Equid semen refers to the reproductive fluid produced by male horses, which contains sperm cells necessary for fertilization. The quality and viability of equid semen are important for successful breeding programs and can be influenced by various factors, including genetics, age, diet, and environmental conditions. Key parameters used to assess semen quality include volume, concentration, motility, and morphology of sperm cells. Techniques for collecting, evaluating, and preserving equid semen, such as cryopreservation, are critical for artificial insemination practices. This page compiles peer-reviewed research studies and scholarly articles that explore the physiology, assessment, and management of equid semen in the context of equine reproduction.
Heath E, Aire T, Fujiwara K.A microtubular mass (MM) defect was found in the spermatozoa of 7 Standardbred stallions; 3 stallions were sons of the same sire. Two of these 3 stallions and 2 other stallions (for a total of 4 out of the 7 stallions) were considered subfertile when the defect was first observed. Fertility improved with time, either during the first breeding season or when a given stallion was used less frequently; however, the MM defect persisted, consisting of tortuous arrays of small abnormal microtubules visible only by transmission electron microscopy. The MM probably contained the protein tubulin as ind...
Hensel B, Jakop U, Schmicke M, Schröter F, Jung M, Schulze M.Artificial insemination (AI) is commonly used in the equine industry to enhance the genetic value in breeding programs and to effectively utilize ejaculates. Many stallions are used as breeding stallions as well as in high-level sports competitions to improve their market value. The goal of the present study was to investigate whether this dual use of stallions influences the animals´ stress levels and/or the quality of their ejaculates. For this purpose, 18 stallions were grouped into two categories: breeding stallions with (BSC = breeding stallion competition), and breeding stallions with...
Tsunoda RH, Serrano-Recalde EC, Arruda RP, Oliveira BMM, Pinto SCC, Celeghini ECC.The aim was to evaluate effects of addition of pentoxifylline to skimmed milk semen extender on uterine inflammatory response. Thirty-six estrous cycles of 15 mares were randomly divided into five groups for artificial insemination (AI): Control: mimicking the AI procedure (n = 7); Extender: deposition of skimmed milk based extender (n = 7); Extender + PTX: skimmed milk based extender plus pentoxifylline (7.18 mM; n = 8); Semen: semen diluted with extender without pentoxifylline (n = 7), and Semen + PTX: semen diluted with extender containing pentoxifylline (n = 7). M...
Miragaya MH, Woods GL, Losinno L.The occurrence of uterine and oviductal inflammation, and fertilisation rates, were measured on Day 3 post ovulation in inseminated mares that had either exhibited intrauterine lumenal fluid during a previous dioestrus (Experiment 1) or had acute endometritis induced by intrauterine infusion of 1% glycogen (Experiment 2). Endometritis was assessed by uterine cytology and histology whereas oviductal inflammation was measured histologically. Fertilisation rates were calculated from the percentage of cleaved ova recovered by retrograde flushing of the oviducts. Mares with or without pre-existing ...
Fayrer-Hosken R, Stanley A, Hill N, Heusner G, Christian M, De La Fuente R, Baumann C, Jones L.The cellular effects of tall fescue grass-associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cell...
Elkhawagah AR, Nervo T, Poletto M, Martino NA, Gallo D, Bertero A, Vincenti L.The aim of the study was to ascertain effects of different concentrations of relaxin added to extender medium during the pre-freezing incubation periods on quality variables of stallion frozen-thawed spermatozoa. Semen samples collected from three stallions were filtered, diluted with skim milk, and centrifuged at 600g for 10 min. Sperm pellets were suspended in BotuCrio freezing medium to a final concentration of 50 × 10 sperm/mL. The diluted semen was divided into five experimental groups supplemented with 0 (control), 12.5, 25, 50, or 100 ng/mL of relaxin. The semen samples were transferre...
Araujo JF, Righini AS, Fleury JJ, Caldas MC, Costa-Neto JB, Marques N.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 ...
Arns MJ, Webb GW, Kreider JL, Potter GD, Evans JW.Bovine serum albumin (BSA) diluents containing lactose, raffinose or sucrose were not different (P greater than 0.05) in their ability to maintain stallion sperm viability, as determined by percentage motile spermatozoa (PMS) and their rate of forward movement (RFM), when stored at 37 or 5 degrees C for 24 h. These diluents did promote a higher (P greater than 0.05) PMS and RFM, when compared with BSA diluents containing arabinose or galactose. The BSA-arabinose and BSA-galactose diluents did not differ (P less than 0.05) in their ability to support sperm viability and were detrimental to sper...
