Population structure and genetic diversity of Polish Arabian horses based on pedigree data

With a history tracing back to at least the 18th century and a substantial global influence on various breeds, Polish Arabian horse population is of paramount importance for both breeders and conservationists. However, its genetic makeup and the population dynamics are still not well understood. This study presents an analysis of the modern Polish Arabian horse population using pedigree data, focusing on the breed's genetic diversity and population structure. Our analysis encompassed 1 498 individuals defined as the reference population (RP) and their 11 065 ancestors, which resulted in the dataset of 12 254 individuals (total population). We traced their genealogy to assess inbreeding coefficients (F), founder effects, and genetic variability measures such as the effective number of founders (fe), ancestors (fa), or founder genome equivalents (fge). The results indicated a good pedigree quality with an average of 28.1 maximum traced generations, revealing high pedigree completeness for initial generations with a decline beyond the seventh generation. The genetic diversity parameters showed a considerable bottleneck effect, with an effective number of founders at 73, which reflects a substantial loss of genetic diversity over time. Despite the vast total number of founders (852), only a few have had a lasting impact on the current population, signaling the need for revised breeding strategies to maintain diversity. The study identified a slight but consistent rise in inbreeding over the last century, with a marginal recent decline, and a significant difference in the contribution of various founders. The average F was 5.8%, with 99.6% of the reference population being inbred. The analysis of effective population size (Ne) highlighted potential risks for genetic diversity, urging for revision of breeding goals to consider a wider array of founder lineages. The study indicated that stallions belonging to RP can be attributed to 15 distinct sirelines, whereas mares to 45 unique damlines, more than considered in the current breeding program (8 and 15, respectively). Conclusively, the study underlines the need for ongoing monitoring and strategic breeding to maintain and enhance the genetic diversity of Polish Arabians, considering the breed's historical significance and contemporary genetic challenges.

Epidemiology of scabies in relation to socio-economic and selected climatic factors in north-east Poland

INTRODUCTION

Scabies is a contagious parasitic disease, a skin infestation caused by Scaroptes scabieri, tiny mites that burrow under the skin. Outbreaks of scabies can be difficult to control and require the implementation of appropriate control programme.

OBJECTIVE

The purpose of the study was to analyze the epidemiology of scabies in north-east Poland, considering socio-economic and selected climatic factors.

MATERIAL AND METHODS

The analysis was based on data reports (n=26,362) obtained from the Polish National Health Fund (NFZ) for the period 2007-2014. Monthly climate data were collected from the Institute of Meteorology and Water Management/National Research Institute (IMGW-PIB) in Warsaw, including data on temperature and relative humidity. Additionally, the influence of socio-economic factors on the prevalence of scabies was analyzed. Data on population size, medical staff, and unemployment rate were obtained from the Central Statistical Office (GUS) in Warsaw, and analyzed using SPSS Statistics 24.0 programme.

RESULTS

The age group of 10-19 years showed the highest infestation rates. Seasonality of scabies was demonstrated. The highest numbers of cases were reported during the autumn and winter months. There was a significant negative correlation (rho = -0.499; p<0.001) between air temperature and the incidence of scabies, and a positive correlation (r = 0.532; p<0.001) between relative humidity and the number of cases reported. A rise in the unemployment rate also caused an increase in the scabies incidence rate (r = 0.294; p<0.001).

CONCLUSIONS

The results suggest that an improvement of socio-economic conditions may contribute to a reduction in the number of scabies infections. The possibility should be considered of monitoring the parameters, such as air temperature and humidity, particularly when scabies outbreaks occur.