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Topic:Semen Analysis
Semen analysis involves the evaluation of semen quality to assess reproductive potential and health in horses. This process typically includes the examination of several parameters such as sperm concentration, motility, morphology, and volume. Semen analysis is used in breeding programs to determine the fertility of stallions and to identify any reproductive issues. The collected data can assist in making informed decisions about breeding management and interventions. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of semen analysis in equine reproduction.
The role of seminal plasma in post-breeding uterine inflammation. The effect of seminal plasma on polymorphonuclear neutrophil (PMN) chemotaxis, PMN phagocytosis and complement-induced cytolysis was determined using blood plasma pooled from four horses and seminal plasma pooled from two stallions. To investigate chemotaxis, complement in blood plasma was activated with E. coli lipopolysaccharide in the presence of 0-50% seminal plasma diluted with a standardized volume of McCoy's medium and placed in a chemotactic chamber. Chemotaxis of blood derived equine PMNs toward the chemoattractants was determined after incubation at 37 degrees C for 45 min. To invest...
Possible role of autoimmunity to spermatozoa in idiopathic infertility of stallions. Testicular degeneration is a major cause of subfertility in stallions, although an aetiological diagnosis cannot be made in most cases. In the present study, autoimmune testicular degeneration was induced and evaluated in stallions by immunizing stallions with their own spermatozoa mixed with an adjuvant. The factors evaluated included changes in semen quality and testicular histology. A large decrease in sperm number and quality was observed in response to sperm autoantigens. An ELISA test specific for antisperm antibodies was developed which enabled antibody titres in serum, seminal plasma a...
Measurements of reproductive function in stallions treated with trimethoprim-sulfamethoxazole and pyrimethamine. To evaluate the effects of trimethoprim-sulfamethoxazole and pyrimethamine treatment on various measures of reproductive function in healthy pony stallions. Methods: Randomized complete block study. Methods: 12 healthy, mature pony stallions. Methods: Stallions were assigned to treatment and control groups balanced for age and various characteristics of reproductive function. The treated group received trimethoprim-sulfamethoxazole and pyrimethamine for 90 days during summer and fall; the control group was not treated. Semen characteristics, sexual behavior, testicular volume, and sperm produc...
Secular sperm trends in stallions between 1981 and 1996. Several reports have suggested that human semen quality has declined throughout the world over the last few decades. Chemicals in the environment acting as endocrine disrupters have been implicated as a possible cause. If this is indeed the case, then similar effects may be observed in animals. We analyzed 1489 ejaculates collected from 390 Breton draught stallions between 1981 and 1996. Semen was collected from all the stallions at a single center, according to standardized semen collection protocols and laboratory methods. Semen volume decreased slightly but significantly and there was an in...
Testicular endocrine function, seasonality and semen quality of the stallion. To gain further information on gonadal function of the stallion, concentrations of testicular steroids in blood plasma (bpl) and seminal plasma (spl) and their distribution in the ejaculate were determined. Blood and semen samples from a total of 11 stallions were collected from November to July. Estrone (E1), estrone sulfate (E1S), estradiol-17beta (E2beta) and testosterone (T) were determined in bpl and spl, and in addition androstenedione (A), dehydroepiandrosterone (DHEA) and 5alpha-dihydrotestosterone (5alpha-DHT) were measured in spl. At certain points of time, aliquots of an ejaculate w...
Prediction of first season stallion fertility of 3-year-old Dutch Warmbloods with prebreeding assessment of percentage of morphologically normal live sperm. In the selection procedure to acquire a breeding licence, 3-year-old Dutch Warmblood stallions have to undergo a breeding soundness test It is questioned whether this evaluation is predictive of the stallion's fertility results in the first breeding season. Therefore, semen parameters at the beginning of their first breeding season were evaluated and correlated to nonreturn at first cycle and foaling rate of mares bred by stallions (n = 13). The total number of mares inseminated with chilled semen from those stallions was 1055. Semen parameters were recorded on 2 ejaculates, collected 1 h apar...
Rapid and sensitive detection of equine arteritis virus in semen and tissue samples by reverse transcription-polymerase chain reaction, dot blot hybridisation and nested polymerase chain reaction. A reverse transcription-polymerase chain reaction (RT-PCR) assay using four different primer pairs for the detection of equine arteritis virus (EAV) RNA in semen and tissue samples was evaluated. A fragment encoding the leader sequence of the EAV genome was most successfully amplified. The specificity and sensitivity of RT-PCR was assessed by virus isolation in cell culture, restriction analysis, dot blot hybridisation and nested PCR. To this end, 23 semen samples from seropositive stallions and 11 tissue samples from 4 aborted foals were tested. Compared to the virus isolation test in cell cu...
Occurrence of prostasome-like membrane vesicles in equine seminal plasma. Equine seminal plasma was shown to contain membrane vesicles that are similar to the well characterized prostasomes in human seminal plasma. Determination of nucleoside and nucleotide concentrations of these particles have shown that ATP, ADP and adenosine are the main components of the nucleotidic pool. 5' nucleotidase, endopeptidase and dipeptidyl peptidase i.v. activities have been found on the surface of the particles. The interaction between these prostasome-like vesicles and spermatozoa was demonstrated by electron micrograph scans which revealed the steps of a fusion-like process leadin...
