bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oviduct flushing as a treatment for infertility in the mare
Authors: ZENT W. W. , LIU I. K. M. , SPIRITO M. A. 
Published: June 2010

SummaryThe oviducts of 8 infertile mares (12–21 years) were flushed from the uterotubal junction to the fimbria in an attempt to clear the oviduct of any oviductal masses that might have been interfering with migration and/or fertilisation of the ovum. None of them had been diagnosed as pregnant for at least 3 consecutive years and the uteri were grade II or III. Flushing was successful (masses extruded) in 5 mares and 3 of these became pregnant. This procedure has the potential of correcting a possible cause of infertility, but it is a major surgical undertaking and should not be attempted unless all other diagnostic procedures have failed to produce a reason for the inability to conceive.
Cryopreservation of equine embryos using glycerol and 1,2‐propanediol as cryoprotectants
Authors: MEIRA C. , ALVARENGA M. A. , PAPA F. O. , OBA E. , e ALVARENGA F. C. LANDIM 
Published: June 2010

SummaryEquine embryos recovered at Day 6 or 7 after ovulation were deep‐frozen using glycerol (Groups 1 and 2) or 1,2‐propanediol (Group 3). Blastocysts (Bl) and expanded blastocysts (Exbl) were used in Group 1 and tight morulae (Tm) and early blastocysts (Ebl) in Groups 2 and 3. In Group 4 (control), fresh embryos were used. Post‐thawed embryos and fresh embryos were non‐surgically transferred, independently of the morphological appearance, into recipient mares at Day 6 or 7 of dioestrus. Embryo recovery rate was 55.3% (93/168); the pregnancy rates in Groups 1, 2, 3 and 4 were 0% (0/12), 40% (6/15), 0% (0/15) and 80% (12/15) at 15 days respectively. Embryonic losses were 16.7% (1/6) and 8.3% (1/12) in Groups 2 and 4 at 60 days. These results indicate that glycerol was superior to 1,2‐propanediol as a cryoprotectant and that Bl and Exbl were unsuitable for cryopreservation.
In‐vivo fertilisation and initial embryogenesis in the mare
Authors: GRØNDAHL C. , NIELSEN C. GRØNDAHL , ERIKSEN T. , GREVE T. , HYTTEL P. 
Published: June 2010

SummaryEleven mares were induced to ovulate by treatment with 3,000 iu hCG and subsequently inseminated with frozen‐thawed semen. The time of ovulation was determined by transrectal ultrasonography of the ovaries performed every 4 h. At different times after ovulation ova were collected from oviducts removed by surgery through a flank incision under general anaesthesia. The presumed fertilised ova were cultured for 20 min in a medium containing [3H]uridine, fixed, embedded in Epon, semithin‐sectioned and processed for autoradiography. Selected semithin sections were re‐embedded and processed for transmission electron microscopy. Spherical, paternal and maternal pronuclei were observed within 12 h after ovulation, and by 19 h the pronuclei had migrated to close apposition. The 2‐cell stage was seen within 34 h and a major activation of RNA synthesis was detected at 64 h after ovulation in 4 blastomeres of a 6‐cell embryo, suggesting maternal‐embryonic transition apparently occurs at the 4th cell cycle.
Modifications in the technique used to recover equine embryos
Authors: ALVARENGA M. A. , e ALVARENGA F. C. LANDIM , MEIRA C. 
Published: June 2010

SummaryIn Experiment I, phosphate‐buffered saline (PBS) or Ringer‐lactate solution (RL) was used to flush embryos from mares, but there was no difference (P>0.05) in pregnancy rate after transfer of embryos: 8/14 (57%) in PBS and 14/22 in RL. There was also no difference (P>0.05) in pregnancy rates in Experiment II when embryos were flushed with PBS alone (53/117, 45%) or PBS + 1% foetal calf serum (37/70, 53%). In Experiment III, the standard technique for embryo recovery gave 55% (11/20) success compared with 75% (18/24) for a modified method whereby 3 min' contact time was allowed in the uterus for each flush, without massage of the uterus, but this was not statistically significant (P>0.05).
The application of embryo transfer to polo ponies in Argentina
Authors: PASHEN R. L. , LASCOMBES F. A. , DARROW M. D. 
Published: June 2010

