bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cryopreservation of equine embryos in 1, 2 propanediol
Authors: SEIDEL G. E. , SQUIRES E. L. , MCKINNON A. O. , LONG P. L. 
Published: June 2010

SummaryEmbryos of good to excellent morphology were recovered 6.5 to 7 days after ovulation, washed in Dulbecco's phosphate‐buffered saline plus 10 per cent heat‐treated foetal calf serum (PBS), and placed in PBS plus 5 per cent 1, 2 propanediol for 5 mins followed by PBS plus 10 per cent 1, 2 propanediol for 10 to 20 mins. The embryos were then placed into 0.5 ml French straws, cooled initially to −6°C at 4°C/min, seeded and cooled further from −6°C to −33°C at a rate of either 0.3°C/min or 0.8°C/min. When straws reached −33°C they were plunged into liquid nitrogen. Within each cooling treatment, straws were thawed either in a 37°C water bath for 20 sees, or at ambient temperature in air. 1, 2 propanediol was removed in four steps, each step of 6 mins duration at room temperature. The thawed embryos were then cultured in Ham's F10 plus 10 per cent FCS in a 5 per cent CO2incubator at 38°C. After 48 h, the morphological appearance of the embryos was evaluated on a scale of 1 to 5 (1 = excellent, 5 = severely degenerate). Four embryos measuring 130 to 175 μm in diameter, 23 embryos measuring 200 to 945 μm and three embryos larger than 1000 μm were included in the experiment. All four of the small embryos showed good morphology at the end of the culture period (scores of 1.5 to 3.5) whereas none of the embryos larger than 1000 μm in diameter survived cryopreservation (all scores 5.0). Post‐treatment scores for the 23 embryos in the middle‐sized group (220 to 945 μm) ranged from 1.5 to 5.0. Rapid thawing was superior to slow thawing (p<0.07) for embryo quality after 48 h of culture, although the rapidly thawed embryos appeared to be more damaged immediately after thawing as determined by cracked capsules or zonae pellucidae, or embryos breaking into pieces. The rate of cooling had no significant effect on any response.
The equine fundus II: normal anatomical variants and colobomata
Authors: MATTHEWS A. G. , CRISPIN SHEILA M. , PARKER J. 
Published: June 2010

SummaryA wide range of fundic variants are encountered during routine ophthalmoscopic examination of visually normal horses, often causing the examiner difficulty in assessing their clinical significance. Many of these are anatomical variants having no significant effect on visual function, and lie within the limits of normality in the horse. This paper illustrates this range of variants and discusses their anatomical basis and physiological consequences. Colobomata are non‐progressive discontinuities in the structure of the anatomic fundus, occasionally noted as incidental findings during ophthalmoscopy. This paper illustrates typical and atypical colobomata of the equine fundus, the latter occurring outside the embryonic optic fissure. The anatomical basis of these colobomata and their possible consequence on vision is discussed.
A comparative study of interval and conventional training in Thoroughbred racehorses
Authors: HARKINS J. D. , KAMERLING S. G. , BAGWELL C. A. , KARNS P. A. 
Published: June 2010

SummaryEight horses with previous racing experience were used in a comparative study of training methods for Thoroughbred racehorses. They were randomly assigned to two groups of four horses each. One group was trained using an interval training method (IT) and the other using conventional training (CT) methods. Peak heart rates, heart rate recovery curves, peak plasma lactate levels, plasma lactate clearance rates and run times were used to evaluate differences in the training methods. Peak heart rates, heart rate recovery curves, and run times were not significantly different between the groups. However, higher lactate production and increased plasma lactate clearance by the IT group demonstrated an increased anaerobic capacity.
The relationship between peak expiratory sound intensity and peak expiratory flow rate in the Thoroughbred horse during exercise
Authors: ATTENBURROW D. P. , FLACK F. C. , PORTERGILL M. J. 
Published: June 2010

SummaryPeak expiratory sound intensity (dB SPL), obtained by means of a radiostethoscope, and peak expiratory flow rate, obtained using a mask incorporating a thermistor flow sensor, were measured in six Thoroughbreds over a range of stride rates from 100 to 140 strides per min. The results show linear relationships between peak dB SPL and stride rate, peak expiratory flow rate and stride rate and also between peak expiratory flow rate and peak dB SPL. Peak expiratory dB SPL can therefore indicate peak expiratory flow rate.
Quantification of skin displacement in the proximal parts of the limbs of the walking horse
Authors: VAN WEEREN P. R. , VAN DEN BOGERT A. J. , BARNEVELD A. 
Published: June 2010

