The effects of age, size, and cage complexity on the behaviour of farmed female chinchillas (Chinchilla lanigera).

Even though chinchillas have been farmed for a century, there are not many studies concerning their behaviour in captivity or their optimal housing conditions, both of which are important factors in the assessment of their welfare. This study aimed to evaluate the effect of different cage types on chinchillas' behaviour and their reactions towards humans. Female chinchillas (n = 12) were kept in three types of cages: standard with a wire floor (S); standard with a deep litter floor of shavings (SR); and enlarged with a deep litter floor of shavings (LR). Animals spent 11 weeks in each type of cage. The chinchillas' reactions toward humans were observed via intruder test. Ethograms were prepared based on round-the-clock video recordings. The activity of the chinchillas was compared, taking into account the different cage types and the animals' varying responses to the hand test. The generalized ordered logistic regression model was used to ascertain whether cage type has an effect on a chinchilla's behaviour towards humans. To compare the time distribution of various activity between chinchillas, the non-parametric Scheirer-Ray-Hare test was used. Animals kept in LR cages presented significantly less timid reactions in comparison to those kept in S and SR cages. The chinchillas spent most of their time resting (68% of the day), in locomotion (23%), and eating or drinking (8%); they spent only 1% on grooming behaviour. Cage enrichment generally reduced the fear of humans. However, the average chinchilla response to the hand test was classified in each type of cage as "cautious". Analyses of the ethograms indicated that the chinchillas were active mostly during the dark stage of the day. In conclusion, the larger cage size and its enrichment (particularly litter) reduced the fearfulness and passivity of the animals, which could be evidence of better welfare conditions.

Development of a brain wave model based on the quantitative analysis of EEG and EEG biofeedback therapy in patients with panic attacks during the COVID-19 pandemic.

The current global crisis facing the world is the COVID-19 pandemic. Infection from the SARS-CoV-2 virus leads to serious health complications and even death. As it turns out, COVID-19 not only physically assails the health of those infected, but also leads to serious mental illness regardless of the presence of the disease. Social isolation, fear, concern for oneself and one's loved ones, all of this occurs when a pandemic overloads people. People exhibit numerous neurological disorders that have never happened to them before. Patients are diagnosed with frequent panic attacks, the result of which can be seen in their Quantitative Electroencephalogram results. This test may be one of the main diagnostic tools of the COVID-19 pandemic. From the results obtained, it is possible to compare and draw conclusions. This method of testing effectively allows EEG biofeedback training and observes its effect on brain activity. The feedback received in this way gives us the opportunity to properly tailor a protocol for the patient and their conditions. Numerous studies support the effectiveness of EEG biofeedback for panic attacks and other psychiatric disorders. The purpose of our study was to show the effectiveness of EEG biofeedback with a Quantitative Electroencephalogram of the brainwave pattern after having COVID-19 and what symptoms may result.

Effects of embryonic cadmium exposure on erythrocyte indices and morphology in newly hatched Gallus gallus domesticus chicks.

The aim of the current study was to assess the influence of embryonic exposure to cadmium on basic and derived erythrocyte indices, the morphology and morphometric properties of erythrocytes, as well as erythrocyte spectrin distribution in newly hatched Gallus gallus domesticus chicks. The eggs were injected with cadmium (Cd) at a dose of 2 µg, 4 µg, 6 µg, or 8 µg per egg on the sixth day of incubation. Blood samples were collected on the first day after hatching. Exposure to cadmium resulted in higher levels of red blood cell count, hemoglobin concentration, and hematocrit value, while derived erythrocyte indices were lower (mean corpuscular volume) or higher (mean corpuscular hemoglobin concentration) in comparison to the control. These changes occurred in animals exposed to higher doses of this toxic agent. In cadmium-treated individuals (2 and 8 µg of Cd), the percentage of erythrocytes which exhibited changed shape increased. Increases in the length (6 and 8 µg) and width (2, 6, and 8 µg) of erythrocytes and the length and width of the nucleus (2-8 µg) of red blood cells were observed. Changes in spectrin distribution were also observed, which indicate alterations at structural and molecular levels.

Chemical properties of the coffee grounds and poultry eggshells mixture in terms of soil improver.

