Grazing is a natural feeding behavior in horses, involving the consumption of grasses and other available forage. This activity is essential for their digestive health and provides necessary nutrients. Horses have evolved as continuous grazers, and their digestive systems are adapted to process fibrous plant material efficiently. The management of grazing involves considerations such as pasture quality, grazing time, and stocking density to ensure optimal health and nutrition. This page compiles peer-reviewed research studies and scholarly articles that explore the impact of grazing on equine health, pasture management practices, and the nutritional aspects of forage consumption in horses.
González-Medina S, Montesso F, Chang YM, Hyde C, Piercy RJ.Several pasture management strategies have been proposed to avoid hypoglycin A (HGA) intoxication in horses, but their efficacy has never been investigated. Objective: To evaluate the effect of mowing and herbicidal spraying on HGA content of sycamore seedlings and the presence of HGA in seeds and seedlings processed within haylage and silage. Methods: Experimental study. Methods: Groups of seedlings were mowed (n = 6), sprayed with a dimethylamine-based (n = 2) or a picolinic acid-based herbicide (n = 1). Seedlings were collected before intervention, and at 48 h, 1 and 2 weeks after. ...
Fitzgerald DM, Walsh DM, Sillence MN, Pollitt CC, de Laat MA.Supraphysiological insulin and incretin responses to a cereal-based diet have been described in horses and ponies with insulin dysregulation (ID). However, the hormonal responses to grazing have not yet been described. Objective: To determine if there is a difference in the insulin and incretin responses to grazing pasture between insulin-dysregulated and healthy ponies. Methods: A cohort of 16 ponies comprising 5 with normal insulin regulation (NIR), 6 with moderate ID (MID), and 5 with severe ID (SID). Methods: In this case-control study, an oral glucose test (OGT) was used to determine the ...
DeBoer ML, Hathaway MR, Weber PSD, Sheaffer CC, Kuhle KJ, Martinson KL.Spring and late fall grazing can lead to metabolic problems in horses (Equus caballus L.) as a result of elevated nonstructural carbohydrates (NSC) in pastures. Therefore, the objectives were to determine the impact of different forage species on blood glucose and insulin concentrations of horses during the spring and late fall. Research was conducted in May (spring) and October (late fall) in St. Paul, MN. Alfalfa (Medicago sativa L.) and mixed perennial cool-season grasses (CSG) were grazed in spring, and CSG and teff (Eragrostis tef [Zucc.] Trotter) were grazed in late fall by six adult hor...
DeBoer ML, Martinson KL, Kuhle KJ, Sheaffer CC, Hathaway MR.The impact of forage species on plasma amino acid (AA) concentrations of grazing horses (Equus caballus L.) is unknown. The objectives of this study were to determine the impact of different forage species on plasma AA concentrations and protein synthesis. Research was conducted in July in St. Paul, MN, USA. Alfalfa (Medicago sativa L.), mixed perennial cool-season grasses (CSGs), and teff (Eragrostis tef [Zucc.] Trotter) pastures were grazed by six horses randomly assigned to one of three forage types in a replicated Latin-square design. Horses had access to pasture each day. Jugular venous b...
Patkowski K, Pluta M, Lipiec A, Greguła-Kania M, Gruszecki TM.The research objective was to assess the behavior patterns of the Polish Konik horse breed and the Uhruska variety of the Polish Lowland Sheep breed under a mixed-grazing system, and their relationship with climatic factors. The observation included 4 adult horses, 27 ewes with lambs and 10 primiparous ewes. The behavior of the animals and the weather conditions were recorded at 60-min intervals. Horses and sheep displayed similarities in both species-specific behavioral patterns and timing of grazing activity, and the duration of foraging sessions was mostly influenced by time of day, lower t...
Healey K, Lawlor C, Knox MR, Chambers M, Lamb J, Groves P.A series of placebo-controlled trials were conducted in horses, cattle and goats in different seasons and bioclimatic regions of New South Wales and Queensland, Australia, to evaluate the ability of BioWorma®, a feed supplement containing the spores of Duddingtonia flagrans IAH 1297, to reduce the larval development of parasitic gastrointestinal nematodes (GIN) and their subsequent migration from faeces onto the surrounding pasture. In each trial, faeces were collected from animals harbouring a burden of nematode parasites following a period of supplementation with a placebo and again after s...
