Animal reproduction science.
Publisher:
Elsevier Scientific Pub. Co.
Frequency: Twenty eight no. a year, 2008-
Country: Netherlands
Language: English
Start Year:1978 -
ISSN:
0378-4320 (Print)
1873-2232 (Electronic)
0378-4320 (Linking)
1873-2232 (Electronic)
0378-4320 (Linking)
Impact Factor
2.2
2022
| NLM ID: | 7807205 |
| (DNLM): | A31035000(s) |
| (OCoLC): | 04122595 |
| Coden: | ANRSDV |
| LCCN: | sc 80000012 |
| Classification: | W1 AN228V |
Effects of a commercial canine gonadotropin releasing hormone vaccine on estrus suppression and estrous behavior in mares. We investigated the effect of immunization against gonadotropin releasing hormone (GnRH) using a commercial canine GnRH vaccine on estrus suppression and unwanted estrous behavior in mares. In experiment 1, mares were immunized (n = 6) twice with vaccine (5 mL) given intramuscularly 4 weeks apart or received a control diluent (n = 5). Transrectal ultrasonographic examination of the reproductive tracts was performed three days a week for 40 weeks after initial vaccination. Blood samples were collected weekly for GnRH antibody titer and progesterone concentration determination. In experiment 2, ...
Characterization of prostaglandin E2 receptors (EP2, EP4) in the horse oviduct. Biological effects of prostaglandin E2 are mediated via one of four receptors designated EP1, EP2, EP3 and EP4 which are encoded by separate genes. In general, EP1 and EP3 induce smooth muscle contraction whereas EP2 and EP4 induce smooth muscle relaxation. The objective of the current study was to characterize the expression of the genes for PGE2 receptors (EP2 and EP4) in the horse oviduct based upon immunohistochemistry (IHC) and quantitative PCR (qPCR). Oviductal tissue was collected from mares at estrus (n=5), at 5 days post-ovulation (n=4), and from prepubertal mares (n=5). Isthmic and a...
Effect of sex sorting on stallion spermatozoa: Heterologous oocyte binding, tyrosine phosphorylation and acrosome reaction assay. The interest on sex sorting by flow cytometry on the equine industry has been increasing over the years. In this work, three different tests were performed in order to evaluate the membrane status of sorted stallion spermatozoa: assessment of binding ability to porcine oocytes, evaluation of acrosome integrity after stimulation with A23187, and detection of tyrosine phosphorylation. These evaluations were made after incubation for 0h, 1.5h and 3h in a capacitating medium. Sorted stallion spermatozoa attached similarly to the porcine oocytes, when compared with control samples. Sorted spermatoz...
Reactive oxygen species in stallion semen can be affected by season and colloid centrifugation. There are anecdotal reports that equine fertility may decline towards the end of the breeding season. Previous studies have examined differences in sperm quality between the breeding season and non-breeding season but few studies have investigated the proportions of superoxide or peroxide containing spermatozoa at different times during the breeding season. The purpose of this study was to measure the content of these reactive oxygen species (ROS) at the beginning and end of the Swedish breeding season, using flow cytometric analysis of the fluorescence produced after staining with hydroethidi...
Oxytocin stimulated release of PGF2α and its inhibition by a cyclooxygenase inhibitor and an oxytocin receptor antagonist from equine endometrial cultures. Uterine inflammation results in a poor uterine environment and early embryonic loss in the mare due to an inhibition of maternal recognition of pregnancy caused from increased prostaglandin F2α (PGF2α). Oxytocin binds to endometrial cell receptors to activate prostaglandin synthesis. An oxytocin receptor antagonist (Atosiban) and a cyclooxygenase inhibitor (indomethacin) both decrease PGF2α production. The aim of this study was to evaluate the in vitro effects of Atosiban and indomethacin on equine uterine prostaglandin secretion. Equine endometrial explants were harvested on day two of beh...
Pre-selection by double layer density gradient centrifugation improves the fertilising capacity of frozen-thawed, capacitated stallion sperm. The effect of combining double layer density gradient centrifugation (DL-DGC) with different capacitation treatments on the fertilising capacity of frozen-thawed stallion sperm was examined via a heterologous assay involving in vitro-matured, zona pellucida-free bovine oocytes. In a first experiment, aliquots of frozen-thawed stallion sperm were subjected to one of five capacitation treatments without DL-DGC - ionomycin at 1.0μM, 0.1μM, 0.05μM or 0.01μM, or caffeine at 200μg/mL. The fertilising capacity of the semen was then assessed at 18h by staining the above oocytes with 4,6-diamidino...