SummarySince the commercial embryo transfer programme for polo ponies in Argentina was started in 1989, 479 of 727 (66%) embryo recovery attempts yielded one or more embryos. Nonsurgical transfer of 580 embryos to synchronised recipient mares resulted in the establishment of 353 pregnancies (61%).
Osteochondrosis in the tarsocrural joint and osteochondral fragments in the fetlock joints in Standardbred trotters. II. Heritability
Authors: Philipsson J. , Andréasson E. , Sandgren B. , Dalin G. , Carlsten J. 
Published: June 2010

SummaryThe progeny (N=793) of 24 Swedish Standardbred trotter stallions were used for genetic studies on radiographic findings of osteochondrosis (OC) in the tarsocrural (hock) joint and palmar/plantar osteochondral fragments (POF) in the metacarpo‐ and metatarsophalangeal (fetlock) joints.Twenty stallions were drawn at random from the population of Swedish Standardbred trotter stallions approved for breeding, and 4 stallions were selected for their own OC and POF status. The progeny groups included 28–39 investigated yearlings per stallion. About half of the horses were born in each of the years 1988 and 1989.Hock joint OC was diagnosed in 71 (10.5%) and fetlock joint POF in 145 (21.5%) offspring of the randomly selected stallions. The incidence of OC and POF varied among the progeny groups between 0–24% and 11–44% respectively (P<0.05). The findings were analysed as all‐or‐none traits and as sire‐offspring regressions. Non‐genetic effects of sex, age at examination and year/month of birth were simultaneously considered with genetic effects of sire. The heritability was estimated to be 0.08–0.09 on the threshold scale for both traits, corresponding to 0.24–0.27 for OC and to 0.17–0.19 for POF on the underlying quantitative scale. Sire‐offspring regressions yielded heritabilities of 0.34 and 0.23 for OC and POF, respectively.Correlations between OC and POF, as well as between these and measures of body size, were contradictory, probably due to the limited amount of data and the all‐or‐none characters of both OC and POF. However, we conclude that the predisposing factors of OC and POF are inherited independently of each other.
Plantar osteochondral fragments in the metatarsophalangeal joints in Standardbred trotters; result of osteochondrosis or trauma?
Authors: Dalin G. , Sandgren B. , Carlsten J. 
Published: June 2010

SummaryHindlimb fetlock joints with plantar osteochondral fragments (POF) were collected from 21 horses (17 Standardbred trotters, 4 Swedish Warmblood riding horses; 8 stallions, 5 geldings, and 8 mares; ages 5 months‐21 years) and from 28 horses with no metatarsophalangeal joint pathology. The morphology of the osteochondral fragments and adjacent tissues was studied by dissection, high‐resolution radiography, and histology. There were 22 joints affected, and 20 out of 25 POF found were located medially. In 3 joints there were fragments both laterally and medially. The fragments were attached to the short sesamoidean ligaments and facing the joint cavity they had a smooth cartilage covered surface which measured between 4 times 2 mm and 12 times 6 mm. A small central trabecular osseous core was seen radiographically in the young horses (<1 year of age), and the proportion of the bony component increased during the first years of life. In 18 out of 25 POF sites, a defect was seen in the adjacent bone of the proximal phalanx. Histology did not show any findings indicative of osteochondrosis.It is suggested that plantar osteochondral fragments are the result of outwardly rotated hindlimb axes and subsequent point loading in the medial fetlock area. Repeated high tension loads in the short sesamoidean ligaments may cause fragments of tissue with osteogenic properties to come off the proximal phalanx into the ligament, later forming osteochondral fragments.
Histomorphometric assessment of bone biopsies from foals fed diets high in phosphorus and digestible energy
Authors: Savage C. J. , McCarthy R. N. , Jeffcott L. B. 
Published: June 2010

