120 research outputs found
Optimization of the Performance Test Length for theSella ItalianoStallion
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
Assessment of limits for racing speed in the Italian trotter population
The current world record for trotter is 68.0 s/km, that is better than the estimates of record limit reported in literature (68.2 s/km for males and 69.1 s/km for females in Swedish Trotters): this is way the record limit was investigated in Italian Trotter using the same methodology applied to Swedish Trotter. The best racing times of 30'587 3-5 year old Italian Trotters, recorded between January 1st, 1992, and October 31th, 2009, have been log transformed to check for trends and asymptotic limit: a positive trend is present, and limits of 61.8 s/km and 62.8 s/km have been respectively estimated for males and females. The Generalized Extreme Value theory, applied to the 3-year old winners of the Italian Trot Derby, estimates a limit of 64.7 s/km. These results indicate that the limit for racing speed is still far from actual values
Analysis of founders and performance test effects on an autochthonous horse population through pedigree analysis: structure, genetic variability and inbreeding.
The Maremmano is an autochthonous Italian horse breed, which probably descended from the native horses of the Etruscans (VI century B.C.); the Studbook was acknowledged in 1980, and it includes 12 368 horses born from that year up to 2015. The aim of this study was to evaluate the effect of the selection program on the genetic variability of the Maremmano population; the analysis was performed using both the 'Endog v 4.8' program available at http://webs.ucm.es/info/prodanim/html/JP_Web.htm and in-house software on official pedigree data. Four Reference Populations were considered, and the most important one was the population of the 12 368 Maremmano horses officially registered in the National Studbook. The pedigree completeness of this population was very good because it was more than 90% at the third parental generation and more than 70% at the fifth generation; the pedigree traced back to a maximum of 10.50 generations with an average of 3.30 complete generations and 5.70 equivalent complete generations. The average generation interval was 10.65±4.72 years, with stallions used for longer periods than mares. The intervals ranged from 10.15±4.45 (mother-daughter) to 10.99±4.93 (father-daughter). The effective number of founders (f e) was 74 and the effective number of ancestors (f a) was 30 so that the ratio f e/f a was 2.47. The founder genome equivalents (f g) was 13.72 with a ratio f g/f e equal to 0.18. The mean of the genetic conservation index was 5.55±3.37, and it ranged from 0.81 to 21.32. The average inbreeding coefficient was 2.94%, with an increase of 0.1%/year, and the average relatedness coefficient was 5.52%. The effective population size (N e) computed by an individual increase in inbreeding was 68.1±13.00; the N e on equivalent generations was 42.00, and this value slightly increased to 42.20 when computed by Log regression on equivalent generations. The analysis confirmed the presence of seven traditional male lines. The percentage of Thoroughbred blood in the foals born in 2015 was 20.30% and has increased 0.21%/year since 1980; in particular, it increased more than twice (0.51%/year) until 1993 and afterwards slightly fluctuated. The pedigree analysis confirmed the completeness of genealogical information and the traditional importance that breeders gave to the male lines; although the genetic diversity of Maremmano seemed to be not endangered by the selection program, some effects on the population structure were found and a more scientific approach to genetic conservation should be incorporated in the selection plans
Exercise induced stress in horses: Selection of the most stable reference genes for quantitative RT-PCR normalization