DeBoer ML, Hathaway MR, Kuhle KJ, Weber PSD, Reiter AS, Sheaffer CC, Wells MS, Martinson KL.Elevated nonstructural carbohydrate (NSC) values in pasture forages can cause adverse health effects in some horses (Equus caballus L.). The objectives of this study were to determine the impact of different forage species on blood glucose and insulin concentrations of horses throughout the grazing season. Research was conducted in July (summer) and September (fall) in St. Paul, MN. Alfalfa (Medicago sativa L.), mixed perennial cool-season grasses (CSG), and teff (Eragrostis tef [Zucc.] Trotter) pastures were grazed by six horses (24 ± 2 years) that were randomly assigned to one of three for...
Usherwood JR, Smith BJH.Many medium and large herbivores locomote forwards very slowly and intermittently when grazing. While the footfall order during grazing is the same as for walking, the relative fore-hind timing-phasing-is quite different. Extended periods of static stability are clearly required during grazing; however, stability requirements are insufficient to account for the timing. Aspects of relatively rapid rolling and pitching-toppling due to the resistance of the back to bending and twisting-can be included in a simplifying geometric model to explain the observation that, in grazing livestock, a step f...
Kenny LB, Ward D, Robson MG, Williams CA.Many methods exist for estimating species composition, but few studies compare those useful in improved horse pastures. The objective of this study was to examine 4 techniques for estimating desirable forage species composition in 2 cool-season horse pastures based on prevalence estimates, repeatability, bias, and practicality, and to select a method for use in a subsequent grazing study. The techniques included Equine Pasture Evaluation Disc (EPED), Line-Point Intercept with 3 transects of 50 observations each (LPI 3-50), LPI with 5 transects of 30 observations each (LPI 5-30), and Step Point...
Carranza J, Yoong WA, Vergara BC, Briones A, Mateos C.Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green-grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seaso...
Hernández JÁ, Sánchez-Andrade R, Cazapal-Monteiro CF, Arroyo FL, Sanchís JM, Paz-Silva A, Arias MS.An approach to preventing strongyle infection in horses was tested, comprising rotational pasturing and the administration of spores of two parasiticidal fungi, Mucor circinelloides and Duddingtonia flagrans. Twenty-two adult Spanish Sport Horses were dewormed with ivermectin (1 mg pour-on/kg body weight) and then randomly divided into three groups. G-1 was maintained with continuous grazing, and G-2 and G-3 were kept on a four-paddock rotation system. Commercial pelleted feed (2.5 kg/horse) was supplied to G-1 and G-2 twice a week; horses in G-3 received pellets containing 2 × 10 spores/kg o...
Misuno E, Clark CR, Anderson SL, Jenkins E, Wagner B, Dembek K, Petrie L.The goals of this study were to report the seasonal shedding patterns of strongyle and spp. eggs in repeated fecal samples for mares ( = 38) and foals ( = 39), and to evaluate the efficacy of ivermectin treatment in mares from 2 selected horse breeding farms in central Saskatchewan. Median strongyle fecal egg counts (FEC) peaked in July and August in adult horses. The farms differed significantly ( = 0.0005) in regard to strongyle shedding categories ( 500 eggs/g) over time, but for each individual horse (both farms combined) these categories did not differ over time ( = 0.13) on samples coll...
Clark A, Sallé G, Ballan V, Reigner F, Meynadier A, Cortet J, Koch C, Riou M, Blanchard A, Mach N.Gastrointestinal strongyles are a major threat to horses' health and welfare. Given that strongyles inhabit the same niche as the gut microbiota, they may interact with each other. These beneficial or detrimental interactions are unknown in horses and could partly explain contrasted susceptibility to infection between individuals. To address these questions, an experimental pasture trial with 20 worm-free female Welsh ponies (10 susceptible (S) and 10 resistant (R) to parasite infection) was implemented for 5 months. Fecal egg counts (FEC), hematological and biochemical data, body weight and g...
