Motility in horses refers to the movement and contraction of the gastrointestinal tract, which is essential for the digestion and passage of feed. It involves a complex interaction of smooth muscle contractions, neural inputs, and hormonal signals that ensure the efficient processing of ingested material. Proper gastrointestinal motility is vital for maintaining digestive health and preventing conditions such as colic, which is a common and potentially serious issue in equine medicine. This page gathers peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and clinical implications of gastrointestinal motility in horses.
Baumber J, Vo A, Sabeur K, Ball BA.Contaminating leukocytes in the ejaculate are an important source of reactive oxygen species (ROS) in human semen. When present in sufficient numbers, they can have a detrimental influence on sperm function in humans. Unfortunately, there is little published information regarding the importance of leukocytes in stallion semen. The objectives of this study were to determine the production of hydrogen peroxide (H2O2) by activated equine neutrophils and to examine the effect of this ROS production on equine sperm motility in vitro. Motile equine spermatozoa (two ejaculates each from four stallion...
Baumber J, Ball BA, Gravance CG, Medina V, Davies-Morel MC.The objective of this study was to examine the influence of reactive oxygen species (ROS), generated through the use of the xanthine (X)-xanthine oxidase (XO) system, on equine sperm motility, viability, acrosomal integrity, mitochondrial membrane potential, and membrane lipid peroxidation. Equine spermatozoa were separated from seminal plasma on a discontinuous Percoll gradient, and spermatozoa were incubated with 0.6 mM X and 0.05 U/mL XO for 30 minutes. Catalase (150 U/mL), superoxide dismutase (SOD, 150 U/mL), or glutathione (GSH, 1.5 mM) were evaluated for their ability to preserve sperm ...
Bedford SJ, Gowdy HL, Hinrichs K.This study was designed to compare the effects of different media and containers on longevity of motility of spermatozoa during in vitro incubation at 38 degrees C in either air or 5% CO2 atmosphere. Three ejaculates were collected from each of 4 stallions. The media tested were skim milk-glucose, modified Krebs/Ringer and Hank's salts solution for incubation in an air atmosphere, and modified Krebs/Ringer and Brackett and Oliphant (BO) defined medium for incubation in a 5% CO2 atmosphere. All samples were incubated in 5-mL borosilicate glass tubes filled with 3 mL of extended spermatozoa, 5-m...
Brinsko SP, Van Wagner GS, Graham JK, Squires EL.The aim of the present study was to determine whether there are characteristics of fresh, cooled and frozen-thawed semen samples that can be used to predict the suitability of stallion semen for preservation by cooling or freezing. Each of three ejaculates obtained from 12 stallions was divided into aliquots to be analysed for sperm motility, morphology and membrane integrity as fresh, cooled and frozen-thawed samples. The percentage of morphologically normal spermatozoa was similar in fresh and cooled samples and both were greater than in the frozen samples. There were no strong linear relati...
Lindeberg H, Kurtén A, Koskinen E, Katila T.The effect of addition of glycine betaine to a lactose-EDTA freezing medium on the post-thaw motility of stallion semen was determined. The first three semen-rich fractions of nine stallions were collected with an open-end Krakow artificial vagina on consecutive weekdays. Semen was frozen using the Hannover method with freezing media containing glycine betaine in various concentrations from 0 to 5%. After thawing, sperm motility was analysed both by a light microscope and by a Hamilton-Thorn Motility Analyser. Total and progressive post-thaw motilities of semen containing 0.25-3% glycine betai...
Cottrell DF, Jones AF, Potter KE.Electromanometric recordings of caecal pressures were made in chronically cannulated ponies. Endoscopy allowed direct observation of the caecal base and cupola while recording intracaecal pressures and enabled a functional interpretation of caecal pressure profiles. Using gas-tight seals, the caecal gas cap baseline pressure (tone) was usually below atmosphere, becoming less negative postprandially. Diurnal variations were observed in the amplitude and frequency of caecal pressure profiles and the direction of caecal movements, during which intra-caecal gas cap pressures briefly became positiv...
