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The low rate of reproductive efficiency in horses may be linked to the equine industry’s practice of maintaining breeding stock that stands out for its athletic or morphological performance but exhibits poor reproductive efficiency. In this study, the age at first foaling, age at last foaling, interval between first and second foaling, average interval between foaling, foaling number and reproductive efficiency, and their relationship with the morphological records in 19,758 Pura Raza Española (PRE) mares were analyzed. After a partial least squares analysis height at withers, lateral hock angle, dorsal-sternal diameter, perimeter of anterior cannon bone, angle of shoulder, thoracic perimeter, hip-stifle distance, and angle of croup were the most important traits related with reproductive traits in PRE mares. A multivariate animal model with both morphological and reproductive traits was applied, including age, geographical area, coat color, and average stud size in the decade of the mare’s first foaling. The results indicate that reproductive selection is feasible, and is enhanced by the use of morphological traits, given the moderate to high magnitudes of heritability values in both types of traits, which oscillated between 0.1 (interval between first and second foaling) and 0.95 (height at withers). The resulting genetic parameters were used to develop a series of selection indexes based on morphological or morphological and reproductive combination traits to improve reproductive efficiency traits in PRE mares and thus compute the expected genetic response (EGR) for the different strategies. The increase in EGR, when comparing EGR using only reproductive traits as selection criteria vs. using a combined index of both morphological and reproductive traits, oscillated between 4.0% for the age at first foaling to 46.8% for the interval between first and second foaling. In addition, two precocity indexes showed positive EGR when the age at last foaling and the interv

El caballo de Pura Raza Española (PRE) es la raza equina autóctona española más importante con respecto a su censo, con 275.018 individuos activos. Su actual Programa de Cría, en la que se incluye el Programa de Mejora, fue aprobado en 2020 y tiene como objetivos la mejora de la morfología, la conformación y la funcionalidad, minimizando el nivel de endogamia y garantizando la conservación de la Raza. Durante las 4 últimas generaciones (aproximadamente 40 años) se hace de forma sistemática controles de paternidad mediante el uso de diferentes herramientas moleculares (grupos sanguíneos, polimorfismos bioquímicos y marcadores microsatélites), lo que hace que la población del caballo de PRE sea ideal para la evaluación de diferentes metodologías para la estimación de la consanguinidad y el estudio de diferentes modelos que estiman las desviaciones en el ratio de transmisión de genes de padres a hijos en caracteres de especial interés económico en esta Raza. La presente Tesis se ha estructurado en tres capítulos. Capítulo I. “Estructura genética de la población equina “Pura Raza Española” y evaluación de la endogamia.” Desde 1912, con la creación del primer Libro de Registro, el caballo de PRE se estableció como una población cerrada, en la que solo pueden inscribirse como reproductores animales procedentes de padres inscritos en el Libro Genealógico. Desde ese momento, el apareamiento de animales emparentados se volvió inevitable y la consanguinidad, relacionada con el incremento de la homocigocidad en el genoma, fue progresivamente incrementándose. Hoy en día, la estimación de la consanguinidad, omnipresente e ineludible en los sistemas productivos de razas puras, es el principal objetivo en la gestión ganadera, sobre todo para aquellos criadores que están interesados en mitigar sus consecuencias negativas. El primer objetivo de este capítulo fue analizar, a partir de información genealógica, el coeficiente de consanguinidad clásica (F), el coeficiente de parentesco, The Pura Raza Española (PRE) horse is a native Spanish equine breed and the most important in terms of its census, with 275,018 active individuals. Its current Breeding Program, which includes the Improvement Program, was approved in 2020 and aims to improve morphology, conformation, and functionality while minimizing the level of inbreeding and ensuring the conservation of the breed. Over the past four generations (40 years approximately), paternity controls have been systematically carried out using different molecular tools such as blood groups, biochemical polymorphisms, and microsatellite markers. This makes the population of PRE horses ideal for determining the evaluation of different methodologies for estimating inbreeding and studying different models that estimate deviations in the gene transmission ratio from parents to offspring in economically important traits within this breed. The present Thesis is structured into three chapters. Chapter I: "Genetic Structure of the Pure Spanish Horse Population and Evaluation of Inbreeding." Since 1912, with the creation of the first Stud Book for PRE horses, it was established as a closed population, where only animals from registered parents in the Genealogical Book can be registered as breeding animals. From that moment, mating between related animals became inevitable, and inbreeding, related to the increase in homozygosity in the genome, progressively increased. Nowadays, estimating inbreeding, which is omnipresent and unavoidable in purebred production systems, is the main objective in livestock management, especially for breeders interested in mitigating its negative consequences. The first objective of this chapter was to analyze, based on genealogical information, the classical coefficient of inbreeding (F), the coefficient of relationship (AR), and the partial coefficient of inbreeding (Fij) in the total PRE population, and determine the ancestors that contribute to 50% of the total genetic variability of th

