Insemination in horses refers to the process of introducing sperm into the reproductive tract of a mare to achieve pregnancy. This can be accomplished through natural breeding or artificial insemination (AI). Artificial insemination involves collecting semen from a stallion and manually depositing it into the mare's uterus. This technique allows for greater control over breeding, including the selection of genetic traits and the management of breeding schedules. Various methods of artificial insemination exist, such as fresh, chilled, or frozen semen insemination, each with specific protocols and considerations. This page compiles peer-reviewed research studies and scholarly articles that explore the techniques, outcomes, and advancements in insemination practices in equine reproduction.
Broussard JR, Goodeaux SD, Goodeaux LL, Thibodeaux JK, Moreau JD, Godke RA, Roussel JD.Control extender was incubated at 4 degrees C for 24 hours. Rubber or plastic syringe plungers were separately incubated in semen extender for 24 hours at 4 degrees C. Following incubation, the extender was stored at -20 degrees C until the time of semen collection. The treatments consisted of the following: Group A = equine semen plus control extender; Group B=equine semen plus extender incubated with rubber plungers and Group C=equine semen plus extender incubated in plastic plungers; Group D=equine semen plus control extended in rubber plunger syringes and Group E=equine semen plus control ...
Schumacher J, Schumacher J, Blanchard T.The endometrial response of mares to repair of third-degree rectovestibular lacerations was evaluated. Endometrial biopsy specimens from 8 mares with third-degree rectovestibular laceration were obtained immediately before surgery and from 9 to 15 days after repair. Presurgical endometrial biopsy specimens were classified as category I for 2 mares; category II, attributable to slight endometritis, for 5 mares; and category III, attributable to moderate-to-severe endometritis, for 1 mare. Within 15 days after rectovestibular repair, all endometrial biopsy specimens were classified as category I...
Jasko DJ, Little TV, Lein DH, Foote RH.Information pertaining to evaluation of single ejaculates of semen and records for 2 consecutive breeding seasons were obtained. In all, data for 99 individual breeding seasons (n = 43 Standardbreds and 56 Thoroughbreds) were evaluated. Included in each semen evaluation was examination of semen characteristics and computer-aided analysis of spermatozoal movement characteristics. On the basis of the analysis of breeding records for 4,175 mares (7,017 estrous cycles), a per-estrous cycle fertility rate was calculated from data for 96 of the breeding seasons. Stallions with lower fertility than t...
Love CC.Semen collection techniques in the stallion have evolved considerably over the last 70 to 80 years and are used today primarily for artificial insemination. Semen can be collected from stallions that are otherwise unable to breed, allowing continued use of valuable animals. There are many options for collection of semen from stallions that present with ejaculatory dysfunction (see the article by McDonnell elsewhere in this issue.) Although there are many advantages to the use of artificial breeding, the collector must understand each step of the collection procedure as well as stallion prefere...
Heinrich B.This research article corrects a common misconception about the energy metabolism in horses during short sprinting and long-distance running events, emphasizing that short sprints are primarily powered by anaerobic activity, […]
Liu DY, Lopata A, Pantke P, Baker HW.The present study demonstrates that horse and marmoset monkey sperm can bind to the human zona of salt-stored oocytes that failed to fertilize in vitro. Marmoset monkey sperm are also able to penetrate the salt-stored human zona. In contrast, human sperm do not bind to the zona of either horse or marmoset monkey oocytes. These results suggest that human sperm binding to the zona pellucida is more strictly species-specific than it is for horse and marmoset monkey sperm. In contrast, horse and marmoset monkey sperm contain receptors recognized by the human zona.
Tekin N, Yurdaydin N, Klug E, Yavas Y, Aksu A, Gülyüz F.Within a German-Turkish university partnership documentation of reproductive data of brood-mares was performed as a part project of the cooperation contract. In the study Arab, Haflinger and cross-breed mares were included. The mares mainly were housed in big studfarms and a smaller part was kept under small private farms. Almost three quarters of both the Arab and Haflinger mares exhibited an estrous length of 1-4 days, whereas the others showed a heat duration of a period of 5-10 days. In the same group of probands a mean length of sexual cycle of 18-24 days could be observed in 38.2% of the...
