Pregnant.

Impish Lady--1986 TB

  • First foal in 1990. Foaled in 2002, rebred live-cover and conceived on one cycle. Has had several foals. Has always been bred live-cover and always conceived. Lost two early pregnancies due to undetermined causes. Due to foal on 3/29/03. Induced on 4/30, no problems. 5/28--ultrasounded, 25 mm follicle
  • 5/29--6/2--teasing "cold," prostaglandin injection on 6/2
  • Breeding plans discontinued--not inseminated.

Summer Prospector--1995 TB

  • First foal in 2002. Rebred live-cover and conceived on one cycle. 
  • Due to foal on 3/30/03. Foaled 4/21, no problems. 
  • 5/21--mare had been in heat for two days, ultrasounded, 52 mm follicle, given i.v. HcG at 4:00 p.m.
  • 5/22--inseminated at 4:00 p.m. with 1/2 dose 85% motility semen
  • 5/23--inseminated at 8:00 a.m. with remaining 1/2 dose, checked for fluid at noon (none), given oxytocin
  • 6/12, 7/14--Pregnant.

Veterinary & Semen Costs / 2003 Breeding Season:

EVA vaccine for two mares, $83.85 

Retail value of semen / Crystal Gallo, $1110.

Total vet Crystal Gallo / two cycles, $844.75.

Retail value of semen / Bubble Dancer, $465.

Total vet Bubble Dancer. $567.25

Retail value of semen / Summper Prospector, $635.

Total vet Summer Prospector, $429.75

Total vet / Impish Lady (breeding discontinued before insemination took place), $85.

TOTAL VET & SEMEN COSTS 2003--4 mares, $4220.60