Belloli C, Re G, Arioli F, Badino P, Carcano R, Odore R, Girardi C, Beretta C.To identify beta-adrenoceptor subtypes involved in motility inhibition of circular and longitudinal smooth muscle layers of equine ileum. Methods: Isolated strips of equine ileum circular smooth muscle and membrane preparations from circular and longitudinal muscle layers. Methods: Functional assays of circular muscle preparations and radioligand binding assays and measurements of cAMP production in smooth muscle membranes from circular and longitudinal layers. Results: Selective beta-adrenergic agonists exerted inhibitory effects on circular muscle preparations. Binding studies of cell membra...
Dabareiner RM, White NA.The cecum is an important site of water and electrolyte absorption, as well as microbial digestion of soluble and insoluble carbohydrates. These functions of the cecum and ascending colon require that ingesta be mixed constantly and retained long enough to complete the digestion of cellulose. Parasites, changes in regional blood flow, diet, and various pharmacologic agents are associated with alterations in normal cecal motility patterns.
Rakestraw PC, Snyder JR, Woliner MJ, Sanders KM, Shuttleworth CW.To evaluate the role of nitric oxide (NO), vasoactive intestinal peptide (VIP), and a transmitter acting through an apamin-sensitive mechanism in mediating inhibitory transmission in the equine jejunal circular muscle, and to determine the distribution of VIP-and NO-producing nerve fibers in the myenteric plexus and circular muscle. Methods: Circular muscle strips were suspended in tissue baths containing an oxygenated modified Krebs solution and attached to isometric force transducers. Responses to electrical field stimulation (EFS), tetrodotoxin, the NO antagonists L-N-nitro-arginine-methyl-...
Wilhelm KM, Graham JK, Squires EL.Computer-assisted motion analyses (CASA) and flow cytometry were used to evaluate stallion spermatozoa prior to and after cryopreservation. Spermatozoa were pretreated with: (1) Hepes-buffered medium (SHB); (2) phosphatidylserine (PS) liposomes; or (3) liposomes composed of both PS and cholesterol (PSCH) prior to dilution in either SHB or skim milk-egg yolk extender (SMEY). After cooling to 5 degrees C in SHB, PS and PSCH pretreatment (23%). Spermatozoal motion parameters were higher for spermatozoa diluted in SMEY than dilution in SHB. In Experiment 2, motion parameters were compared for sper...
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...
Stick JA, Arden WA, Chou CC, Parks AH, Wagner MA, Johnston CC.Using isolated autoperfused intestinal segments, the effects of flunixin meglumine administration on systemic arterial blood pressure, jejunal blood flow, vascular resistance, motility, arteriovenous oxygen difference, and oxygen consumption were determined in 10 anesthetized ponies ventilated with a mixture of halothane and oxygen. Saline solution or flunixin meglumine (1.1 mg/kg of body weight) was infused as a single bolus into the left jugular vein. By 10 minutes, flunixin meglumine increased systemic arterial blood pressure and increased intestinal vascular resistance. The jejunal blood f...
Stick JA, Chou CC, Derksen FJ, Arden WA.Isolated jejunal segments were perfused at a constant blood flow rate to determine simultaneously the effects of xylazine on intestinal vascular resistance, motility, compliance, and oxygen consumption in 12 anesthetized ponies. Xylazine was infused into the artery perfusing the intestinal segment (group 1), or into the jugular vein as a single IV bolus (group 2), or 3 times as IV boluses repeated at 10-minute intervals (group 3). Dose-response curves in group 1 indicated a biphasic response to the drug with vasoconstriction, increased motility, and increased oxygen consumption at lower doses ...
Davies JV, Gerring EL.Small intestinal ischaemia is a cause of pain in man and horses. Occlusion of the vascular supply to Thiry loops in experimental ponies caused severe discomfort and loss of motility within a few minutes but these effects could not be reproduced by a similar procedure in intact gut preparations. However, embolisation of the mural vascular network produced ischaemia of the small intestine of anaesthetised ponies which led to a cessation of motility in the affected segments, though unaffected segments became hypermotile with a characteristic motility pattern. These results suggest the need for re...