SummaryDisplacement of skin over the underlying skeletal structures in the proximal parts of the limbs was investigated in four walking Dutch Warmblood horses. Movement of the skin was visualised with self adhesive spot labels whereas that of the skeletal parts was visualised indirectly by means of a plastic strip connected to a transcutaneous Steinmann pin, driven into the bone of interest. Consistent results for all four horses were found. Individual and mean total displacements ranged from 1 to 4 cm (distal scapula) to 13 to 17 cm (caudal part of the greater trochanter of the femur). Displacements of this magnitude are of considerable importance to the interpretation of results of modern gait analysis techniques.
Structural and developmental relationship between capsular glycoproteins of the horse (Equus caballus) and the donkey (Equus asinus)
Authors: ORIOL J. G. , BETTERIDGE K. J. , HARDY J. , SHAROM F. J. 
Published: June 2010

SummaryIn the present study, we have investigated the molecular structure and biosynthesis during development of the donkey capsule, which replaces the zona pellucida and envelops the conceptus during the 2nd and 3rd weeks of gestation, before uterine attachment, and compared it with that of the horse. Amino acid analysis of capsules from accurately aged donkey conceptuses indicated that the polypeptide backbone of the constituent glycoproteins was very similar in both species. Carbohydrate analysis and lectin histochemical staining showed that, as in the horse, the major sugars present were sialic acid, N‐acetylgalactosamine and galactose. However, the donkey capsule contained substantially lower amounts of sialic acid. Removal of the covalently‐bound O‐linked carbohydrate by β‐elimination indicated that the donkey capsule resembles that of the horse in being O‐glycosylated mainly on threonine residues. The dry masses of donkey capsules remained low between Days 8.5 and 11.5, and increased rapidly with blastocyst expansion up to Day 17.5, as in the horse. However, the maximum capsular weight attained in the donkey (2.5 mg) was only half that of the horse and the decline in capsule weight up to Day 22.5, shortly before its disappearance, was steeper and occurred earlier. A monoclonal antibody (OC‐1), which reacts with a developmentally regulated epitope in the horse capsule, cross‐reacted strongly with both the capsule and trophoblast in frozen sections of donkey conceptuses. The differences in OC‐1‐reactive antigen expression in the donkey trophoblast mirrored those observed for the increase in capsular dry mass. The biochemical and developmental similarities observed between the capsule of the donkey and the horse suggest that this structure has been highly conserved in equids.
Influence of embryonic secretory chemicals on selective oviductal transport in mares
Authors: WEBER J. A. , WOODS G. L. 
Published: June 2010

SummaryEquine embryos are selectively transported from oviducts to uteri from 5 days 10 h to 5 days 22 h after ovulation. Selective transport appears to be initiated by a characteristic of equine oviductal embryos that is not present in unfertilised ova. To test the hypothesis that selective oviductal transport is initiated by stage‐specific secretion of embryonic chemicals, experiments were completed to identify chemicals whose secretion by embryos was temporally associated with oviductal transport, and which initiated oviductal changes that were consistent with oviductal transport. Day‐6 embryos incubated in vitro secreted minimal amounts of proteins, steroids and prostaglandin F2α, and relatively high amounts of prostaglandin E2 (PGE2). Embryonic PGE2 secretion was not detected on Day 3 or Day 4, was first detected on Day 5 and in larger amounts on Day 6. PGE2 bound specifically to equine oviducts on Days 2 and 5. Uterine entry of oviductal embryos was hastened in 6 of 11 mares by intraoviductal PGE2 treatment, but was not hastened by saline vehicle treatment or no treatment. These results support the hypothesis that embryonic PGE2 initiates oviductal transport in mares.
In‐vitro maturation of equine oocytes in co‐culture with granulosa and theca interna cells
Authors: OKÓLSKI A. , SLONINA DOROTA , BANASINSKA KATARZYNA 
Published: June 2010

