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The objective of the current study was to determine the photoperiod-induced variations and the impact of exercise on oxidative stress biomarkers [2-thiobarbituric acid reactive substances (TBARS), aldehydic (AD) and ketonic (KD) derivatives of oxidatively modified proteins (OMP), total antioxidant capacity (TAC), and activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)] and biomarkers of metabolic alterations [glucose, urea, and uric acid and the activity of lactate dehydrogenase (LDH)] in the blood of Shetland pony mares and stallions involved in recreational horseback riding. Twenty-one healthy adult Shetland ponies (11 mares and 10 stallions) aged 6.5 ± 1.4 years old from the central Pomeranian region in Poland were used in this study. Blood samples were taken once per season for one year: spring (3 April), summer (5 July), autumn (1 October) and winter (25 January). A MANOVA analysis revealed that the photoperiod factor had a leading role in alterations of these biomarkers, while the exercise and sex of the ponies exerted a lower impact. The lipid peroxidation biomarkers, for example, the plasma TBARS level, indicated the maximum adjusted coefficient of determination R2ad = 0.77. Before exercise (at rest), the plasma of the stallions and mares exhibited minimum values of TBARS levels in the spring and summer photoperiods and maximum levels in autumn and winter. A statistically significant reduction in the levels of both aldehydic and ketonic derivatives of OMP in the blood of ponies was observed during the autumn and winter periods; additionally, the level of ketonic derivatives of OMP declined after exercise in spring. TAC was statistically significant in the spring and winter photoperiods both before and after exercise. SOD activity did not have a pronounced photoperiod-induced pattern but was dependent on the sex and exercise. CAT activity varied and was statistically significant only in the plasma of the mares after exercise in the spring, summer, and winter photoperiods. The minimum GPx activity in the blood of the mares before exercise (at rest) was observed in autumn, while the maximum was noted in winter and summer. Photoperiod- and exercise-induced alterations in markers of oxidative stress and antioxidant defences may contribute to the adaptation of animals to exercise, depending on sex. The seasonal variations in the antioxidant defences demonstrated in our study, as well as substrates of energy metabolism in the blood of mares and stallions, depending on exercise capacity, could be an important aspect in the ability of endogenous adaptive mechanisms of animals to react in advance to environmental changes associated with seasons. [ABSTRACT FROM AUTHOR]

Seminal plasma proteins and pathways associated with sperm motility have not been elucidated in stallions. Therefore, in the current study, using the high throughput LC/MS-MS approach, we profiled stallion seminal plasma proteins and identified the proteins and pathways associated with sperm motility. Seminal plasma from six stallions producing semen with contrasting sperm motility (n = 3 each high-and low-motile group) was utilized for proteomic analysis. We identified a total of 1687 proteins in stallion seminal plasma, of which 1627 and 1496 proteins were expressed in high- (HM) and low- motile (LM) sperm of stallions, respectively. A total number of 1436 proteins were co-expressed in both the groups; 191 (11%) and 60 (3.5%) proteins were exclusively detected in HM and LM groups, respectively. A total of 220 proteins were upregulated (>1-fold change) and 386 proteins were downregulated in SP from LM group stallions as compared to HM group stallions, while 830 proteins were neutrally expressed in both the groups. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed dysregulation of the important proteins related to mitochondrial function, acrosome, and sperm cytoskeleton in the seminal plasma of stallions producing ejaculates with low sperm motility. High abundance of peroxiredoxins and low abundance of seminal Chaperonin Containing TCP1 Complex (CCT) complex and Annexins indicate dysregulated oxidative metabolism, which might be the underlying etiology for poor sperm motility in LM group stallions. In conclusion, the current study identified the seminal plasma proteomic alterations associated with poor sperm motility in stallions; the results indicate that poor sperm motility in stallions could be associated with altered expression of seminal plasma proteins involved in oxidative metabolism. [ABSTRACT FROM AUTHOR]

