bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of anti‐freeze protein (AFP) on the cooling and freezing of equine embryos as measured by DAPI‐staining
Authors: LAGNEAUX D. , HUHTINEN M. , KOSKINEN E. , PALMER E.
Published: June 2010

Equine embryos recovered on Day 6 after ovulation were cooled to +4°C, or frozen with AFP alone or together with glycerol. Twenty embryos (140–200 μm in diameter) were randomly assigned to 6 treatment groups. In the first 3 groups, the embryos were cooled from room temperature to +4°C at a rate of 3°C/min and warmed again at a rate of 32°C/min in a programmable freezer. In the second 3 groups, the embryos were frozen using a standard protocol, stored in liquid nitrogen for 5–7 days and then thawed in a 37°C waterbath. After cooling/warming or freezing/thawing all the embryos were stained with DAPI. The percentage of dead cell area was significantly lower in the cooling groups than in the freezing groups and no significant differences were apparent between the cryoprotectants used in the study.
Cryopreservation of equine embryos with glycerol plus sucrose and glycerol plus 1,2‐propanediol
Authors: FERREIRA J. C. P. , MEIRA C. , PAPA F. O. , e ALVARENGA F. C. LANDIN , ALVARENGA M. A. , BURATINI J.
Published: June 2010

Six or 7‐day‐old equine embryos were divided into 4 groups;Group 1, n = 15, Day 7 embryos destined for immediate transfer;Group 2, n = 15, Day 6 embryos destined for deepfreezing with glycerol plus sucrose as cryoprotectant;Group 3, n = 10, Day 6 embryos destined for deep‐freezing with glycerol plus 1,2‐propanediol as cryoprotectant andGroup 4, n = 3, fresh embryos destined for ultrastructural analysis. All the frozen/thawed embryos were transferred to recipient mares, except 3 embryos inGroup 3that were subjected to ultrastructural analysis. After thawing the cryoprotectants were removed by successive dilutions in PBS + 15% v:v fetal calf serum (FCS) containing decreasing concentrations of the cryoprotectants. Pregnancy was diagnosed ultrasonographically in 53.3%, 13.3% and 0% of the mares inGroups 1, 2 and 3respectively.

Ultrastructural analysis showed differences between frozen/thawed and fresh embryos. In the former, embryonic cells were deformed and showed dilation of the intercellular and perivitelline spaces, a decrease of desmosome number in the junctional complexes, few microvilli on the apical surface of the trophectoderm and an almost total absence of pinocytotic vesicles. Most of the mitochondria showed regions containing dilation and irregularities on the cristae, which appeared electron‐dense. The results obtained withGroups 2and3embryos showed that the cryoprotectants employed were not effective in protecting the embryos against damage during freezing and thawing. Indeed, the ultrastructural changes observed in theGroup 3embryos explained the absence of any established pregnancies in this group of mares.
The effect of sucrose in the thawing solution on the morphology and mobility of frozen equine embryos
Authors: HUHTINEN MIRJA , LAGNEAUX D. , KOSKINEN E. , PALMER E.
Published: June 2010

Seventy‐five embryos were collected 6 days after ovulation. Sixty embryos were frozen in straws using glycerol as the cryoprotectant in an automatic freezer. In Experiment 1 the freezing and thawing media were supplemented with 1.3 g/l PVP; in Experiment 2 the supplement was 5% FCS. The embryos were thawed for 30 s at +37°C in a waterbath. In Experiment 1 glycerol was removed from 10 embryos in 6 steps. In 10 other embryos, glycerol and sucrose were both removed from the medium in 6 steps. After glycerol and sucrose removal, the embryos were stained with 4′,6′‐diamidino‐2‐phenylindole (DAPI) to count the percentage of dead cells. Fluorescent rate (FR) was defined as a ratio of fluorescent area versus total area. Mean (± s.d.) FR in this experiment was significantly lower (P < 0.01) in embryos thawed with sucrose (0.28 ± 0.13) than in embryos thawed with glycerol alone (0.53 ± 0.25). In Experiment 2, 40 embryos were frozen and glycerol, with or without sucrose, was removed after thawing as for Experiment 1. Ten embryos in both groups were stained with DAPI. All the frozen‐thawed embryos were transferred nonsurgically to recipient mares. Fourteen fresh embryos were transferred as controls, 7 of which were stained with DAPI before transfer. There was no difference in pregnancy rates between DAPI‐stained versus nonstained embryos, indicating that the staining process had no negative effects on embryonic survival. Insufficient embryos were transferred to be able to demonstrate any difference in pregnancy rates between embryos thawed with or without sucrose in the medium.
Living fibroblast cells in the oviductal masses of mares
Authors: AGUILAR J. J. , WOODS G. L. , MIRAGAYA M. H. , OLSEN L. M.
Published: June 2010

The object of this experiment was to estimate the number and type of living cells in oviductal masses of mares. Oviducts of abattoir mares were dissected, divided into 3 sections, and flushed individually. Oviductal masses were recovered from 220 of 250 mares and from 389 of 500 oviducts. A greater number of masses was recovered from the left than the right oviducts. A higher percentage of masses was recovered from the ampullary‐isthmic junction than from the ampulla or isthmus. The number of masses increased slightly with increasing mare age and was weakly correlated with the number of unfertilised oocytes recovered per oviduct Prepubertal mares had fewer recovered masses than anovulatory, early luteal phase, late luteal phase, or pregnant mares.

