Abstract: The objective of the study was to determine which cross-country obstacles are more difficult for eventing horses. Jumping scores were considered in terms of the horse's reaction to novelty and to the fearfulness of novel objects which are the fences situated in novel terrain. The data concerned 11 classes of One to Four Star level (stars showing the difficulty of the class) held at the Olympic Games and three international Three Day Events. A total of 400 entries, in which 259 horses jumped 372 obstacles were considered. Scores of 11,341 jumps at particular fences were categorized either as faulty jumps or non-faulty jumps. Factors describing the fences versus the jumping scores were studied with least square analysis of variance, with respect to the interaction between the star level and the fence traits. The overall frequency of faults at the cross-country amounted to 4.33 ± 0.57%. Among the effects analyzed, the difficulty of cross-country fences for the horses depends upon whether an obstacle is single or is an element of a combination, whether it is straight or requiring an effort in both height and spread, is broad or narrow, has a solid top or a brush, has an alternative or not and whether it is a water crossing or not. At One Star level, the less experienced horses react differently to certain fence traits compared to horses participating in Three or Four Star levels. It is concluded that the equine visionary system, being less developed towards identification of stationary objects than the human visionary system may be a key towards explaining the horse's behaviour while jumping the obstacle. The height-spread obstacles, those of the narrow front, with the brush and with the alternative seem to involve more faults because of the equine low-acuity vision. The same reason may justify the similar frequency of faults at the single obstacles and the first elements in combinations. Accurate methods of measuring equine vision would complement behavioural tests and should both be introduced into the selection of eventing horses.

Abstract: Summary Since the therapeutic use of horse riding has been realised, several research studies investigating the physical and psychosocial effect of therapeutic riding have been conducted. A summary is given of therapeutic riding research studies where formal statistical tests were used to analyse the data as well as a summary of studies where different techniques were used to process the data. These summaries give an overview of the variables measured in previously conducted therapeutic riding studies. The general problems experienced by therapeutic riding researchers are given after the summaries. Possible explanations are discussed for some of these problems. In conclusion a few suggestions are given for future research, not only for therapeutic riding studies, but for any study where the effect of a therapeutic intervention is investigated.

Abstract: To establish a method for assessing equine temperament by use of a questionnaire, we carried out two surveys. The subject animals were all thoroughbreds maintained at the same farm. Respondents were the primary caretaker and two colleagues working with each horse. Factor analysis was performed on the responses to each survey. In both surveys, five factors were extracted and four of them were common between the two surveys. The common factors were [`]Anxiety', [`]Trainability', [`]Affability', and [`]Gate entrance'. There were sufficient internal consistencies in responses about [`]Anxiety', [`]Trainability', and [`]Affability' in the two surveys to indicate the validity of this questionnaire in evaluating these factors in equine temperament.

Abstract: The noncoding region between tRNAPro and the large conserved sequence block is the most variable region in the mammalian mitochondrial DNA D-loop region. This variable region (ca. 270 bp) of four species of Equus, including Mongolian and Japanese native domestic horses as well as Przewalskii's (or Mongolian) wild horse, were sequenced. These data were compared with our recently published Thoroughbred horse mitochondrial DNA sequences. The evolutionary rate of this region among the four species of Equus was estimated to be 2-4 x 10(-8) per site per year. Phylogenetic trees of Equus species demonstrate that Przewalskii's wild horse is within the genetic variation among the domestic horse. This suggests that the chromosome number change (probably increase) of the Przewalskii's wild horse occurred rather recently.

Abstract: The phylogenetic relationship between Equus przewalskii and E. caballus is often a matter of debate. Although these taxa have different chromosome numbers, they do not form monophyletic clades in a phylogenetic tree based on mtDNA sequences. Here we report sequence variation from five newly identified Y chromosome regions of the horse. Two fixed nucleotide differences on the Y chromosome clearly display Przewalski's horse and domestic horse as sister taxa. At both positions the Przewalski's horse haplotype shows the ancestral state, in common with the members of the zebra/ass lineage. We discuss the factors that may have led to the differences in mtDNA and Y-chromosomal observations.