Cox AH, Amador JA.Historically, much of the New England landscape was converted to pasture for grazing animals and harvesting hay. Both consumer demand for local sustainably produced food, and the number of small farms is increasing in RI, highlighting the importance of characterizing the effects livestock have on the quality of pasture soils. To assess how livestock affect pasture on Charlton and Canton soils series in RI, we examined soil quality in farms raising beef cattle (Bos taurus), sheep (Ovis aries), and horses (Equus ferus caballus), using hayed pastures as a control. We sampled three pastures per li...
McGorum BC, Pirie RS.Equine dysautonomia (ED; also known as equine grass sickness) is a neurological disease of unknown cause, which primarily affects grazing adult horses. The clinical signs reflect degeneration of specific neuronal populations, predominantly within the autonomic and enteric nervous systems, with disease severity and prognosis determined by the extent of neuronal loss. This review is primarily focused on the major clinical decision-making processes in relation to ED, namely, (1) clinical diagnosis, (2) selection of appropriate ancillary diagnostic tests, (3) obtaining diagnostic confirmation, (4)...
Odriozola ER, Rodríguez AM, Micheloud JF, Cantón GJ, Caffarena RD, Gimeno EJ, Bodega JJ, Gardey P, Iseas FB, Giannitti F.Solanum glaucophyllum, a toxic plant known for its calcinogenic effects, causes enzootic calcinosis in ruminant and monogastric animals. We describe an outbreak of enzootic calcinosis that occurred in a herd of 110 horses grazing pastureland heavily contaminated with S. glaucophyllum in Buenos Aires province, Argentina. Ten horses developed clinical signs, and 6 horses died. Clinical signs included abnormal gait (stiff-legged action, short strides), stiffness, thoracolumbar kyphosis, reluctance to move, wide stance, chronic weight loss, weakness, recumbency, and difficulty standing. Autopsy of...
Thompson KR, Clarkson L, Riley CB, van den Berg M.To gain an understanding of general horse-keeping practices in Australia, including shelter, social contact, exercise, watering and supplementary feeding. Methods: An online survey was conducted with 505 owners in relation to one 'representative' horse in their care. Results: The majority (83%) of horses were managed at pasture. Approximately one-quarter of those horses were housed alone (26%) or with one companion animal (27%). If horses were confined to a stable or small yard, the most recorded means of exercise was riding (65%) at a daily frequency (60%). Over half of the horse owners provi...
Finch SC, Munday JS, Sutherland BL, Vlaming JB, Fletcher LR.AIMS To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO. METHODS Four horses were grazed on AR542-infected Mediterranean tall fescue pasture (from Day 0) for 7 days prior to being subjected to euthanasia. Two of these horses...
Kaczensky P, Burnik Šturm M, Sablin MV, Voigt CC, Smith S, Ganbaatar O, Balint B, Walzer C, Spasskaya NN.The Przewalski's horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski's horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski's horse...
Domínguez R, Pateiro M, Crecente S, Ruiz M, Sarriés MV, Lorenzo JM.The aim of this study was to assess the effect of finishing diet (control concentrate vs. linseed concentrate) and slaughter age (13 vs. 26 months) on meat and nutritional quality of foal meat. For this study, 46 foals from crossing Galicia Mountain x Burguete breeds were used. Results: The obtained results showed that slaughter age had an influence on chemical composition and colour parameters. Foals slaughtered at the age of 13 months had lower content of intramuscular fat and higher cholesterol contents than those slaughtered at 26 months of age. Regarding colour parameters, older foals sho...
López López C, Ferreira LMM, García U, Moreno-Gonzalo J, Rodrigues MAM, Osoro K, Ferre I, Celaya R.The number of horses in northern Spanish mountains has increased in recent decades, but little is known about their grazing behaviour, performance and potential for foal meat production. This research aimed to study the diet selection, liveweight (LW) changes and parasitic status of dry and lactating mares, and foals' LW gains, grazing on heathlands with different botanical composition. The experimental design consisted of three vegetation types: dominated by heather (Ericaceae) species (H), dominated by gorse (Ulex gallii; G) and co-dominated by gorse and heath-grasses (G-G), with four replic...
