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Heritability Estimates of Traits Assessed in Field Performance Tests of Polish Warmblood Mares
Background/objectives: Knowledge of the genetic background of evaluated traits has been the basis for genetic progress in every horse-breeding population and is essential for precise breeding and up-to-date decision-making. The study aimed to estimate the heritability coefficients for field performance traits in mares. Methods: The research was based on 1408 evaluations of mares conducted during the years 2002–2021 in 51 training centers in Poland. The preliminary analyses of the effects, significant for the investigated traits, were obtained using analysis of variance, and these additional data are also presented (SAS program, GLM and Mixed procedures). The final statistical model for the AI-REML procedure of the DMU program included a fixed effect of the training center-season-year of evaluation, a random effect of the animal, and a regression on age in years. Results: The heritability coefficients of the performance traits were moderate to high (0.32–0.60) with the SE within the range of 0.06–0.08. The highest heritability was estimated for the free jumping, trot, and overall results. The lowest heritability was achieved for the rideability. Conclusions: The level of heritability estimations allowed for the population progress in the evaluated traits.
Comparison of the training and gait parameters of sport and leisure warmblood horses using the Seaver device
Carnivora consists of two large groups, namely Feliformia and Caniformia. These two large groups of animals clearly differ from each other morphologically and behaviourally. They are primarily predators whose hunting habits have led to the development of specific appearance traits. The locomotor apparatus, which is a key system in the hunting process, is controlled by the nervous system. The part responsible for the thoracic limb is the brachial plexus (PB). As indicated in domestic mammals, the structure of the PB has a general pattern that is subject to modifications depending on the species. Among Carnivora, there is similarity in PB structure, but crucial differences are also present. In this article, the ventral branches of the spinal nerves, nerve trunks, nerve cords and peripheral nerves are discussed along with their branches in the arm and antebrachium. The main aim of this paper is to demonstrate the structure of the brachial plexus specific to Carnivora and to distinguish the modifications that occur in this group of animals. Due to the high phylogenetic diversity of the species, the plexus structure was analysed against the current taxonomy of the IUCN Red List of Threatened Species.
Comparison of Conformation and Movement Characteristics in Dressage and Jumping Sport Warmblood Mares Based on Point Evaluation and Linear Scoring System
The aim of this study was to analyze the influence of factors on the results of 100-point judging systems, linear scoring and basic measurements, as well as differences between systems for dressage and jumping warmblood mares. The research covered official data on 1547 warmblood mares. Analysis of variance and phenotypic correlations (Pearson and partial) were used. The analysis showed that sport type significantly influenced 1/3 of biometric measurements, 2/9 traits on the 100-point system and 7/37 of linear scored traits. The influence of horse type evaluation is more significant in linear scoring than in the 100-point evaluation, which provides an argument for using the first system in breeding. In the linear evaluation for warmblood mares grouped as jumping or dressage, the most significant differences (p < 0.001) were noted between the traits of shoulder position, line of the loins and shape of the croup. In the point-based evaluation, differences (p < 0.05) were found in forelimbs and walking, as well as chest circumference in basic measurements. None of the traits in the two evaluation systems is identical to any other (r > 0.8). The comparison of systems showed meaningful correlations only between general traits. The differences between sport types of warmblood mares were smaller than expected. More objective traits should be discovered to increase accuracy in discriminating between horse types.
Comparative Analysis of the Stallion Field Performance Test at Different Training Stages and Horse Age
Breeding value estimations of Warmblood horses in Poland are based on field performance, but the amount of stallions’ data is still insufficient (334 horses). The first study’s aim is to compare stallions’ results in different stages and evaluate the overall ability using both stages. The effects on preselection (first stage free movement) and performance tests (second stage under rider) were analyzed separately and together as the overall ability. Spearman correlations were evaluated. The second aim was to evaluate the training period on the results. Due to the pandemic and lack of tests, horses had different training periods during the six years studied. The combined year-place effect, horse specialization group, and birth country had effects on four of twelve traits. The regression on age influenced only the preselection jumping trait (p = 0.04), while the training period influenced canter (p = 0.04) and “success” (passed/or not) in the performance test (p = 0.04). It seems that the training period and horse age are more significant for young horses’ performance. The correlations between stages for the same traits are moderate for gaits (<0.53) and low for jumping (<0.3). Thus, at least on a basic phenotypical level, results do not correspond strongly with each other.
Studies of mitochondrial DNA D-loop sequence variation may support the Polish Primitive Horse (Konik) conservation programme
The protection and balanced development of all existing maternal lines is one of the primary goals of the Polish Primitive Horse (PPH or Konik) conservation programme. However, previous studies have indica- ted that managing PPH conservative breeding may encounter challenges because of the numerous existing pedigree errors. We therefore attempted to check whether mtDNA markers may prove useful in correcting PPH pedigrees and improving the breed conservation programme. A 510 bp mtDNA D-loop fragment was sequenced for 396 samples representing all sixteen officially recognised maternal lines. These samples were derived from different time points in the PPH breeding history. Our analysis confirmed the presence of nineteen mtDNA haplotypes. A comparison of the molecular and pedigree data showed that the frequency of particular haplotypes was highly uneven. Although for the majority of the maternal lines we were able to identify a potential 'founder haplotype', only four of them (Dzina I, Popielica, Geneza and Bona) turned out to be 'genetically pure'. Our study confirmed that an mtDNA analysis is a useful method for assessing PPH maternal genetic diversity and illustrating the breed's history. Our findings suggest that PPH conservation programmes would benefit from revising the official pedigrees using molecular data alongside breeding records.