Oviductal masses were classified morphologically as being branched, compact, or cumulus. Living cells were identified with a carboxy fluorescein diacetate stain and dead cells were identified with a propidium iodide fluorescent stain. In branched masses, the proportion of the surface area covered with total cells (live and dead) was 33.7 ± 14.3%, and with only live cells was 6.2 ± 7.3%. In compact masses, the proportion of the surface area covered with total cells was 42.4 ± 21.2%, and with only live cells was 10.7 ± 13.1%. The detection of living cells was confirmed by isolating and culturing cells. Cells cultured from cumulus masses were viable in 57.1% of wells, whereas cells from branched and compact masses were viable in only 18.1% and 17.7% of wells, respectively. In addition, more of the surface area of wells containing cells from cumulus masses were covered with cells, compared to wells containing cells from either branched or compact masses. Most cells appeared to be fibroblasts because 90–95% of cells from branched and compact masses were stained with a fibroblast cell marker.
Endometritis, salpingitis and fertilisation rates after mating mares with a history of intrauterine lumenal fluid accumulation
Authors: MIRAGAYA M. H. , WOODS G. L. , LOSINNO L.
Published: June 2010

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 uterine fluid during dioestrus that were inseminated showed a higher incidence of endometritis than control mares without pre‐existing uterine fluid that were not inseminated (n = 7 mares/group). However, inseminated mares with uterine fluid did not show a higher incidence of endometritis than inseminated mares without uterine fluid. Mares with or without pre‐existing uterine fluid showed a higher incidence of endometritis than salpingitis and these 2 groups of mares showed equivalent rates of fertilisation and oviductal oocyte recovery.

Mares inseminated with semen alone or semen following 1% glycogen treatment had a higher incidence of endometritis than control noninseminated mares (n = 17 mares/group) but mares that received semen plus 1% glycogen did not show a higher incidence of endometritis than mares that received semen alone. Both these groups of mares showed a higher incidence of endometritis than salpingitis and those that received semen plus 1% glycogen showed an equal recovery rate of recently ovulated ova but a lower fertilisation rate than the mares that received semen alone.
Tubule density of thestratum mediumof horse hoof
Authors: REILLY J. D. , COLLINS S. N. , COPE B. C. , HOPEGOOD L. , LATHAM R. J.
Published: June 2010

The number of tubules/mm2(tubule density) of horse hoof horn was quantified in samples taken from the left forefeet of 8 randomly selected slaughterhouse horses in order to establish the normal tubule density characteristics at the midline dead centre (MDC) for thestratum mediumof horse hoof. In the past the measurement of tubule distribution within the hoof has lacked objectivity. The horse hoof tubule density results are compared to a recent objective study carried out on pony hoof. A similar 4 zone pattern of tubule density was observed, although the precise zonal boundaries and tubule density values differed to those found for pony hoof. There were significant differences in tubule density between zones. Comparison with pony hoof revealed significant tubule density differences in zones 1, 2 and 4; however, there was no significant difference in zone 3. The existence of a 4 zoned pattern of tubule density for horse hoof, as for pony hoof, has been confirmed.
Exploring the possible functions of equine hoof wall tubules
Authors: KASAPI M. A. , GOSLINE J. M.
Published: June 2010

Possible functions of equine hoof wall tubules were investigated in this study. Hydration tests were conducted on blocks of hoof wall tissue in order to test the hypothesis that hollow tubules facilitate the conduction of water vapour distally. Although water loss or gain was inhibited through the outer wall surface, the increase in surface area provided by medullary spaces was ineffective in facilitating hydration through the face with exposed tubule ends. Rather, hollow tubules appear to allow for a higher dehydration rate through their exposed ends. Analysis of medullary space indicates that the presence of these voids does not provide either a significant increase in flexural stiffness, or a decrease in thermal conductivity. These findings suggest that nonmechanical roles of hoof wall tubules are unlikely and, therefore, the hollow nature of tubules may be a reflection of manufacturing constraints in producing keratin fibres at steep angles to the coronary border.
Effect of hoof trimming on the occurrence of distal phalangeal palmar process fractures in foals
Authors: KANEPS A. J. , O'BRIEN T. R. , WILLITS N. H. , DYKES J. E. , STOVER SUSAN M.
Published: June 2010