Spent coffee grounds (SCG) as well as chicken (CES) or duck eggshells (DES) left over from the artificial hatching technology are proposed as potential soil improver and/or organic-mineral fertiliser components. Therefore, it seems interesting and necessary to evaluate the chemical composition of these wastes and their mixtures in terms of their possible use for that purpose. The study was conducted under the incubation experiment conditions using a mixture of SCG and eggshells (10:1 ratio). Macronutrients, i.e. C, N, S, were determined by the catalytic combustion method, while P, K, Mg, Ca, Na by atomic spectrometry. It was found that SCG were rich in C, N, P, and K, while eggshells in Ca, Mg, Na, and S. However, CES compared to DES were richer in deacidifying components (i.e. Ca, Mg, K). At the same time, the content of macronutrients in eggshells decreased gradually along with the embryo development. For this reason, the mixture of SCG and shells of unembryonated chicken eggs (CES I) had the best chemical and usable proprieties. To conclude, the chemical properties of the mixtures of spent coffee grounds and eggshells indicate their possible application in soil bioengineering.

The Effect of α-Tocopherol on the Reduction of Inflammatory Processes and the Negative Effect of Acrylamide.

Our research aimed to show acrylamide's influence on inflammatory processes, the oxidative stress it causes in the cholinergic system, and the possibility of reducing inflammation via supplementation with α-tocopherol. For this purpose, an in ovo model was used where the embryos were exposed to acrylamide, α-tocopherol and a cocktail of these substances. After 48 h of exposure, we collected brain samples and performed biochemical assays to examine the effect of the chosen substances on oxidative stress (malondialdehyde-MDA and reduced glutathione-GSH) and acetylcholinesterase activity (AChE). The results showed that acrylamide decreased AChE activity in the examined brain samples by about 25% in comparison to the control group, and this effect was decreased by administering α-tocopherol. The concentration of malondialdehyde significantly increased in the group given acrylamide, while, in the group with α-tocopherol, the observed concentration was lower in comparison to the control group. Moreover, a decrease in glutathione concentration was observed after the administration of acrylamide; however, the protective effect of α-tocopherol was only slightly visible in this case. In conclusion, α-tocopherol minimizes the harmful effects of acrylamide on AchE, and it can minimize the concentration of MDA.

Effect of Staphylococcus aureus infection on the heat stress protein 70 (HSP70) level in chicken embryo tissues.

Staphylococcus aureus bacteria are components of physiological biocenosis of skin or mucous membranes in some animals' genera but also they are dangerous opportunistic pathogens responsible for infections of various localization, course or manifestations. Proteins produced by these bacteria destroy tissues, leukocytes and cause haemolysis of erythrocytes. Host organisms respond by defence mechanisms. Production of heat stress proteins (HSPs) is one of defence responses of infected host organism. To evaluate infection and host defence mechanisms some animal models of experimental infection are reported. Use of chick embryo model allows demonstrating adequate differences in staphylococcal virulence depending on the strain genotype. The aim of the study was to examine the changes in heat shock protein HSP70 levels in chick embryo tissues after infection caused by S. aureus strains no. tu2, pa3, ch5, ch10, ch24, and ch25 isolated from chickens. The bacteria were injected directly into fluid of amnion cavity and incubated for 10 days. The mortality of particular chick embryos was reported and the tissues for further analysis were taken every day from day 13 to day 19. The levels of heat stress protein HSP70 were determined by dot-blot method. Results showed that the strains no. ch5, ch24, and ch25 were the most virulent. HSP70 levels increased in all groups of injected embryos at the same time the hatching process was started. The presented study showed that the infected chick embryos were characterized by higher HSP level from 12.3% up to 19.7% compared to the control group. The morphological analysis showed numerous erythrocytes with damaged cell membranes and morphological changes of erythrocytes. Changes in the level of HSP70 protein can be a useful indicator of infection caused by S. aureus bacteria. Additionally, chicken embryo is a helpful research model in studies of pathogenesis of diseases caused by bacteria.

Effects of embryonic exposure to chromium (VI) on blood parameters and liver microstructure of 1-day-old chickens.

