The effect of caponization on bone homeostasis of crossbred roosters. I. Analysis of tibia bone mineralization, densitometric, osteometric, geometric and biomechanical properties

The presented study focuses on assessing the effect of caponization on the densitometric, osteometric, geometric and biomechanical parameters of tibial bones in crossbred chickens. The study was carried out on 96 hybrids between Yellowleg Partridge hens (Ż-33) and Rhode Island Red cockerels (R-11) aged 16 weeks, 20 weeks and 24 weeks. Birds were randomly assigned to 2 groups-the control group (n = 48; which consisted of intact roosters) and the experimental group (n = 48, which consisted of individuals subjected to caponization at the age of 8 weeks). The caponization had no effect on the densitometric, osteometric and geometric parameters (except the horizontal internal diameter of 16-week-old individuals) of tibia bone, as well as the content of calcium (Ca), phosphorus (P) and the Ca/P ratio in the bone mineral fraction in all analyzed age groups of animals. However, it contributes to a lower percentage of ash in the bones of capons at 20 and 24 weeks of age compared to cockerels. On the contrary, some mechanical and material parameters show the negative effect of caponization. Ultimate load and bending moment decreased in capons in all of the analyzed age groups of animals and yield load, stiffness and ultimate stress also decreased but only in the group of 20-week-old and 24-week-old individuals. This can contribute to the weakening of the capon bones, and in the perspective of prolonged maintenance to their deformation and even fracture.

Factors and Mechanisms Affecting Seasonal Changes in the Prevalence of Microbiological Indicators of Water Quality and Nutrient Concentrations in Waters of the Białka River Catchment, Southern Poland

This 3-year study was aimed to understand the factors and mechanisms that cause the temporal changes in the concentration of microbiological indicators of water quality and nutrient concentration in selected sites of the Białka river catchment (southern Poland) situated in direct vicinity of the largest ski station in the region. The analysis comprised 35 sampling campaigns conducted in five sites. Water temperature, pH, and electrical conductivity were measured during sampling, laboratory analyses included determination of the selected nutrients content (NH4, NO3, NO2, PO4); and the number of mesophilic and psychrophilic bacteria, coliforms, fecal coliforms, and Escherichia coli. Based on the cluster analysis, the collected samples were grouped into three to four groups, depending on the most characteristic features. Seasonal variation was evident, showing the predominance of either anthropogenic or natural-environment factors, depending on the considered season. On the other hand, principal component analysis revealed clear effect of various forms of land use in different sites.