Hellander JC, Samper JC, Crabo BG.At the beginning of the breeding season an eight-year-old standardbred stallion had semen with virtually zero sperm motility and an approximately 90 per cent incidence of midpiece and tail defects. The motility of the sperm improved to 7 per cent when semen was collected daily but its morphology did not improve. Electron microscopy revealed that the defects consisted mainly of a loss of microtubules in the axoneme and of disorganised midpieces. A pregnancy rate of 24 per cent per cycle and 44 per cent for the season was achieved in 32 mares after the insemination of whole ejaculates collected ...
Samper JC, Hellander JC, Crabo BG.Studies were designed to investigate whether sperm motility determined with a Hamilton-Thorn HTM-2000 motility analyzer (HTM), or the percentage of spermatozoa that passed through glass wool (GW), Sephadex (S), or glass wool/Sephadex (GWS) filters could be used to predict the fertilizing potential of fresh or frozen semen. In the fresh semen study, 10 randomly selected ejaculates from 4 stallions exclusively used for A.I. breeding were assayed during the season. The 521 mares used were inseminated with 500 x 10(6) motile spermatozoa after gynaecological examination every 2 days. In the frozen ...
Hinrichs K, DiGiorgio LM.A technique was developed in which immature horse oocytes, obtained from slaughterhouse specimens, were transferred to the pre-ovulatory follicle of a mare in vivo, with resulting oocyte maturation, ovulation, fertilization and embryo development. Oocytes were collected from all follicles greater than 3 mm, and were classified as immature, maturing, expanded or denuded. The transfers were performed in the standing, tranquilized mare. The ovary containing the pre-ovulatory follicle was grasped per rectum. A trochar and cannula were placed through the abdominal wall in the flank area, ipsilatera...
Palmer E, Bézard J, Magistrini M, Duchamp G.Since the first successful collection of oocytes by non-surgical puncture, there have been numerous attempts to fertilize them but few segmented embryos have resulted. The latest attempts at follicular puncture (Palmer et al., 1987) provided 159 oocytes. Oocytes found broken (18%) were probably already broken, or at least fragile, before puncture. The 41 oocytes were fertilized only with semen treated with Ionophore A23187. Following ionophore treatment of semen, 16 ova segmented (of 113 inseminated oocytes) indicating fertilization, and another 7 showed signs of fertilization but not segmenta...
Krause HD, Sieme H, Merkt H, Bader H, Wöckener A.A reduction in the motility of the spermatozoa in stallion semen stored in pellet form for 23 years in liquid nitrogen at -196 degrees C could not be seen after thawing. The insemination of a mare with this semen resulted in a normal pregnancy. A normally developed, healthy male foal was born after a gestational period of 321 days.
Woods J, Bergfelt DR, Ginther OJ.The effects of pre-ovulatory and post ovulatory insemination on pregnancy rate and embryonic-loss rate were studied in 268 mares in two experiments. Within each experiment mares were randomised within replicates as follows: to be inseminated on the day the pre-ovulatory follicle reached 35 mm (pre-ovulatory group), to be inseminated on the day of ovulation (Day 0 group), and to be inseminated on the day after ovulation (Day 1 group). Ultrasonic pregnancy diagnoses were performed on Days 11, 12, 13 and 14 (Experiment 1) and Days 11, 12, 13, 14, 15, 20 and 40 (Experiment 2). Combined for the two...
Zhang JJ, Muzs LZ, Boyle MS.In vitro fertilizing ability of stallion spermatozoa was assessed using horse follicular oocytes matured in vitro. After collection, stallion spermatozoa were either: 1) washed and incubated in TALP medium with 3 mg/ml bovine serum albumin (BSA) and 10 micrograms/ml heparin for 4h, 2) washed and incubated in TALP with 3 mg/ml BSA for 3 h and cultured for a further 1 h with 1 mM caffeine and 5 mM dbcAMP, 3) washed and incubated in TALP medium with 3 mg/ml BSA at pH 7.9-8.2 for 2-4 h, or 4) diluted and incubated in TALP medium with 10 mg/ml BSA and 7.14 microM calcium ionophore A 23187 for 5-10 ...
