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.
The objective of this study was to enhance the in vitro sperm quality and in vivo fertility of frozen-thawed equine semen by the addition of l-carnitine (LC) to post-thawed semen. Different concentrations of LC were added to thawed samples to obtain four treatments control and 0.5, 1 and 2 mM LC. In the in vitro experiments, sperm motility and kinematics, membrane integrity and intracellular calcium ion concentration ([Ca ] ) were investigated, and the antioxidant bioactivity of LC was assessed by measuring hydrogen peroxide and nitrite concentrations (NO ). The fertility rate was assessed v...
Love CC, Thompson JA, Brinsko SP, Rigby SL, Blanchard TL, Lowry VK, Varner DD.Relationships between sperm motility parameters and viability were evaluated using two fluorescent staining techniques in fresh extended semen (fresh and after 24 h storage at 5 degrees C) that had various concentrations of dead sperm added to simulate different levels of viable and nonviable sperm. Both protocols incorporated SYBR-14 and propidium iodide (PI) while the second protocol added the mitochondrial probe JC-1. The relationship between total sperm motility and percent viable sperm was high between staining protocols (r = 0.98). Time (0 h versus 24 h, P<0.0001) and treatment (0, 10, 2...
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...
Hemberg E, Lundeheim N, Einarsson S.To minimize the number of matings/inseminations, controlled ovulation has been practised since a long time ago. A potent short-term implant, releasing the GnRH analogue deslorelin (Ovuplant((R))) has been used in Australia and North America for several years for hastening the ovulation time in mares, but the product is not registered on the European market. This study was aimed to investigate: (1) ovulation time in mares implanted with Ovuplant when the largest follicle was 42 mm or more in size, (2) repeatability of ovulation time in successive oestruses when treated with Ovuplant, (3) pregna...
Balao da Silva CM, Ortega Ferrusola C, Gallardo Bolaños JM, Plaza Dávila M, Martín-Muñoz P, Morrell JM, Rodriguez Martínez H, Peña FJ.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...
Aurich J, Kuhl J, Tichy A, Aurich C.Differences in the cryotolerance of spermatozoa exist among stallions, but it remains to be determined to what extent such differences are affected by breed. In this study, post-thaw semen quality in stallions presented for semen cryopreservation was analysed retrospectively (1012 ejaculates from 134 stallions of 5 breeds). The percentage of frozen-thawed ejaculates acceptable for artificial insemination (AI) and the number of insemination doses per cryopreserved ejaculate was calculated. Logistic regression analysis revealed sperm motility in raw semen as the most important explanatory variab...
Tkachev AV, Tkacheva OL.The article presents the results of the studies of cytotoxic effect of zearalenone and T-2 toxin on sperm of horses and bulls during incubation and after thawing according to the technology of sperm obtaining and cryopreservation in Kharkov. We first have shown in vitro toxic effects of different concentrations of zearalenone and T-2 toxin (from 0.5 to 0.01 mM) on the membrane stability, as well as quantitative and qualitative indicators of semen in stallions and bulls before and after freezing and thawing. It has been found that the biological activity of the native sperm in 1 h after additio...
Gibb Z, Aitken RJ, Sheridan AR, Holt B, Waugh S, Swegen A.The in vitro storage of stallion spermatozoa for use in artificial insemination leads to oxidative stress and imbalances in calcium homeostasis that trigger the formation of the mitochondrial permeability transition pore (mPTP), resulting in premature cell death. However, little is understood about the dynamics and the role of mPTP formation in mammalian spermatozoa. Here, we identify an important role for mPTP in stallion sperm Ca2+ homeostasis. We show that stallion spermatozoa do not exhibit "classical" features of mPTP; specifically, they are resistant to cyclosporin A-mediated inhibition...
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...
Becerro-Rey L, Martín-Cano FE, Fabres Robaina Sancler-Silva Y, Gil MC, Ortega-Ferrusola C, Aparicio IM, Gaitskell-Phillips G, da Silva-Álvarez E....Conservation of equine semen in the liquid state is a central procedure in horse breeding and constitutes the basis of associated reproductive technologies. The intense mitochondrial activity of the stallion spermatozoa increases oxidative stress along the storage period, leading to sperm demise within 24-48 h of storage, particularly when maintained at room temperature. Recently, the relationship between metabolism and oxidative stress has been revealed. The study aimed to extend the period of conservation of equine semen, at room temperature through modification of the metabolites present i...