Hexavalent chromium (Cr(VI)) has carcinogenic, nephrotoxic, hepatotoxic, and neurotoxic effects. Exposure to Cr(VI) can also lead to hematological alterations and blood biochemical changes. The literature on Cr(VI) toxicity concerns mostly adult forms of vertebrates. In this study, an attempt was made to determine the effect on the developing chicken embryo of Cr(VI) in ovo administration. It was observed that chromium affected the hatchability of chicks in a dose-dependent manner. At a dose from 25 to 250 µg per egg, Cr(VI) resulted in a statistically significant reduction of hatchability. Chromium administrated at lower doses (1.56 and 2.5 µg per egg) caused a statistically insignificant increase of hatchability. However, chromium at a level of LD50 (15.6 µg per egg) or 1/10 LD50 (1.56 per egg) did not cause major changes in hematological parameters or plasma biochemical indices in newly hatched chicks. The same doses did not lead to any histopathological changes in the liver.

The effect of methionine and folic acid administered in ovo on the hematological parameters of chickens (Gallus gallus domesticus).

Methionine (Met), an essential amino acid in poultry diets, when overdosed may cause hyperhomocysteinemia, which is mainly a trigger for cardiovascular diseases in humans. Homocysteine is neutralized (remethylated) in the presence of folic acid (FA), which also plays an important role in hematopoiesis and participates in the synthesis of DNA, and its deficiencies may result in the development of neural tube defects. One of the basic tools in studying the impact of both xenobiotics and nutrients on the animal organism is hematological analysis. Thus, the aim of this study was to determine the effect of in ovo supplementation with Met and FA on the hematological parameters of broiler chickens. On the 17th day of incubation, embryonated eggs (Ross 308) were injected with 5 or 25 mg of Met per egg (M5 and M25), 3 and 15 mg of FA per egg (F3 and F15), or a mixture of these 2 compounds (M5/F3 and M25/F15). The broilers were reared in accordance with welfare regulations and fed with commercial diets ad libitum. Blood samples were collected on the first, seventh, and 35th day of rearing (D1, D7, and D35), and complete hematological analysis was performed. The observed changes in red blood cell parameters probably result from physiological changes occurring during bird growth. Mean erythrocyte volume decreased with the age of chickens in the control, M5, and M25 groups, but not in those supplied with FA. Among supplemented groups, the number of white blood cells on D1 was lower only in group M5 than in the sham (C) group. The analysis of leukograms showed no significant differences between the groups. Comparing D1 with D7 in the group injected with a higher dose of Met and FA (MF25/15), a statistically significant increase in the percentage of lymphocytes and a significant decrease in the percentage of heterophils were observed. In addition, in the group injected with a higher FA dose (F15), there was statistically significant reduction in the percentage of eosinophils and a significant increase in the percentage of monocytes at day 7 compared with day 1. It seems that Met supplementation led to temporary immunosuppression in the animals.

Preliminary evaluation of application of a 3-dimensional network structure of siloxanes Dergall preparation on chick embryo development and microbiological status of eggshells.

The spatial network structure of Dergall is based on substances nontoxic to humans and the environment which, when applied on solid surfaces, creates a coating that reduces bacterial cell adhesion. The bacteriostatic properties of siloxanes are based on a purely physical action mechanism which excludes development of drug-resistant microorganisms. The aims of the present study were to 1) evaluate a Dergall layer formed on the eggshell surface regarding the potential harmful effects on the chick embryo; 2) evaluate antimicrobial activity and estimate the prolongation time of Dergall's potential antimicrobial activity. Dergall at a concentration of 0.6% formed a layer on the eggshell surface. In vitro testing of the potential harmful effects of Dergall by means of a hen embryo test of the chorioallantoic membrane showed no irritation reaction at a concentration of 3% and lower. The hatchability of the groups sprayed with a Dergall water solution with a concentration of 0 to 5% was 89.1 to 93.8% for fertilized eggs (P > 0.05) but decreased to 63.7% (P < 0.05) in the group sprayed with a 6% concentration of the solution. This phenomenon was caused by embryo mortality in the first week of incubation. At the concentration of 0.6%, Dergall exhibited strong antibacterial properties against bacteria such as Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, Shigella flexneri, and Salmonella typhimurium. For Streptococcus pyogenes, the highest antibacterial activity of Dergall was reported in the concentrations of 100 and 50%. For Pseudomonas aeruginosa, no antibacterial activity of Dergall was generally observed, but in vivo testing showed a strong decrease of all gram-negative bacteria growth. Moreover, a prolonged antimicrobial effect lasting until 3 D after disinfection was observed, which makes Dergall a safe and efficient disinfectant.