Nielsen MK, Lyons ET.Cyathostomins (small strongyles) are ubiquitous in grazing horses and are known pathogens as cause of larval cyathostominosis. As part of their life cycle, cyathostomin larvae invade the mucosal walls of the large intestines and undergo encystment. Newly ingested third stage larvae are known to undergo arrested development and this can lead to an accumulation of encysted burdens over the course of a grazing season. It is believed that the host immune system plays a significant role in triggering this arrestment. Little is known about the development and progression of larval stages in foals th...
Burnik Šturm M, Ganbaatar O, Voigt CC, Kaczensky P.1. Competition among sympatric wild herbivores is reduced by different physiological, morphological, and behavioral traits resulting in different dietary niches. Wild equids are a rather uniform group of large herbivores which have dramatically declined in numbers and range. Correlative evidence suggests that pasture competition with livestock is one of the key factors for this decline, and the situation may be aggravated in areas where different equid species overlap. 2. The Dzungarian Gobi is currently the only place where two wild equid species coexist and share the range with the domestica...
Munday JS, Finch SC, Vlaming JB, Sutherland BL, Fletcher LR.To investigate whether Mediterranean tall fescue (Lolium arundinaceum (Schreb.) Darbysh. (syn Festuca arundinacea)) infected with selected fungal endophytes (Epichloë coenophiala (formerly Neotyphodium coenophialum)) caused equine fescue oedema when grown in New Zealand, and to examine the pathological changes associated with this intoxication. Methods: Horses were grazed on Mediterranean tall fescue that was infected with the endophytes AR542 (n=2), or AR584 (n=3), or Mediterranean tall fescue that was endophyte-free (n=2). Blood samples were taken up to 7 days after the start of feeding to ...
Moinardeau C, Mesléard F, Dutoit T.Extensive grazing by domestic herbivores is a widespread management practice used since the 80s in many European agro-ecosystems such as semi-natural grasslands to maintain open habitats and to enhance biodiversity. Such grazing systems have principally been tested in cultural ecosystems of high nature value threatened by grazing abandonment. However, there have been few case studies of grazing management in very anthropized ecosystems, such as the new ecosystems created by urban or industrial conversions. In Southern France, the Rhône channeling for navigation and electricity production gene...
Hernández JÁ, Arroyo FL, Suárez J, Cazapal-Monteiro CF, Romasanta Á, López-Arellano ME, Pedreira J, de Carvalho LMM, Sánchez-Andrade R....The usefulness of pellets industrially manufactured with spores of parasiticide fungi as a contribution to integrated nematode control was assessed in grazing horses throughout sixteen months. Two groups of 7 Pura Raza Galega autochthonous horses (G-T and G-P) were dewormed pour-on (1mg Ivermectin/kg bw) at the beginning of the trial, and other group (G-C) remained untreated. The G-P was provided daily with commercial pellets to which was added a mixture of fungal spores during the industrial manufacturing (2×10 spores of Mucor circinelloides and same dose of Duddingtonia flagrans/kg), and G-...
Love S, Burden FA, McGirr EC, Gordon L, Denwood MJ.Domesticated grazing animals including horses and donkeys are frequently housed using deep litter bedding systems, where it is commonly presumed that there is no risk of infection from the nematodes that are associated with grazing at pasture. We use two different approaches to test whether equids could become infected with cyathostomines from the ingestion of deep litter straw bedding. Two herbage plot studies were performed in horticultural incubators set up to simulate three straw bedding scenarios and one grass turf positive control. Faeces were placed on 16 plots, and larval recoveries pe...
Wilson CS, Brookes VJ, Hughes KJ, Trope GD, Ip H, Gunn AJ.In human subjects, arytenoid chondritis can be caused by chemical trauma of mucosa attributable to gastro-oesophageal reflux. Although a similar process may be involved in the aetiopathogenesis of arytenoid chondritis in horses, the oesophageal lumen pH in this species is poorly understood. Objective: To determine if gastro-oesophageal reflux occurs in horses by characterising oesophageal lumen pH. Methods: Blinded, randomised, placebo-controlled, crossover, experimental study. Methods: Luminal oesophageal pH in six yearling horses was recorded over four 24 h periods using an ambulatory pH rec...
