Comparison of the content of selected heavy metals in the liver tissue of the wild boar (Sus scrofa), red fox (Vulpes vulpes) and red deer (Cervus elaphus), living in north-eastern Poland.

The study aimed to determine the content of selenium (Se), zinc (Zn), copper (Cu) and cadmium (Cd) in the liver of predominantly plant-eating omnivore wild boar (Sus scrofa), predominantly meat-eating omnivore red fox (Vulpes vulpes) and herbivore red deer (Cervus elaphus), from North-Eastern Poland (Warmia and Mazury), in order to verify the distribution of these elements in the trophic pyramid. Furthermore, the study was used to assess the risk of eating venison. Samples were analyzed using atomic absorption spectrophotometry. The average concentration of Se was 3.9 (p⟨0.001) and 1.8-fold higher (p0.001) in the wild boar and red fox, respectively, in comparison to the red deer, and 2.1-fold higher in the wild boar comparing to the red fox (p⟨0.001). There was no difference in the average concentration of Zn. The average concentration of Cu was 9.3. Concentration of this element was 5.4-fold higher in red deer in comparison to red fox (p⟨0.001) and 9,34-fold higher than in wild boar (p⟨0.001). The average concentration of Cd was 1.9-fold higher in wild boar in comparison to the red fox (p⟨0.029). Correlation between Cu and Cd concentrations was also observed in the case of the red deer and red fox, while no such correlations were observed between the tested elements in the wild boar. In conclusion, the liver concentrations of these heavy metals in selected wild animas species from the hunting areas of Warmia and Mazury, do not exceed standard safe values for consumers. Moreover, the wild red deer population in North-Eastern Poland is significantly Se deficient.

Food transit time, nutrient digestibility and nitrogen retention in farmed and feral American mink (Neovison vison)--a comparative analysis.

The aim of this study was to determine whether farming leads to changes in gastrointestinal function and nitrogen metabolism in farmed mink (FA), as compared with their wild-living counterparts. Three digestibility and balance trials were carried out. Experiment I was performed in May, and experiments II and III were conducted in September 2011. Farmed mink with the standard coat colour were purchased from a production farm in south-eastern Poland. Feral mink were harvested using cages in the hunting grounds of the Polish Hunting Association, Branch in Olsztyn. The experimental materials comprised of the following: trial I - adult males (eight animals per group), trial II - young females (six animals per group), trial III-young animals (five males and five females per group). Food transit time was measured during digestibility trials, on 10 consecutive days. The coefficients of nutrient and energy digestibility and daily nitrogen balance values were compared between groups in each experiment. It was found that farming contributed to changes in gastrointestinal function and nitrogen metabolism in mink. Farmed animals were characterized by a longer bowel transit time, a tendency towards higher nutrient digestibility and higher nitrogen retention, which resulted from selection for higher productivity.

Calcium concrements in the pineal gland of the Arctic fox (Vulpes lagopus) and their relationship to pinealocytes, glial cells and type I and III collagen fibers.

The aim of the present study was to analyze the presence and morphology of the pineal concretions in the Arctic fox and their relationship to pinealocytes, glial cells and collagen fibers. Pineals collected from 7-8 month-old and 3-4 year-old foxes (6 in each age-group) were investigated. Sections of the glands were stained with HE, Mallory's method and alizarin red S as well as subjected to a combined procedure involving immunofluorescent staining with antibodies against antigen S, glial fibril acid protein (GFAP), type I and III collagen and histochemical staining with alizarin red S. The pineal concretions were found in 2 of 6 investigated Arctic foxes aged 3 years and they were not observed in animals aged 7-8 months. The acervuli were present in the parenchyma and the connective tissue septa. They were more numerous in the distal part than in the proximal part of the gland. The acervuli stained with alizarin red S revealed an intensive red fluorescence, what enabled the use of this compound in a combined histochemical-immunofluorescent procedure. A majority of cells in the fox pineal showed positive staining with antibodies against antigen S, a marker of pinealocytes. GFAP-positive cells were especially numerous in the proximal part of the gland. Both antigen S- and GFAP-positive cells were frequently observed close to the concrements. Collagen fibers of type I and III were found in the capsule, connective tissue septa and vessels. Immunoreactive fibers did not form any capsules or basket-like structures surrounding the concrements.

Nutrient digestibility in Arctic fox (Vulpes lagopus) fed diets containing animal meals / Digestibilidade dos nutrientes em raposa polar (Vulpes lagopus) alimentada com dietas que continham farinhas de origem animal

Three digestibility experiments on Arctic foxes were carried out. Control groups were fed standard diets (C1 and C2) composed of fresh or frozen animal by-products and steamed ground grain. Dry experimental diets (E1 and E2) contained animal meals, extracted meals and fat, were mixed with water prior to administration. In a preliminary experiment, the digestibility of dry diet E1 moistened with water for 15min and 24h was compared to determine the optimum moistening time during the experimental period proper. The preliminary experiment showed that moistening time had no significant effect on digestibility. In the main experiment, two independent digestibility trials were performed to compare the digestibility of diets fed to foxes during growth (C1 vs. E1) and fur development (C2 vs. E2). Better nutrient digestibility was noted for control diets, compared to experimental. The greatest differences were reported for total protein digestibility. Protein contained in meals undergoes denaturation during heat treatment, which reduces digestibility. It was found that the retention of nitrogen in relation to nitrogen digestion was higher in foxes fed experimental diets (E1 and E2).

Realizaram-se três ensaios de digestibilidade em raposas polares. Os grupos controles receberam dietas-padrão (C1 e C2) compostas por subprodutos de origem animal frescos ou congelados e sementes de cereais em grão. As dietas secas (E1, E2) usadas nos ensaios que continham farinha de origem animal e sementes em grãos extrudadas eram hidratadas antes de administradas. Em ensaio preliminar, avaliou-se a digestibilidade da dieta seca E1, submetida a 15 minutos e a 24 horas de hidratação. Verificou-se que o tempo de hidratação não influenciou a digestão. No experimento principal, foram realizados dois ensaios para comparar a digestibilidade das dietas fornecidas às raposas no período de crescimento (C1 vs E1) e no desenvolvimento de pelo (C2 vs E2). Melhor digestibilidade dos nutrientes foi observada para as dietas controle. As maiores diferenças foram relatadas para a proteína total. A desnaturação das proteínas, durante o tratamento térmico, reduz o índice de digestibilidade das dietas. Observou-se alto teor de retenção de hidrogênio em relação ao hidrogênio digerido nas raposas alimentadas com as dietas E1 e E2.