Magdalena Pieszka

Usefulness of Selected Incisor Characteristics for Determining the Age of Hucul HorsesThe aim of this study was to assess the suitability of selected characteristics of incisors for age determination in Hucul horses. The study included 173 Hucul horses (137 mares, 28 stallions and 8 geldings) from one day to 27 years of age. Breeding documentation was used to determine the actual age of the horses, which were then divided into age groups. Each group of horses was assigned a specific incisor characteristic to help identify their age. Selected incisor characteristics were used to evaluate the age of the horses according to the method reported by Pruski (2007) and the results were compared with the actual age, indicating the percentage of errors made. It was found that most errors were made in the case of horses over 11 years old, when assessing the changing shape of the occlusal surface of incisors (Table 1). In this group the percentage of errors was significantly higher (P≤0.01) than that found for horses from the first three youngest age groups, in which the eruption time of deciduous incisors, the disappearance of cups on deciduous incisors and the eruption time of permanent incisors were taken into account. Compared to the above traits, errors were made significantly more often (P≤0.01) when age was determined based on the disappearance of permanent incisors, in a group of horses aged between 6 and 11 years. The eruption time of deciduous incisors and permanent incisors were the traits which enabled the most accurate determination of the horses' age. The results obtained suggest that age determination based on dentition is not accurate enough and can only play a subsidiary role, for example when no breeding records are available.

The aim of this study was to evaluate the effect of specific factors on ossification of the distal epiphyseal cartilage of the radial bone in Thoroughbred horses. The study was carried out on 452 Thoroughbred horses, two years old, that were under race training. X-ray tests were conducted and interpreted every month starting at the 18th month of life and continuing until ossification of the distal epiphyseal cartilage of the radial bone occurred. In the statistical model, the year of birth, sex, birth season, sire, and breeder were treated as constant effects. Horses that were born in the spring season were characterized by a shorter time until the closure of the distal radial epiphyseal cartilage in comparison to horses born in the winter season; the difference between these times was found to be highly significant. Furthermore, it was shown that the ossification time of cartilage was also significantly influenced by the year of birth, the sire, and the breeder. Knowledge and monitoring of factors affecting the rate of somatic maturity in Thoroughbred horses can be useful in breeding and veterinary practices. This fact, in conjunction with the analysis of somatotrophic processes, will provide a basis for improving the feeding, training, and management system of Thoroughbred horses as well as aiding in the early diagnosis, treatment, or prevention of various diseases associated with intensive growth in the early period of life.

As a result of long-term work by Polish breeders the special type called ‘Polish type’ of Arabian horses has been created. Polish Arabians differ from their ancestors who were bred by Bedouins in the deserts of Arabia. The main differences are slightly more height, better stature and correct conformation. The process of Arabian improvement is on going and must be adapted to modern trends and conditions which is reflected in changes of biometric parameters (Budzynski et al., 1976). Height at withers HW (cm), girth circumference GC (cm) and cannon bone circumference CC (cm) are basic measurements that make it possible to compare horses born at different times and in different studs. The objective of this study was to evaluate the changes in biometric parameters of Arabian horses bred in Poland after the World War II until now.This study used data concerning basic measurements (HW, GC and CC) of 1218 Arabian horses (1076 mares and 142 stallions measured at 5 years of life) used in Polish state breeding after the World War II.