Braun J, Schefels W, Stolla R.In 1970 semen from a Haflinger-stallion was frozen by the pellet method. 18 years later semen samples were used to inseminate 4 mares. Inseminations were performed shortly after ovulation with a total number of motile spermatozoa between 150 and 636 x 10(6), the percentage of motile spermatozoa being 20% to 40%. Three mares conceived after a single insemination, one mare got pregnant after 4 inseminations during 3 oestrous periods. Meanwhile, 3 foals were born and one of the mares is still pregnant. The results demonstrate that long-term storage of frozen semen in liquid nitrogen does not impa...
McCue PM, Hughes JP.Mares (n = 37) were treated on Days 2 and 4 post partum with a uterine lavage of 10 l of warm, sterile NaCl (0.9%) solution. Endometrial cytology and culture were performed on Day 7. Mares were bred on the first postpartum estrus by artificial insemination. Pregnancy rates were determined by ultrasound examination at Day 16 post ovulation. No differences were noted in degree of uterine inflammation or presence of uterine bacteria at Day 7 post partum between treated (n = 18) and control (n = 19) mares. Pregnancy rates at the first postpartum estrus for treated mares (55.5%) was not statistical...
Koskinen E, Lindeberg H, Kuntsi H, Ruotsalainen L, Katila T.In a first experiment, 11 Finnhorse mares were examined every six hours during late oestrus by rectal palpation and ultrasonography to determine the time of ovulation. The mares were inseminated over one to three subsequent cycles, 6-12 (n = 5), 12-18 (n = 5), 18-24 (n = 5) and 24-30 (n = 5) hours after ovulation. Pregnancies were terminated by prostaglandin injection 21 days after insemination. All mares inseminated within 18 hours of ovulation conceived but no mare inseminated 24 hours or more after ovulation conceived. In a second experiment, 14 mares were examined every day at about the sa...
Varner DD, Blanchard TL, Meyers PJ, Meyers SA.A breeding trial was conducted to evaluate the effect of in vitro storage time and temperature on fertilizing capacity of equine spermatozoa. Semen obtained from one stallion and diluted with skim milk-glucose extender was used to artificially inseminate 45 estrussynchronized mares. The mares were assigned to one of three treatment groups (15 mares per group): 1) insemination with fresh semen (collected within 0.5 h of use), 2) insemination with semen stored for 24 h at 20 degrees C or 3) insemination with semen stored for 24 h at 5 degrees C. The mares were inseminated daily during estrus, fr...
Vogelsang MM, Vogelsang SG, Lindsey BR, Massey JM.Mares were subjected to frequent examination by diagnostic ultrasound and data were compiled with respect to reproductive efficiency. The data were collected over a 3-yr period on 1032 light horse mares. The cummulative pregnancy rate at 35 d post-ovulation was 96.8% and the pregnancy rate per cycle was 76.0% as determined by ultrasound examination. The average number of cycles per conception was 1.43, with an average of 2.29 inseminations per cycle. The incidence of early embryonic death was 7.8%. Mares were subjected to an average of 5.04 scans during the follicular phase of the cycle. The a...
Geary RT, Weber JA, Woods GL.The purposes of this experiment were 1) to test the hypothesis that placing rabbit embryos into the mare's uterus would hasten oviduct transport and 2) to determine if placing fluid into the uterus of bred mares on Day 4 and/or Day 5 would subsequently disrupt the mare's pregnancy. The hypothesis that placing rabbit embryos into the mare's uterus would hasten oviduct transport was not supported, since the uterine recovery rate of equine embryos on Day 5 was not significantly higher (P>0.05) for mares receiving rabbit embryos on Day 4 than for mares receiving no uterine infusion on Day 4 (1 10 ...