Oliveira SN, Andrade LRP, Silva LFMC, Araujo EAB, Rayashi RM, Segabinazzi LGTM, Alvarenga MA, Dell'Aqua CP, Dell'Aqua JA, Papa FO.Treatments for seminal vesiculitis have poor outcomes in stallions; thus, the development of alternative strategies is warranted. This study aimed to evaluate fractionated semen collection as a method to restore the fertility of stallions diagnosed with seminal vesiculitis. Eighteen ejaculates from six stallions (three ejaculates/stallion) diagnosed with seminal vesiculitis were harvested in fractions, as follows: Fraction A (FA), the first two jets; Fraction B (FB), the third and fourth jets; and Fraction C (FC), the fifth and remaining jets of the ejaculate. All fractions were subject to sta...
Kenney RM, Cummings MR, Teuscher C, Love CC.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...
Braun J, Hochi S, Oguri N, Sato K, Torres-Boggino F.Three experiments were conducted to evaluate the effect of different macromolecule components (egg yolk, skim milk, and BSA) in a widely employed extender for cryopreservation of horse semen. Spermatozoal motility (MOT) and the percentage of spermatozoa with an intact plasma membrane (IPM) were evaluated in frozen-thawed samples. In the first experiment (four Draft Horse stallions, four ejaculates each) a standard freezing extender containing 20% whole egg yolk was modified by replacing extender components (glucose-EDTA solution, 11% lactose solution) with an increasing volume of a skim milk d...
De Botton D, Janett F, Burger D, Imboden I, Kähn W, Thun R.The aim of the present study was to investigate the spermatogenic and Leydig cell activity in stallions with impaired semen quality after treatment with equine somatotropin. Experiments were performed using 18 adult clinically healthy stallions with poor semen quality which did not pass breeding soundness evaluation. The animals were randomly divided into a treatment (n = 9) and a control (n = 9) group. Over a period of 90 days, nine stallions received a daily intramuscular injection of 10 mg recombinant equine somatotropin (EquiGen, BresaGen Limited, Adelaide, Australia) and 9 control animals...
Held JP, Prater P, Stettler M.A 9-year-old Arabian stallion with a 3-year history of infertility was evaluated for breeding soundness. Both testes were small. Ultrasonography revealed a small amount of free fluid between the tunics of both testes. Results of cytologic examination of the fluid were unremarkable. On semen examination, progressive motility was 10%, and total number of spermatozoa in the ejaculate was 6.6 x 10(9), of which 92% were abnormal. Predominant abnormalities were head defects (75%): 57% of the heads had single or multiple vacuoles, and 60% also had midpiece swelling or bending.
de Moura TCM, Arruda LCP, Cahú TB, Bezerra RS, Carneiro GF, Guerra MMP.Semen cryopreservation ensures the storage of stallion genetics for an unlimited time. The improvement of extenders with new antioxidant substances can optimize the properties of post-thawed semen. The study aimed to investigate the addition effect of medium-molecular-weight carboxymethylchitosan (CQm) derivates to freezing diluent of stallion sperm after freezinf/thawing. Twice a week, five ejaculates of four stallions were obtained, totalizing 20 ejaculates. Semen was diluted in commercial freezing extender (Botucrio) supplemented with CQm: control (0), 0.75, 1.5, and 3 mg/mL. Samples were ...
Boye JK, Katzman SA, Kass PH, Dujovne GA.In equids, it is common to inject lidocaine into the testicles at the time of routine castration to provide analgesia. The effects of lidocaine on equine sperm have not been evaluated in vitro or on epididymal sperm collected following castration. The aims of this study were to determine effects of clinically relevant doses of lidocaine on equine spermatozoa in vitro using freshly collected semen and to compare the characteristics of epididymal spermatozoa after routine castration with or without intra-testicular lidocaine administration. We hypothesized that increasing concentrations of lid...
Dietz JP, Sertich PL, Boston RC, Benson CE.Ticarcillin and piperacillin were compared to determine their effect on sperm motility and bacterial growth of equine semen samples diluted in Kenney's glucose skim milk semen extender. Each ejaculate (n=11) was divided into three portions and glucose skim milk semen extender solution was added. The control semen extender solution contained extended semen and no antibiotic, whereas ticarcillin and piperacillin solutions contained extended semen plus 1.0mg/mL of ticarcillin or piperacillin, respectively. An aliquot was removed (1h after collection) to evaluate sperm motility and microbial conce...
