M. Solé

Evaluation of conformation against traits associated with dressage ability in unridden Iberian horses at the trot.

The work describes and compares the conformation traits and gait characteristics in the main native Iberian dressage Purebreds (Lusitano, Spanish and Menorca horses). In total, 4 strides belonging to each of 66 males (4-14 years old) were recorded at handled trot, using a 3D semi-automatic movement analysis system. Principal component analysis (PCA) and intraclass Correlations (iC) were computed. The Menorca Purebred showed proportionally higher limbs (23.8 and 15.1cm for the forelimb cannon and pastern lengths), the Lusitano Purebred had larger inclinations (66.1°, 37.7° and 47.9° for the scapula and pastern angles), and the Spanish Purebred presented a longer scapula (41.5 cm) and a larger hip angle (132.1°), apparently showing a better conformation for dressage gaits. However, the three breeds presented undesirable tarsus joint conformation (<155.5°) for dressage performance. In general, all of them showed good features in the kinematics of the forelimbs. Nevertheless, the functional capacity of their hindlimbs and linear parameters probably need to be improved for their competitiveness.

Genetic analysis of kinematic traits at the trot in Lusitano horse subpopulations with different types of training

The possibility of using quantitative kinematic traits as indirect selection criteria for sport performance could be beneficial to perform an early genetic evaluation of the animals. The genetic parameters for objectively measured kinematic traits under field conditions have been estimated for the first time, in order to potentially use these traits as indicators of gait quality in future selection of the Lusitano breed. The repeatability within three different types of training (dressage, bullfighting and untrained) was also discussed. A total of 176 males (4 to 14 years old) were recorded at trot in hand using a 3D videographic system. The speed and 10 kinematic traits were studied (one temporal, two linear and seven angular variables). The genetic parameters of the kinematic variables were estimated using VCE software. The heritability estimates were moderate to high (0.18 to 0.53). The stride length and the forelimb angular variables presented the highest heritabilities (0.49 to 0.53), whereas the hindlimb angular variables revealed the lowest values (0.18 to 0.40). More than half of the genetic correlations were moderately to highly positive (mostly 0.20 to 0.70; up to 0.88 between hindlimb traits). The dressage and bullfighting groups presented the highest repeatabilities (over 0.6) in the majority of the traits, maybe because of the acquired gait regularity expected in animals subjected to specific training, and suggesting a greater influence of the individuals over the kinematic traits studied in these two subpopulations than in the untrained subpopulation. The longer swing phase duration and the larger range of motion of the elbow, hock and pelvis joints observed in the dressage group may indicate a better gait quality of this group, according to FEI (International Equestrian Federation) standards. The bullfighting and untrained groups were more similar to each other in terms of kinematic traits. Selection of young horses for characteristics such as stride length and the hindlimbs traits can apparently contribute to further genetic improvement of the performance of Lusitano breed.

Stress level effects on sport performance during trotting races in Spanish Trotter Horses

The stress level is suggested to have a negative effect on horses during equestrian competitions, specifically in trotter racing. The main objectives of this study were to measure stress levels in Spanish Trotter Horse races with a reliable non-invasive method, and determining the threshold level of stress that leads to the best performance results and also shows when the stress perceived by the horse becomes distress. One hundred and thirty individuals were evaluated, measuring their performance (based on racing time per kilometre (TPK)) and their stress (based on eye temperature, assessed with infrared thermography, and heart rate) in different competitions. Eye temperature and heart rate measurements were collected 2h before the race and immediately following the race, and the increases of eye temperature (∆ET) and heart rate were estimated. ∆ET and eye temperature before the race showed significant differences related to the performance level after a GLM analysis. The segmented regression analysis indicated that when the animal was more stressed before the race than just after finishing it (∆ET<0), it showed the poorest competition results, and from the breakpoint (reached at ∆ET=-0.97%), horses performance started to improve. When comparing eye temperature variables and TPK with a response surface plot, TPK was optimum (77.27s) when the eye temperature before the race and ∆ET reached values of 37.61°C and 7.57%, respectively. Therefore, the stress levels of the horse before the race influence its competition results, and ∆ET during competitions reaching a threshold point is related to an improvement in performance results.

Genetic structure and connectivity analysis in a large domestic livestock meta-population: The case of the Pura Raza Español horses

The Pura Raza Español (PRE) is an autochthonous Spanish horse population distributed in 65 countries and managed by a single association. Since 1960s, breeding animals have been steadily exported to other countries to establish local subpopulations. We analysed the genetic structure of a PRE horse meta-population (MP) of 215,500 animals from countries with at least 80 active animals (27 countries comprising 77% of the total animals in the complete pedigree). Genotypes from active animals (59% of the total animals in the complete pedigree) were also studied. Genetic analysis of the MP was performed using classical parameters such as inbreeding (F), coancestry, founder contribution, effective number of founders/ancestors (fe/fa) and gene flow between countries. Results showed that the MPF coefficient decreased in the last two decades (1990-2013), indicating an explicit management against F. Founder contribution to genetic variability across countries mainly came from females (73.6%). In general, unbalanced contributions of founders reflected the high loss of genetic diversity along generations (fe/fa as low as 32/19 for the whole MP). Despite this differential contribution, the proportional contribution to the global diversity of each country was similar. The highest within-country coancestry value corresponded to Cuba (0.1509), being the only country with highly inbred individuals (over 12%), and the lowest value corresponded to Spain (0.0574). These results should help to avoid further declines in genetic variability and increases in F levels, especially in small countries like Cuba. In parallel, only nine countries presented descendants in a single population, suggesting a common origin for all countries and/or a substantial exchange of genetic material between populations. Spain and the US showed the highest gene flow rates. These results support the need of a coordinated management strategy, especially promoting the exchange of genetic material to increase the effective population size and maintain the levels of genetic diversity in the PRE horse population.

Carcass and Meat Quality Traits in an Embden×Toulouse Goose Cross Raised in Organic Dehesa.

This study assessed the influence of genetic type (Embden-Anser anser, EE; Toulouse-Anser anser, TT and F1 cross, ET) for meat characteristics (carcass, meat quality and fatty acid (FA) profiles), of domestic geese “Anser anser domesticus” raised in dehesa as an alternative, organic feeding system. Carcass and breast muscle weight (p<0.01) were greater for the ET group at the same live weight. None of the groups showed differences in the production of fatty liver with this type of feeding. Higher values were found for maximum Warner–Bratzler shear force (between 7.62 and 8.87 kg/cm2), which implies the improvement of this parameter. High levels of oleic FAs were obtained, especially for the TT group. The polyunsaturated/saturated FA ratio was highest for the ET group (p<0.001), reflecting the optimum nutritional values as a component of a healthy consumer diet.