Infrared Thermography as an Indicator of Heat Loss in Fur-Chewing Chinchillas (Chinchilla Lanigera).

Fur-chewing is a common problem in chinchilla (Chinchilla lanigera). It may affect the welfare of animals due to heat loss, thereby possibly impacting food and water intake to maintain body temperature. In this context, infrared thermography seems to be a suitable method of measuring heat emissions from the surface of objects. Sexually mature male domestic chinchillas were divided into two groups: "non-fur chewers", exhibiting normal behaviour (n = 25), and "fur chewers" displaying fur-chewing behaviour (n = 23). Food and water intake (mean ± SD) measured in the control animals amounted to 20.7 ± 4.52 g and 15.9 ± 3.45 mL, while in fur-chewing chinchillas were 25% and 33% higher, respectively. Metabolic energy intake, were calculated 2.2 and 2.8 W for the control and fur-chewing animals, respectively. Heat flux through chewed areas was 6.06 mW cm-2, which is 2.8 times higher than through undamaged chinchilla fur. To sum up, thermal imagingexplicitly shows that fur-chewing causes increased heat loss. Disturbances in the maintenance of thermal homeostasis may be an additional factor that reduces the welfare of these animals.

The phenomenon of the monovular twinning in the endangered zatorska goose.

The phenomenon of multiple embryos in birds and other oviparous vertebrates is very rare and thus poorly studied. Some populations of wild birds or lines of poultry, including the zatorska goose, may be particularly predisposed to developing monovular twin embryos (MTE). The aim of the study was to investigate the frequency of single yolk twin embryos in the zatorska goose and to establish whether these embryos are generated as a result of polyembryony or other developmental anomalies.Embryopathological analysis, which included identification of the developmental stages of all MTEs at the time of death, was carried out on 1,955 unhatched eggs obtained from 20 pedigree breeding flocks of the zatorska goose. Post-mortem examinations revealed as many as 13 MTEs (0.66% compared to embryonated eggs) at varying developmental stages.The results of genotyping of the microsatellite loci of 7 pairs of twins demonstrated genetic similarity in 6 of them; this suggests that they developed from 1 blastoderm, while differences in 2 loci of 1 pair show that the MTE originates from 2 blastodiscs. Pedigree analysis of the MTEs does not provide evidence that predisposition toward twinning results from the genetic background. However, more frequent MTE occurrence could be seen in eggs stored for more than 8 d. It seems that embryos of the zatorska goose are more susceptible to duplication under special conditions, such as prolonged egg storage.

Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains.

Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR) and non-virulent (NVIR) phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains. Staphopain C (StpC) was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC, and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model.

Immunolocalization of Leptin Receptor and mRNA Expression of Leptin and Estrogen Receptors as well as Caspases in the Chorioallantoic Membrane (CAM) of the Chicken Embryo.

The chicken chorioallantoic membrane (CAM) is used as a model in tests of angiogenesis, the biocompatibility of materials as well as tumor invasive potential. To assess the properties of CAM tissue, the localization of leptin receptor in the CAM, and the mRNA expression of two leptin receptor isoforms, estrogen receptors (ERα and ERß) and caspases (-1 and -3) in the CAM on embryonic days 12 (E12), 15 (E15) and 18 (E18) were investigated. The leptin receptor was immunolocalized in each structure of the CAM (chorionic epithelium, allantoic epithelium, mesodermal layer and the walls of blood vessels) and did not change among analyzed stages of embryonic development (E12, E15 and E18) and between sexes. Expression of mRNA of genes encoding leptin and estrogen receptors as well as caspases was detected in the CAM of female and male chicken embryos at all three analysed stages of development. The relative mRNA expression of the long form of leptin receptor exceeded that of its short isoform. The mRNA expression of ERß was significantly higher than ERα as well as caspase-3 in comparison with caspase-1. There were no differences in mRNA expression of these genes between sexes and among analyzed developmental days. The results indicate that the CAM is a target tissue for leptin as well as for estrogens and that CAM development is partially regulated by caspase-1 and caspase-3 dependent cell death. These results should be taken into consideration in studies in which the CAM is used as an experimental model.

The virulence of Staphylococcus aureus correlates with strain genotype in a chicken embryo model but not a nematode model.