This study sought to determine if extensive trimming of the front hooves of foals results in a higher incidence of palmar process fractures compared to untrimmed foals, and to characterise the clinical course of foals with palmar process fractures with physical findings, hoof measurements and radiography. Twenty foals age 4–8 weeks of multiple breeds were examined every 2 weeks over a 12 week period. Ten foals had both front hooves extensively trimmed every 4 weeks, while 10 foals remained untrimmed. Palmar process fractures occurred in 4 trimmed and 3 untrimmed foals. Four foals with fractures had brief lameness (Grades I‐II/V) and hoof tester sensitivity was found inconsistently with fractures. All foals with fractures were sound at the end of the study. Fractures healed based on radiographic evaluations in an average of 8.4 weeks. Two of 3 foals with fractures developed club‐footed conformation. None of the measured hoof parameters significantly differed between foals with and without fractures. We conclude that extensive trimming of the heels did not appear to affect the occurrence of palmar process fractures in this group of foals.
Effects of season and diet on tensile strength and mineral content of the equine hoof wall
Authors: LEY W. B. , PLEASANT R. SCOTT , DUNNINGTON E. A.
Published: June 2010

Studies evaluating nutritional and seasonal influences on hoof strength and composition in horses, as well as the scientific justification for feeding supplements to improve hoof quality, are lacking. The horseman and veterinarian need controlled studies in this area to make informed decisions. This project quantified, in 2 trials, relative elasticity, tensile strength, % moisture, and mineral composition of hooves of 48 mature Thoroughbred mares maintained on different nutritional/management regimens, sampled quarterly over 12 month periods. Tensile strength was positively associated with sulphur content. Per cent moisture was not significantly associated with tensile strength, relative elasticity, or mineral content measures. Results indicated that both seasonal trends and nutritional regimes greatly affected hoof wall strength and mineral composition.
Cytokeratins of the equine hoof wall, chestnut and skin: bio‐ and immunohisto‐chemistry
Authors: WATTLE O.
Published: June 2010

The equine skin and its appendages (chestnut, hoof capsule, ergot, sebaceous glands, sweat glands and hair) consist mainly of keratinocytes. The intermediate filament cytoskeleton of these cells is involved in specialised functions, such as mechanical co‐ordination of the cytoskeleton of the cell or tissue. In this study, 7 monoclonal antibodies, one polyclonal antibody and immunoblot analysis were used to characterise cytokeratins (separated by 1‐ and 2‐dimensional gel electrophoresis) from the hoof wall and chestnut. The tissue distribution of these cytokeratins was studied by immunohistochemical staining of sections from the skin, chestnut, periople, matrix of thestratum mediumof the hoof wall, and thestratum internumof the hoof wall. The results of analysis revealed a difference in the content of cytokeratins between: 1) cell layers within the same tissue, 2) skin and more proliferative epidermal tissues, i.e., chestnut and periople, 3) tissues containing astratum granulosum(skin, chestnut and periople) and tissues withoutstratum granulosum(stratum mediumandinternumof the hoof wall), 4)stratum mediumandstratum internumof the hoof wall and 5)stratum internumat the most proximal level and at the mid level of the hoof wall.
Effect of rider and riding style on deformation of the front hoof wall in Warmblood horses
Authors: SUMMERLEY H. L. , THOMASON J. J. , BIGNELL W. W.
Published: June 2010

A rider modifies the weight distribution and dynamic balance of the horse. But what effect does a rider have on the mechanical behaviour of the hoof during each stance phase? Does riding style have any effect on this behaviour? We attempted to answer these questions using strains recorded from 5 rosette strain gauges glued to the surface of the front hooves of 4 Warmblood horses. Comparisons were made between strains with and without a rider, and when the rider was sitting, rising at a trot, or in a forward seated position. The change in strains from trot to lead or nonlead at a canter, and the effect of turning were also studied.

Changing lead at a canter had as least as much effect on strain magnitudes as did turning; strains were up to 43% higher for the nonlead foot, but with little redistribution. Perhaps surprisingly, strains were significantly lower on the quarters by up to 30% with a rider than without, with a 10% increase or decrease at the toe, depending on the individual. Riding style changed strain magnitudes by up to 20% and also caused strain redistribution: strains were higher medially for sitting, and laterally for forward seat, with strains for a rising trot being more evenly distributed and intermediate in magnitude. Studying the range of, and causes of variation in hoof wall strain gives baseline data aimed, in the long term, at providing a biomechanical definition of hoof balance.
Variation in surface strain on the equine hoof wall at the midstep with shoeing, gait, substrate, direction of travel, and hoof shape
Authors: THOMASON J. J.
Published: June 2010

Objectives were to examine the deformation of the healthy equine front hoof during locomotion, by recording strains on its outer surface, and to test whether its mechanical behaviour is significantly altered under different locomotory conditions and variation in hoof shape. Strains were recordedin vivofrom 5 rosette gauges around the circumference of the right forehooves of 12 horses. The magnitudes and orientations of principal strains at the midstep were compared statistically for different conditions of shoeing (shod vs. unshod), gait (walk vs. trot), substrate (treadmill vs. ground), and direction of travel (straight, right turn, left turn). Principal strains were regressed on 4 variables describing hoof shape ‐ toe length, toe angle, and medial and lateral wall angle ‐ to describe their contribution to variations in strain and hoof deformation.