Aboling S, Drotleff AM, Cappai MG, Kamphues J.Because the occurrence of Claviceps in European pastures may have been overlooked to cause serious health problem for grazing animals, we documented the degree of Claviceps contamination in two horse pastures and estimated whether the horses could have ingested a critical quantity of alkaloids. We counted the Claviceps sclerotia and determined alkaloid levels using high performance liquid chromatography with fluorescence detection. Depending on the location, the number of sclerotia varied from 0.09 to 0.19 per square meter (central area) and from 0.23 to 55.8 per square meter (border strips). ...
Karlíková R, Široká J, Jahn P, Friedecký D, Gardlo A, Janečková H, Hrdinová F, Drábková Z, Adam T.Atypical myopathy (AM) is a potentially fatal disease of grazing horses. It is reportedly caused by the ingestion of sycamore seeds containing toxic hypoglycin A. In order to study metabolic changes, serum and urine samples from nine horses with atypical myopathy and 12 control samples from clinically healthy horses were collected and then analysed using a high-performance liquid chromatography coupled with tandem mass spectrometry; serum metabolic profiles as the disease progressed were also studied. Metabolic data were evaluated using unsupervised and supervised multivariate analyses. Signif...
Romaniuk K, Reszka K, Lasota E.On the turn of July and August the prevalence and intensity of internal parasites of cattle, deer, and primitive Polish horses were estimated. It was determined, that all groups of animals were infected with parasites. The prevalence and intensity of infection were diversified and depended on the animal species, breed, age, and even sex. For instance, dairy cows of lowland black-and-white breed were six times stronger infected than Polish red breed, despite using the same pasture and the same cowshed. Nematodes and coccidia were present in calves using small, frequently wet, calf-runs and at h...
Kjellberg L, Morgan K.Interest in the use of open barns on Swedish horse farms is increasing as an alternative to keeping horses in box stalls and as a 2007 law requires phasing out of tie stalls. To provide adequate forage to satisfy welfare requirements for nutrition, gut health and behavioural needs, the use of automated feeding is also increasing. Studies on forage intake rate report wide variation but provide little information on how to introduce horses to an automatic forage station and on how forage intake rate varies in individual horses fed using an automatic forage station. This study documented the proc...
Giles SL, Harris P, Rands SA, Nicol CJ.Individual animals experience different costs and benefits associated with group living, which may impact on their foraging efficiency in ways not yet well specified. This study investigated associations between social dominance, body condition and interruptions to foraging behaviour in a cross-sectional study of 116 domestic horses and ponies, kept in 20 discrete herds. Social dominance was measured for each individual alongside observations of winter foraging behaviour. During bouts of foraging, the duration, frequency and category (vigilance, movement, social displacements given and receive...
Stegelmeier BL, Colegate SM, Knoppel EL, Rood KA, Collett MG.Wild parsnip (Pastinaca sativa) has been associated with livestock and human photosensitization. An investigation of a natural occurrence of photosensitization of grazing horses identified wild parsnip as a possible cause. HPLC-MS and MS/MS analysis of this plant identified five furanocoumarins i.e., xanthotoxin, bergapten, isopimpinellin, imperatorin and a putative methoxyimperatorin. Goats fed this wild parsnip were largely unaffected. Xanthotoxin was not detected in the serum of parsnip-fed goats or in the serum of goats dosed orally or intravenous with purified xanthotoxin. Cutaneous appli...
Williams S, Horner J, Orton E, Green M, McMullen S, Mobasheri A, Freeman SL.A change in management from pasture to stabling is a risk factor for equine colic. Objective: To investigate the effect of a management change from pasture with no controlled exercise to stabling with light exercise on aspects of gastrointestinal function related to large colon impaction. The hypothesis was that drinking water intake, faecal output, faecal water content and large intestinal motility would be altered by a transition from a pastured to a stabled regime. Methods: Within-subject management intervention trial involving changes in feeding and exercise using noninvasive techniques. M...