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...
Sex sorting increases the permeability of the membrane of stallion spermatozoa. At present, the only repeatable means of selecting the sex of offspring is the Beltsville semen sorting technology using flow cytometry (FC). This technology has reached commercial status in the bovine industry and substantial advances have occurred recently in swine and ovine species. In the equine species, however, the technology is not as well developed. To better understand the changes induced in stallion spermatozoa during the sorting procedure, pooled sperm samples were sorted: sperm motility and kinematics were assessed using computer assisted sperm analysis, sperm membrane integrity wa...
Oral L-arginine supplementation impacts several reproductive parameters during the postpartum period in mares. L-arginine is an amino acid which can alter pituitary function and increase blood flow to the reproductive tract. The objective was to determine the effect of supplementing 100g of L-arginine on plasma arginine concentrations, follicular dynamics and ovarian and uterine artery blood flow during the estrus that occurs subsequent to foaling. In Experiment 1, mares were fed 100g L-arginine for 1 day during the last 3 weeks of pregnancy and plasma samples taken for every hour for the first 4h and every other hour until 12h.L-arginine supplementation elevated plasma arginine concentrations from 1 t...
Expression of fluorescent reporter protein in equine embryos produced through intracytoplasmic sperm injection mediated gene transfer (ICSI-MGT). Sperm mediated gene transfer (SMGT) has been reported to be a powerful tool for producing transgenic livestock with applications in biomedicine and agriculture. To date, two studies have reported the production of transgenic equine embryo with, however, low efficiency in blastocyst production and transgene expression. The aim of the present study was to develop a method which allowed the efficient production of transgene-expressing embryos of the equine species through SMGT. To overcome problems due to in vitro fertilization (IVF) in horses, the ICSI procedure was associated with SMGT. The upt...
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=...
Evaluation of growth models for follicle development and ovulation in Lusitano mares. Several growth models are commonly used in the biological sciences, to model the follicle growth occurring in the estrous cycle. The aim of this project was to find the model that best fit the follicular size growth data for Lusitano mares. Retrospective data collected from reproduction book records of n=84 mares and n=124 cycles was used to find the series to be fitted to the models. The exponential, Gompertz, logistic, von Bertalanffy, Richards and Weibull models were used, and the most parsimonious and best fit was achieved with the logistic model (r(2)=0.999). The logistic model fits the L...
Evaluation of growth models for follicle development and ovulation in Lusitano mares. Several growth models are commonly used in the biological sciences, to model the follicle growth occurring in the estrous cycle. The aim of this project was to find the model that best fit the follicular size growth data for Lusitano mares. Retrospective data collected from reproduction book records of n=84 mares and n=124 cycles was used to find the series to be fitted to the models. The exponential, Gompertz, logistic, von Bertalanffy, Richards and Weibull models were used, and the most parsimonious and best fit was achieved with the logistic model (r(2)=0.999). The logistic model fits the L...
Characteristics of stallion epididymal spermatozoa at collection and effect of two refrigeration protocols on the quality of the frozen/thawed sperm cells. Cryopreservation of epididymal spermatozoa is a useful tool to preserve genetic material of valuable stallions after emergency castration or unexpected death. For that, testicles and epididymides are generally sent refrigerated to the laboratory. Collection of epididymal spermatozoa is a simple procedure that reduces the volume of the material to be shipped, and may improve the quality of the chilled epididymal sperm cells. In the present study we compared the characteristics of frozen/thawed epididymal spermatozoa after refrigeration of the epididymis or after direct refrigeration of the exte...
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...
Equine spermatozoa stored in the epididymis for up to 96h at 4°C can be successfully cryopreserved and maintain their fertilization capacity. After injury or death of a valuable male, recovery of epididymal spermatozoa may be the last chance to ensure preservation of its genetic material. The objective of this research was to study the effect of sperm storage, at 4°C up to 96h, in the epididymides obtained from castrated horses and its effect on different functional sperm parameters. Aims were to study the effect of (1) sperm storage on viability and chromatin condensation; (2) pre-incubation of recovered epididymal sperm in the freezing extender, prior cryopreservation, on viability and chromatin condensation; and (3) freezing-tha...