Keywords: Conservation; breeding plan; inbreeding; horse; optimum contribution; selection EN Conservation breeding plan inbreeding horse optimum contribution selection 127 130 4 05/12/20 20200301 NES 200301 Introduction The Jutland Horse is an original Danish horse breed and is regarded as Denmark's national draft horse. Optimum contribution selection of stallions and creation of mating list In February 2019, optimum contribution selection (OCS) was applied for the 11 stallions participating in the project. Finally, we used the contributions (number of matings) from each of the 11 stallions from RUN1 in addition to 4 pre-assigned matings per stallion to obtain mating pairs with the lowest average relationships between the 11 stallions and the 88 mares (RUN2). [Extracted from the article]

Three sequential studies were performed to evaluate the effects of tying horses while wearing overchecks (strap from the bridle to backpad). In an observational study, horses (n = 305) wore high (HC), low (LC), or no overchecks (NC) with frequencies of 29.2%, 51.8% and 19.0% respectively. Study 1 (Latin square, n = 6) consisted of a 90-min tie test (90TT) with treatments (HC, LC, NC) x periods (1–3). Horses wearing HC had higher plasma cortisol (P < 0.01) when compared to LC and NC. Muscle soreness (MSS) and tightness (MTS) were evaluated pre and 24 hr post 90TT and were higher (P < 0.01) 24 hrs after 90TT regardless of treatment. In study 2, in order to determine if acclimation to tying with overchecks could reduce the cortisol response in study 1, horses (n = 6) were tied 60 minutes/day for 2 weeks followed by a 60-min TT (60TT). Neither plasma cortisol nor heart rate were elevated above baseline levels, suggesting adaptation to novel stressors. Tying with restrictive HC appears to be a stressor, which may be reduced if an adaptation period is provided. [ABSTRACT FROM AUTHOR]

Mare taxidermy specimens of quaggas (Equus quagga quagga, an extinct subspecies of the plains zebra that was endemic to South Africa) are significantly longer and marginally taller than stallions – unlike the situation in extant subspecies of plains zebras where the stallions are usually larger than the mares. The possibilities that these differences were due to sampling error, shrinkage of the hides, or distortion during specimen mounting are addressed. It is likely, however, that the taxidermy specimens reflect a sexual dimorphism that existed in quaggas. Differences in body size between mares and stallions might have been an adaptation to their comparatively cold and arid environment, or it might have been caused by genetic drift in a geographically isolated population, or it might have been brought about by a combination of these circumstances. [ABSTRACT FROM AUTHOR]

EXCAVATIONS AT the castle complex of Cēsis, Latvia, uncovered an unusual find of large quantities of horse bones, some of which were partially articulated, along with equestrian equipment. These were associated with a destroyed building at the edge of the southern outer bailey. The horses included large males, most probably stallions, and pathology on several of the recovered vertebrae suggests these individuals had been used for riding. The size of the horses was within the range for medieval war horses, and the associated tack also pointed to prestigious riding animals. Radiocarbon dating of the bones placed them firmly within the Teutonic Order's period of rule. We conclude here that these horses fulfilled a military role in the final decades of the Teutonic Order's rule in Livonia in the late 15th/early 16th century and that the better-known equestrian culture of late-medieval Prussia was comparable in character, if not in scale, to that in Livonia. [ABSTRACT FROM AUTHOR]

There is substantial international influence on the Swedish Warmblood (SWB) sport horse population. The SWB Association suspects that imported horses are pre-selected based on their anticipated performance level, which could lead to biased estimated breeding values (EBVs) for stallions. This study examined different strategies to handle records for imported horses in the genetic evaluation. The stallions were evaluated for 10 traits using 3 different EBV estimation methods that were compared based on ranking comparisons of stallions, accuracy, correlations and absolute differences between EBVs. The results showed that the stallions’ EBVs were affected by imported offspring which, as a group, had higher average scores than horses born in Sweden. Sire EBVs differed by up to 0.6 genetic standard deviation of the trait between methods for stallions with >50% imported offspring. Excluding imported offspring lowered the accuracies and caused larger re-ranking compared with including a fixed effect of origin in the model. [ABSTRACT FROM AUTHOR]