Forteau L, Dumont B, Sallé G, Bigot G, Fleurance G.Strongyle infection is an important issue in horse breeding. It impairs horse health and performance, with young horses being the most sensitive. Strongyle control has long relied on the systematic use of chemical treatments. However, expanding anthelmintic resistance among strongyles calls for alternative options. Mixed grazing is assumed to reduce strongyle load on the pasture as the result of a dilution effect. This has been shown in small ruminants grazing with cattle, but the putative benefits of co-grazing between horses and cattle have not yet been evaluated. Here, we conducted field su...
Zentek J, Aboling S, Kamphues J.Meteorism and colics were observed in horses after grazing on young pasture. The botanical analysis of a sample as taken by the owner revealed a great diversity of grasses, herbs and legumes. Houndstongue (Cynoglossum officinale) in its rosette stage was identified in amounts of 1% of the total sample, although this cannot be regarded as representative for the composition of the green fodder. This plant has been reported to be highly toxic for horses and other species, mainly during the early growth stadium due to its contents of pyrrolizidin alkaloids with a strong hepatotoxic activity. In th...
Bachmann I, Staﾬher M.Out of a representative sample of 1861 Swiss horse yards, 622 horse keepers (35.2%) with 2536 horses, ponies and donkeys sent back a questionnaire about general farm characteristics, their horse-specific training, horse stock, housing conditions, intraspecific social contacts, feeding, ability to move freely, use of the horses and management. 83.5% of horses were kept individually (thereof 18.3% tethered, 32.3% in a loose box indoors, 28.4% in a loose box outdoors, and 4.5% in a loose box with permanent access to a paddock or an individual pasture), and 16.5% lived in group housing systems. 36...
Richards N, Nielsen BD, Finno CJ.Many forage types are available, typically divided into cool or warm season grasses and legumes, which can be fed as fresh pasture or after preservation. Testing for nutrient content confirms what should be supplemented to make up shortfalls. Although testing is recommended, it is not always practical. Typical values for the forage type are available; however, they cannot be relied on for actual content. Non-nutritional aspects must also be taken into account. The provision of complementary feeds to ensure adequate vitamin and mineral intake is recommended. Additional supplementary high-qualit...
Irby LR, Norland JE, Westfall JA, Sullivan MA.We developed a forage allocation model using a deterministic, linear optimization module in a commercially available spreadsheet package to help resource managers in Theodore Roosevelt National Park (TRNP), North Dakota determine optimum numbers of four ungulate species, bison (Bison bison), elk (Cervus elaphus), mule deer (Odocoileus hemionus), and feral horses, in the Park. TRNP staff actively managed bison, elk, and feral horse numbers within bounds suggested by our model from 1983 to 1996. During this period, we measured vegetation at 8 grassland and 12 wooded sites at 1-3 year intervals t...
Celaya R, Ferreira LM, García U, Rosa García R, Osoro K.As the number of horses is steadily increasing in Cantabrian less-favoured areas, mostly occupied by nutritionally poor heathland communities, the objective of this research was to study and compare diet selection and performance of crossbred horses and beef cattle (Asturiana de los Valles breed) grazing these areas during the summer. A total of 20 cows (seven lactating their calves and thirteen dry) and 20 mares (eight lactating their foals and twelve dry) were managed during 3 years on a heathland area from June to September and October. The proportion of grass (mostly Pseudarrhenatherum lon...
Goodwin D, Davidson HP, Harris P.To investigate the choices of foraging location of horses, 10 to 12 horses were introduced for five minutes into each of two similar stables containing a single forage or six forages, in four replicated trials. The horses were then removed and released into the gangway between the stables, and allowed five minutes to choose between the stables. Their initial and final choices, mean duration in each stable and proportional frequency of change of location were compared. Most of the horses initially entered the closest stable on release (P<0.05); if the closest stable contained a single hay, m...
Hoffman RM, Kronfeld DS, Cooper WL, Harris PA.The glucose tolerance test in the horse may be used to determine metabolic responses to diet, disease, or physiologic state. The objective of this study was to determine the effect of reproductive stage (gestation and lactation) and supplemental dietary energy source (sugar and starch [SS] or fiber and fat [FF]) on glucose metabolism in grazing mares using an oral glucose tolerance test. Twelve mares, six on each supplement, were examined on three occasions: one in the third trimester of pregnancy, the second in early lactation, and the third in late lactation. During each test, venous samples...
