Publications by authors named "Maria J Sanchez-Guerrero"
Article Synopsis
- The study highlights that low reproductive efficiency in horses may be due to breeding practices focusing on athletic performance over reproductive capability.
- Researchers analyzed various reproductive and morphological metrics of 19,758 Pura Raza Española mares to identify the traits most associated with reproductive success.
- Findings suggest that integrating both morphological and reproductive traits in selection can significantly enhance reproductive efficiency, with expected genetic response improvements ranging from 4.0% to 46.8% based on different indices.
Hair whorls are a hereditary feature in horses that may be associated with temperament and coat color. Hair whorls are described as changes in the hair pattern and may take various forms, such as circular and linear whorls. We first carried out a frequency analysis of hair whorls (circular and linear).
View Article and Find Full Text PDFThe Arabian horse is a generally reliable sport horse, and continues to be a remarkable endurance horse, so the relevance of the expected value of the proportion of Arabian genes (EV%AG) in horses participating in eventing could be a relevant factor. A total of 1089 horses participating in eventing (8866 records) were used. A GLM revealed that the EV%AG was significant in dressage, show jumping and cross-country.
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- Fertility plays a crucial role in the success of horse farms, but there's been little focus on it due to challenges in measuring it objectively, particularly in closed populations like the Pura Raza Española (PRE) breed.
- This study aimed to analyze genetic parameters for reproductive traits in PRE mares and estimate inbreeding depression effects from common ancestors, using data from 22,799 mares.
- The findings showed that heritability estimates for reproductive traits were low to moderate, and significant correlations between inbreeding depression loads and genetic values indicate that selecting mares with lower inbreeding loads could mitigate negative effects from inbreeding.
Rabbits often experience stress when they perceive certain stimuli, such as handling. The physiological response of animals to stress and temperament is associated with feeding efficiency, with those with the least capacity to react to stress showing the highest performance. The aim of this study was to evaluate the impact of stress due to heat (temperature-humidity index; THI) or handling, assessed using infrared thermography, on the performance parameters of rabbits of a Spanish Common breed.
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- The study examines how the effort and recovery phases of horses during sports events impact their performance, focusing on Spanish Sport Horses.
- Researchers measured eye temperature using infrared thermography to evaluate horses' adaptations to sport performance across different genetic lines and sexes.
- Findings indicate that stallions generally recover better than mares, and while there is a positive correlation between effort and recovery phases, better ranking positions are associated with higher increases in eye temperature, suggesting genetic influences on these traits.
Measurements from 13 different morphological traits of importance in the Pura Raza Español (PRE) horse were used to estimate genetic and environmental parameters following a heteroscedastic model in which data were assigned to stallions. Data sets used ranged from 20,610 (height at withers) to 48,486 measurements (length of shoulder), and the number of animals analysed in the pedigrees varied from 17,662 (height at withers) to 23,962 (dorsal-sternal diameter). Results of heritabilities of the traits varied from 0.
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- Inbreeding results from mating between related individuals, leading to reduced fitness, known as inbreeding depression, which varies significantly among founder individuals.
- This study aimed to analyze the population structure and general inbreeding in the Pura Raza Española horse breed while also testing a new method to predict hidden inbreeding depression related to three morphological traits and two defects.
- The results indicated significant inbreeding depression across the population, with varying heritability and inbreeding depression load ratios among traits, although many horses still showed positive traits despite average negative inbreeding depression loads.
Ewe Neck is a relatively common morphological defect in Pura Raza Español (PRE) horses and other Baroque type horse breeds, which adversely affects the breeding industry; (1) objectives: to establish the within-breed prevalence, possible associated factors, and heritability of Ewe Neck in PRE horses; (2) methods: the database included evaluations of 35,267 PRE horses. The Ewe Neck defect, 16 morphological traits, and 4 body indices were recorded. A Bayesian genetic animal model included the following systematic effects: sex, age, coat color, geographical area of the stud, and birth stud size were used; (3) results: in this PRE population, a total of 27.
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- * Over the past two decades, the average inbreeding coefficient for the PRE population has declined from 8.45% to 7.51%, indicating a shift towards greater genetic diversity.
- * Changes in breeding practices, including increased population size and selective breeding based on functionality rather than pedigree, have contributed to a decrease in inbreeding and alterations in the influence of common ancestors.
Gene mutations influencing melanocytes also impact on physiological and behavioural functions. In this study, we investigated their association with four different coat colours in the Pura Raza Español (PRE) horse using morphological traits and molecular datasets. Four different subpopulations were identified according to individual coat colour: grey, bay, chestnut and black.
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