Timoney PJ, O'Reilly PJ, Harrington AM, McCormack R, McArdle JF.The ability of Haemophilus equigenitalis, the causal agent of contagious equine metritis 1977, to survive in various antibiotic-containing semen extenders was studied at different environmental temperatures. Gentamicin sulphate was found to be markedly superior to ampicillin or a combination of sodium benzyl penicillin and polymyxin B sulphate, Semen treated with the former antibiotic was either sterile at cultural examination or else yielded appreciably fewer colonies of H. equigenitalis than the untreated semen control. Ampicillin had no observable effect on the survival of this organism. Ge...
Seidel GE.Principles for selecting future research projects include interests of investigators, fundability, potential applications, ethical considerations, being able to formulate testable hypotheses and choosing the best models, including selection of the most appropriate species. The following 10 areas of assisted reproduction seem especially appropriate for further research: efficacious capacitation of bovine spermatozoa in vitro; improved in vitro bovine oocyte maturation; decreasing variability and increasing efficacy of bovine superovulation; improved fertility of sexed semen; improving equine IV...
Tekin N, Wöckener A, Klug E.The effect of a skim milk extender and a glycine-containing extender on sperm motility and acrosome morphology of stallion semen was examined. There was no difference concerning acrosome morphology. After 24 hours of preservation motility of the ejaculates diluted with glycine extender was significantly superior to those handled with skim milk extender. Storage at 5 degrees C in all cases gave better results than storage at room temperature. Skim milk extender is an appropriate diluent when the semen is used for al on the day of its collection, whereas the glycine-containing extender offers th...
Fanelli D, Moroni R, Sala G, Melanie P, Tarabella I, Telleschi N, Maltinti S, Giorgi M, Barsotti G, Passamonti F, Marmorini P, Rota A, Camillo F....Two studies were conducted to evaluate the use of medical ozone (O) in commercial extenders for equine semen cryopreservation. In the first study (Study 1), 0, 5, and 15 µg/mL of O were added to diluents of refrigerated or frozen semen. Samples were evaluated for sperm kinematics at different time points for the chilled samples and after a thermoresistence test for the frozen/thawed samples. In the second study (Study 2), 0, 5, and 10 µg/mL of O were added to an antibiotic-free diluent for refrigerated semen for comparison with the control group in which semen was diluted in the same diluent...
Hosek L, James RJ, Taylor WTT.Among the most widely used methods for understanding human-horse relationships in the archaeological record is the identification of human skeletal pathologies associated with mounted horseback riding. In particular, archaeologists encountering specific bony changes to the hip, femur, and lower back often assert a causal link between these features and prolonged periods of mounted horseback riding. The identification of these features have recently been used to assert the early practice of mounted horseback riding among the Yamnaya culture of western Eurasia during the third and fourth millenn...
Luis-Calero M, Muñoz-García CC, Fernández-Hernández P, Macías-García B, González-Fernández L.A protocol for conventional in vitro fertilization (IVF) in horses using fresh semen has been described, using a prolonged incubation in FERT-TALP medium (22 h) at 38.2°C in the presence of penicillamine, hypotaurine and epinephrine (PHE). Our work aimed to develop a protocol that maintains quality parameters in frozen-thawed equine spermatozoa incubated for 22 h in the presence of PHE using different media (FERT-TALP and INRA96) and incubation temperatures (30 and 38.2°C). Twelve frozen ejaculates from four stallions were thawed and then incubated in either FERT-TALP or INRA96 with PHE...
Resende AM, Miranda BA, Silva LB, Oliveira AB, Castro MB, Macêdo IL, Dallago BSL, Barud HS, Borges MAC, Ribeiro CA, Dias DS, Campebell RC.Background/Objectives: Skin injuries are common in the equine clinical practice, requiring effective treatment to support natural healing. Bacuri butter is gaining attention for its potential in wound healing and its anti-inflammatory, antimicrobial, and antioxidant properties. Natural polymers such as onion (Allium cepa) bioplastics have been investigated for their potential as occlusive dressings and for tissue regeneration. Methods: This study evaluated the healing process of experimentally induced skin wounds on horses treated with bacuri butter, washed onion film, and unwashed onion film....
