Topic:Artificial Insemination
Artificial insemination (AI) in horses is a reproductive technique involving the collection of semen from a stallion and its subsequent introduction into the reproductive tract of a mare. This method is utilized to facilitate breeding, enhance genetic diversity, and improve the management of equine reproduction. AI can employ fresh, cooled, or frozen semen, each with specific handling and storage requirements to maintain sperm viability. The process requires careful timing to coincide with the mare's estrous cycle, maximizing the likelihood of successful fertilization. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and outcomes of artificial insemination in equine reproduction.
Cytological and bacteriological sampling from filters used for embryo recovery to evaluate the uterine status of donor mares. While testing for uterine bacterial infection is usually performed prior to artificial insemination (AI), samples taken during or after embryo flushing are generally not assessed either in subfertile and old mares or in fertile mares, even though knowledge of the status of the uterine environment in which the embryo is to develop would help to predict the outcome of embryo transfer programmes. The presence of bacteria and inflammatory cells in the liquid retained in the filter after uterine flushing in donors was determined at the moment of embryo recovery. Primarily, a group of mares (n = 8) ...
Olfactory stimulation or inhibition of sexual behavior of stallions in non-breeding season. Stallions show decreased sexual responses and activities during short days in winter. To evaluate the importance of sexual olfactory communication in horses, we tested whether sexual responses could be stimulated through various sexual olfactory stimulations in winter. To this end, we presented stallions with various olfactory stimulations (urine from mares at different stages of the reproductive cycle, urine from stallions or geldings, or chemically defined synthetic odorant) during the non-breeding season and measured their behavioral responses through (1) a test of olfactory investigation (...
Maternal parity affects placental development, growth and metabolism of foals until 1 year and a half. Primiparous mares are known to produce smaller foals than multiparous mares. This difference seems to be partly explained by the reduced exchange surface and volume of the placental villi in primiparous compared to multiparous placentas. The effect of maternal parity on foals' post-natal growth, metabolism and sexual maturation, however, has been given little consideration. The objectives of this work were to analyse placental biometry and structure at term, growth of foals and yearlings, their metabolism and testicular maturation at one year of age. Twenty multiparous mares (M), aged over 6 y...
Placental structure and function in different breeds in horses. Ponies and sometimes draft horses are often used as experimental models for horses although size and metabolic parameters are known to vary between horse breeds. So far, there is little information about differences of placental structure and no information about differences of placental function between breeds. The aim of this study was to investigate differences in placental size, structure and function at birth in relation to foal size and weight in ponies, Saddlebred and draft horses. Pony, Saddlebred and draft horse pregnancies were obtained by artificial insemination over 2 successive br...
Morphological evaluation of Day 8 embryos developed during induced aluteal cycles in the mare. A novel in vivo model utilizing serial administrations of PGF2α to induce aluteal cycles in the mare was used to evaluate the effects of progesterone-deprivation on the morphology of in vivo preimplantation embryos. We hypothesized that equine embryos produced during induced aluteal cycles (AL) would be developmentally affected, characterized by earlier embryo stage at collection, smaller embryo diameter, and lower quality grade, compared with those collected on the same day post-ovulation from control cycles during diestrus (high progesterone; > 4 ng/mL). Seven cyclic mares with a median ...
Uterine clinical findings, fertility rate, leucocyte migration, and COX-2 protein levels in the endometrial tissue of susceptible mares treated with platelet-rich plasma before and after AI. Persistent mating-induced endometritis (PMIE) results in decreased fertility in horses, thereby causing a significant impact in the horse market. Platelet-rich plasma (PRP), a modulator of the inflammatory response, has been largely used in veterinary medicine. Here, we investigated the effects of PRP on uterine inflammation, conception rate, endometrial polymorphonuclear neutrophil (PMN) migration, and COX-2 protein levels in the endometrial tissue. Thirteen PMIE-susceptible mares were used for artificial insemination (AI). The mares were inseminated with fresh semen in three consecutive cycl...
Epigallocatechin-3-gallate (EGCG) and green tea polyphenols do not improve stallion semen parameters during cooling at 4°C. Stallion semen storage for artificial insemination is mainly based on liquid cooled storage. In many stallions this technique maintains sperm quality for an extended period of time (24-72 hr) at 7°C. While this technique is commonly used in the horse industry, there can be a decline in fertility in some stallions, due to an inability of their sperm to tolerate the cool storage process. The aim of the present work was to evaluate the effect of two natural antioxidants (epigallocatechin-3-gallate (EGCG) at 20, 60 and 120 μm and green tea polyphenols, and p at .001, .01 and .1 mg/ml) on some...