SummaryThe ovaries of 173 mares were collected at slaughter from September 1991 to September 1992 and follicles (5–20 mm in diameter) were isolated and dissected to obtain oocytes for culture. Cumulus‐oocyte complexes (669) were cultured for 24, 30, 36, 42 or 48 h in medium alone (n = 319) medium plus 3 times 106 granulosa cells/ml (n = 133) medium plus 0.3 times 106theca interna cells/ml (n = 138) or medium plus 3 times 106granulosa cells/ml plus 0.3 times 106 theca interna cells/ml (n = 79). After culture cumulus cell expansion and stage of nuclear maturation were determined. The percentage of oocytes with full dispersion of cumulus cells was significantly higher from 24 to 42 h in culture with follicular cells, especially theca interna cells, than in culture with oocytes alone. The majority of oocytes reached full nuclear maturation after 30 h.
Physiological responses to the endurance test of a 3‐day‐event during hot and cool weather
Authors: KOHN CATHERINE W. , HINCHCLIFF K. W. 
Published: June 2010

SummaryPhysiological data were collected during two 3‐day‐event competitions: one (H) held in hot and the other (CL) in cool conditions. During H, ambient temperature and relative humidity were 2.5°C‐35°C and 74‐36% respectively, while during CL, ambient temperature and relative humidity were 7.8°C‐8.3°C and 46%‐41%, respectively. Rectal temperature, heart and respiratory rates were recorded on arrival at the event, at the end ofPhase Cand 6 min later, at the end ofPhase Dand for 30 min at 10 min intervals after each horse finishedPhase D(Recovery Period). Because of the heat, the rest‐pause during the Endurance Test was extended from 10 to 15 min for horses competing in H, and horses at H were aggressively cooled by repetitive bathing with ice water during the rest‐pause and the 30 min Recovery Period. Heart rate was significantly higher (P<0.05) at the end ofPhase Cin horses participating at H, as compared to those participating at CL. Heart rates were significantly decreased in both groups after 6 min in the rest‐pause and by 10 min after the finish ofPhase D.Rectal temperatures were significantly higher in horses competing at H than in those competing at CL at the end ofPhase Cand 6 min later, and at 10 and 20 min after the finish ofPhase D.In both groups, rectal temperatures decreased significantly during the first 6 min in the rest‐pause and at 10 and 20 min after the finish ofPhase D.Fifty‐five of 79 (69.6%) horses startingPhaseA at H completedPhase D, as compared to 23 of 28 (82.1%) of starters at CL (P>0.05). Of 10 horses eliminated during the rest‐pause at H, 3 were lame, 1 had exertional rhabdomyolysis, 4 were exhausted and 2 were lame and exhausted. Two horses were eliminated during the rest‐pause at CL: 1 was lame and the other had exertional rhabdomyolysis. There was marked individual variation in horses' responses to heat at H. Heat may have limited the effectiveness of evaporative cooling in horses at H, and resultant thermal stress probably contributed to exhaustion in horses unable to complete the Endurance Test. Aggressive cooling during the rest‐pause and the Recovery Period was important to facilitate heat dissipation in horses at H. These measures were not necessary at CL.
Kinematic analysis of the locomotion symmetry of sound horses at a slow trot
Authors: POURCELOT P. , DEGUEURCE C. , AUDIGIÉ F. , DENOIX J. M. , GEIGER D. 
Published: June 2010

SummaryThis study of the locomotion symmetry was undertaken to provide standard symmetry indices of a group of sound horses at the trot Using a 3D data collection system, the kinematics of the limb joints of 13 clinically nonlame horses were recorded while trotting in the standard conditions of the clinical lameness examination. A kinematic symmetry indice based on an inter‐correlation method was defined and applied to the vertical displacement‐time and joint angle‐time diagrams of the left and right joints of the horses. For each horse, the mean symmetry indice of each joint was calculated using values from 5 trials. For each joint, these means were then averaged. To evaluate the repeatability of the locomotion symmetry, the intra‐ and inter‐individual variabilities of the symmetry indices were studied.The levels of symmetry of the markers of the trunk were generally lower than those of the limbs. Moreover, during the 5 trials these levels of symmetry were strongly variable but their mean values were very similar from one horse to another. In our experimental conditions the trunk presented a higher degree of freedom than the limbs. This high infra‐individual variability indicated also that several trials are necessary to quantify the locomotion symmetry of a trotting horse.In the same way, a lower level of symmetry of the hindlimbs, compared to the forelimbs, was proved by their lower values of symmetry indices. As opposed to the supporting role of the forelimbs, the propulsive role of the hindlimbs may explain this feature.
Gait analysis in laying hens and broilers with and without leg disorders
Authors: REITER K. , BESSEI W. 
Published: June 2010