The 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. A BLUP genetic evaluation was computed with five genetic models (without the EV%AG (0) using as a covariate (A), as a fixed effect (B), with variance heterogeneity, and in genetic groups without (C) and with (D)). Dressage heritability ranged from 0.103 to 0.210, show jumping ranged from 0.117 to 0.203 and cross-country ranged from 0.070 to 0.099. The lowest DIC value was used as a criterion of fitness. The best fits (those which included variance heterogeneity) showed fewer than two points of difference in DIC values. The highest average estimated breeding value in dressage, show jumping and cross-country was found for horses with an expected value of the proportion of Arabian genes of 0%, 1% to <25%, and 100%, respectively. Therefore, the best way to model the EV%AG effect seems to be by considering the variance heterogeneity.

The Pura Raza Espanola ˜ (PRE) horse is an autochthonous Spanish horse characterized by its versatility, mental balance, and its balanced conformation, which makes it suitable for sports disciplines such as dressage. The aim of this study was to determine the genetic correlation between the quality of natural gaits in young horses, when the horse is evaluated in the Basic Aptitude Test (free movements, FM) and during dressage competitions (functionality tests and gaits under rider, UR). A total of 37,822 and 2730 PRE horses were evaluated for FM and UR, respectively, of which 1023 horses had records for both (coincidence animals). Genetic parameters were estimated using VCE software. Effects were included in the final model according to significant results in analyses of variance (GLM). For FM and UR, the genetic model included age as a linear covariate, gender, coat colour and stud size as fixed effects, and for UR, the rider and permanent environmental effects were also included as random effects. The pedigree file information included a minimum of 4 generations: 88,558 horses (FM), 13,837 horses (UR) and 9072 horses (coincidence animals). Heritabilities were estimated for the two data sets (FM and UR) and, for the coincidence population, heritabilities and genetic correlations were also estimated. The heri tability for walk, trot and canter (FM) were 0.20, 0.22, 0.22, while for UR they were 0.26, 0.31, 0.33, respec tively. For coincidence animals, the heritability for walk, trot and canter (FM) were 0.43, 0.33, 0.22, while for UR they were 0.23, 0.11, 0.10, respectively. The genetic correlations between FM and UR traits were high and positive; 0.49 for walk, 0.61 for trot and 0.54 for canter. The genetic parameters obtained highlight the possi bility of preselecting gait traits in young horses destined to participate in sporting competitions.

Horses have been valued for their diversity of coat color since prehistoric times. In particular, the pleiotropic effect that coat color genes have on behavior determines the way the horse perceives and reacts to its environment. The primary aim of this study was to evaluate the influence of coat color on basal reactivity assessed with infrared thermography as eye temperature at rest (ETR), determine their relation with the results obtained by these horses in Show Jumping competitions and to estimate the genetic parameters for this variable to test its suitability for genetic selection. A General Linear Model (GLM) and Duncan post-hoc analysis indicated differences in ETR due to coat color, sex, age, location, and breed-group factors. A Spearman’s rank correlation of 0.11 (p < 0.05) was found with ranking, indicating that less reactive horses were more likely to achieve better rankings. Heritability values ranged from 0.17 to 0.22 and were computed with a model with genetic groups and a model with residual variance heterogeneity. Breeding values were higher with the last genetic model, thus demonstrating the pleiotropic effect of coat color. These results indicate that ETR has a suitable genetic basis to be used in the breeding program to select for basal reactivity due to coat color.