Shoeing did not essentially change the magnitudes of the larger, compressive principal strain, but caused some strain reorientation. Shoes decreased the variation in strains indicating that they tend to stabilise the deformation of the hoof. Strain magnitudes were significantly greater at trot than walk, but there was little change in orientation indicating that the general pattern of deformation of the hoof is constant between these 2 gaits. Strain patterns showed small but significant differences between locomotion on the treadmill and on ground, with the differences being more apparent at the toe than at the sides of the hoof. When turning, the quarter on the inside of the turn experienced 40% more strain than during straightline motion, while strain was similarly reduced on the opposite quarter. Strain magnitudes increase with toe length and toe angle, but were inversely proportional to medial and lateral angles. The change with toe length correlated with the range of body size of the animals in the sample. The change with toe angle was contrary to that found inin vitrotests. The change with medial and lateral angles indicated that hooves with more upright quarters are stiffer and possibly provide less impact absorption.
In vitroattenuation of impact shock in equine digits
Authors: LANOVAZ J. L. , CLAYTON H. M. , WATSON L. G.
Published: June 2010

This study was designed to test the impact characteristics of the equine digitin vitrowith the objective of providing a better understanding of the role of the digital structures in the attenuation of impact shock. Uni‐axial accelerometers were mounted on cadaver digits on the distolateral hoof wall, the proximolateral hoof wall, the dorsal surface of the second phalanx, and the mid‐lateral first phalanx. The hoof‐mounted accelerometers were aligned with the hoof tubules while the bone‐mounted accelerometers were oriented along the longitudinal axis of the bone. Each digit was mounted in a test apparatus designed to simulate impact of the hoof with the ground during locomotion. The digits were subjected to 3 impact trials against a barrier at each of 3 vertical impact velocities that simulated a forward trotting velocity in the range of 2.67 to 4.46 m/s. The impact deceleration tended to increase with impact velocity. Attenuation of the impact shock by the digital tissues resulted in a reduction in impact deceleration in the more proximal measuring locations. The interphalangeal joints appeared to play a larger role in amplitude attenuation than the hoof wall or the soft tissue structures within the hoof wall. The signal frequency data showed that the soft tissues within the hoof acted as a ‘low‐pass’ filter, attenuating the higher deceleration frequencies. The hoof wall and the interphalangeal joints showed little frequency attenuation.
Finite element analysis of static loading in donkey hoof wall
Authors: NEWLYN H. A. , COLLINS S. N. , COPE B. C. , HOPEGOOD L. , LATHAM R. J. , REILLY J. D.
Published: June 2010

A finite element model of donkey hoof wall was constructed from measurements taken directly from the hoof capsule of the left forefoot. The model was created with a 2 mm mesh and consisted of 11608 nodes. A linear elastic analysis was conducted assuming isotropic material properties in response to a 375 newton (N) load, to simulate static loading. The load was applied to the wall via 400 laminae in order to simulate the way in which the pedal bone is suspended within the donkey hoof capsule. Displacement, stress concentration, principal strain, and force distribution across the hoof wall were evaluated. The hoof wall model revealed loading responses that were in broad agreement with previously reportedin vivoand modelled observations of the equid hoof. Finite element analysis offers the potential to model hoof wall function at the macroscopic and microscopic level. In this way, it could help to develop further our understanding of the functional relationship between the structural organisation and material properties of the hoof wall.
Batimastat (BB‐94) inhibits matrix metalloproteinases of equine laminitis
Authors: POLLITT C. C. , PASS M. A. , POLLITT S.
Published: June 2010

A method for culturing explants of lamellar hoof was developed to investigate the process of lamellar separation that occurs in laminitis. Explants, consisting of hoof wall, dermal and epidermal lamellae and the adjacent sub‐lamellar connective tissue remained intact when cultured in tissue culture medium for 2 days. However, when cultured in the presence of the matrix metalloproteinase (MMP) activator aminophenylmercuric acetate (APMA), the lamellae separated when tension was applied by pulling the hoof wall in an opposite direction to the connective tissue. The separation occurred between the epidermal basal cells and the basement membrane therefore mimicking the lesion of laminitis. Electrophoresis of culture medium from control hoof explants into gradient polyacrylamide gels co‐polymerised with gelatin revealed that the explants had produced 2 gelatinases of molecular weight 92 and 72 kDa corresponding to EqMMP‐9 and EqMMP‐2 respectively. Minor bands of lower molecular weight were the active forms of these enzymes. The zymograms of culture medium from APMA treated explants revealed an increase in the amount of active MMPs. Equine polymorphs cultured for 2 days produced only EqMMP‐9. Lamellar explant medium from horses with acute laminitis contained increased amounts of zymogen and active EqMMP‐2 and EqMMP‐9 particularly in explants from the fore hooves. Zymography of homogenates of normal lamellar hoof tissue revealed only EqMMP‐2 and a minor active band. However, homogenates of lamellar tissue from horses with laminitis showed that EqMMP‐9 was present as well as increased EqMMP‐2 in both zymogen and active forms. Addition of the MMP inhibitor batimastat (BB‐94) to the culture medium of APMA treated explants prevented lamellar separation. BB‐94 incubated with polyacrylamide strips containing the MMPs from laminitis affected lamellar explants inhibited enzymatic activity at a concentration of 1 mmol/l. It is concluded that activation of MMPs may be responsible for the lamellar separation seen in laminitis and that MMP inhibitors may be useful clinically for preventing this process.
Decreased glucose metabolism causes separation of hoof lamellaein vitro: a trigger for laminitis?
Authors: PASS M. A. , POLLITT S. , POLLITT C. C.
Published: June 2010

