Monitoring of antibiotic use in broiler turkey flocks in the Warmia and Mazury province in 2019-2021.

Introduction: The increasing resistance of bacteria to antibiotics has obliged the EU Member States to reduce by 50% the use of antibiotics in animal production by 2030. This study was undertaken with the aim to analyse the use of antibiotics in flocks of broiler turkeys reared in the Warmia and Mazury province in a two-year period. Material and Methods: From data from 238 production records of turkey flocks provided by the County Veterinary Inspectorates, the use of antibiotics (mg/kg) was analysed in turkey flocks reared in 2019-2021. The data provided the year of rearing, turkey sex and immunoprophylactic measures. Results: A significant decrease in antimicrobial use was reported in the male turkey flocks in 2021 (157 mg/kg body weight) in comparison to 2020 (241 mg) and 2019 (299 mg). In both male and female turkeys, the use of antimicrobials gradually decreased from 2019 to 2021. Significantly lower antibiotic use was reported in turkey flocks using autogenous vaccines. Conclusion: The positive trend shown in this study proves the possibility of meeting the EU recommendations for 50% reduction in the use of antibiotics in animal production by 2030. More emphasis should be placed on minimising the risk of infectious diseases requiring antibiotic therapy with welfare, biosecurity, immunomodulation and specific prophylaxis measures.

Muscle Tissue Quality of Raw and Sous-Vide Cooked Wild and Farmed Pikeperch.

The aim of the study was to compare the chemical and fatty acid composition, colour, and sensory quality of wild and farmed pikeperch. Raw wild pikeperch had a higher moisture and ash contents, as well as pH value, but lower fat and protein contents than farmed pikeperch. In sous-vide fillets, a higher fat and a lower protein content were noted in farmed fish. Slight differences in colour attributes between farmed and wild fish affected neither chroma nor hue in raw and sous-vide fillets. Wild and farmed fish fillets prepared using sous-vide were scored similarly in the sensory assessment. Although wild fish had a more beneficial fatty acid composition demonstrated by a higher proportion of polyunsaturated fatty acids, including eicosapentaenoic and docosahexaenoic, a higher fat concentration in farmed pikeperch resulted in obtaining similar or even higher concentration of these fatty acids in sous-vide fillets. Regardless of the origin of pikeperch it might be recommended as a valuable part of a daily diet.

Molecular Changes in Chronic Myeloid Leukemia During Tyrosine Kinase Inhibitors Treatment. Focus on Immunological Pathways.

Introduction: The aim of our research was to investigate changes in the molecular background of the immune response in the chronic phase (CP) of chronic myeloid leukaemia (CML) during treatment with tyrosine kinase inhibitors (TKIs). Methods: Global gene and miRNA expression profiles were assessed using genome-wide RNA and miRNA microarray technology in bone marrow mononuclear cells. Fifty-one patients were recruited, and bone marrow samples were taken at diagnosis before treatment with TKIs and after 3, 6, and 12 months of treatment with TKIs. The largest number of upregulated genes was observed when the 0-month group (time of diagnosis) was compared to the 3-month group; 1774 genes were significantly upregulated, and 390 genes were significantly downregulated. Discussion: Upregulated biological processes according to gene ontology (GO) classification involved basic cellular processes such as cell division, cell cycle, cell-cell adhesion, protein transport, mitotic nuclear division, apoptosis, and DNA replication. Differentially expressed miRNAs were annotated using GO classification to several immunity-related processes, including the T cell receptor signalling pathway, T cell costimulation, immune response, and inflammatory response. TKI therapy exerts a significant impact on cellular cycle processes and T-cell activation, which was proven at the molecular level.

IgA-Based Secretory Response in Tears of COVID-19 Patients: A Potential Biomarker of Pro-Inflammatory State in Course of SARS-CoV-2 Infection.

Mucosal immunity, including secretory IgA (sIgA), plays an important role in the early defence against SARS-CoV-2 infection. However, a comprehensive evaluation of the local immune response in tears in relation to blood antibody reservoirs has not yet been conducted. A total of 179 symptomatic laboratory-confirmed COVID-19 patients were included in this single-centre study. Conjunctival swabs were analysed by a reverse transcription polymerase chain reaction for the detection of SARS-CoV-2 RNA. In parallel, tear samples collected by Schirmer test strips and plasma samples were analysed by ELISA to detect anti-S1 IgA levels. The concentrations of selected inflammatory cytokines in tears were determined by a magnetic bead assay. Anti-SARS-CoV-2 sIgA was present in the tears of 81 (45.25%) confirmed COVID-19 patients, and the tear IgA levels were correlated with the plasma IgA levels (Rs = +0.29, p = 0.0003). SARS-CoV-2 RNA in the conjunctival sac was identified in 18 COVID-19 patients (10%). Positive correlations between the tear IgA level and the concentrations of several cytokines TNF-α (Rs = +0.23, p = 0.002), IL-1ß (Rs = +0.25, p < 0.001), IL-2 (Rs = +0.20, p = 0.007), IL-4 (Rs = +0.16, p = 0.04), IL-5 (Rs = +0.36, p < 0.001), IL-6 (Rs = +0.32, p < 0.001), IL-8 (Rs = +0.31, p < 0.001), VEGF (Rs = +0.25, p < 0.001) and GM-CSF (Rs = +0.27, p < 0.001) were also found. Quantitative tear film-based sIgA could potentially serve as a rapid and easily accessible biomarker of external mucosal immunity to SARS-CoV-2. The concentration of sIgA is directly related to individual host immune responses to SARS-CoV-2 infection.

