The paper reviews the various factors affecting dystocia in cattle. It is based mainly on the recent studies found in the literature of the subject but refers occasionally to some older papers as well. The factors are grouped into four main categories: direct factors, phenotypic factors related to calf and cow, non-genetic and genetic factors. The first group includes malpresentations and uterine torsion. The second one includes: calf birth weight, multiple calvings, perinatal mortality, cow pelvic area, cow body weight and body condition at calving, gestation length. The non-genetic factors are: cow age and parity, year and season of calving, place of calving, maintenance practises, disorders, calf sex and nutrition. Other non-genetic factors are the level of hormones in the periparturient period, in vitro production of embryos and embryo cloning. Finally, the genotypes of cow, bull and calf, inbreeding, muscular hypertrophy, selection and quantitative trait loci form the fourth group of genetic factors.

Associations between polymorphism localised in the third exon of the prolactin gene (PRL-RsaI) and milk production traits of Black-and-White and Jersey cattle were analysed. A total of 427 cows were included in the study. PCR-RFLP method was used. The frequencies of genotypes and alleles were as follows: 0.7107 -AA, 0.2851 -AB, 0.0042 -BB; 0.8533 -PRL A and 0.1467 -PRL B for Black-and-White cattle and 0.0919 -AA, 0.4324 -AB, 0.4757 -BB; 0.3081 -PRL A and 0.6919 -PRL B for Jersey cattle. Statistically significant differences between the breeds were observed in the frequencies of genotypes and alleles. Associations between PRL-RsaI polymorphism and milk production traits of Jersey cows and lack of associations with these traits in Black-andWhite cows were observed.

Lipids and proteins of skin cells are the most exposed to harmful ultraviolet (UV) radiation contained in sunlight. There is a growing need for natural compounds that will protect these sensitive molecules from damage, without harmful side effects. The aim of this study was to investigate the effect of sea buckthorn seed oil on the redox balance and lipid metabolism in UV irradiated cells formed different skin layers to examine whether it had a protective effect. Human keratinocytes and fibroblasts were subjected to UVA (ultraviolet type A; 30 J/cm2 and 20 J/cm2) or UVB (ultraviolet type B; 60 mJ/cm2 and 200 mJ/cm2, respectively) radiation and treated with sea buckthorn seed oil (500 ng/mL), and the redox activity was estimated by reactive oxygen species (ROS) generation and enzymatic/non-enzymatic antioxidants activity/level (using electron spin resonance (ESR), high-performance liquid chromatography (HPLC), and spectrophotometry). Lipid metabolism was measured by the level of fatty acids, lipid peroxidation products, endocannabinoids and phospholipase A2 activity (GC/MS (gas chromatography/mass spectrometry), LC/MS (liquid chromatography/mass spectrometry), and spectrophotometry). Also, transcription factor Nrf2 (nuclear erythroid 2-related factor) and its activators/inhibitors, peroxisome proliferator-activated receptors (PPAR) and cannabinoid receptor levels were measured (Western blot). Sea buckthorn oil partially prevents UV-induced ROS generation and enhances the level of non-enzymatic antioxidants such as glutathione (GSH), thioredoxin (Trx) and vitamins E and A. Moreover, it stimulates the activity of Nrf2 leading to enhanced antioxidant enzyme activity. As a result, decreases in lipid peroxidation products (4-hydroxynonenal, 8-isoprostaglandin) and increases in the endocannabinoid receptor levels were observed. Moreover, sea buckthorn oil treatment enhanced the level of phospholipid and free fatty acids, while simultaneously decreasing the cannabinoid receptor expression in UV irradiated keratinocytes and fibroblasts. The main differences in sea buckthorn oil on various skin cell types was observed in the case of PPARs—in keratinocytes following UV radiation PPAR expression was decreased by sea buckthorn oil treatment, while in fibroblasts the reverse effect was observed, indicating an anti-inflammatory effect. With these results, sea buckthorn seed oil exhibited prevention of UV-induced disturbances in redox balance as well as lipid metabolism in skin fibroblasts and keratinocytes, which indicates it is a promising natural compound in skin photo-protection.

No abstract

The objective of the study was to examine a population of free-living carnivorous mammals most commonly found in Poland (red fox, beech marten, and raccoon) for the occurrence of bacteria that are potentially pathogenic for humans and other animal species and to determine their virulence potential (the presence of selected virulence genes). From the total pool of isolates obtained (n = 328), we selected 90 belonging to species that pose the greatest potential threat to human health: Salmonella spp. (n = 19; 4.51%), Yersinia enterocolitica (n = 10; 2.37%), Listeria monocytogenes and L. ivanovii (n = 21), and Staphylococcus aureus (n = 40; 9.5%). The Salmonella spp. isolates represented three different subspecies; S. enterica subsp. enterica accounted for a significant proportion (15/19), and most of the serotypes isolated (S. Typhimurium, S. Infantis, S. Newport and S. Enteritidis) were among the 10 non-typhoidal Salmonella serotypes that are most often responsible for infections in Europe, including Poland. Y. enterococlitica was detected in the smallest percentage of animals, but 60% of strains among the isolates tested possessed the ail gene, which is responsible for attachment and invasion. Potentially pathogenic Listeria species were isolated from approx. 5% of the animals. The presence of all tested virulence genes was shown in 35% of L. monocytogenes strains, while in the case of the other strains, the genes occurred in varying numbers and configurations. The presence of the inlA, inlC, hlyA, and iap genes was noted in all strains, whereas the genes encoding PI-PLC, actin, and internalin Imo2821 were present in varying percentages (from 80% to 55%). S. aureus was obtained from 40 individuals. Most isolates possessed the hla, hld (95% for each), and hlb (32.5%) genes encoding hemolysins as well as the gene encoding leukotoxin lukED (70%). In a similar percentage of strains (77.5%), the presence of at least one gene encoding enterotoxin was found, with 12.5% exhibiting the presence of egc-like variants. In two animals, we also noted the gene encoding the TSST-1 toxin. The results of the study showed that free-living animals may be a significant reservoir of bacteria that are potentially pathogenic for humans. The results of the statistical analysis revealed that, among the animals species studied, the red fox constitutes the most important source of infections.