Explants of horses' hooves remained intact for up to 8 days when incubated in Dulbecco's modified Eagle medium (D‐MEM) containing 25 mmol/l glucose but separated within 36 h when incubated in saline. The separation occurred between the basal epidermal cells and their basement membrane which is characteristic of the hoof separation that occurs in laminitis. Separation of hoof explants was prevented by addition of glucose to saline and was induced by adding 2‐deoxyglucose or aminophenylmercuric acetate to D‐MEM. Glucose consumption by the hoof explants was inhibited by 2‐deoxyglucose and aminophenylmercuric acetate. The explants consumed relatively large amounts of glucose during the first 2 days of incubation and then little over the next 6 days. Despite the reduced glucose consumption, the hoof explants did not separate over 8 days of incubation. The results indicated that the integrity of the hoof explants was initially dependent on consumption of glucose and provide a possible explanation for the development of laminitis caused by conditions such as carbohydrate overload, acute inflammatory conditions, corticosteroid therapy and hyperlipidaemia. It would be expected that these conditions would induce a major hormonally‐mediated metabolic shift away from glucose consumption by many peripheral tissues. It is suggested, therefore, that if the metabolic change occurred faster than the hoof tissue could adapt to an alternative energy substrate, then hoof separation and laminitis would occur.
The identification of abnormal behaviour and behavioural problems in stabled horses and their relationship to horse welfare: a comparative review
Authors: COOPER J. J. , MASON GEORGIA J.
Published: June 2010

Many behaviours in domestic animals, such as the 'stable vices' of horses, are treated because they are considered undesirable for economic or cultural reasons, and not because the activity affects the horse's quality of life. The impact of a behaviour on the human reporter is not a function of its impact on the animal performer, and an understanding of the causes and effects of the particular activity is necessary to assess the costs and benefits of treatment Where the behaviour is a sign of poor welfare, such as an inadequate environment, treatment can best be achieved by removing these underlying causal factors. Pharmacological or physical prevention of a behaviour can be justified only if the behaviour causes harm to the performer or to others. In these cases, prevention of the behaviour without addressing its causes is no cure and may result in its perseverance in a modified form or the disruption of the animal's ability to adapt to its environment. Where the behavioural 'problem' causes no harm and is not related to poor housing, then the education of the reporter, rather than treatment of the performer, may be the best solution.
Personality and individual differences in the horse, their significance, use and measurement
Authors: MILLS D. S.
Published: June 2010

The biological diversity of a species gives rise to individual differences in behavioural tendency. Traditionally, this variation has been considered to be of little scientific importance or value, but the description and quantification of the fundamental basis of this variability is relevant to many aspects of equine science. The reliable identification of these features may allow the development of more accurate diagnostic and prognostic indicators for a range of clinical diseases. Biologically based traits also provide a more rational basis for selective management and breeding programmes in which specific behavioural tendencies are sought. Individual differences in behaviour also reflect the range of subjective feelings experienced by animals and therefore need to be understood by those concerned with animal welfare. Psychometric techniques concerned with the assessment of personality may provide a suitable basis for scientific study in this field. Potentially methodologies include: behavioural tests, objective behaviour measures or the quantification of reports from those familiar with the subjects. The assessment of the validity and reliability of the variables measured in these tests is an integral part of their development. Interobserver correlation in an experiment based on the subjective rating of 20 horses with respect to 14 familiar terms used to describe horse personality was generally low. This suggests that, with the exception of the terms 'flighty' and 'sharp', the empirical terminology commonly used to describe horse personality is unreliable.
A cross‐sectional study on compulsive behaviour (stable vices) in horses
Authors: LUESCHER U. A. , McKEOWN D. B. , DEAN HELENA
Published: June 2010