SummaryBone turnover was estimated from biopsy cores from the wing of ilium in 24 mixed‐bred foals, aged 4.5–6.5 months and divided into 4 groups. A control group was fed according to NRC recommendations for foals growing at 0.65 kg/day, experimental groups diet for 16–18 weeks with additions of phosphorus (P, 388% of control level), digestible energy (DE, 129% of control level) or crude protein (CP, 126% of control level). Bone biopsies were taken in Week 7/8 and again at the end of the trial.In the first biopsy no significant differences between dietary groups were found. Cortical bone porosity increased over time (P = 0.001) in foals fed High P (17.09 ± 2.25%vs22.41 ± 2.62%). At the end of the study cortical bone porosity was greater (P = 0.02) in foals fed excess P than in other groups. In High P fed foals the extent of osteoid covered surfaces of cancellous bone decreased over time (P = 0.03), and there was a trend towards increased resorption surfaces in the cancellous bone with a subsequent slight decrease in cancellous bone volume. Cortical bone porosity tended to increase in foals fed High DE (P = 0.07) yet no significant alteration was seen in cancellous bone volume. Joint lesions of dyschondroplasia (DCP) were found atpost mortemin foals fed High DE and High P. However, only minor changes in the measurements of bone remodelling were found by histomorphometric analysis. Changes in foals fed High P were consistent with a mild form of nutritional secondary hyperparathyroidism, although no clinical signs were noted.
Longitudinal development of the kinematics of 4‐, 10‐, 18‐ and 26‐month‐old Dutch Warmblood horses
Authors: BACK W. , BARNEVELD A. , SCHAMHARDT H. C. , BRUIN G. , HARTMAN W. 
Published: June 2010

SummaryThe forelimb kinematics of 24 Dutch Warmbloods were recorded at the trot on a treadmill (4m/s) at the age of 4, 10, 18 and 26 months using a modified CODA‐3 apparatus to study the development of the equine locomotor apparatus. Stride and stance duration increased with age, but swing duration and pro‐/retraction angle were consistent. The timing of maximal fetlock extension during the stance phase and carpal flexion during the swing phase did not change significantly as horses grew older. Moreover, individual angle‐time and angle‐angle diagrams recorded at 4 and 26 months showed a remarkable resemblance, both visually and numerically. From these data it can be concluded that horses seem to have an inherent intralimb coordination pattern.
Comparison of the collected, working, medium and extended canters
Authors: CLAYTON HILARY M. 
Published: June 2010

SummaryHigh speed cinematography (150 Hz) was used to determine the linear and temporal characteristics of the collected, working, medium and extended canters in 6 highly trained dressage horses. Analysis of variance and Waller‐Duncan Bayes K‐ratio t‐tests were applied to determine which of the measured variables changed significantly among the 4 gait types. The mean speed increased progressively from the collected to working to medium to extended canters (p<0.01). Changes in speed were due to adjustments in stride length while stride duration remained constant. An increase in stride length was the result of increases in the distances between successive limb placements except the diagonal distance between the leading hind and trailing front limbs which did not change. The greatest increase was between the leading front limb and the subsequent placement of the trailing hind limb. Although the same stride duration was maintained in the 4 canter types, there were significant changes in the temporal relationships between the footfalls. The step duration between the 2 front limbs was significantly reduced from the collected to working to medium to extended canters (p<0.01). The step duration between the 2 hind limbs was significantly shorter in the extended than the collected canter (p<0.01). The stride duration was maintained by increasing the duration between the leading front and trailing hind limbs.
The use of a panning camera technique in equine kinematic analysis
Authors: DREVEMO S. , JOHNSTON C. 
Published: June 2010

SummaryA method applicable for field studies of equine locomotion based on recordings by high‐speed cinematography/videography with a panning camera is presented. A ground reference plane/line was defined by a number of ground reference plates at equidistant intervals along the filming range. One ground reference plate in the middle of the range was predefined and designated as Ref0. The camera position was determined in such a way that the camera axis was perpendicular to the reference line when aiming towards Ref0. The maximum error introduced by the experimental setup was less than 3% and the perspective errors at the end of the recording range less than 0.02 m in a single position determination. The method was applied to study some basic temporal and linear variables and the pastern, metacarpal segment and fetlock joint angles in 6 young Standardbred trotters at 10.2 ± 0.17 m/s. The mean stride and stance durations for the group of horses were 503 ± 15 ms and 131 ± 6 ms, respectively. Indications of laterality in individual horses were observed when diagonal and contralateral pairs of limbs were studied. Sudden angle changes were observed in the fetlock segment and fetlock joint at full support following braking of the fore‐aft horizontal hoof movement.
Analysis of equine gait using three‐dimensional accelerometers fixed on the saddle
Authors: GALLOUX P. , RICHARD N. , DRONKA T. , LEARD M. , PERROT A. , JOUFFROY J. L. , CHOLET A. 
Published: June 2010