The recovery of spermatozoa from the cauda epididymis may be the last chance to obtain genetic material from stallions undergone to castration. The aim of the current study was to evaluate the efficiency of cryopreservation and the use of two different extenders for equine epididymal spermatozoa. Testicles obtained from castration were divided into two groups: cauda epididymis processed immediately after orchiectomy and cauda epididymis processed after 24 h storage in saline solution at 4 °C of the testis. The epididymal spermatozoa were collected through manual slicing of the cauda epididymis of each testicle. In addition, spermatozoa obtained from different processed testes were diluted alternatively with either modified Palmer or EGG TECH®extenders to produce frozen straws. Motility parameters in fresh and frozen-thawed material were analysed by means of the computer-aided sperm analysis (CASA). The recorded CASA data were analysed with a mixed linear model. Motility parameters in fresh semen yielded better results than in frozen semen (p = 0.008), but no difference (p > 0.05) was observed between spermatozoa collected immediately after castration or after 24 h of storage; in frozen-thawed samples, EGG TECH®tended to improve the percentage of progressively motile spermatozoa in epididymal frozen-thawed semen (p = 0.08) compared with modified Palmer. We conclude that the processing of epididymal spermatozoa can occur up to 24 h after stallion castration and both common extenders used are suitable for preserving this material. [ABSTRACT FROM PUBLISHER]

The Sella Italiano stallions are selected by 100-day perfomance test, but many breeders organisations use station test of shorter length. In twelve editions, 17,394 ten-point scores both for character and gaits, and 6291 scores for jumping were assigned to 314 candidate stallions. By means of the comparison of univariate EBVs, calculated from the complete dataset or from the reduced subsets, a dataset lasting only from 33rd day to 78th day of the training period was selected: it included less than 70% of the original data. The subset was validated by 3-trait AM BLUP: there were no evident effects on the estimates of variance component or ratio, and the aggregated selection index for the three traits showed a 99% rank correlation with the official index. These findings demonstrate that the training period could be reduced without affecting the genetic progress in the Sella Italiano breed. [ABSTRACT FROM AUTHOR]

The objective of the study was to compare the horse's body parts in position at the first approach stride, with the size of the jump. The size of the jump was accepted as the measure of the horse's performance. The experiment included the filming of 540 young warmblood stallions free jumping a 120 cm high oxer. Ten traits assumed to be connected with the size of the jump were measured by digital image analysis. Pearson's correlations between the parameters were calculated. Our results demonstrated the four traits that are most important in judgement of the young horse's jumping ability at the approach stride 1. The low angle of bending at poll positively influences the size of the jump. Angles of the positions of neck and trailing hindlimb cannon have a positive effect only up to 100° and up to 40°, respectively. The poll–obstacle distance should not exceed 120 cm. [ABSTRACT FROM PUBLISHER]

Stallion sperm exhibits great male-to-male variability in survival after cryopreservation. In this study, we have investigated if differences in sperm freezability can be attributed to membrane phase and permeability properties. Fourier transform infrared spectroscopy (FTIR) was used to determine supra and subzero membrane phase transitions and characteristic subzero membrane hydraulic permeability parameters. Sperm was obtained from stallions that show differences in sperm viability after cryopreservation. Stallion sperm undergoes a broad and gradual phase transition at suprazero temperatures, from 30-10°C, whereas freezing-induced dehydration of the cells causes a more severe phase transition to a highly ordered gel phase. Sperm from individual stallions showed significant differences in post-thaw progressive motility, percentages of sperm with abnormal cell morphology, and chromatin stability. The biophysical membrane properties evaluated in this study, however, did not show clear differences amongst stallions with differences in sperm freezability. Cyclodextrin treatment to remove cholesterol from the cellular membranes increased the cooperativity of the suprazero phase transition, but had little effects on the subzero membrane phase behavior. In contrast, freezing of sperm in the presence of protective agents decreased the rate of membrane dehydration and increased the total extent of dehydration. Cryoprotective agents such as glycerol decrease the amount of energy needed to transport water across cellular membranes during freezing. [ABSTRACT FROM AUTHOR]