A researcher‐administered survey study was performed involving 769 horses from 32 Thoroughbred, Standardbred, and pleasure horse stables in southwestern Ontario. Data were gathered on individuals (breed, age, and sex) and at the stable level (housing, management). The effects of these factors on cribbing, stall‐walking, weaving, stall‐kicking, tongue playing, and pawing were assessed by unconditional analysis (Chi‐square,ttest) and conditionally using stepwise logistic regression. Individual level factors had significant effects on most compulsive behaviours. Some stable level factors, in most cases, those related to type and amount of exercise, had a significant effect on the prevalence of compulsive behaviours when tested unconditionally, but were not significant if entered into a logistic regression model after stable type. Stall‐kicking was more common in horses which had physical contact with other horses, and this factor remained significant in the logistic regression analysis. Stable level factors should be regarded as modulating factors rather than as causes and in some cases, may reflect an attempt to treat the problem. Increased turn‐out of affected horses likely reflects an ineffective attempt to treat problems, while reduced forced exercise (riding, lungeing) of affected horses is more likely to represent a cause.
Physiological correlates associated with cribbing behaviour in horses: changes in thermal threshold, heart rate, plasma β‐endorphin and serotonin
Authors: LEBELT D. , ZANELLA A. J. , UNSHELM J.
Published: June 2010

The aim of the present study was to obtain information on the possible mechanisms underlying cribbing behaviour in horses. To investigate the horse's responsiveness to an external stimulus, a device for telemetric measurement of thermal threshold, using the forelimb withdrawal reflex, was developed and validated. Measurements of thermal threshold took place in cribbing horses (n = 11) before and during cribbing periods. Heart rate was monitored continuously in the same horses. Blood samples were collected before and during cribbing periods as well and in age‐ and sex‐matched control horses (n = 11). β‐endorphin and Cortisol were determined in plasma using radioimmunoassay techniques, serotonin was analysed by high performance liquid chromatography.

Compared with basal values, thermal threshold was significantly (P = 0.003) lower during cribbing periods. The mean difference was 4.9°C. Heart rate decreased significantly (P = 0.026) and showed a mean reduction of 2.4 beats/min during cribbing. Given the fact that arousal usually is associated with an increase in nociceptive threshold and in heart rate, the decrease in both during cribbing provide evidence that cribbing may reduce stress.

Cribbers showed 3 times higher basal β‐endorphin levels than controls (mean 49.5 vs. 16.2 pmol/l, P = 0.006) and there was a trend for lower basal serotonin levels (mean 201.5 vs. 414.3 nmol/l, P = 0.07). These data indicate differences in cribber's endogenous opioid and serotonergic systems.
The effect of short term prevention on the subsequent rate of crib‐biting in Thoroughbred horses
Authors: McGREEVY P. D. , NICOL CHRISTINE J.
Published: June 2010

The results of an experimental study of the motivational consequences of short‐term prevention of crib‐biting are reported here. Eight test horses wore a cribbing collar for 24 h. This was effective in preventing crib‐biting in 6 subjects. Using analysis of co‐variance that accounted for baseline differences in crib‐biting rate, test horses showed significantly more crib‐biting than control horses on the first day after prevention (P < 0.05). There was also a highly significant increase in the crib‐biting rate of test horses on the first day after prevention in comparison with their baseline rate (P < 0.01). This defines the increase as a post inhibitory rebound. An increase in the novelty of the cribbing bar and an increase in feeding motivation during the period of prevention are rejected as explanations of the rebound in this study. Instead, it is suggested that the rebound reflected a rise in internal motivation to crib‐bite during the period of prevention. Behaviours that exhibit this pattern of motivation are generally considered functional; and it has been argued that their prevention may compromise welfare.
Prevention of crib‐biting: a review
Authors: McGREEVY P. D. , NICOL CHRISTINE J.
Published: June 2010

Crib‐biting is a common oral stereotypy. Because of perceived deleterious effects on the health and appearance of subjects the prevention of crib‐biting is regularly attempted. The resourcefulness of horses in satisfying their motivation to perform this behaviour often frustrates owners' efforts at prevention. This paper reviews the efficacy and observable consequences of attempting to prevent crib‐biting by a variety of methods. These include attempts to prevent the grasping of objects, to interfere with air‐engulfing and to introduce punishment for grasping and neck‐flexion. Other approaches include the use of surgery, acupuncture, pharmaceuticals, operant feeding and environmental enrichment. A remedy that is effective for every crib‐biter remains elusive. We conclude that, rather than concentrating on remedial prevention, further research should be directed at establishing why horses crib‐bite and how the emergence of crib‐biting can be avoided.
Applying learning theory to the management of the horse: the difference between getting it right and getting it wrong
Authors: MILLS D. S.
Published: June 2010

Horses constantly modify their behaviour as a result of experience. This involves the creation of an association between events or stimuli. The influence of people on the modification and generation of certain behaviour patterns extends beyond the intentional training of the horse. The impact of any action depends on how it is perceived by the horse, rather than the motive of the handler. Negative and positive reinforcement increase the probability of specific behaviours recurring i.e strengthen the association between events, whereas punishment reduces the probable recurrence of a behaviour without providing specific information about the desired alternative. In this paper the term 'punishers' is used to refer to the physical aids, such as a whip or crop, which may be used to bring about the process of punishment. However, if their application ceases when a specific behaviour occurs they may negatively reinforce that action. Intended 'punishers' may also be rewarding (e.g. for attention seeking behaviour). Therefore, contingency factors (which define the relationship between stimuli, such as the level of reinforcement), contiguity factors (which describe the proximity of events in space or time) and choice of reinforcing stimuli are critical in determining the rate of learning. The many problems associated with the application of punishment in practice lead to confusion by both horse and handler and, possibly, abuse of the former. Most behaviour problems relate to handling and management of the horse and can be avoided or treated with a proper analysis of the factors influencing the behaviour.
Investigating the origins of horse domestication
Authors: LEVINE M. A.
Published: June 2010