Adams SB, Lamar CH, Masty J.Bipolar stainless steel electrodes were surgically implanted in 4 ponies to record myoelectrical and mechanical activity of the distal portion of the jejunum and pelvic flexure. After determining normal activity, the effects of neostigmine, xylazine, flunixin meglumine, dipyrone, panthenol, and atropine sulfate were determined. Flunixin meglumine, dipyrone, and panthenol had no effect on the motility of the jejunum or pelvic flexure. Xylazine and atropine sulfate decreased motility of the distal portion of the jejunum and pelvic flexure, with atropine sulfate having a greater effect and lastin...
Engle CE, Foley CW, Witherspoon DM, Scarth RD, Goetsch DD.Three experiments were conducted on the metabolism of stallion sperm. In experiment 1, whole and washed sperm were incubated under aerobic and anaerobic enviroments and analyzed before and after controlled incubation for motility, pH, lactic acid, glucose, fructose, and O2 comsumption. In experiment 2, whole and washed sperm were incubated aerobically and anaerobically with and without uterine tubal fluids. Experiment 3 was the same as experiment 2, except added substrates of glucose and lactic acid were studied. The same examinations were made in experiments 2 and 3 as for experiment 1. Motil...
Initial treatment of colic is aimed at maintaining hydration and acid-base balance, controlling pain and reestablishing peristalsis. A poor response to medical treatment in the first 12-18 hours suggests the need for laparotomy. Other indications for surgery include: rising pulse rate, exceeding 60/minute for several hours; congested mucosae; delayed capillary refill; silent abdomen; gastric reflux; distended or displaced loops of bowel on rectal examination; intractable pain; and adverse laboratory findings. Postoperative care should consist of hand-walking for 30 days, followed by confinemen...
Lindeberg H, Kurtén A, Koskinen E, Katila T.The effect of addition of glycine betaine to a lactose-EDTA freezing medium on the post-thaw motility of stallion semen was determined. The first three semen-rich fractions of nine stallions were collected with an open-end Krakow artificial vagina on consecutive weekdays. Semen was frozen using the Hannover method with freezing media containing glycine betaine in various concentrations from 0 to 5%. After thawing, sperm motility was analysed both by a light microscope and by a Hamilton-Thorn Motility Analyser. Total and progressive post-thaw motilities of semen containing 0.25-3% glycine betai...
Stick JA, Arden WA, Chou CC, Parks AH, Wagner MA, Johnston CC.Using isolated autoperfused intestinal segments, the effects of flunixin meglumine administration on systemic arterial blood pressure, jejunal blood flow, vascular resistance, motility, arteriovenous oxygen difference, and oxygen consumption were determined in 10 anesthetized ponies ventilated with a mixture of halothane and oxygen. Saline solution or flunixin meglumine (1.1 mg/kg of body weight) was infused as a single bolus into the left jugular vein. By 10 minutes, flunixin meglumine increased systemic arterial blood pressure and increased intestinal vascular resistance. The jejunal blood f...
Engle CE, Foley CW, Witherspoon DM, Scarth RD, Goetsch DD.Three experiments were conducted on the metabolism of stallion sperm. In experiment 1, whole and washed sperm were incubated under aerobic and anaerobic enviroments and analyzed before and after controlled incubation for motility, pH, lactic acid, glucose, fructose, and O2 comsumption. In experiment 2, whole and washed sperm were incubated aerobically and anaerobically with and without uterine tubal fluids. Experiment 3 was the same as experiment 2, except added substrates of glucose and lactic acid were studied. The same examinations were made in experiments 2 and 3 as for experiment 1. Motil...