For many years, dogs have been trained to detect objects through smell and help humans to locate dif ferent items. These dogs are specially trained to maximize their search capabilities, that this increased concentration could lead to high levels of stress in the animal. The main aim of this study was to assess the stress levels at rest of working police dogs, measured with infrared thermography and by the heart rate (HR). To achieve this, we evaluated 18 working dogs (13 males and 5 females), half of which had been trained for drug detection and the other half for explosives detection. Eye temperature (ET) assessed with infrared thermography was collected in the kennels (ETK) and inside the police car (ETC), to test differences due to place of location. The mean value between ETK and ETC (MET) and the difference between them (ETD) were also assessed. HR was evaluated inside the police car. The influence of different factors (sex, breed, training type and age) on the stress perceived by these animals was also measured. The results indicated that these animals showed higher ETK (36.8±1.1°C) than ETC (36.1±1.0°C), with a similar coefficient of variation (3.0% and 2.8%, respectively). This could be due to the fact that working dogs tend to be calmer when they expect to carry out the assigned job. On the other hand, no statisti cally significant correlations were found between ET variables and HR, thus supporting previous studies indicating that these parameters differ in their physiological background. The GLM statistical analysis found that females (for sex factor) and dogs trained for explosives detection (for training type factor) showed higher ETK and ETD than males or dogs trained for drug detection. As for breed group, statistical differences between means were found only for ETD, with Shepherd dogs showing higher increases than Retrievers. Thus, the results obtained in this study are the first to show that ET measured using infrared thermography is a suitable

The way a horse activates (effort phase-EP) and recovers (recovery phase-RP) during a sport event can affect its sport performance. The aim of this manuscript was to test horses’ adaptation to sport performance and its genetic basis, using eye temperature assessed with infrared thermography. EP and RP were measured in 495 Spanish Sport Horses, during a performance test, considering sex (2) and genetic lines (5) as fixed effects. The ranking position obtained on an official sport competition was also collected. Differences in variables due to genetic line and sex effects were found, showing that, regardless of the genetic line, stallions tended to recover better than mares after the sport test developed. High positive intra-class correlations (p < 0.001) were found between EP and RP for both fixed effects, so that the higher the EP, the higher the RP. However, for the ranking position, a low negative correlation (p < 0.01) was found, so that the higher the eye temperature increase, the better the position. Heritabilities showed medium–high values with a medium positive genetic correlation between them. Thus, breed origins and sex influence horses’ effort and recovery during sport performance, showing a genetic basis adequate for selection.

Fertility is a key factor in the economic success of horse farms. However, it has received little attention due to the difficulty of measuring fertility objectively. Since its studbook creation (1912), the Pura Raza Española (PRE) breed has been a closed population and become high in-bred resulting in inbreeding depression (poor phenotypic values). Nevertheless, heterogeneous effects of inbreeding depression have been detected among founders and nonfounders. The aims of this study were (1) to analyze the genetic parameters for reproductive traits in mares of the PRE horse breed and (2) to estimate, for the first time, the inbreeding depression load associated with common ancestors of the breed. A total of 22,799 mares were analyzed. Heritability estimates ranged from 0.05 (interval between first and second foaling) to 0.16 (age at first foaling), whereas inbreeding depression load ratios ranged from 0.06 (parturition efficiency at 6th foaling) to 0.17 (age at first foaling), for a partial inbreeding coefficient of 10%. Although heritability is related to the variability expressed in the population, inbreeding depression load ratios measure the potential variability, whether expressed in the population or not. Most correlations between additive and inbreeding depression load genetic values were significant (P < 0.001) and of low to moderate magnitude. Our results confirm that individual inbreeding depression loads allow us to select horses that have a genetic value resistant to the deleterious effects of inbreeding.