Before the development of firearms, the horse was crucial to warfare and, before the invention of the steam engine, it was the fastest and most reliable form of land transport. It is crucial to the life of nomadic pastoralists on the Eurasian steppe and played a major role in the evolution of human society during the Bronze Age and Iron Age. Understanding the human past requires knowledge of the origins and development of horse husbandry. The problem of being able to identify the early stages of horse domestication is one that many researchers have grappled with for the most part unsuccessfully. Until recently the most important criteria used had been that of increased relative abundance. That is, around 3500 BC, in some parts of Eurasia, there was an apparent increase in the proportions of horse bones and teeth found in archaeological deposits by comparison with preceding periods. However, other evidence suggests that the observed increase during the Copper Age could be explained as well, or even better, by increased hunting rather than by domestication.
The importance of ethology in understanding the behaviour of the horse
Authors: GOODWIN D.
Published: June 2010

Domestication has provided the horse with food, shelter, veterinary care and protection, allowing individuals an increased chance of survival. However, the restriction of movement, limited breeding opportunities and a requirement to expend energy, for the benefit of another species, conflict with the evolutionary processes which shaped the behaviour of its predecessors. The behaviour of the horse is defined by its niche as a social prey species but many of the traits which ensured the survival of its ancestors are difficult to accommodate in the domestic environment. There has been a long association between horses and man and many features of equine behaviour suggest a predisposition to interspecific cooperation. However, the importance of dominance in human understanding of social systems has tended to overemphasise its importance in the human‐horse relationship. The evolving horse‐human relationship from predation to companionship, has resulted in serial conflicts of interest for equine and human participants. Only by understanding the nature and origin of these conflicts can ethologists encourage equine management practices which minimise deleterious effects on the behaviour of the horse.
Understanding equine stereotypies
Authors: NICOL C.
Published: June 2010

It is frequently asserted that equine stereotypies, such as crib‐biting, wind‐sucking and weaving, are caused by boredom. However, this explanation is too general to be of practical use in discerning the causes of each stereotypy or in devising management practices to prevent their occurrence. The majority of equine stereotypies start within one month of weaning when both the nutritional and social environment of the foal are substantially altered. Epidemiological research has revealed that the provision of low quantities of forage and minimal opportunities for social contact are associated with a higher reported prevalence of stereotypic behaviour. Experimental data also suggest that oral stereotypies develop in response to a low forage diet but this may be partially adapative. Oral stereotypies may increase salivary flow therefore reducing the acidity of gastric tract and speeding the transit of ingested feed. Stereotypic horses may be less reactive to short‐term aversive stimulation. Neither direct nor circumstantial evidence confirms anecdotal reports that horses copy stereotypies from each other. Surgical and pharmacological methods of prevention should not be attempted unless the underlying causes are removed.
Horses and the rural economy in the United Kingdom
Authors: SUGGETT R. H. GRAHAM
Published: June 2010

The horse industry is large and varied, but until comparatively recently its contribution to the economy of the UK has been virtually ignored and this, together with the disparate nature and small size of the individual businesses involved, has resulted in a general lack of universally available data. What is undoubtedly true, however, is that the horse touches upon the professional and recreational aspects of many peoples' lives and that, without the horse, not only would a significant proportion of the rural working population be unemployed but many ancillary industries would have considerably less work available. This paper reinforces the concept of the horse being at the centre of a large, though disparate and dispersed industry and, what is more, that it is an industry of essential importance both to the welfare of the countryside and to the economic viability of the UK. It also attempts to quantify the size of the horse industry based upon limited information. The paper concludes that 125,000 people (expressed in full time equivalents) are employed directly, there are 600,000 horses and an economic contribution in excess of £m1000.
The human‐horse relationship: how much do we know?
Authors: ROBINSON I. H.
Published: June 2010

Human relationships or interactions with horses have varied throughout history depending on human needs, but it is horses' ability to carry a human individual that has had perhaps the greatest impact on their relationship with man. Despite our long association with the horse, there have been few studies on human‐horse relationships. There is little historical evidence on individual relationships with horses but indications of strong human‐horse relationships have been noted in mounted societies, such as North American Plains Indians. Riding a horse has traditionally been associated with power, and was reserved for the ruling elite in many areas. Demographic data suggest that human relationships with horses may have changed in recent times. Although the lack of land and the relatively high cost of horse care may reduce the possibility of ownership for many people, the availability of riding establishments and increases in leisure time mean that riding is no longer restricted to the upper classes.