Equivalent seminal characteristics in human and stallion at first and second ejaculated fractions. Sperm quality was assessed in normozoospermic human (n = 10) and Spanish breed stallion (n = 10) after sperm fractionation during ejaculation. The first ejaculated fraction was separated from the second. A third sample was reconstituted using equivalent proportion of both fractions (RAW). Fraction 1, Fraction 2 and RAW semen were incubated for 30 min at 37°C to homogenise the impact of iatrogenic damage between both species. Sperm concentration, motility and sperm DNA damage were assessed in each fraction and RAW semen. The results showed two important facts: (i) spermatozoa confined at ...
[A case of 63,X/64,XX mosaicism in a subfertile pony mare]. 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...
Inflammatory response in chronic degenerative endometritis mares treated with platelet-rich plasma. Degenerative changes of the endometrium are directly related to age and fertility in mares. Chronic degenerative endometritis (CDE) is correlated with uterine fluid retention and reduced ability to clear uterine inflammation. Recent research in the areas of equine surgery and sports medicine has shown that platelet-rich plasma (PRP) treatment acts as an immunomodulator of the inflammatory response. Therefore, the aim of this study was to determine if the uterine infusion of PRP could modulate the local inflammatory response and modify the intrauterine NO concentrations after artificial insemin...
Milk, caseinate and lactoferrin addition to equine semen cooling extenders. Cooled semen has been used routinely to prolong sperm viability until artificial insemination time. However, spermatozoa are subjected to oxidative stress. The aim of the present work was to investigate the protective and antioxidant effect of the milk proteins lactoferrin (Lf) and caseinate added to equine semen cooling extenders. Semen from six stallions was cooled at 5 °C after resuspension with C1) milk- and glucose-based, C2) 0.6% caseinate, C3) C2 + Lf 200 μg ml-1 , C4) C2 + Lf 500 μg ml-1 and C5) C2 + Lf 1000 μg ml-1 extenders, and kept at 5 °C for 24 h. Sperm motili...
Analysis of breed effects on semen traits in light horse, warmblood, and draught horse breeds. In the present study, systematic effects on semen quality traits were investigated in 381 stallions representing 22 breeds. All stallions were used for AI either at the Lower Saxon National Stud Celle or the North Rhine-Westphalian National Stud Warendorf. A total of 71,078 fresh semen reports of the years 2001 to 2014 were edited for analysis of gel-free volume, sperm concentration, total number of sperm, progressive motility, and total number of progressively motile sperm. Breed differences were studied for warmblood and light horse breeds of both national studs (model I) and for warmblood b...
Pregnancy disruption in artificially inseminated domestic horse mares as a counterstrategy against potential infanticide. In a previous study, we suggested that the common practice of transporting a mare for mating and then bringing her back to an environment that also contains males that did not sire the fetus may be a major cause of high percentages of pregnancy disruption in domestic horses. In this study, we tested whether disruption of pregnancies induced by AI occurs as frequently as after mating with a strange stallion away from home and is affected by the same factors in the home social environment. Based on 77 records, the probability of pregnancy disruption after AI depended on the social environment in...
The effect of the interval from PGF treatment to ovulation on embryo recovery and pregnancy rate in the mare. The objective of this study was to determine the effect of the interval from induced luteolysis to ovulation on fertility of mares from two different farms. At farm 1, 215 mares were inseminated with frozen/thawed semen during 513 estrous cycles over seven consecutive breeding seasons. Estrus was induced with analogues of PGF2α in 179 cycles. At farm 2, 375 embryo flushings were performed in 65 donor mares inseminated with fresh semen; of which, 327 were performed following artificial insemination after PGF-induced luteolysis. In both farms, the intervals from PGF treatment to ovulation (ITO)...
Cryopreservation of semen from domestic livestock. In modern livestock breeding, cryopreserved semen is routinely used for artificial insemination. Sperm cryopreservation secures future reproduction, and insemination doses can be easily shipped. Processing of semen for cryopreservation can be done with minimal efforts and relatively low costs. In this chapter we describe the entire cryopreservation process for stallion and bull sperm including dilution of sperm in primary and freezing extender, cooling and packaging in straws, freezing in liquid nitrogen vapor, cryogenic storage, and thawing. Special emphasis is given on preparation of commonl...