Sirois J, Betteridge KJ.To recover intact Day-10.5 to Day-16.5 equine conceptuses (Day 0 = ovulation), a rigid catheter was used for 131 collections from donor mares diagnosed pregnant by ultrasonography. A total of 139 conceptuses were recovered, comprising 124 singletons, six pairs of twins and one set of triplets. Of these, 120 (86%) were intact after the collection, 14 (10%) had collapsed, and in five cases (4%), collapsed trophoblastic membranes were surrounded by an intact capsule. The recovery rate of intact conceptuses ranged from 99% on Days 10.5 to 12.5 to 40% on Day 16.5. More uterine flushes per recovery ...
Kloppe LH, Varner DD, Elmore RG, Bretzlaff KN, Shull JW.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. ...
Kino S, Osawa T, Mizuno S, Watanabe G, Taya K, Izaike Y.To clarify effect of postbreeding intramuscular administration of deslorelin on mares, plasma LH and progesterone concentrations and conception rate were evaluated. In Experiment 1, deslorelin, buserelin, or a placebo was administered on day 9 (day 0=day of last breeding or AI). Plasma samples were collected daily from days 6 to 15, and additional samples were taken after treatment. There was a significant increase in hormonal concentrations after deslorelin treatment. In Experiment 2, deslorelin or placebo was injected on day 9. There was no difference in conception rates at days 15 and 30 be...
Broussard JR, Goodeaux SD, Goodeaux LL, Thibodeaux JK, Moreau JD, Godke RA, Roussel JD.Control extender was incubated at 4 degrees C for 24 hours. Rubber or plastic syringe plungers were separately incubated in semen extender for 24 hours at 4 degrees C. Following incubation, the extender was stored at -20 degrees C until the time of semen collection. The treatments consisted of the following: Group A = equine semen plus control extender; Group B=equine semen plus extender incubated with rubber plungers and Group C=equine semen plus extender incubated in plastic plungers; Group D=equine semen plus control extended in rubber plunger syringes and Group E=equine semen plus control ...
Held JP, Blackford JT.Three cases of vaginal perforation after coitus are discussed. The most consistent clinical sign is a small amount of blood escaping from the vulvar lips immediately after breeding. Secondary infection and posttraumatic swelling may cause abdominal pain due to rectal impaction. Treatment with high levels of an appropriate antibiotic is important to reduce the risk of a severe infectious peritonitis. The use of artificial insemination or a breeding roll to prevent full intromission is recommended.
Merkt H, Klug E, Krause D, Bader H.Stallion semen frozen by the pellet method showed no significant loss of sperm motility and fertility over long periods of storage in liquid nitrogen. Eighteen of thirty mares conceived after insemination with semen recovered in nine ejaculates from seven stallions and stored for 18 months to 7 years.
Sertich PL, Love LB, Hodgson MR, Kenney RM.Equine embryos were collected by transcervical uterine flush 7 d after ovulation. The flush solution was Dulbecco's phosphate buffered saline (PBS) with 1% newborn calf serum and penicillin-streptomycin. Each embryo was washed in modified Dulbecco's PBS with 1% newborn calf serum and 0.4% bovine serum albumin, and placed in 4-ml polystyrene test tube containing this same medium. Embryos were packaged in a commercial semen transport container which cooled (-0.3 degrees C/min) and maintained the embryo at 4 to 6 degrees C. After 24 h, 16 embryos were transcervically transferred into recipient ma...
Morris L.Advanced artificial insemination techniques, such as deep uterine,hysteroscopic, oviductal, and intrafollicular insemination, are described in the context of the different types of spermatozoa that are now available for insemination, including fresh, chilled, frozen,sex-sorted, and epididymal spermatozoa. The implementation of these new technologies answers and poses questions about the interactions of sperm and oocytes in vivo.