There is a wide range in type and intensity of potential interactions with horses, indicating that human‐horse relationships are likely to vary considerably. Some people appear to sacrifice a great deal in order to own a horse. However, the motivation behind these activities and the process by which an individual assesses personal costs of ownership versus their perceived benefits remains to be studied. Future research should focus on characterising the human‐horse relationship, and the degree of individual and cultural variation. A greater understanding of horse owner perceptions of ‘costs’ versus ‘benefits’ may also increase our understanding of the relationship and the economic importance of horses in society.
Review of equine feeding and stable management practices in the UK concentrating on the last decade of the 20th Century
Authors: HARRIS P. A.
Published: June 2010

Equine feeding and stable management practices for horses kept in the UK vary greatly and it is probable that almost any permutation of regimen could be found somewhere. Unfortunately, there is uncertainty about the number of horses in the UK and very limited data are available on the ways horses are being fed and managed. This paper reviews some of the information that is available and provides an outline of some of the factors influencing the practices used. To a certain extent, the way UK horses are fed and managed primarily reflects the purpose for which they are kept (e.g. racing Thoroughbred vs. native breeding pony) as well as their location (urban vs. rural); the time of year; their breed/age as well as the owner's financial situation. In very general terms, the various ways that horses can be kept and managed fall between 2 extremes: the professional riders/owners/ trainers who tend to keep horses and ponies either in large barns/stable yards managed by themselves or a head stable person and the more amateur competitor/leisure riders who tend to keep their horses at a livery yard or at their own or a friend's home. Many of these animals are kept under either part or full do‐it‐yourself (DIY) conditions. Common feeding practices range from feeding traditional home cereal‐based mixes to feeding coarse mixes/pelleted compound manufactured feeds. Very few people, however, feed just a simple single grain or compound feed plus roughage diet. Many add other separate feeding stuffs and supplements including soaked sugar beet or straight molasses, primarily as palatability enhancers. Other common additions include cod liver oil, various types of vegetable oil, carrots, one or more vitamin/mineral mixes, herbal mixes and certain agents with ergogenic/ performance‐enhancing claims. Especially for horses used for competition purposes, provision of supplementary salt is common either by means of a salt block or lick or as an addition to the feed. The soaking of hay, for a variable time period, is another common practice. Although the type and amount of feed fed fundamentally varies according to the work load of the horse there tends to be marked seasonal variations in feeding practices due to the weather and the availability of pasture.
Normal equine gastroduodenal secretion and motility
Authors: MERRITT A. M.
Published: June 2010

This article represents an attempt to provide an overview of the current knowledge of equine gastroduodenal secretory and motor activity, with respect to howe these functions are controlled and interact First, the equine gastric mucosal anatomy is discussed in comparison with other monogastric species, with some attention directed at the large nonglandular portion in relation to its function, or lack thereof. Next, control of gastric acid secretion, as assessed by the collection of gastric contents from a cannula or continuous measurement of their changes in pH, is reviewed, pointing out that there appears to be a relatively unobstructed movement of contents between stomach and duodenum in the horse, which can have a strong influence on pH of the gastric contents in particular. Then, methods of evaluating gastroduodenal motility, including recording of myoelectrical activity and changes in intraluminal pressure, and transit of radiolabelled contents from stomach into duodenum, are discussed. Finally, the apparent influence of the gastroduodenal migrating motility complex (MMC) on the composition of fasting gastric contents is introduced to underscore the observation that reflux of duodenal contents into the stomach is probably a common occurrence in the horse, particularly during periods of MMC‐related cessation of antral motility.
Cross‐sectional study of gastric ulcers of the squamous mucosa in Thoroughbred racehorses
Authors: VATISTAS N. J. , SNYDER J. R. , CARLSON G. , JOHNSON B. , ARTHU R. M. , THURMOND M. , ZHOU H. , LLOYD K. L K.
Published: June 2010

†California Veterinary Diagnostic Laboratory Service, California 95616, California 91024, USA.

Although gastric ulcers have been identified relatively frequently in racing Thoroughbreds, there have been no large scale studies to determine their effect on health and performance. Two hundred and two Thoroughbred horses in active race training were selected by the attending veterinarians for gastro‐endoscopic examination. Images of the stomach mucosa were stored in a digitised format for subsequent evaluation. The number of ulcers and a score of severity were determined. Gastric ulceration of the squamous mucosa was identified in 82% of horses. Seventy‐three (39%) horses displayed clinical signs consistent with gastric ulceration. Increasing Furr and Murray Score was associated with poor hair coat (P = 0.03), colic (P = 0.03), and increasing serum creatinine concentration (P = 0.029). There were no associations between haematology and serum biochemistry values (other than serum alkaline phosphatase concentration and serum creatinine concentration) and gastric ulceration. Our study confirmed the relatively high incidence of gastric ulceration in Thoroughbred horses involved in active race training. Gastric ulceration is a potential, but rare, cause of overt colic, but may produce more subtle detrimental effects on a horse's condition. It is concluded that the diagnosis of gastric ulceration should be based on an endoscopic examination of the stomach, although future studies are required to elucidate further the aetiology and clinical significance of gastric ulceration.