Aim of study: To assess the potential of using infrared ocular thermography (IROT) as a tool to predict beef quality at the slaughterhouse. Area of study: The study was carried out in the Salteras’s slaughterhouse (Seville, Spain). Material and methods: Ocular temperature images were captured from 175 lean young bulls prior to slaughter. Carcasses were classified into three groups according to weight: ˂250 kg, 250-310 kg and ˃310 kg. IROT was measured just before slaughter and pH was measured 24 h later. Colour parameters (CIELAB space) were evaluated 48 h post-slaughter. Water holding capacity was evaluated at seven days after slaughter. Main results: IROT mean values were higher in heavier bulls (p<0.05), probably due to these animals appeared to movilize a greater blood flow, thus increasing ocular temperature. Furthermore, IROT showed a statistically significant correlation with both pH from light carcasses (r=0.66; p<0.001), and mean Hue value from all carcass weights (r=-0.22; p<0.05). A quadratic regression analysis accounting carcass weight as a continuous variable, found medium to strong fit values for pH (R2=0.52; RMSE=0.032; p<0.01) and medium fit values for H* (R2=0.41; RMSE=3.793; p<0.001), changing their relation with IROT depending on carcass weight. Research highlights: IROT showed potential to become a useful tool to assess pH in light carcasses and to assess H* in all carcasses of young bulls prior to slaughter, regardless their weight. However, further studies would be recommended under more variable pre slaughter stress conditions.

Aim of study: To assess the potential of using infrared ocular thermography (IROT) as a tool to predict beef quality at the slaughterhouse.Area of study: The study was carried out in the Salteras’s slaughterhouse (Seville, Spain).Material and methods: Ocular temperature images were captured from 175 lean young bulls prior to slaughter. Carcasses were classied into three groups according to weight: ˂250 kg, 250-310 kg and ˃310 kg. IROT was measured just before slaughter and pH was measured 24 h later. Colour parameters (CIELAB space) were evaluated 48 h post-slaughter. Water holding capacity was evaluated at seven days after slaughter.Main results: IROT mean values were higher in heavier bulls (p<0.05), probably due to these animals appeared to movilize a greater blood ow, thus increasing ocular temperature. Furthermore, IROT showed a statistically signicant correlation with both pH from light carcasses (r=0.66; p<0.001), and mean Hue value from all carcass weights (r=-0.22; p<0.05). A quadratic regression analysis accounting carcass weight as a continuous variable, found medium to strong t values for pH (R2=0.52; RMSE=0.032; p<0.01) and medium t values for H* (R2=0.41; RMSE=3.793; p<0.001), changing their relation with IROT depending on carcass weight.Research highlights: IROT showed potential to become a useful tool to assess pH in light carcasses and to assess H* in all carcasses of young bulls prior to slaughter, regardless their weight. However, further studies would be recommended under more variable pre-slaughter stress conditions.

The Blanca Serrana goat is selected for meat production and usually raised in an extensive farm system. The meat goat industry is getting bigger in Spain, evolving to more intensive farming systems. The negative influence of stress produced by daily management on animal welfare is even bigger in these animals as they are not used to getting so close to humans. Eye temperature has recently appeared as an appropriate and noninvasive tool for welfare assessment in cattle, but no previous studies have been developed in goats. Thus, the main aim of this pilot study was to test eye temperature as a noninvasive tool to explore stress levels associated with a semi-intensive farming system for meat goats in comparison with the standard measurements of stress. For that, 24 Blanca Serrana goats were used. Heart rate (HR), respiratory rate (RR) and eye temperature (ET), assessed with infrared thermography samples, were collected just before and just after a stressful situation created to check how the routine management of semi-intensive farming systems affected this species. A factorial ANOVA, least square means and Scheffe post hoc comparison analyses found statistically significant differences due to the stress test moment for RR (p<0:05) and ET (p<0:001) with higher values shown after the stress test than before it. Differences due to age were found just for HR (p<0:05) and RR (p<0:01) stress parameters, with kids showing higher results than adults. Pearson correlations between HR, RR and ET parameters showed a medium-high positive correlation of 0.56 between RR and ET. Thus, ET appears as an appropriate and noninvasive tool to explore stress levels associated with a semiintensive farming system for meat goats.