Parker WG, Sullivan JJ, Larson LL.The diagnostic value of rectal palpation and immunological assay of PMSG was tested at different stages of pregnancy in mares inseminated with frozen semen in three separate studies. The results were based on foaling success and particular attention was paid to the numbers of inconsistent results obtained by the two tests. Generally, the number of false positive diagnoses was lower for the immunological assay than for palpation in early pregnancy (Days 40 to 60) and the relationship became reversed later in gestation.
Shideler RK, Squires EL, Pickett BW, Anderson EW.Twenty-three geldings were used to determine changes in seminal characteristics following castration and the effect of frequency of ejaculation on these seminal characteristics. In Exp. 1, semen was collected from 8 geldings every other day after castration until the number of spermatozoa per ejaculate was below 1% of the precastration value. An average of 3 ejaculates was required to reduce the number of spermatozoa below this level. In Exp. 2, 15 stallions were castrated and each stallion was assigned to 1 of 3 groups for seminal collection at 7, 14 or 21 days post-castration. The ejaculates...
Krause HD, Sieme H, Merkt H, Bader H, Wöckener A.A reduction in the motility of the spermatozoa in stallion semen stored in pellet form for 23 years in liquid nitrogen at -196 degrees C could not be seen after thawing. The insemination of a mare with this semen resulted in a normal pregnancy. A normally developed, healthy male foal was born after a gestational period of 321 days.
Merkt H.The use and techniques of artificial insemination for horses in Germany over the last 30 years is described. Artificial insemination appears to produce pregnancy percentages equal to those from normal breeding methods and its continued availability under veterinary supervision is recommended in conditions where disease, disability or distance debar normal service.
Katila T, Combes GB, Varner DD, Blanchard TL.Three containers commonly used to transport cooled equine semen (Equitainer, ExpectaFoal and a Swedish-designed semen-transport container, previously called the Salsbro Box and now called Equine Express) were compared, using four ejaculates from each of three stallions. Each ejaculate was diluted to a spermatozoal concentration of 25 x 10(6)/ml with a nonfat dry milk-glucose extender containing amikacin sulfate (1 mg/ml) and potassium penicillin G (1000 units/ml). Extended semen was divided into three 40-ml aliquots for placement in each of the three semen-transport containers. The extended se...
Tischner M, Bielański A.Observations were made on 14 mares which were non-surgically flushed on one or more occasions for recovery of embryos on Days 7-9 after ovulation. Flushing alone shortened the oestrous cycle by about 2.7 days but increased the number of mares failing to ovulate. Flushing followed by an injection of a prostaglandin analogue shortened the cycle by about 4.5 days and hence increased the frequency of ovulations. From a total of 70 flushings performed, 27 embryos were recovered and of 12 mares inseminated during the first oestrus after embryo collection, 6 conceived and foaled. The other 7 mares we...
Carnevale EM, Maclellan LJ, Coutinho da Silva MA, Checura CM, Scoggin CF, Squires EL.Insemination of recipients for oocyte transfer and gamete intrafallopian transfer (GIFT) in five experiments were reviewed, and factors that affected pregnancy rates were ascertained. Oocytes were transferred into recipients that were (1) cyclic and ovulated at the approximate time of oocyte transfer, (2) cyclic with aspiration of the preovulatory follicle, and (3) noncyclic and treated with hormones. Recipients were inseminated before, after, or before and after transfer. Intrauterine and intraoviductal inseminations were done. Pregnancy rates were not different between cyclic and noncyclic r...
Tkachev AV, Sheremeta VI, Tkacheva OL, Rossokha VI.The possible presence of the physiological relationship of erythrocyte antigens of the A, C, D, K alleles of the blood group systems in the examined horses of the Ukrainian selection with the spermogram major parameters has been demonstrated. It has been found that when investigating ad/bcm and dg/cgm alleles of the blood group system D in the stallions, there was the physiological tendency of the decrease in the semen activity on average less than 5 points; at the presence of ad/cgm, ad/d, ad/ de, ad/dk, bcm/d, bcm/de, bcm/dg bcm/dk cegm/cgm, cegm/d, cegm/dg, cegm/dk cgm/ceg, cgm/cgm, cgm/dg,...