Glutathione-independent prostaglandin D2 synthase in ram and stallion epididymal fluids: origin and regulation. Microsequencing after two-dimensional electrophoresis revealed a major protein, glutathione-independent prostaglandin D2 synthase (PGDS) in the anterior epididymal region fluid of the ram and stallion. In this epididymal region, PGDS was a polymorphic compound with a molecular mass around 30 kDa and a range of pI from 4 to 7. PGDS represented 15% and 8% of the total luminal proteins present in this region in the ram and stallion, respectively. The secretion of the protein as judged by in vitro biosynthesis, and the presence of its mRNA as studied by Northern blot analysis, were limited to the ...
Neoplasia of the male reproductive tract. Genital neoplasms in the male horse are relatively uncommon. Squamous cell carcinomas and squamous papillomas are the most commonly diagnosed neoplasms of the penis and prepuce. Geldings appear to be overrepresented for these types of neoplasms, and accumulation of smegma may be a contributing factor. Early diagnosis and treatment are essential for salvaging these organs before lesions become excessively large and invasive or are allowed to metastasize. Newer treatment modalities such as 5-fluorouracil appear to be promising alternatives to surgical excision. Although generally considered to b...
Aerobic bacterial flora of semen and stallion reproductive tract and its relation to fertility under field conditions. This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was...
Prostasome-like particles in stallion semen. Human semen contains membranous vesicles called prostasomes. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin, and Ca2+. Prostasomes enhance the motility of ejaculated spermatozoa and are involved in a number of additional biological functions. No prostasome-like vesicles have been described in horse semen up to now. We have demonstrated the presence of prostasome-like vesicles in the equine semen and characterized them as to size, morphology, and lipid composition; we have found that they are similar to human prostasomes in many respects. We prop...
[Clinical aspects of fertility in stallions]. The studies described in this thesis investigated the factors that can affect the fertility of stallions. The introduction describes the male gamete and the processes that occur during maturation of sperm and fertilization. Methods to evaluate the quality of sperm and ova are then discussed. Fertility can be expressed in various ways and is also affected by many factors such as the stallion, the mare and management factors. The fertility of stallions is usually assessed a good year after they have served mares, because then the number of foals is known. However, it would be preferable to be ab...
Assessing the fertility potential of equine semen samples using the reducible dyes methylene green and resazurin. The objective of this study was to determine if spermatozoal reduction of the dyes methylene green to colorless and resazurin to pink or colorless was associated with the fertility potential of an equine semen sample. Fifty samples from 38 stallions were evaluated for the number of spermatozoa per milliliter and number of motile sperm per milliliter. Methylene green (20 micrograms/mL of semen) or resazurin (85 micrograms/mL of semen) was added to 3-mL aliquots of semen. Semen samples were identified as having low fertility potential (< 200 x 10(6) total cells/mL and or = 200 x 10(6) total ...
Detection of equine arteritis virus in the semen of carrier stallions by using a sensitive nested PCR assay. A nested PCR, developed for the detection of equine arteritis virus (EAV) in semen, detected less than 2.5 PFU of EAV per ml of naturally infected seminal plasma. Based on results from testing 88 semen samples from 70 stallions, the sensitivity and specificity of the test were 100 and 97%, respectively.
Effect of milk fractions on survival of equine spermatozoa. Milk-based semen diluents are known to be practical and effective in protecting equine spermatozoa during storage. Due to complex composition of milk, the components which are beneficial or harmful to spermatozoa are unknown. To address these unknowns the effect of various milk fractions on motility of stallion spermatozoa was evaluated. The fractions tested were native phosphocaseinate (NPPC), beta-casein, whey protein concentrate (WPC), alpha-lactalbumin, beta-lactoglobulin, microfiltrate, and ultrafiltrate. The standard reference diluents were INRA 82, commercial skim milk, and Hank's salts...
Estrogen concentrations in semen of the stallion. Large amounts of estrogens are secreted by the tests of the mature stallion. In a recent study by Claus et al. [Claus, Dimmick, T., Gimenez, T., Hudson, L.W., 1992. Estrogens and prostaglandin F2 alpha in the semen and blood plasma of stallions. Theriogenology 38, 687-693.], it was stated that high levels of estrogens were also present in semen. As a preliminary step to study possible implications for fertility in the stallion, we have measured estrone sulphate (E1S), the principal estrogen in blood, in both seminal plasma and spermatozoa. Semen was collected from four Standardbred stallions a...
Assessment of viability and mitochondrial function of equine spermatozoa using double staining and flow cytometry. An objective double-staining method was developed to evaluate viability and mitochondrial function of stallion spermatozoa using flow cytometry. Sperm viability was assessed by propidium iodide (PI) exclusion, and mitochondrial function was measured by the intensity of rhodamine 123 (R123) fluorescence. Flow cytometry estimates of sperm viability measured by PI were equivalent (P > 0.05) to estimates made using Hoechst 33258 stain and fluorescent microscopy (% dead: 25 +/- 2.4 vs 21.5 +/- 3.5). The use of both PI and R123 was validated by addition of various proportions of freeze-shocked (m...