Belloli C, Re G, Arioli F, Badino P, Carcano R, Odore R, Girardi C, Beretta C.To identify beta-adrenoceptor subtypes involved in motility inhibition of circular and longitudinal smooth muscle layers of equine ileum. Methods: Isolated strips of equine ileum circular smooth muscle and membrane preparations from circular and longitudinal muscle layers. Methods: Functional assays of circular muscle preparations and radioligand binding assays and measurements of cAMP production in smooth muscle membranes from circular and longitudinal layers. Results: Selective beta-adrenergic agonists exerted inhibitory effects on circular muscle preparations. Binding studies of cell membra...
Puglisi R, Bornaghi V, Severgnini A, Vanni R, Balduzzi D, Galli A.Fresh 36 ejaculates of 13 stallions were split into two volumes, centrifuged with and without cushion and frozen with Conventional and two prototype, Drum and Directional, methods using 0.5 ml straws for the Conventional and Drum, and 2 ml flat straws for both the Drum and Directional. Cushioned centrifugation increased total motility (61.2 ± 18.6% vs. 57.5 ± 18.6%; P < 0.001) and mean velocity (84.3 ± 15.6% vs. 83.2 ± 13.8%; P < 0.05) when compared to not cushioned centrifugation, estimated after cooling the sperm at 4⁰C for 90 min before freezing. Cushioned centrifugation also in...
Talluri TR, Jhamb D, Paul N, Singh J, Dedar RK, Mehta SC, Legha RA, Pal Y.The recovery of spermatozoa from the cauda epididymis may be the only option to obtain genetic material from elite stallions that had undergone castration or sudden death due to colic or severe injury. Objective: To evaluate two different protocols for retrieval of stallion epididymal spermatozoa and to evaluate different cryoprotectants on the freezability of the epididymal spermatozoa. Methods: Six epididymides from three stallions were collected immediately after routine castration under general anesthesia. In the first experiment, each epididymis (of two testes) of the same stallion were p...
Haralambus R, Juri M, Mokry A, Jenner F.Effective management of postoperative pain is essential to ensure patient welfare, reduce morbidity and optimize recovery. Opioids are effective in managing moderate to severe pain in horses but concerns over their adverse effects on gastrointestinal (GI) motility and associated increased colic risk limit their widespread use. Studies investigating the impact of systemic opioids on both GI motility and colic incidence in horses have yielded inconclusive outcomes. Therefore, this retrospective study aims to assess the influence of systemic administration of butorphanol, morphine, and methadone ...
Davies JV, Gerring EL.Small intestinal ischaemia is a cause of pain in man and horses. Occlusion of the vascular supply to Thiry loops in experimental ponies caused severe discomfort and loss of motility within a few minutes but these effects could not be reproduced by a similar procedure in intact gut preparations. However, embolisation of the mural vascular network produced ischaemia of the small intestine of anaesthetised ponies which led to a cessation of motility in the affected segments, though unaffected segments became hypermotile with a characteristic motility pattern. These results suggest the need for re...
Initial treatment of colic is aimed at maintaining hydration and acid-base balance, controlling pain and reestablishing peristalsis. A poor response to medical treatment in the first 12-18 hours suggests the need for laparotomy. Other indications for surgery include: rising pulse rate, exceeding 60/minute for several hours; congested mucosae; delayed capillary refill; silent abdomen; gastric reflux; distended or displaced loops of bowel on rectal examination; intractable pain; and adverse laboratory findings. Postoperative care should consist of hand-walking for 30 days, followed by confinemen...
Cottrell DF, Jones AF, Potter KE.Electromanometric recordings of caecal pressures were made in chronically cannulated ponies. Endoscopy allowed direct observation of the caecal base and cupola while recording intracaecal pressures and enabled a functional interpretation of caecal pressure profiles. Using gas-tight seals, the caecal gas cap baseline pressure (tone) was usually below atmosphere, becoming less negative postprandially. Diurnal variations were observed in the amplitude and frequency of caecal pressure profiles and the direction of caecal movements, during which intra-caecal gas cap pressures briefly became positiv...