Evolution of long-distance communication in equids may correspond with species-specific types of social organization. To compare harem-forming species (type I) with those that do not establish permanent social units (type II), we conducted a comparative analysis of stallion long-range calls in seven species/breeds of equids: two breeds of domestic horses (archaic and modern breeds) and five wild species: Przewalski's horse, kiang, Somalian ass, Grevy's zebra, Grant's zebra). Acoustic features allowed assigning calls of stallions with 92% average classification success to the correct species. The duration of the call dearly separated horses (type I) from type II species: kiang, Somalian ass and Grevy's zebra. Accordingly to its harem social system (type I), the pattern of long-range call in Grant's zebra deviates from that of its relatives in the direction of horses. Frequency of the first dominant band that was associated with body size separated modern horses from the archaic breed and Przewalski's horse. Playback experiments confirmed that equids, especially the type II species, respond strongly to conspecific calls but also to calls of other equids. [ABSTRACT FROM AUTHOR]

We build a model inspired by the standard hedonic approach developed by Rosen (1974) and completed by Landon and Smith (1997, 1998) to analyse the price of French vaulting stallion semen in 2004. We show that reputation, modelled as an endogenous factor, plays a less important role than information on true quality for the explanation of price dispersion. This result is explained by the fact that information on studhorses is not only available but also reliable, insofar as the quality of a stallion is stable over time, contrary to nondurable products like wine or cigars. This explains also why consumers on this market do not use expert opinions to make their choices. [ABSTRACT FROM AUTHOR]

A simple trypan blue-neutral red-Giemsa staining procedure for simultaneous evaluation of acrosome, sperm head, and tail membrane integrity and morphology has been used to evaluate equine spermatozoa. Some special characteristics and problems have arisen in evaluating stallion semen. One problem was the differentiation of intact vs. damaged sperm tails primarily in frozen and thawed samples. After freezing and thawing, a high percentage of spermatozoa with an unstained head and stained tail were observed. These cells are considered immotile. Therefore, unambiguous differentiation of intact vs. damaged sperm tail membrane is very important for evaluating semen quality. The aim of our study was to develop a method especially for stallion sperm to distinguish more accurately the different cell types. We compared Chicago sky blue 6B (CSB) to trypan blue (TB) for viability staining. CSB/Giemsa staining showed good repeatability and agreement with TB/Giemsa measurements. For densitometry analysis, individual digital images were taken from smears stained by CSB/Giemsa and by TB/Giemsa. A red-green-blue (RGB) histogram for each area of spermatozoa was drawn. Differences of means of RGB values of live vs. dead tails and separate live vs. dead heads from each photo were used to compare the two staining procedures. CSB produced similar live/dead sperm head differentiation and better tail differentiation. TB can be replaced by CSB and this results in more reliable evaluation. After staining with 0.16% CSB and 4 min fixation, 2–4 h Giemsa staining at 25–40° C is recommended for stallion semen. [ABSTRACT FROM AUTHOR]

The annual growth rate of the horny wall of the hoof was investigated in 38 horses—31 mares and seven stallions. Experimental subjects were Konik horses kept in a conservative breeding herd. The horses hooves of both limbs: the right fore limb and the right hind limb were measured and next growth rate of the horny wall was analysed at five points of the hoof capsule. On the basis of Principal Component Analysis it was found that the subjects needed to be considered in three groups: three-year old mares, older mares and stallions. Next the growth increments were averaged in each investigated group and compared. The dynamics of hoof horn growth turned out to be the highest in the group of young mares, followed by the group of stallions and the group of adult mares. In the winter months the lowest growth increment of the hoof horn was observed in all the analysed groups. In the period of the elongating solar day, i.e. from May to July, the growth was rapid and reached the highest values. Starting from August the growth of the hoof horn decreased. [ABSTRACT FROM AUTHOR]