<p>Abstract</p> <p>Background</p> <p>Adequate stress response is a critical factor during athlete horses' training and is central to our capacity to obtain better performances while safeguarding animal welfare.</p> <p>In order to investigate the molecular mechanisms underlying this process, several studies have been conducted that take advantage of microarray and quantitative real-time PCR (qRT-PCR) technologies to analyse the expression of candidate genes involved in the cellular stress response.</p> <p>Appropriate application of qRT-PCR, however, requires the use of reference genes whose level of expression is not affected by the test, by general physiological conditions or by inter-individual variability.</p> <p>Results</p> <p>The expression of nine potential reference genes was evaluated in lymphocytes of ten endurance horses during strenuous exercise. These genes were tested by qRT-PCR and ranked according to the stability of their expression using three different methods (implemented in <it>geNorm</it>, <it>NormFinder </it>and <it>BestKeeper</it>). Succinate dehydrogenase complex subunit A (<it>SDHA</it>) and hypoxanthine phosphoribosyltransferase (<it>HPRT</it>) always ranked as the two most stably expressed genes. On the other hand, glyceraldehyde-3-phosphate dehydrogenase (<it>GAPDH</it>), transferrin receptor (<it>TFRC</it>) and ribosomal protein L32 (<it>RPL32</it>) were constantly classified as the less reliable controls.</p> <p>Conclusion</p> <p>This study underlines the importance of a careful selection of reference genes for qRT-PCR studies of exercise induced stress in horses. Our results, based on different algorithms and analytical procedures, clearly indicate <it>SDHA </it>and <it>HPRT </it>as the most stable reference genes of our pool.</p
Exercise-induced up-regulation of MMP-1 and IL-8 genes in endurance horses
<p>Abstract</p> <p>Background</p> <p>The stress response is a critical factor in the training of equine athletes; it is important for performance and for protection of the animal against physio-pathological disorders.</p> <p>In this study, the molecular mechanisms involved in the response to acute and strenuous exercise were investigated using peripheral blood mononuclear cells (PBMCs).</p> <p>Results</p> <p>Quantitative real-time PCR (qRT-PCR) was used to detect modifications in transcription levels of the genes for matrix metalloproteinase-1 (<it>MMP-1</it>) and interleukin 8 (<it>IL-8</it>), which were derived from previous genome-wide expression analysis. Significant up-regulation of these two genes was found in 10 horses that had completed a race of 90–120 km in a time-course experimental design.</p> <p>Conclusion</p> <p>These results suggest that <it>MMP-1 </it>and <it>IL-8 </it>are both involved in the exercise-induced stress response, and this represents a starting point from which to understand the adaptive responses to this phenomenon.</p
Exploring the Italian equine gene pool via high-throughput genotyping
Introduction: The Italian peninsula is in the center of the Mediterranean area, and historically it has been a hub for numerous human populations, cultures, and also animal species that enriched the hosted biodiversity. Horses are no exception to this phenomenon, with the peculiarity that the gene pool has been impacted by warfare and subsequent “colonization”. In this study, using a comprehensive dataset for almost the entire Italian equine population, in addition to the most influential cosmopolitan breeds, we describe the current status of the modern Italian gene pool.Materials and Methods: The Italian dataset comprised 1,308 individuals and 22 breeds genotyped at a 70 k density that was merged with publicly available data to facilitate comparison with the global equine diversity. After quality control and supervised subsampling to ensure consistency among breeds, the merged dataset with the global equine diversity contained data for 1,333 individuals from 54 populations. Multidimensional scaling, admixture, gene flow, and effective population size were analyzed.Results and Discussion: The results show that some of the native Italian breeds preserve distinct gene pools, potentially because of adaptation to the different geographical contexts of the peninsula. Nevertheless, the comparison with international breeds highlights the presence of strong gene flow from renowned breeds into several Italian breeds, probably due to historical introgression. Coldblood breeds with stronger genetic identity were indeed well differentiated from warmblood breeds, which are highly admixed. Other breeds showed further peculiarities due to their breeding history. Finally, we observed some breeds that exist more on cultural, traditional, and geographical point of view than due to actual genetic distinctiveness
Early Hemorrhagic Transformation of Brain Infarction: Rate, Predictive Factors, and Influence on Clinical Outcome
Background and Purpose—
Early hemorrhagic transformation (HT) is a complication of ischemic stroke but its effect on patient outcome is unclear. The aims of this study were to assess: (1) the rate of early HT in patients admitted for ischemic stroke, (2) the correlation between early HT and functional outcome at 3 months, and (3) the risk factors for early HT.