Staphylococcus aureus infections are of major importance in human and veterinary medicine. Studies of the virulence of this bacterium are complicated by inconsistent results obtained in different animal models. We searched for an uncomplicated and inexpensive model suitable to study virulence of poultry strains of S. aureus using a genome-wide approach. We determined that a useful model would clearly differentiate strains of high and low virulence, and that this would generally correlate with the genetic relatedness among strains. To this end Gallus gallus (chicken) embryo and Caenorhabditis elegans (nematode) models were selected, and their response to challenge by a set of well-characterized Staphylococcus strains was evaluated. The chicken embryo model allowed to determine variation in virulence among strains of poultry and human origin. The survival of embryos ranged from 0% to almost 100% for the various strains. In contrast, variation in virulence of most strains in the nematode model was comparable, regardless of their origin or genotype, demonstrating limited usefulness of this model. Most importantly, a clear correlation was found between the virulence level in the embryo model and the genotype of the tested poultry strains. Our findings indicate the potential usefulness of embryo model for future identification of host-specific adaptations and virulence factors in S. aureus.

Protective effect of zinc on cadmium embryotoxicity and antioxidant status of blood plasma in newly hatched chicks.

Among the multiple mechanisms of cadmium toxicity proposed, the most common is the disruption of the cellular antioxidant system, which may be limited by pre- or co-treatment with zinc. The aim of this study was to determine if simultaneous zinc supplementation of hen's egg could reduce embryotoxic effect of cadmium. Egg albumen was injected on day 4 of incubation with cadmium alone (50 nmol per egg) or in combination with zinc (100 and 500 nmol). Hatching results and antioxidant activity in plasma of newly hatched chicks were determined by photochemiluminescence (PCL) and FRAP methods. Administration of cadmium markedly reduced hatchabilty (30.2 %), while both zinc doses used were embryotoxic (43.2 and 48.9 %) as compared to the control group (61.9 %). This adverse effect was reduced by simultaneous zinc administration (completely at 10-fold higher molar concentration). This observation was confirmed by examination of the antioxidant capacity in plasma of Cd-treated chicks. A slight decrease in the hydrophilic and lipophilic antioxidant capacity induced by cadmium was compensated by a co-treatment with higher zinc dose administration, whereas the exposure of hen embryos to zinc caused an increase in antioxidant potential in the plasma of chicks. It is concluded that Zn supply in conditions of exposure to Cd can protect against Cd-induced oxidative stress in chicken embryos.

Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on steroid concentrations in blood and gonads of chicken embryo.

The aim of the present study was to examine the effect of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) injected at the early stage of incubation on hormonal activity of the chicken ovary and testis during the second half of embryogenesis measured by steroid concentrations in blood plasma and gonads. The effect of TCDD on hatchability was also evaluated. In the first experiment TCDD was administrated to chicken eggs on day 7 of embryogenesis (E7) at doses of 0 (control), 2.5, 5 and 10ng/egg dissolved in 50µl of peanut oil. Blood plasma for estradiol (E2) and testosterone (T) determination was collected from embryos at E14, E18, E20 and at hatching (D1). In the second experiment TCDD at doses of 0 (control), 2.5, 5 and 10ng/egg dissolved in 50µl of DMSO was injected on E6. Blood plasma and gonads were collected on the day of hatching for progesterone (P4), T and E2 concentrations measured by means of the RIA method. It was found that TCDD injection: (1) increased the level of T and decreased the level of E2 in the plasma of female chicken embryos during the second half of embryogenesis, while on the other hand in male embryos the effect of TCDD was opposite, (2) increased T and E2 concentrations in plasma of newly hatched female chickens with a concomitant decrease of these hormones in the ovary; P4 in the ovary was elevated by TCDD, (3) decreased P4 and T in plasma and testes, whereas increased E2 concentration in the plasma of newly hatched male embryos (E2 concentration in the testes was below the sensitivity of the applied RIA method), and (4) decreased hatchability at all examined doses. The results obtained clearly demonstrate that exposure to TCDD at an early stage of embryogenesis affects steroid production and secretion by chicken gonads. The effect of TCDD depends on (1) the applied dose, (2) the day of embryogenesis, and (3) the sex. It is suggested that dioxins are potent modulators of the process of steroidogenesis in the chicken gonads. Moreover, the data obtained indicate that dioxins exert an effect on embryo development and the hatching process.