SummaryThe aim of this study was to give riding teachers, physiotherapists and research workers a better understanding of the three‐dimensional movement of the horse's saddle. The gaits of 7 horses were recorded on the treadmill by an accelerometric crown fixed to the front of a saddle. After a Fourier analysis of the signal, noise was eliminated; after a double integration data were obtained describing the crown's movement, assuming that after each stride the saddle returns to the original place. The movement was visualised in two and three dimensions. The walk showed more twisting motions, whereas the trot had more rolling, longitudinal and lateral movement. The canter showed the highest amplitude of motion, with a strong pitching rotation but little twisting. The pitching movement was the most important type of rotation for the three gaits. The speed at the canter did not influence the shape of the movement patterns.
Shortening of the hind limb in the horse during the stance phase
Authors: HJERTÉN G. , DREVEMO S. , ERIKSSON L.‐E. 
Published: June 2010

SummaryCompressions of the hind limb in a horse trotting at 3.7 m/s were studied by use of high‐speed cinematography. It is concluded that distal loading, beginning at the hoof, resulted in a longer impact time and smaller impact forces compared to a theoretical stiff limb. Shortening of the hind limb during the stance occurs from hoof to stifle, while there is an elongation of the distance between the stifle and tuber coxae.
Kinematics of the hind limb push‐off in elite show jumping horses
Authors: VAN DEN BOGERT A. J. , JANSEN MARGOT O. , DEUEL NANCY R. 
Published: June 2010

SummaryThe sagittal plane kinematics of trunk, neck, and hind limb were analysed in a group of 15 elite show jumping horses during the push‐off of the hind limbs before jumping a 1.50 m upright fence. Similar movement patterns were observed in all horses. Ensemble averages of the kinematic variables of the group were calculated after spline smoothing and time‐normalisation with respect to the support phase. The final support phase of the hind limbs was symmetrical and had a duration of 221 ± 19 ms. During the first half of this period, the trunk rotated towards a more upright orientation and the height of the estimated centre of mass was decreased by about 0.05 m. These movements were accompanied by 25 degrees of hip extension and 40 degrees of flexion in the stifle and hock joints. These movements bring the hind limbs into a favourable, flexed position to produce mechanical power and transfer it to the trunk. Maximal flexion in the tarsal joint was reached at 98 ms after ground contact, followed by the stifle joint at 124 ms. After maximal flexion, the total extension movement of the tarsal and stifle joints was 45 and 22 degrees respectively. The extension of the hip continued until 152 ms after ground contact, and the angle remained stationary afterwards. The extension of the hind limb was accompanied by a large increase in horizontal and vertical velocity of the trunk, and a reversal of the rotation of the trunk. The average rate of mechanical power production during the entire push‐off, estimated from the change in kinetic and potential energy, was 59,000 W. By comparing total energy at the beginning and end of the support phase, it was concluded that most of the energy required to clear the fence was produced by the hind limbs during the final support phase, and that the previous actions of the forelimbs are merely bringing the horse into a good position for the final push‐off.
Pulsed wave Doppler echocardiography in normal horses
Authors: BLISSITT KAREN J. , BONAGURA J. D. 
Published: June 2010

SummaryReference values were established for selected Doppler derived variables from a group of 40 normal Thoroughbred and Thoroughbred cross horses. Standard two‐dimensional (2‐D) images used for guiding the Doppler sampling site allowed accurate alignment with flow. Tricuspid inflow velocities during rapid filling (E) and atrial contraction (A) were significantly higher when recorded from a right parasternal angled view than from a right parasternal long‐axis view. In 8 horses the tricuspid inflow peak A velocity was higher than the peak E velocity. The peak acceleration of blood flow was higher (P=0.000) in the aorta (mean 8.01 m/s/s) than in the pulmonary artery (4.45 m/s/s). Significant differences were also noted in the pre‐ejection period, ejection time and acceleration time between the 2 vessels. Horses with functional ejection murmurs had lower peak aortic acceleration and a longer acceleration time than horses without flow murmurs. Horses with filling murmurs over the left hemithorax had a significantly higher peak mitral E velocity than horses without such murmurs. Measurements from Doppler waveforms were repeatable and may prove useful in assessing ventricular function in this species.
Physiological valvular regurgitation in clinically normal young racehorses: prevalence and two‐dimensional colour flow Doppler echocardiographic characteristics
Authors: MARR CELIA M. , REEF VIRGINIA B. 
Published: June 2010