Un año más me es grato presentar, en el marco del Programa de Mejora del Caballo Anglo-árabe el sexto Catálogo de Reproductores de esta raza, en el que se recogen los caballos que han alcanzado alguna de las Categorías Genéticas recogidas en su Esquema de Selección (Jóvenes Reproductores Recomendados y Reproductores Élites), para las disciplinas hípicas de Concurso Completo de Equitación, Salto de Obstáculos y Raid. Como en años anteriores, la información genealógica, fenotípica y genética de los animales en Catálogo se presenta a modo de ficha individual, con objeto de proporcionar la mayor información posible de cada animal. Las valoraciones genéticas de las distintas disciplinas evaluadas, que nos han permitido determinar los animales con Categorías Genéticas, se han realizado tanto a partir de los controles de rendimientos de las Pruebas de Selección de Caballos Jóvenes (PSCJ) como de las pruebas federativas (Real Federación Hípica Española -RFHE-). Para la disciplina de Concurso Completo de Equitación se han valorado un total de 9.980 caballos (1.197 de raza Aá), a partir de construir la matriz de parentesco de los 1090 caballos (259 Aá) participantes en las PSCJ y en la RFHE (los registros de las PSCJ se complementan con los de la RFHE con objeto de aumentar el número de registros y de este modo contribuir significativamente a aumentar la fiabilidad de las valoraciones genéticas) con un total de 8.331 registros (2.671 de los cuales pertenecen a caballos Aá). Para la disciplina de Salto de Obstáculos se han valorado a 22.488 animales (949 Aá) a partir de las 10.438 participaciones registradas (261 Aá) por los 1.893 caballos participantes (65 Aá). La valoración realizada, para la obtención de los animales con la categoría de Reproductor Élite, uniendo información de las PSCJ y de las pruebas de la RFHE, se ha realizado sobre un total de 22.488 caballos (949 Aá) a partir de las 196.649 participaciones registradas (2.654 de caballos Aá). Para la valoración genétic

Me es grato presentar el sexto Catálogo de Reproductores del Caballo de Deporte Español (CDE), en el que se recogen los animales que han alcanzado las Categorías Genéticas de Jóvenes Reproductores Recomendados, de Reproductores Mejorantes o Reproductores Élite, para las disciplinas hípicas de Salto de Obstáculos, Doma Clásica, Concurso Completo de Equitación y Raid. Para realizar las valoraciones genéticas que han dado lugar a que los animales alcancen las distintas categorías genéticas ha sido preciso contar con los controles de rendimientos realizados tanto en las Pruebas de Selección de Caballos Jóvenes (PSCJ) como en las pruebas federativas (Real Federación Hípica Española ‐ RFHE). La información genealógica, fenotípica y genética de los animales con categoría genética se ha recogido en el presente Catálogo de Reproductores, a modo de ficha individual, con objeto de difundir la mejora de la raza Caballo de Deporte Español. En la valoración genética realizada para obtener la categoría de Joven Reproductor Recomendado en la disciplina de Salto de Obstáculos se han valorado a 22.488 animales a partir de las 10.438 participaciones registradas por los 1.952 caballos participantes (1.617 de CDE). Así mismo, se ha realizado una valoración genética con los datos generados tanto en las PSCJ como en las pruebas de la RFHE, con objeto de aumentar el número de registros y de este modo contribuir significativamente a aumentar la fiabilidad de las valoraciones genéticas realizadas. La valoración genética, para alcanzar la categoría de Reproductor Mejorante y Reproductor Élite se ha realizado sobre un total de 22.488 caballos (3.133 de CDE) a partir de las 196.649 participaciones registradas (53.585 de animales CDE) procedentes de 8.446 ejemplares (2.388 CDE). En la valoración genética realizada para la disciplina de Concurso Completo de Equitación, se han contabilizado, para obtener las categorías de Joven Reproductor Recomendado, Reproductor Mejorante y/o Reproductor Élite