Ovulation-inducing factor in seminal plasma: a review. Ovulation in mammals involves pulsatile release of GnRH from the hypothalamus into the hypophyseal portal system with subsequent release of LH from the anterior pituitary into systemic circulation. Elevated circulating concentrations of LH induce a cascade of events within the mature follicle, culminating in follicle rupture and evacuation. The broad classification of species as either spontaneous or induced ovulators is based on the type of stimulus responsible for eliciting GnRH release from the hypothalamus. In spontaneously ovulating species (e.g., human, sheep, cattle, horse, pigs), relea...
Transcriptome analyses of bovine, porcine and equine endometrium during the pre-implantation phase. Different reproductive strategies evolved in various mammalian groups to achieve recognition, establishment and maintenance of pregnancy. The complexity of these processes is reflected by a high incidence of embryonic loss during this critical period in many mammalian species. Besides studies in mice and humans a number of transcriptome studies of endometrial tissue samples and also of early embryos have been performed during the pre-implantation phase in cattle, swine and horse to identify genes associated with embryo-maternal interaction. Results of these studies are reviewed and compared be...
Effects of FSH and LH on ovarian and follicular blood flow, follicular growth and oocyte developmental competence in young and old mares. Objectives of the experiment were to determine the effects of mare age and gonadotropin treatments on dominant follicle vascularity, ovarian blood flow and dominant follicle growth and to associate follicular vascularity with oocyte developmental capacity. Growing follicles >30 mm from young (4-9 years) and old (>20 years) mares were assessed for blood flow using color Doppler ultrasonography before maturation induction with recombinant equine LH (eLH) and immediately prior to oocyte collection at 20-24 h after eLH. Pulsed Doppler was used to obtain resistance indices of ovarian arteries...
Iodixanol density gradient centrifugation for selecting stallion sperm for cold storage and cryopreservation. Density gradient centrifugation can be used for selection of sperm of superior quality and removal of seminal plasma for use in artificial insemination. In this study, the use of two-layer iodixanol density gradient centrifugation was evaluated for processing of stallion semen. The protocol includes centrifugation through a 16% iodixanol top layer of 1.090 g mL(-1) and collection of motile and intact sperm on a 30% iodixanol bottom layer of 1.165 g mL(-1). Sperm recovery and effects on sperm quality were determined during cold storage as well as after cryopreservation and compared with ordinar...
Cytological diagnosis of endometritis in the mare: investigations of sampling techniques and relation to bacteriological results. Aim of this study was to compare uterine smears made using the Knudsen catheter, the cytology brush and a uterine culture swab with regard to diagnostic usefulness and the occurrence of neutrophils. Additionally correlation between culture results and the occurrence of neutrophils in uterine smears was investigated. Samples were collected from 340 mares, 81.5% of which were in estrus. Smears made using the cytology brush yielded more endometrial cells per high-power field than those made using the other two instruments (p<0.0001), and a larger proportion had PMNs compared with smears made u...
Calcium/calmodulin and cAMP/protein kinase-A pathways regulate sperm motility in the stallion. In spite of the importance of sperm motility to fertility in the stallion, little is known about the signaling pathways that regulate motility in this species. In other mammals, calcium/calmodulin signaling and the cyclic AMP/protein kinase-A pathway are involved in sperm motility regulation. We hypothesized that these pathways also were involved in the regulation of sperm motility in the stallion. Using immunoblotting, calmodulin and the calmodulin-dependent protein kinase II β were shown to be present in stallion sperm and with indirect immunofluorescence calmodulin was localized to the acr...
Androcoll-E large selects a subset of live stallion spermatozoa capable of producing ROS. The aim of this study was to elucidate if SLC after 24 h storage selects the subpopulation of spermatozoa that better withstands osmotic shock. To test this hypothesis, viability, mitochondrial membrane potential (MMP) and superoxide anion (O(2)(·-)) production of uncentrifuged (UC) and single layer centrifugation (SLC) - selected spermatozoa were analyzed following SLC after storage of the semen. An aliquot of the extended ejaculate (100×10(6) spermatozoa/mL) was centrifuged through a single layer of a silane-coated silica based colloid formulation optimized for equine spermatozoa (Androcol...