Bonilla Lemos Pizzi GL, Holz K, Kowalski ÉA, Fonseca Ribeiro P, Blake R, Ferreira Martins C.The esbarrada and volta sobre patas manoeuvres are critical in Criollo horse equestrian activities, yet their kinematics remain largely unexplored. This observational study aimed to kinematically describe the manoeuvres in Criollo breed horses and explore the relationship between static goniometry and dynamics. A 2D kinematic analysis was conducted on 31 Criollo horses performing the manoeuvres using high-speed cameras. Joint angles were measured using static goniometry and analysed in relation to dynamic performance. The esbarrada covered a distance of 4.28 ± 0.99 m in 1.15 ± 0.11 s at a ve...
MacKechnie-Guire R, Murray R, Williams JM, Nixon J, Fisher M, Fisher D, Walker V, Clayton HM.Poor noseband adjustment could create high pressures that may risk pain or tissue damage. Objective: To quantify sub-noseband pressures dorsally over the nasal bone and ventrally over the mandibular rami for a Cavesson, Swedish (crank), Drop and Flash noseband at five tightness levels (2.0 to 0.0 finger equivalents). Methods: In vivo experiments. Methods: Eight high-level dressage horses were ridden at the trot in a straight line by their usual riders. Two small pressure mats, attached to the noseband over the nasal bone and the mandibular rami, collected force (N) and pressure (kPa) data from...
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...
Brito LFC, Felix MR, Linardi RL, Martinez de Andino EV, Balamurugan NS, Hernández-Avilés C, Hinrichs K.Intracytoplasmic sperm injection (ICSI) is a valuable assisted reproduction technology in clinical practice, especially when semen availability is limited. Since the number of sperm required per ICSI cycle is much less than the number of sperm available in a standard straw of frozen semen, refreezing semen at lower sperm concentrations could yield multiple straws for ICSI use. However, there is little data on the effect of sperm refreezing on ICSI outcomes, especially on the effect of extender used for refreezing. The objective of the present study was to evaluate the effect of refreezing exte...
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....
Samper JC, Hernandez Aviles JC, Ramirez-Agamez LF, Love CC, Gonzalez-Marin C, Fleury P, Dini P, De La Fuente A, Foss R, Campos FL, Ross PJ.The application of sex-sorted semen in horses has historically lagged the bovine industry due to differences in the reproductive physiology and grater variability in equine semen quality. Recent advancements, including SuperGen™ sorters and Ultraplus™ semen processing methods developed by STgenetics® (Navasota, Texas), have significantly improved the efficiency of the sex-sorting process and reduced the sperm damage previously reported. To facilitate the broader use sex-sorted semen in the equine industry, it is essential to address challenges such as shipping cooled semen to a central so...
MacKechnie-Guire R, Clayton H, Williams J, Marlin D, Fisher M, Fisher D, Walker V, Murray R.Measuring tools designed to objectively determine equine noseband tightness are inserted on the dorsal nasal planum in a rostro-caudal direction. The lateral aspect of the horse's head has several areas where minimal soft tissue intervenes between the skin and underlying bone, which makes them potentially useful sites for measuring noseband tightness. One hundred horses were fitted with a snaffle bridle with a cavesson, Swedish or dropped noseband in random order. The tightness of each noseband type was adjusted sequentially to 2.0, 1.5, 1.0, 0.5 and 0.0 finger-equivalents using an ISES Taper ...
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...
Sultan T, Chaudhary AK, Mehta JS, Mehra R, Manuja A, Talluri TR, Bhattacharya TK.Sperm cryopreservation is one of the most important procedures in the development of biotechnologies for assisted reproduction. Cryopreservation of stallion spermatozoa tends to cause plasma membrane damage due to the low ratio of cholesterol to phospholipids. Different substances and compounds can be added to semen extenders to improve sperm quality. Objective: To investigate the effect of supplementing semen extender with zinc nanoparticles (ZnONPs) and gold nanoparticles (AuNPs) on cooled and frozen-thawed spermatozoa of Marwari stallion. Methods: A total of 20 ejaculates from four Marwari ...
Usuga A, Vergara AK, Tobón MC, Vargas S, Rojano B, Restrepo G.Maintaining sperm energy homeostasis in vitro is very important to improve the efficacy of stallion sperm preservation. Equine spermatozoa preferentially utilize oxidative phosphorylation over glycolysis to generate ATP. Metformin and rosiglitazone are antidiabetic compounds that enhances metabolic flexibility and glucose utilization. The aim of this study was to evaluate metformin and rosiglitazone supplementation of the freezing medium on quality and oxidative status of thawed stallion semen. A total of 15 ejaculates from five horses were collected and supplemented before freezing with metfo...
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, ...
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...