Avanzando en el Programa de Mejora de la raza equina Anglo-árabe (Aá), me es grato presentar el sexto Catálogo de Reproductores de esta raza, en el que se recogen los caballos que han alcanzado alguna de las Categorías Genéticas recogidas en su Programa de Mejora (Jóvenes Reproductores Recomendados y Reproductores Élites), para las disciplinas hípicas de Concurso Completo de Equitación, Salto de Obstáculos y Raid. Como en años anteriores, la información genealógica, fenotípica y genética de los animales en Catálogo se presenta a modo de ficha individual, con objeto de proporcionar la mayor información posible de cada animal. Las valoraciones genéticas de las distintas disciplinas evaluadas, que nos han permitido determinar los animales con Categorías Genéticas, se han realizado tanto a partir de los controles de rendimientos de las Pruebas de Selección de Caballos Jóvenes (PSCJ) como de las pruebas federativas (Real Federación Hípica Española -RFHE-). Para la disciplina de Concurso Completo de Equitación se han valorado un total de 9.083 caballos (1.169 de raza Aá), a partir de construir la matriz de parentesco de los 958 caballos (253 Aá) participantes en las PSCJ y en la RFHE (los registros de las PSCJ se complementan con los de la RFHE con objeto de aumentar el número de registros y de este modo contribuir significativamente a aumentar la fiabilidad de las valoraciones genéticas) con un total de 6.933 registros (2.264 de los cuales pertenecen a caballos Aá). Para la disciplina de Salto de Obstáculos se han valorado a 21.537 animales (938 Aá) a partir de las 10.106 participaciones registradas (256 Aá) por los 1.819 caballos participantes (62 Aá). La valoración realizada, para la obtención de los animales con la categoría de Reproductor Élite, uniendo información de las PSCJ y de las pruebas de la RFHE, se ha realizado sobre un total de 21.536 caballos (934 Aá) a partir de las 173.161 participaciones registradas (2.499 de caballos Aá). Para la valoración genética q

The aims of this study were, first, to evaluate eye temperature (ET) with infrared thermography and heart rate (HR) to measure stress in horses during show jumping competitions and their relationship with competition results, and second, to evaluate the influence of different extrinsic and intrinsic factors of the horse on the stress measurements analysed. One hundred and seventy-three Spanish Sport Horses were analysed for ET and HR, and these measurements were taken 3 h before the competition, just after and 3 h after it. Two interval measurements were also assessed for each parameter. Positive significant correlations were found between ET and HR, measured before (r=0.23), just after competition (r= 0.28) and for the later interval (r= 0.26), whereas negative correlations with competition results were found only for ET when measured just after competing (r=− 0.25). Two intrinsic factors (genetic line and age) and no extrinsic factors showed significant differences for ET, whereas one intrinsic factor (age) and two extrinsic factors (journey duration and number of training hours) showed significant differences for HR. The marginal means showed significantly higher ET values for the Anglo-Arab genetic line and for 5-year-old animals. HR values were significantly higher for 4-year-old animals, for horses which had travelled 4 to 6 h and for horses that had 3 to 6 h of daily training. This study suggests that, although ET and HR seemed to share a similar physiological basis, the factors that most influenced each parameter were different. Finally, ET seems to be a suitable tool for assessing stress during show jumping competitions in horses.

Desde el año 2004 el MAPyA organiza en España Pruebas de Selección de Caballos Jóvenes (PSCJ), para diferentes disciplinas, entre las que se encuentra el Salto de Obstáculos. Participan animales jóvenes (4 a 6 años). Con la información acumulada en estos 3 años (4.441 participaciones de 87 caballos participantes) hemos analizado los factores externos que condicionan los resultados obtenidos por los animales en este tipo de pruebas. Para ello se ha utilizado un modelo padre mediante el Proc MIXED del SAS, incluyendo como variables dependientes las penalizaciones finales y el ranking transformado. Se han analizado 14 factores, relacionados con el propio animal (edad, sexo…), el lugar de celebración del concurso y las condiciones de la pista, las condiciones climatológicas, el día de la prueba, el nivel de entrenamiento y el nivel de cansancio/estrés del animal antes de la competición. El jinete y el padre se han incluido como factores aleatorios en el modelo y el orden de salida, como covariable. Aunque la mayoría de los factores y combinaciones de factores han sido estadísticamente significativos, han explicado una muy baja varianza (entre 0,07% y 1,78%) con excepción de la edad (2,40%), padre (9,25%) y jinete (8,28%)., Since 2004, the Ministry of Agriculture, Fisheries and Food of Spain organize the Young Horses Performance Selection Tests, for different disciplines, like Show Jumping. Only young animals participate in these events (4 to 6 years old). With the data collected during 3 years (4.441 participations from 87 different horses), we have analyzed the environmental factors that influence the performance results of the animal in these type of tests. A Proc MIXED model from SAS was used, including final penalizations and transformed ranking as dependent variables. 14 factors, related to the animal (age, sex…), the competition location and the racetrack conditions, the climatologic conditions, the training level and the stress level of the animal, were analyzed before the competition. The rider and the father were included in the model as random factors, and the participation order as the covariate. Although most of the factors and their combinations were significant, they explained a very low variance (from 0.07% to 1.78%), excluding the age (2.40%), the father effect (9.25%) and the rider (8.28%).

