bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SummarySeventy‐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

SummaryThe 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

SummaryThe 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

SummaryThe 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

SummaryPossible 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

SummaryThis 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

SummaryStudies 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

SummaryThe 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

SummaryA 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

SummaryObjectives 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

SummaryThis 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

SummaryA 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

SummaryA 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

SummaryExplants 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

SummaryMany 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.