Effect of overnight staining on the quality of flow cytometric sorted stallion sperm: comparison with tradtitional protocols. Flow cytometry is considered the only reliable method for the separation of X and Y chromosome bearing spermatozoa in equines. The MoFlo SX DP sorter is highly efficient, allowing the production of foals of the desired sex. However, to achieve acceptable pregnancy rates the currently used protocol requires working with fresh semen obtained close to, or at, the sorting facility. An alternative protocol was tested during two consecutive breeding seasons. Fresh stallion semen was cooled for 20 h, during which staining with Hoechst 33342 took place. On the following day, this sample was flow sort...
Fixed-time insemination with frozen semen in mares: is it suitable for poorly fertile stallions? The purpose of the present study was to compare two protocols for equine frozen semen programs using either postovulation insemination or fixed-time insemination (FT), evaluating both pregnancy rates and intrauterine fluid (IUF) accumulation after artificial insemination with semen obtained from either highly or poorly fertile stallions. Six ejaculates from two stallions (n = 12) were processed. After thawing, semen samples were evaluated by computerized semen analysis. Fifteen mares (30 cycles) were inseminated with frozen semen from highly fertile stallion A, and 14 mares (28 cycles) were in...
Naturally and stimulated levels of reactive oxygen species in cooled stallion semen destined for artificial insemination. The decrease in foaling rates after artificial insemination with cooled semen warrants the search for new predictors of fertility. The objectives were to investigate levels of naturally occurring reactive oxygen species (ROS) in cooled, stored stallion semen doses for artificial insemination (AI), and their relationship with parameters of semen quality and with pregnancy rate. Semen was collected from warmblood stallions (n=15) and used to prepare commercial semen doses for AI. Sperm quality was evaluated after cooled transport to the laboratory overnight. The results were correlated with obse...
Dense spermatozoa in stallion ejaculates contain lower concentrations of mRNAs encoding the sperm specific calcium channel 1, ornithine decarboxylase antizyme 3, aromatase, and estrogen receptor alpha than less dense spermatozoa. Stallions are unique among livestock in that, like men, they commonly receive medical treatment for subfertility. In both species, about 15% of individuals have normal semen parameters but are subfertile, indicating a need for novel analyses of spermatozoa function. One procedure for improving fertilizing capability of stallions and men is isolation of dense spermatozoa from an ejaculate for use in artificial insemination. In the current study, dense and less dense spermatozoa were purified by density gradient centrifugation from individual ejaculates from seven reproductively normal adult sta...
Effect of artificial insemination protocol and dose of frozen/thawed stallion semen on pregnancy results in mares. Deep intra-uterine insemination is commonly accepted as a routine procedure for artificial insemination in horses. The motives and principles of deep insemination are well described, but the equipment used may differ. In this trial, the efficiency of two different insemination pipettes for deep intra-uterine insemination in the mare was compared with insemination into the uterine body using commercially available frozen-thawed semen of two stallions of proven fertility. These inseminations were performed using two different doses. The semi-flexible Minitube pipette was compared with a newly de...
Oral and injectable synthetic progestagens effectively manipulate the estrous cycle in the Przewalski’s horse (Equus ferus przewalskii). To date, there has been limited research on manipulation of the estrous cycle in endangered equids. The objectives of this study were to assess the efficacy of using combinations of: (a) oral altrenogest and PGF2α, and (b) injectable altrenogest and PGF2α for manipulation of ovarian activity in Przewalski's mares. Reproductive cycles were monitored by assessing follicular changes with rectal ultrasound and changes in urinary steroid hormones. In Study 1, five cycling mares were treated with oral altrenogest (n=11 cycles) for 14 days. In Study 2, cycling mares were treated with oral altrenoge...
Influence of the uterine inflammatory response after insemination with frozen-thawed semen on serum concentrations of acute phase proteins in mares. The aim of this study was to investigate the clinical relevance of measuring blood concentrations of serum amyloid A (SAA), haptoglobin (Hp) and fibrinogen (Fib) in horse reproductive management, and changes in response to artificial insemination (AI) with frozen-thawed semen. Standardbred mares (n=18) with different reproductive status (eight healthy mares in first postpartum oestrus, five healthy barren mares and five mares with endometritis) were inseminated with frozen-thawed semen. Endometritis was evaluated during oestrus by bacteriological culture, cytology and presence of ultrasonicall...
Sperm yield after single layer centrifugation with Androcoll-E is related to the potential fertility of the original ejaculate. Many attempts have been made to identify laboratory tests that are predictive of sperm fertility, both to improve the quality of stallion semen doses for artificial insemination (AI) and to identify potential breeding sires if no fertility data are available. Sperm quality at the stud is mostly evaluated by assessing subjective motility, although this parameter can be poorly indicative of fertility. Sperm morphology and chromatin integrity in Swedish stallions are correlated to pregnancy rate after AI. Because single layer centrifugation (SLC) selects for spermatozoa with normal morphology and...