Denniston DJ, Squires EL, Bruemmer JE, Brinsko SP, McCue PM, Graham JK.The aim of the present study was to determine whether antioxidants in semen extenders help to maintain the motility and viability of stallion spermatozoa incubated for 48 h at 5 degrees C. Semen samples were collected from ten stallions and washed to remove the seminal plasma. Five antioxidant treatments (control, xanthurenic acid, glutathione, taurine and hypotaurine) were prepared in each of three different semen extenders (skimmed milk, skimmed milk + egg yolk, and cream gel extenders). The spermatozoa were suspended in 15 treatments (three extenders x five treatments). Sub-samples from eac...
Berghuis GA.The conception rates of semen intended for shipment and those of recently obtained semen are compared in the present paper. Conception rates using recently obtained semen were significantly superior to those obtained with semen intended for shipment. A number of factors to which this difference could be due are briefly discussed.
Pugliesi G, Fürst R, Carvalho GR.The effects of freezing technique and thawing protocol on thawed semen viability and fertility were studied. Ejaculates from 5 stallions (n = 25) were frozen by conventional or a fast-freezing technique. Frozen semen was thawed by two thawing protocols (37 °C 30 s(-1) or 75 °C 7 s(-1) ). Thawed semen was evaluated by progressive motility, vigour, morphology and plasma membrane integrity. Mares (n = 25) were inseminated with 300 (n = 11) or 150 (n = 14) million spermatozoa. A greater (P < 0.05) vigour and progressively motile spermatozoa were detected, respectively, at thawing a...
Wöckener A, Colenbrander B.Two experiments were conducted to examine the effects of liquid storage extender and of a modified freezing protocol on motility and morphology parameters of 3-year-old pony stallions. In experiment 1 ejaculates were diluted 1 + 1 (v+v) with glycine-egg-yolk extender (D11) or skim milk extender (SME), centrifuged, resuspended in the corresponding extender and kept at +5 degrees C. Concerning motion characteristics, both progressive motility and average path velocity of semen stored in SME was significantly superior to semen stored in D11 after 6, 18 and 42 hrs. However, over time of storage th...
Pieńkowska-Schelling A, Handler J, Neuhauser S, Schelling C.The present case report describes a 6-year old subfertile pony mare, which became pregnant after the eleventh artificial insemination. The examination of the ovaries and the uterus did not reveal any abnormal clinical findings and the mare showed a regular oestrous cycle. Based on cytogenetic and molecular genetic analyses it became possible to elucidate the observed subfertility. The mosaic karyotype of the mare consisted of 63,X (20%) and 64,XX (80%) cells. A PCR analysis failed to amplify sequences from the equine SRY gene. The observed classic 63,X/64,XX mosaicism is a plausible explanatio...
Preis KA, Carnevale EM, Coutinho da Silva MA, Caracciolo di Brienza V, Gomes GM, Maclellan LJ, Squires EL.Transportation of equine ovaries would allow shipment of oocytes for research purposes or transfer after the death of a valuable mare. The objective of this study was to compare two temperatures for maintaining ovaries during a transport interval of 18-24 h. The goal was to obtain pregnancies after transport of ovaries, maturation of oocytes in vitro, and transfer of oocytes. Each shipment was composed of ovaries four to seven mares collected from an abattoir. From each mare, one ovary was packaged at approximately 12 degrees C, and the other was packaged at approximately 22 degrees C. Upon ar...
Guay P, Rondeau M, Boucher S.The effect of different glycerol concentrations (0 to 5.3 per cent) on motility, viability and aspartate aminotransferase (AST) release of stallion spermatozoa was studied before and after deep-freezing. Addition of glycerol to a TRIS-fructose-egg yolk diluent used to extend stallion semen had no effect on motility and viability of spermatozoa and it did not increase AST release. Inclusion of glycerol in the extender only partially preserved the motility and viability of stallion semen during deep-freezing. A fertility trial revealed that concentrating stallion semen by centrifugation, followe...