Haptoglobin baseline value in jennies and the effect of ovariectomy on its serum concentration. The study was conducted to determine the baseline concentration of serum haptoglobin (Hp) in jennies during the breeding and nonbreeding season and to evaluate the effects of ovariectomy on serum Hp concentrations in jennies. Eighteen adult jennies were divided in three groups: nine jennies (OVA) were ovariectomized using laparoscopic surgery, six jennies (LAP) were exploratory examined by laparoscopic surgery, and three jennies were used as a control group. Blood samples were collected from the animals at Day -6, -2, -1, 0, 1, 2, 5, 8, 15, 22, 29 and 36 of surgery. Serum samples were analyzed...
Effect of Hoechst 33342 on stallion spermatozoa incubated in KMT or Tyrodes modified INRA96. The only known means of effectively separating populations of X and Y bearing sperms is the Beltsville sexing technology. The technology implies that each individual sperm is interrogated for DNA content, measuring the intensity of the fluorescence after staining the spermatozoa with Hoechst 33342. Because there are no data regarding the effect of the staining on stallion sperm, ejaculates were incubated up to 90 min in presence of 0, 4.5, 9, 22.5, 31.5, 45, 54, 67.5, 76.5 and 90 μM of Hoechst 33342, in two media, KMT or INRA-Tyrodes. After 40 and 90 min of incubation, motility (CASA) and mem...
Luteogenic and luteotropic effects of eCG during pregnancy in the mare. The role of eCG during pregnancy was evaluated through the study of the temporal relationships between changes in eCG and progesterone concentrations and the formation of supplementary corpora lutea (SCL) in mares impregnated with donkey semen (mule pregnancies) or with horse semen (equine pregnancies). Concentrations of eCG were higher (p<0.01) in equine than in mule pregnancies between weeks 6.5 and 13. Progesterone concentrations were higher in equine than in mule pregnancies between weeks 9 and 17. All animals developed at least one SCL, but more SCL accumulated during equine pregnancie...
p- and m-Cresols emitted from estrous urine are reliable volatile chemical markers of ovulation in mares. Urine samples from 14 mares, belonging to five breeds, were collected at estrus and diestrus to search for estrous specific volatile compounds which could be used to determine ovulation time. Around 150 volatiles were collected from urine head-space samples by solid phase micro extraction technique, and analyses were conducted by gas chromatography-mass spectrometry methods. Comparison of chromatographic profiles of volatile substances revealed that concentrations of m- and p-cresols were significantly greater during estrus while diethylphthalate was more abundant at diestrus. Monitoring of m-...
Immunohistochemical localisation of progesterone and oestrogen receptors at the placental interface in mares during early pregnancy. Previous reports documenting progesterone receptors (PR) and oestrogen receptors (ER) in the endometrium of early pregnant mares included specimens only up to Day 20 post ovulation. This study aimed to localise PR and ERα on equine feto-maternal tissues between Days 20 and 68 to encompass the period around fixation of the conceptus, development of the endometrial cups and attachment and initial interdigitation of the allantochorion. During early pregnancy mares had the same pattern of PR in the endometrium as that reported for other mammals; namely, a loss of PR from the endometrial epithelia...
Replacing egg yolk with soybean lecithin in the cryopreservation of stallion semen. The objective of this study was to determine whether replacing the egg yolk with soybean lecithin in the Botu-Crio® cryodiluent would maintain the fertility of cryopreserved stallion sperm. Two experiments were performed to evaluate cell freezability. In experiment 1, sperm from 15 stallions were frozen in Botu-Crio® (BC) or Botu-Crio® which contained 45g/L soybean lecithin (BCLS45) in place of the egg yolk. In experiment 2, we compared different concentrations of soybean lecithin: 0, 10.0, 12.5, 15.0, 17.5 and 20.0g/L (BC, BCLS10, BCLS12.5, BCLS17.5 and BCLS20, respectively). In experiment...
Hormone concentration changes temporally associated with the hour of transition from preluteolysis to luteolysis in mares. The temporal associations of cortisol, estradiol-17β, and oxytocin with pulses of PGFM at the common hour of transition between preluteolysis and luteolysis was studied in plasma from hourly blood samples in mares (n=8). The transitional hour was determined from progesterone concentrations and occurred between 2PM and 2AM in all mares. Pulses of PGFM were grouped into those occurring at the last pulse of preluteolysis (preluteolytic pulse), at the hour of transition (transitional), and during luteolysis (luteolytic). The preluteolytic PGFM pulse (45±16pg/ml at peak) and transitional pulse (4...