En esta ponencia invitada se resumen las principales características de los programas de selección de las razas autóctonas que se están llevando a cabo en España. Se describen para cada una de ellas la población controlada, los caracteres registrados, los objetivos y criterios de selección, la valoración genética de los reproductores, los aspectos organizativos, la utilización de la información por parte de los ganaderos y los factores limitantes del progreso genético. Los más antiguos de estos programa comenzaron al principio de la década de los 80 del pasado siglo, la mayoría lo hicieron al final de dicha década o en la siguiente y unos pocos en la década actual. Debido a esta disparidad de fechas de iniciación y a otros factores estructurales y organizativos, sus niveles de desarrollo y efectividad son muy variables. Entre los factores limitantes de dicho desarrollo y efectividad más frecuentemente citados se encuentran los reducidos tamaños de los núcleos de selección, la reducida implantación de la I.A. y, consecuentemente, el bajo número de sementales en prueba de descendencia y las bajas fiabilidades de las valoraciones genéticas, la escasa utilización por parte algunos de los ganaderos de las valoraciones genéticas de sus animales para elegir la reposición en los rebaños y, en un cierto número de casos, la escasa participación e interés de los mismos., This invited contribution summarizes the most important characteristics of selection programs being applied to Spanish indigenous breeds. Population and traits being recorded, selection objectives and criteria, breeding values estimation, managing aspects, diffusion to and use of genetic information by breeders and constraints to genetic progress are synthetically described for each breed. The oldest programs started at the beginning of the eighties of the last century. Most of them began at the end of the eighties or in the nineties and a few were initiated within present decade. Due to these age differences, and to other structural and managing factors, their developmental and effectiveness levels are very variable. Small number of animals being registered and, therefore, selected, low number of dams inseminated an its consequence on the capacity to sire testing and on the reliability of estimated breeding values, the scanty use that some of the breeders make of the genetic evaluations and the low participation of farmers in the programs, are among the most important factors limiting their development and their effectiveness in terms of genetic progress obtained.

Una de las principales fuentes de información funcional para la valoración genética precoz de los animales para las distintas disciplinas ecuestres son las Pruebas de Selección de Caballos Jóvenes (PSCJ), reguladas por el MAPyA, que se están celebrando en nuestro país desde el año 2004. Las PSCJ son muy importantes en la selección de los équidos deb ido a las altas correlaciones genéticas que se han encontrado entre las variables analizadas en animales jóvenes y los resultados obtenidos posteriormente en las competiciones, lo cual implica una buena predicción del rendimiento en el animal adulto (Wallin et al. , 2003). El concurso completo de equitación (CCE), conocido internacionalmente como “Eventing”, es una disciplina ecuestre que combina distintas pruebas (doma, salto y cross), exigiendo al animal un elevado grado de diversas aptitudes. Las principales razas de caballos participantes en España en CCE son, el Caballo de Deporte Español (CDE), el caballo de raza Anglo-árabe (A-á) y el Pura Raza árabe (PRá) El objetivo de este estudio ha sido establecer los modelos genéticos idóneos para la estimación de los valores de mejora y obtener estimas de heredabilidad de los caracteres de la disciplina de CCE