Sperm head morphometry analysis of ejaculate and dismount stallion semen samples. The evaluation of seminal characteristics is important in the clinical detection of stallion subfertility. Conventional semen evaluation includes subjective determination of sperm concentration, motility, and gross morphology. Due to the subjectivity and variability of the manual morphology assessment, computer automated sperm morphology analyses has been developed. Computer automated sperm morphology analysis was applied in the current study to determine if the morphometric measurements of sperm heads from collected and dismount samples of the same ejaculate were similar. If the post-ejaculat...
Isolation and characterization of heparin- and phosphorylcholine-binding proteins of boar and stallion seminal plasma. Primary structure of porcine pB1. In the bovine, seminal plasma heparin-binding proteins bind to sperm lipids containing the phosphorylcholine group and mediate the capacitating effects of heparin-like glycosaminoglycans during sperm residence in the female genital tract. We report the characterization of heparin- and phosphorylcholine-binding proteins of stallion and boar seminal plasma. Horse seminal plasma proteins HSP-1 and HSP-2, and boar protein pB1, belong to the same family as the bull heparin- and phosphorylcholine-binding proteins BSP-A1/2, BSP-A3, and BSP-30K. We have determined the amino acid sequence and posttrans...
Determination of daily sperm production in stallion testes by enumeration of germ cells in homogenates. Thirty adult stallion testes were selected with high (n = 15) and low (n = 15) Daily Sperm Production (DSP)/testis. Parenchymal samples were prepared for morphometric analysis, and the numbers of germ cells and Sertoli cells were determined. Testicular samples were homogenized, and germ cells and Sertoli cells were enumerated using phase contrast microscopy. Numbers of germ cells and Sertoli cells and potential DSP during spermatogenesis were determined. Significant correlations existed between morphometric and homogenate determinations of number per testis of preleptotene, leptotene plus zygo...
Subjecting horse spermatozoa to hypoosmotic incubation: effects of ouabain. Although hypoosmotic tests are widely used to assess spermatozoal quality in different species, they have not been used extensively in the stallion. Moreover, the role of the Na (+)K (+), ouabain sensitive-ATP-ase in the response of equine sperm to hypoosmotic shock is not well understood. This study tests two hypotheses: 1) that equine spermatozoa will respond to a hypoosmotic medium by swelling of the tail, and 2) that addition of ouabain will increase the percentage of swollen sperm tails. Ejaculates from 3 stallions were collected with an artificial vagina and diluted in Kenney's medium (T...
Effect of 19-norandrostenololylaurate on semen characteristics of colts. The long-term effects of the anabolic steroid 19-norandrostenololylaurate on semen characteristics of Finnhorse colts were studied in 3 experiments. Semen was collected initially at 24 months of age and then twice a year. In experiment I, 500 mg or 100 mg of steroid per animal was given every 3rd week from 12 or 16 months to 24 months of age. In colts treated with 500 mg of anabolic steroid every 3rd week, azoospermia was observed in 3 out of 5 colts in the first semen collections, immediately after the end of treatment. The other 2 colts had low sperm numbers and a high percentage of proximal...
Seasonal rhythm of semen characteristics of a Brazilian breed (“Mangalarga”) stallion. An attempt has been made to define semen seasonality in a horse in the Southern Hemisphere. Repeated measurements of three variables in the semen were made for 36 months (Jan/90-Dec/92) in a 21-year old "Mangalarga" stallion living under natural photoperiod and temperature conditions in a farm situated in São José do Rio Pardo, São Paulo, Brazil (latitude 21 degrees) 36'S; longitude 46 degrees 53' W). The horse fed on natural pasture and a nutritionally balanced feed twice a day (11:00 and 17:00 h). Water and mineral supplement were available ad libitum. Semen was collected almost daily by ...
[The effect of the season and sexual stress on the concentration of testosterone and estradiol-17beta in the seminal plasma of stallions]. Semen from three stallions was collected weekly for six months (December through May) to determine semen parameters and hormones (testosterone and estradiol-17 beta) in seminal plasma. Once a month three ejaculates were collected at intervals of one hour and examined accordingly. Testosterone and estradiol-17 beta were also determined in peripheral blood plasma (V. jugularis) collected twice a week. Semen parameters (volume, gel-free volume and sperm concentration) were clearly influenced by season. The testosterone concentration in peripheral blood plasma was lowest during December whereas in...
Replication of equid herpesvirus-1 (EHV-1) in the testes and epididymides of ponies and venereal shedding of infectious virus. Six Welsh Mountain pony colts were infected intranasally with the Ab4 isolate of EHV-1. Clinical and virological monitoring demonstrated mild upper respiratory tract disease, with nasal shedding of virus and establishment of a cell-associated viraemia. Detailed pathological examination of the urogenital tract was performed post mortem on days 4-9 post-infection (PI). EHV-1 was isolated from the epididymis on day 8 and the testis on day 9 PI, with viral replication in endothelial cells of these organs and an associated necrotizing vasculitis and thrombosis. Productive viral infection of germina...