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...
Fracaro PL, Corcini CD, Souza Gatti NL, Filho JS, Acosta IB, Filho JS, Hartwig FP, Rosa Curcio BD, Varela Junior AS.Glycerol is a cryoprotectant widely used in the freezing of mammalian semen, but no study has demonstrated its optimum concentration and the appropriate exposure time for equine species. Objective: To demonstrate that the exposure time (15, 30, 45, 60, 75 and 90 min) versus concentration (2, 3, 4 and 5%) of the cryoprotectant glycerol influences the freezing success of equine semen. Methods: The ejaculate of 12 stallions were frozen in different glycerol concentrations following different exposure times. The thawed sperm was evaluated for kinetic parameters using a Computer Assisted Semen Anal...
Uhlmannsiek L, Shen H, Eylers H, Martinsson G, Sieme H, Wolkers WF, Oldenhof H.Cryopreserved semen is routinely shipped in liquid nitrogen. Dry ice could serve as an alternative coolant, however, frozen storage above liquid nitrogen temperatures (LN2, -196 °C) may negatively affect shelf-life and cryosurvival. In this study, we determined critical temperatures for storage of cryopreserved stallion sperm. We evaluated: (i) effects of cooling samples to different subzero temperatures (-10 °C to -80 °C) prior to storing in LN2, (ii) stability at different storage temperatures (i.e., in LN2, dry ice, -80 °C and -20 °C freezers, 5 °C refrigerator), and (iii) sperm...
Peña FJ, Martín-Cano FE, Becerro-Rey L, Ortega-Ferrusola C, Gaitskell-Phillips G, da Silva-Álvarez E, Gil MC.We are currently experiencing a period of rapid advancement in various areas of science and technology. The integration of high throughput 'omics' techniques with advanced biostatistics, and the help of artificial intelligence, is significantly impacting our understanding of sperm biology. These advances will have an appreciable impact on the practice of reproductive medicine in horses. This article provides a brief overview of recent advances in the field of spermatology and how they are changing assessment of sperm quality. This article is written from the authors' perspective, using the sta...
Artificial insemination with cooled-shipped semen is the primary method used in the equine breeding industry; yet, sperm quality and fertility can be suboptimal for some stallions when standard techniques are used. Therefore, there is a critical need to develop alternative approaches for these stallions. Objective: To assess sperm quality parameters and fertility of cooled-stored stallion semen processed by SpermFilter® or centrifugation and resuspended in three extenders. Methods: Controlled and field study. Methods: In Experiment 1, semen was collected from 21 stallions classified as having...
Morris L, Harteveld R, Gibb Z.Insemination of mares with frozen-thawed spermatozoa requires intensive management and results in 40%-60% per cycle pregnancy rates. Objective: To determine if satisfactory fertility is possible for frozen-thawed semen after processing it through a microfluidic device, followed by storage at 17°C for up to 24 h before fixed-time insemination. Methods: Uncontrolled field trials. Methods: A pilot study evaluated the motility of frozen-thawed spermatozoa after centrifugation and storage (17°C) in two different media for up to 48 h. Subsequently, the motility of frozen-thawed semen processed...
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...
Vilela VMT, Zutter BM, Gomes LLO, Silva DF, Diniz JHW, Sancler-Silva YFR, Ignácio FS, Papa FO, Monteiro GA.This study investigated the effects of cholesterol-loaded cyclodextrin (CLC) before cryopreservation and the use of FertTalp (FT) after thawing on the structural and functional quality of equine spermatozoa. Methods: Two ejaculates from twelve stallions were divided into four groups: G1 (0 mg CLC), G2 (1.0 mg), G3 (1.5 mg), and G4 (2.0 mg). Post-thaw semen quality was evaluated through computer-assisted sperm analysis and flow cytometry. Results: In Experiment I, supplementation with 1.5 mg (G3) significantly improved total motility (64.9 ± 10.1 %) and progressive motility (40.5 ± 8.8 %) com...