Methods—
Consecutive patients with ischemic stroke were included in this prospective study in 4 study centers. Early HT was assessed by CT examination performed at day 5±2 after stroke onset. Study outcomes were 3-month mortality or disability. Disability was assessed using a modified Rankin score (≥3 indicating disabling stroke) by neurologists unaware of the occurrence of HT in the individual cases. Outcomes in patients with and without early HT were compared by χ
2
test. Multiple logistic regression analysis was used to identify predictors for HT.
Results—
Among 1125 consecutive patients (median age 76.00 years), 98 (8.7%) had HT, 62 (5.5%) had hemorrhagic infarction, and 36 (3.2%) parenchymal hematoma. At 3 months, 455 patients (40.7%) were disabled or died. Death or disability was seen in 33 patients with parenchymal hematoma (91.7%), in 35 patients with hemorrhagic infarction (57.4%) as compared with 387 of the 1021 patients without HT (37.9%). At logistic regression analysis, parenchymal hematoma, but not hemorrhagic infarction, was independently associated with an increased risk for death or disability (OR 15.29; 95% CI 2.35 to 99.35). At logistic regression analysis, parenchymal hematoma was predicted by large lesions (OR 12.20, 95% CI 5.58 to 26.67), stroke attributable to cardioembolism (OR 5.25; 95% CI 2.27 to 12.14) or to other causes (OR 6.77; 95% CI 1.75 to 26.18), high levels of blood glucose (OR 1.01; 95% CI 1.00 to 1.01), and thrombolytic treatment (OR 3.54, 95% CI 1.04 to 11.95).
Conclusions—
Early HT occurs in about 9% of patients. Parenchymal hematoma, seen in about 3% of patients, is associated with an adverse outcome. Parenchymal hematoma was predicted by large lesions attributable to cardioembolism or other causes, high blood glucose, and treatment with thrombolysis
Prediction of early recurrent thromboembolic event and major bleeding in patients with acute stroke and atrial fibrillation by a risk stratification schema: the ALESSA score study
Background and Purposes—This study was designed to derive and validate a score to predict early ischemic events and major bleedings after an acute ischemic stroke in patients with atrial fibrillation.
Methods—The derivation cohort consisted of 854 patients with acute ischemic stroke and atrial fibrillation included in prospective series between January 2012 and March 2014. Older age (hazard ratio 1.06 for each additional year; 95% confidence interval, 1.00–1.11) and severe atrial enlargement (hazard ratio, 2.05; 95% confidence interval, 1.08–2.87) were predictors for ischemic outcome events (stroke, transient ischemic attack, and systemic embolism) at 90 days from acute stroke. Small lesions (≤1.5 cm) were inversely correlated with both major bleeding (hazard ratio, 0.39; P=0.03) and ischemic outcome events (hazard ratio, 0.55; 95% confidence interval, 0.30–1.00). We assigned to age ≥80 years 2 points and between 70 and 79 years 1 point; ischemic index lesion >1.5 cm, 1 point; severe atrial enlargement, 1 point (ALESSA score). A logistic regression with the receiver-operating characteristic graph procedure (C statistic) showed an area under the curve of 0.697 (0.632–0.763; P=0.0001) for ischemic outcome events and 0.585 (0.493–0.678; P=0.10) for major bleedings.
Results—The validation cohort consisted of 994 patients included in prospective series between April 2014 and June 2016. Logistic regression with the receiver-operating characteristic graph procedure showed an area under the curve of 0.646 (0.529–0.763; P=0.009) for ischemic outcome events and 0.407 (0.275–0.540; P=0.14) for hemorrhagic outcome events.
Conclusions—In acute stroke patients with atrial fibrillation, high ALESSA scores were associated with a high risk of ischemic events but not of major bleedings
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