SummaryColour flow Doppler echocardiographic examinations were performed on 15 horses; 10 Thoroughbreds and 5 Standardbreds; 9 mares, 5 geldings and 1 stallion; mean ± s.d. 3.4 ± 1.1 years. Cardiac murmurs were audible in 12 horses (80%), but these had characteristics consistent with functional murmurs in all horses. A standardised two‐dimensional (2‐D) and M‐mode echocardiographic examination was unremarkable in all horses except that aortic valve prolapse was identified in 3 horses, tricuspid valve prolapse in 2 horses and mitral valve prolapse was present in one horse. Colour flow Doppler echocardiography revealed laminar antegrade flow in most sites but variance was noted in the right ventricular outflow tract in some horses. Small regurgitant jets associated with the aortic valve were seen in 12 horses (80%), with the tricuspid valve in 7 horses (46%), with the pulmonary valve in 4 horses (26%) and the mitral valve in 4 horses (26%). It was concluded that with colour flow Doppler echocardiography, as in other species, small regurgitant jets could be detected in many normal horses.
The haemodynamic effects of milrinone HCl in halothane anaesthetised horses
Authors: MUIR W. W. 
Published: June 2010

SummaryThe haemodynamic effects of milrinone hydrochloride were determined in halothane‐anaesthetised horses. Six healthy adult horses were anaesthetised with guaifenesin and thiamylal and maintained with halothane in oxygen (end‐tidal halothane concentration of 1.15%). Baseline haemodynamic data were recorded after a 45 min stabilisation period. All 6 horses received a single loading dose of milrinone HCl, 0.2 μg/kg i.v., followed by progressively increasing infusions of 2.5, 5, 10 and 20 μg/kg bwt/min. Each infusion lasted for 15 min and produced dose related increases in heart rate, mean arterial blood pressure, cardiac output, maximum rate of increase and decrease of left ventricular pressure (± dP/dtmax) and ejection fraction in halothane anesthetised horses. Median artery blood flow increased following milrinone administration. Right atrial and pulmonary artery pressures, systemic vascular resistance and left ventricular end‐diastolic and end‐systolic volumes decreased. Most haemodynamic changes were sustained throughout the infusion period and for 30 min following the termination of milrinone infusion. Systemic vascular resistance was increased above baseline values at 30 min following the termination of milrinone infusion. No adverse side effects were observed during this study although a milrinone infusion rate of 20 μg/kg bwt/min increased heart rate to values greater than 50 beats/min. The results of this study suggest that milrinone produces beneficial haemodynamic effects in halothane anaesthetised horses and is potentially useful in the treatment of patients with a reduced cardiac output.
Plasma volume and ions during exercise in cool, dry; hot, dry; and hot, humid conditions
Authors: LINDINGER M. I. , GEOR R. J. , ECKER GAYLE L. , McCUTCHEON L. J. 
Published: June 2010

SummaryWe studied the effects of heat and relative humidity (RH) on plasma volume (PV) and ion responses to submaximal exercise and 60 min recovery in Thoroughbreds. Five horses were exercised at 50% of peak V̇O2in cool, dry (CD, T=22°C, RH=45–55%), and hot, humid (HH, T=30–34°C, RH=80–85%) conditions until a pulmonary artery temperature of 41.5°C was reached. Blood was obtained from the carotid artery. Body mass was measured at rest and after 30 min of recovery. The thermal conditions had no effect on the PV and ion responses during exercise and initial 30 min of recovery. Exercise resulted in an 8.5% decrease in PV within the first 2 min and, in the absence of changes in plasma [Na+] and [Cl−], was responsible for a 150 to 185 mmol decrease in plasma Na+and Cl−contents. The decrease in PV was responsible for about 50% of the increase in packed cell volume (37% at rest; 51% at 2 min of exercise).Plasma [K+] and K+content increased rapidly during the first 2 min of exercise. With cessation of exercise, plasma [K+] declined with a half time of about 2 min; recovery of PV and plasma Na+and Cl−contents occurred with a half time of 10–15 min, with nearly complete recovery by 30 min. In the HD trial, between 30 and 60 min of recovery there were further decreases in PV and ion contents. It is concluded that with this exercise protocol, thermal stress had minimal influence on the rate and magnitude of exercise‐induced changes in PV and ion contents. However, thermal stress during recovery from exercise may impede the restoration of PV and ion contents.