SummarySelection of broiler strains for high body weight has changed the anatomical characteristics and in connection to that, the pattern of locomotion. In addition, rapid growing broilers show a high incidence of leg disorders which compromise the walking ability of the birds. Differences in the patterns of locomotion between laying hens and broilers and between broilers with and without leg disorders can be demonstrated and quantified by gait analysis. The gait pattern was recorded by videotracking. Three points of the body ‐ the cloacal region and both feet joints ‐ were marked by small patches of reflecting foils. The vertical and horizontal movements of the marked points were recorded by a camera in posterior position, while the bird was walking on a treadmill. The camera was connected with a PC‐operated videotracking system1. The vertical and horizontal movements of the 3 marked points were recorded simultaneously and plotted against the time axis. Kinetograms show clearly the differences in the walking pattern between broilers and layers. Layers place the legs directly under the centre of gravity and, therefore, the body moves in a straight line. Broilers, in contrast, move the centre of gravity step by step laterally towards the position of the supporting leg. This pattern may be caused by the anatomical characteristics of broilers. Limping in broilers with leg problems can be measured by differences in the lateral and vertical movements of the right and left leg.
Cumulus expansion, chromatin configuration and meiotic competence in horse oocytes: A new hypothesis
Authors: HINRICHS KATRIN 
Published: June 2010

SummaryWhen recovered from the follicle, horse oocytes may be categorised as having either a compact or an expanded cumulus. Cumulus expansion is strongly associated with follicle atresia. Oocytes with expanded and compact cumuli have similar proportions in the germinal vesicle stage when recovered from the follicle. However, duringin vitroculture, a higher proportion of oocytes with expanded cumuli mature, and they do so more quickly, than do oocytes with compact cumuli. Using Hoechst 33258 to label chromatin, in the germinal‐vesicle stage horse oocytes can be divided into those in which the nucleus fluoresces diffusely (FN), and those in which the chromatin is condensed as a mass within the germinal vesicle (condensed chromatin; CC). The CC configuration is more common in oocytes with expanded rather than compact cumuli. The occurrence of the condensed chromatin configuration in oocytes with compact cumuli rises with increasing follicle size to the point that, in follicles >20 mm diameter, almost 80% of oocytes with compact cumuli have condensed chromatin. This suggests that the chromatin of fully grown oocytes condenses prior to the gonadotropin stimulation that induces ovulation. The number of oocytes maturingin vitrocorrelates strongly with the presence of the condensed chromatin configuration at the beginning of culture for both cumulus types. This suggests that the condensed chromatin configuration represents the meiotically competent oocyte. In contrast, FN oocytes appear to be meiotically incompetent, although 61% of oocytes from small, apparently viable follicles, have the FN configuration. This leads to the hypothesis that the FN configuration represents viable germinal vesicle stage oocytes that have yet to acquire meiotic competence. As oocytes achieve meiotic competence, the chromatin appears to condense to the CC configuration. This change occurs during growth of the preovulatory follicle but it can also occur during follicular atresia. Information about the inherent meiotic competence of different populations of oocytes will assist in the selection of oocytes for experiments involvingin vitromaturation and fertilisation in equids.
Distribution of putative primordial germ cells in equine embryos
Authors: CURRAN S. , URVEN L. , GINTHER O. J. 
Published: June 2010