Bolwell CF, Rosanowski SM, Scott I, Sells PD, Rogers CW.Against a global background of increasing anthelmintic resistance in parasites, little is known about the current parasite control strategies adopted within the equine industry in New Zealand. The aim of the study was to describe and compare the current parasite management and control practices used on Thoroughbred and Standardbred stud farms in New Zealand. An online questionnaire was used to collect data on the demographics of respondents, parasite control methods, grazing management, and use of faecal egg counts. Questions regarding parasite control strategy, how often horses were dewormed,...
Shingu Y, Kondo S, Hata H.In this study, grazing behavior of mares and cows was compared on woodland pastures, in the context of foraging hierarchy. A horse-group (12 native Hokkaido horses) and a cattle-group (5 Hereford cows) were grazed on the woodland pastures of 13.3 ha and 5.8 ha, respectively. They grazed mainly on Sasa nipponica. Grazing behavior at a feeding station (FS) scale was recorded for three focal animals in each group. Mares took one bite per FS at a high percentage of FSs (24.3%) and cows took one, two and three bites per FS at high percentage (20.3%, 19.2% and 15.4%, respectively). Although feeding ...
Lea KM, Smith SR.Central Kentucky horse pastures contain significant populations of tall fescue (Schedonorus arundinacea (Schreb.) Dumort) infected with an endophyte (Epichloë coenophialum (Morgan-Jones and Gams) Bacon and Schardl) known to produce several ergot alkaloids, with ergovaline in the highest concentration. While most classes of horses are not adversely affected by average levels of ergovaline in pastures, late term pregnant mares have a low tolerance to ergovaline and the related ergot alkaloids. Endophyte-infected tall fescue has been known to cause prolonged gestation, thickened placenta, dystoc...
Ward NI, Savage JM.The elemental (Br, Cd, Cr, Cu, Mn, Ni, Pb, Se, V, and Zn) content of blood and wool or hair from animals (sheep, horses and alpacas) exposed to motor vehicle emissions alongside the London Orbital (M25) motorway is reported. Elemental values were determined by inductively coupled plasma mass spectrometry (ICP-MS) quality control assessment using flameless atomic absorption spectroscopy (for Pb, correlation coefficients of whole blood r = +0.87, and hair r = +0.82), and replicate (n = 10) analysis of the international reference material IAEA A13 Animal Blood. For Pb very good agreement was obta...
Hansen TL, Chizek EL, Zugay OK, Miller JM, Bobel JM, Chouinard JW, Adkin AM, Skurupey LA, Warren LK.Bermudagrass (Cynodon dactylon) and other warm-season grasses are known for their increased fiber concentrations and reduced digestibility relative to cool-season grasses and legumes. This study investigated the digestive characteristics and passage kinetics of three maturities of Coastal bermudagrass hay. A 5 × 5 Latin square design experiment was used to compare the digestion of five hays: alfalfa (Medicago sativa, ALF), orchardgrass (Dactylis glomerata, ORCH), and Coastal bermudagrass harvested at 4 (CB 4), 6 (CB 6), and 8 weeks of regrowth (CB 8). Horses were fed cobalt-ethylenediaminetet...
Cohen ND, Toby E, Roussel AJ, Murphey EL, Wang N.Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study. Objective: To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study. Objective: The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic. Methods: Feeding practices of cases of DPJ diagnosed betwee...
Wolter R, Pantel N, Stefanski V, Möstl E, Krueger K.The maintenance and development of conservation areas by grazing of large herbivores, such as Przewalski's horses, is common practice. Several nature conservation areas house male bachelor groups of this species. When males are needed for breeding they are removed from the groups, often without considering group compositions and individual social positions. However, alpha animals are needed for ensuring group stability and decision making in potentially dangerous situations in several species. To investigate the role of the alpha male in a bachelor group, we observed the behaviour of five Prze...
Masey O'Neill HV, Keen J, Dumbell L.The purpose of this study was to gain evidence on the prevalence of dental abnormalities in stable-kept horses in comparison with free-living horses. It is expected that free-living horses that graze for as much as 16 h/day will have fewer dental abnormalities than stable-kept horses. In this study, the latter group was fed a diet that was based on a relatively high-energy, cereal-based feed. This was thought to be a representative of common practice in domesticated, stable-kept horses. Compound diets such as this have previously been shown to increase the frequency of chewing cycles and decre...