Influence of L-arginine supplementation on reproductive blood flow and embryo recovery rates in mares. Supplementation with L-arginine can increase uterine arterial blood flow and vascular perfusion of the preovulatory follicle in mares. Increased vascular perfusion of the preovulatory follicle has been correlated with successful pregnancy in mares. The objective of this study was to determine if supplemental L-arginine would increase ovarian arterial blood flow, vascular perfusion of the preovulatory follicle, and embryo recovery rates in mares. Mares were blocked by age and breed and assigned at random within block to L-arginine supplementation or control groups. Mares were fed L-arginine beg...
First field results on the use of stallion sex-sorted semen in a large-scale embryo transfer program. Flow cytometry sex-sorting technology was developed in 1989. However, it is only the bovine species in which offspring of the desired sex are obtained at a commercial level. The aim of the present work was to evaluate efficiency parameters when using fresh sexed semen in a large-scale equine commercial embryo transfer program. During the 2009, 2010 and 2011 breeding seasons, 938 synchronized cycles were artificially inseminated. One hundred (10.6%) mares failed to ovulate, and for the remaining 838 useable cycles, 887 doses of sexed semen were used, representing 1.06 doses per cycle. In genera...
Development of the genital microflora in stallions used for artificial insemination throughout the breeding season. An important factor influencing stallion fertility is the microbial contamination of semen. Aims of this study were to investigate changes in the microbiological population of the genital mucosa and semen in artificial insemination stallions (n=16) from before to after one breeding season (February-August). MALDI-TOF-MS (matrix assisted laser desorption/ionization time-of-flight mass spectrometry) was used for identification of microbial agents. For bacteriology, swabs from the urethral opening, urethral fossa and penile sheath as well as semen were collected at 4-week-intervals. For semen mot...
Ovarian response to porcine FSH in association with ablation-induced or spontaneous follicular wave development during the estrous cycle in crossbred and Brazilian Warmblood mares. The primary objective of this study was to examine the follicular and ovulatory responses following treatment with pFSH in association with ablation-induced or spontaneous follicular wave emergence or follicle deviation during diestrus in crossbred (Mangalarga×Arabian) and Brazilian Warmblood mares with a propensity for spontaneous multiple ovulations; secondary considerations were given to the collection of embryos. In Experiment 1, crossbred mares were administered (im) saline (control, n=7) or pFSH (25mg) when the largest follicle of the ablation-induced follicular wave reached ≥13mm (n=...
Induction of double ovulation in mares using deslorelin acetate. This study aimed to determine whether deslorelin acetate could induce double ovulation in mares. In Experiment 1, eight mares were treated with prostaglandin on Day 8 (D8) after ovulation, then treated with saline or with 100 μg of a controlled-release formulation of deslorelin acetate vehicle intramuscularly (IM) every 12h from D8 after ovulation until at least two follicles reached 33 mm. At this time, ovulation was induced with 2500 IU of hCG. Artificial insemination was performed 24h after induction, and embryos were collected on the eighth day after ovulation was first detected. In Exper...
Effect of antimicrobial-containing semen extender on risk of dissemination of contagious equine metritis. To determine the impact of antimicrobial-containing semen extender on the growth of Taylorella equigenitalis in semen culture-positive for contagious equine metritis (CEM) and the development of CEM after artificial insemination with CEM-positive semen extended with antimicrobial-containing semen extender. Methods: Prospective study. Methods: 21 mature mares free of CEM, 1 mature stallion experimentally infected with CEM, and semen from a stallion naturally infected with CEM. Methods: CEM-positive semen was incubated in semen extender with and without antimicrobials (amikacin [final concentrat...
Stallion spermatozoa selected by single layer centrifugation are capable of fertilization after storage for up to 96 h at 6°C prior to artificial insemination. One of the challenges faced by equine breeders is ensuring delivery of good quality semen doses for artificial insemination when the mare is due to ovulate. Single Layer Centrifugation (SLC) has been shown to select morphologically normal spermatozoa with intact chromatin and good progressive motility from the rest of the ejaculate, and to prolong the life of these selected spermatozoa in vitro. The objective of the present study was a proof of concept, to determine whether fertilizing ability was retained in SLC-selected spermatozoa during prolonged storage. Results: Sixteen mares were insemi...