SummaryEighteen equine embryos, 3 each on Days 20, 22, 24, 26, 28 and 30 post ovulation, were collected transcervically by uterine lavage, fixed in 4% paraformaldehyde and embedded in paraffin wax. Ten micron serial sections were stained to determine alkaline phosphatase (AP) activity in the cells. Positive cells were counted and their approximate location determined. The cells were approximately 8 μm in diameter and the entire cell, except the nucleus, stained strongly with many small round areas of intense staining in the cytoplasm. The cells varied from round to elongated in shape and pseudopodia were often present. Thus, they were similar in shape and staining pattern to primordial germ cells described in other species.A total of 2 AP‐positive cells were found in the 3 Day 20 embryos and the mean number of AP‐positive cells changed (P < 0.05) over the succeeding days as follows; Day 20 = 1; Day 22 = 251; Day 24 = 1484; Day 26 = 2385; Day 28 = 3267; Day 30 = 2424. AP‐positive cells present in the liver were not included in the calculations. In the Day 22 embryos, 10% of the putative primordial germ cells were found within the vascular system, including the heart chambers, and only 4% were found along the genital ridge. The percentage of cells found in the vascular system decreased from 10% on Day 22 to 1% on Day 30, although not significantly. The percentage of cells found along the genital ridge changed (P < 0.05) over gestational age as follows; Day 22 = 4%; Day 24 = 10%; Day 26 = 28%; Day 28 = 28%; Day 30 = 16%. Once the putative primordial germ cells reached the developing gonads they were no longer AP‐positive and nor was the gonadal stroma. The rest of the cells were distributed along the dorsal mesentery (range, 14–24%), near the dorsal aorta (16–29%), in the mesonephros (1–3%) and in other areas of the embryo (27–44%). Large numbers were in the cranial portion of the embryo.Although it is likely that the population of AP‐positive cells counted included the primordial germ cells, other cells, such as haematopoietic precursor cells, could not be ruled out. The AP reactivity, the appearance of the cells and their migratory pattern through the dorsal mesentery to the gonadal ridge were consistent with descriptions of primordial germ cells in other species. Their distribution throughout the embryo, especially its cranial aspect and their location within, or in close proximity to, blood vessels suggested that the equine embryo is unusual among mammals in that some of its primordial germ cells migrate through the blood.
Fetal development of the white line (Zona alba) of the equine hoof
Authors: BRAGULLA H. , BUDRAS K.‐D. , REILLY J. D. 
Published: June 2010

SummaryThe fetal development of the white line (Zona alba) in the equine hoof is described. Its specific structure of lamellar and interlamellar horn, which in turn is composed of cap and terminal horn, is formed in the second half of the hoof's fetal development. In equine fetuses with a crown‐rump length of less than 550 mm, the hoof capsule lacks a 'characteristic' white line since no borders between stratum medium, stratum internum and sole horn are discernible.In the hoof of an equine fetus with a crown‐rump length of 550 mm, a narrow white line has taken shape. Its shallow lamellae are arranged like arcades. Between the horn lamellae lie the polyhedral cells of the interlamellar horn. Up until birth, the height of the horn lamellae and, therefore, the width of the white line increases significantly. In the white line of the hoof of newborn foals, the terminal horn contains horn tubules with a characteristic architecture.
Effect of a supplementary dietary evening primrose oil mixture on hoof growth, hoof growth rate and hoof lipid fractions in horses: a controlled and blinded trial
Authors: REILLY J. D. , HOPEGOOD L. , GOULD L. , DEVISMES L. 
Published: June 2010

SummaryThe lipid chemistry of the normal equine hoof, together with the effect of oral supplementation with an evening primrose oil mixture (EPOM) on its growth, growth rate and lipid content was assessed in a controlled and blinded feeding trial at the Defence Animal Centre. Twelve horses were paired as closely as possible according to sex, age, weight, height and colour and then one from each pair was randomly allocated to treatment or control groups. The treatment group received 30 ml of oral EPOM/day, otherwise the nutrition and management regimes were the same for all horses. No significant differences (P>0.05) were seen between treatment and control groups for hoof horn growth or growth rate. However, there was a significant difference (P<0.05) in hoof horn growth within the treatment group only between weeks 4 and 8 after the start of supplementation. Thestratum mediumcontained significantly higher amounts of cholesterol ester (P<0.05), triglycerides (P<0.001) and free fatty acids (P<0.05) than the periople. The periople contained significantly higher levels of free cholesterol and phospholipid (P<0.001) than thestratum mediumof the hoof wall. There were no significant differences (P>0.05) between treatment and control groups for any of the lipid fractions measured for thestratum mediumfrom the clippings of the hoof wall. However, there were differences in perioplic lipid analysis with significant increases (P<0.05) in cholesterol esters and partial glycerides and a significant reduction (P<0.001) in free cholesterol in the treatment group following supplementation.
The development of equestrianism from the baroque period to the present day and its consequences for the welfare of horses
Authors: ÖDBERG F. O. , BOUISSOU M.‐F. 
Published: June 2010

SummaryMany saddle horses are slaughtered at a young age which could be indicative of a welfare problem. Bad riding is probably an underestimated source of poor welfare. Widespread knowledge of ‘academic’ riding should be encouraged and should be beneficial to all horses, at all schooling levels, for all purposes. In particular, 18th century principles tend to be forgotten and in this article the authors illustrate some differences to modern dressage. Various suggestions are made in order to improve welfare.