Uzal FA, Robles CA.Mal seco is a grass sickness-like syndrome of horses which has mainly been observed in Patagonia, Argentina, although some reports indicate that the disease may exist in other Argentinian provinces and in the south of Chile. The aetiology of mal seco remains unknown but the disease seems to be restricted to animals grazing on natural pastures and not receiving supplementary feeding. Mal seco is clinically characterized by total or partial bowel stasis and the main findings at post-mortem examination are almost exclusively restricted to the bowel. The most striking histopathological changes fou...
Siwińska N, Łuczka A, Żak A, Słowikowska M, Niedźwiedź A.The aim of this study was to assess sand accumulation in the gastrointestinal tract and fecal sand excretion in Silesian foals using three diagnostic methods and taking into account the sex and age of the animals. Another aim of the study was to compare the three diagnostic methods. The study was carried out on 21 clinically healthy Silesian foals (10 females and 11 males) from 9-28 weeks old grazed on permanent pasture. The sand intake was assessed using a sedimentation test, abdominal ultrasonography and a quantitative evaluation of sand per 100 g of stool. In the sedimentation test, the san...
Eysker M, Boersema JH, Kooyman FN.Two groups of three ponies were used to study the effect of three ivermectin or pyrantel treatments given at intervals of 5 weeks at the beginning of the grazing season. Although each pyrantel treatment resulted in a greater than 95% reduction in faecal egg counts during the first 3 weeks, high pasture larval counts were seen from the beginning of August onwards and substantial cyathostomine burdens were found at necropsy in December. The ivermectin treatments resulted in an even more pronounced reduction in faecal egg output, and the pasture larval counts and cyathostomine burdens at necropsy...
Mazhitova AT, Kulmyrzaev AA.This study was carried out to determine the influence of milking season on amino acid (AA) profile and chemical composition of milk samples from Kyrgyz native breed mares under traditional pasture conditions. Milk samples were collected monthly from May to August 2014 from mares grazing at 2,200 m above sea level. The AA composition was determined by precolumn derivatization with diethyl ethoxymethylenemalonate in HPLC and 18 AA were determined in mare milk. The analytical parameters of linearity (0.01-4 μg/mL), precision of the method (0.26-4.88% relative standard deviation), derivatization ...
Fleurance G, Duncan P, Fritz H, Gordon IJ, Grenier-Loustalot MF.The spatial heterogeneity of grasslands determines the abundance and quality of food resources for grazing animals. As plants mature, they increase in mass, which allows greater instantaneous intake rates, but the cell wall concentrations increase too, reducing diet quality. In ruminants, daily intake rates are often constrained by the time needed for the ingesta to pass through the rumen, which is influenced by the rate of digestion. It has been suggested that the digestive constraint should have much less effect on hindgut fermenters such as equids. Horses play an increasing role in the mana...
Misuno E, Clark CR, Anderson SL, Jenkins E, Wagner B, Dembek K, Petrie L.The goals of this study were to report the seasonal shedding patterns of strongyle and spp. eggs in repeated fecal samples for mares ( = 38) and foals ( = 39), and to evaluate the efficacy of ivermectin treatment in mares from 2 selected horse breeding farms in central Saskatchewan. Median strongyle fecal egg counts (FEC) peaked in July and August in adult horses. The farms differed significantly ( = 0.0005) in regard to strongyle shedding categories ( 500 eggs/g) over time, but for each individual horse (both farms combined) these categories did not differ over time ( = 0.13) on samples coll...
Weinert JR, Werner J, Williams CA.Field studies characterizing equine grazing activity primarily rely on observational protocols, limiting the quantity and accuracy of collected data. The objectives of this study were to validate an automated chew sensor technology, the EquiWatch System (EWS), for detecting grazing behaviors and to demonstrate potential applications of the EWS in equine grazing research. Eight mature standardbred mares were used in this study. EquiWatch System validation was completed in two phases: grazing time was evaluated in experiment 1 and chew counts in experiment 2. The correlation between visual obser...