Felix MR, Dobbie T, Woodward E, Linardi R, Okada C, Santos R, Hinrichs K.We recently reported successful equine IVF using fresh semen pre-incubated for a prolonged period (22 h) before co-culture with oocytes. In this study, we evaluated the feasibility of equine IVF with frozen-thawed sperm and evaluated capacitation-related changes in these sperm over the pre-incubation period. Sperm selected via a commercial sperm separation device (SSD) yielded significantly higher fertilization than did sperm selected by swim-up or by colloid centrifugation. Using the SSD method, fertilization rates with sperm pre-incubated for 15 min, 3 h, 6 h, and 9 h were 7.1, 22.2, 38...
Al-Kass Z, Morrell JM, Ntallaris T.Sperm quality is adversely affected by cryopreservation due to the increased production of reactive oxygen species, which affects the integrity of sperm membranes, motility, and DNA fragmentation. Three methods for removing seminal plasma, washing (centrifuging extended semen at 800× for 10 min) and Single Layer Centrifugation with high or low density Equicoll, were used to prepare 29 ejaculates from ten stallions for freezing. Sperm quality parameters (kinematics, plasma membrane integrity, superoxide and hydrogen peroxide production, mitochondrial membrane potential, and DNA fragmentation)...
Bugno-Poniewierska M, Bielecka M, Pietras N, Kij-Mitka B, Podstawski Z, Długosz B.The Hucul horse is a Polish primitive breed with a small population size, which highlights the importance of preserving the genetic resources. The cryopreservation of semen is essential for creating gene banks, but its effect on the acrosome reaction in Hucul stallions has not yet been investigated. The acrosome reaction is one of the most important physiological events associated with the fertilization process. Therefore, our goal was to determine the level of acrosome reaction in chilled and frozen/thawed Hucul stallion semen using the FluoAcro test and the SCA semen analysis system. We foun...
Alves NC, Freitas MM, Faria JRD, Horta CL, Martins-Filho OA, Araújo MSS, Costa GMJ, Costa EA, de Almeida FRL, Amaral PHR, Pérez JCG, Lana ÂQ....Niacin acts as an antioxidant that protects cells from oxidative damage. This study evaluated the effects of adding niacin to the equine semen freezing extender on sperm quality and gene expression after cryopreservation. Ejaculates from ten stallions were frozen using the INRA 96 extender (control) or extenders supplemented with 10- and 20-mM niacin. After thawing, sperm were analysed for motility, kinematics, viability, membrane integrity, mitochondrial potential, lipid peroxidation, nitrite, hydrogen peroxide, malondialdehyde and reactive oxygen species (ROS) concentrations, DNA integrity, ...
Nunes MM, Gurgel JRC, Munhoz ML, de Giuli V, Carneiro GF, Miragaya MH, Gallelli MF, Guimaraes JD.The aim of this study was to assess the effect of lyophilized freezing extenders, which can be stored at room temperature, on stallion post-thaw sperm total motility (TM). Ejaculates of 28 stallions were frozen with four different extenders: two commercial freezing extenders offered worldwide and two novel lyophilized extenders (STAR and MX3), and two different cryopreservation protocols (CP1 with an equilibration period of 20 min. and CP2 with an equilibration period of 60 min.). The TM was assessed after thaw. Mean TM did not show significant differences between cryopreservation protocols wi...
Caldevilla M, Ferrante A, Neild DM.The addition of antioxidants to cryopreservation media reportedly improves sperm post-thaw quality and reproductive performance after artificial insemination. Therefore, the objectives of this study were to evaluate if the addition of L-carnitine and pyruvate to freezing media, or their addition to samples after thawing, improves the post-thaw quality of equine spermatozoa. Thus, in Experiment 1, stallion semen samples were cryopreserved in: (1) EDTA-glucose-based extender with 20% egg yolk and 5% dimethylformamide (EDTA control); (2) skim milk-based extender with 20% egg yolk and 5% dimethylf...
Medica AJ, Gibb Z, Aitken RJ.In vitro semen purification techniques have been developed that seek to mimic the in vivo selection process in order to generate the highest possible chance of oocyte fertilization following artificial insemination. Numerous methods have been developed to isolate functional spermatozoa for artificial insemination, yet only one method, single-layer centrifugation using commercial preparations like EquiPure, has been widely employed. In this study, we have introduced a novel approach for isolating spermatozoa and compared their quality to those isolated using EquiPure. The AI port system (Mempha...