Dietary Protected Butyrate Supplementation of Broilers Modulates Intestinal Tight Junction Proteins and Stimulates Endogenous Production of Short Chain Fatty Acids in the Caecum.

Short chain fatty acid (SCFA) butyrate has various beneficial effects on the gut microbiota as well as on the overall health status and metabolism of the host organism. The modulatory role of butyrate on gut barrier integrity reflected by tight junction protein expression has been already described in mammalian species. However, there is limited information available regarding chickens. Therefore, the main aim of this study was to monitor the effects of protected butyrate on claudin barrier protein and monocarboxylate transporter 1 abundance in different gastrointestinal segments of chickens as well as the growth performance of broiler chickens. The effect of protected butyrate on the caecal microbiota was monitored by quantifying the concentrations of total eubacteria and key enzymes of butyrate production. Furthermore, intestinal SCFA concentrations were also measured. Based on the data obtained, protected butyrate increased the overall performance as well as the barrier integrity of various gut segments. Protected butyrate also positively affected the SCFA concentration and composition. These findings provide valuable insight into the complex effects of protected butyrate on broiler gut health, highlighting the beneficial effects in improving intestinal barrier integrity and performance parameters.

In Silico Identification of lncRNAs Regulating Sperm Motility in the Turkey (Meleagris gallopavo L.).

Long non-coding RNAs (lncRNAs) are transcripts not translated into proteins with a length of more than 200 bp. LncRNAs are considered an important factor in the regulation of countless biological processes, mainly through the regulation of gene expression and interactions with proteins. However, the detailed mechanism of interaction as well as functions of lncRNAs are still unclear and therefore constitute a serious research challenge. In this study, for the first time, potential mechanisms of lncRNA regulation of processes related to sperm motility in turkey were investigated and described. Customized bioinformatics analysis was used to detect and identify lncRNAs, and their correlations with differentially expressed genes and proteins were also investigated. Results revealed the expression of 863 new/unknown lncRNAs in ductus deferens, testes and epididymis of turkeys. Moreover, potential relationships of the lncRNAs with the coding mRNAs and their products were identified in turkey reproductive tissues. The results obtained from the OMICS study may be useful in describing and characterizing the way that lncRNAs regulate genes and proteins as well as signaling pathways related to sperm motility.

Yucca schidigera Improves Performance and Lowers Oocyst Counts in Eimeria Challenged Broilers.

Coccidiosis is one of the main challenges for the worldwide poultry industry, and several anticoccidial treatments have been used to fight these protozoa. Resistance of Eimeria parasites against anticoccidials-and the public opinion about these treatments-demands for alternatives. In this trial, we tested Yucca schidigera (500 g/T) as a natural alternative in broilers challenged with Eimeria. This treatment was compared to three other treatments: An unchallenged control, a challenged control, and a challenged anticoccidial (625 g/T) treatment with focus on performance, oocyst per gram counts (OPG), and lesion scores. Both the anticoccidial and the Yucca schidigera group showed significant improvement in body weight (2.150 and 2.058 vs. 1.998 and 1.971 kg). growth (60.2 and 57.6 vs. 55.8 and 55.1 g/d). and feed-conversion ratio (1.456 and 1.510 vs. 1.527 and 1.575), compared to both control groups. No significant differences were found between the treatments on OPG collection days 18 and 25. On day 35, lowest OPG counts were found in the unchallenged group (93), followed by the Yucca schidigera group (114), the anticoccidial group (243), and the challenged group (650). Adding Yucca schidigera abolished the effect of the challenge resulting in comparable (FCR) or better (ADG) performance results compared to the unchallenged birds. Yucca schidigera consistently showed lower numbers for OPG counts compared to the anticoccidial and challenged group. Therefore, Yucca schidigera can be considered as an effective alternative for anticoccidial treatment in broilers.

Predictors of COVID-19 severity among pregnant patients.

Coronavirus disease 2019 (COVID-19) was declared a pandemic and has spread around the globe, unsparingly affecting vulnerable populations. Effective prevention measures for pregnant women, who are particularly affected, include early identification of those patients at risk of developing in-hospital complications, and the continuous improvement of maternal-fetal treatment strategies to ensure the efficient use of health resources. The objective of our retrospective study was to determine which patient biomarkers on hospital admission correlate with disease severity as measured by disease course classification, the need for oxygen supplementation and higher demand for oxygen, the need for mechanical ventilation, intensive care unit admission, and length of hospital stay. Analysis of 52 PCR SARS-CoV-2 positive pregnant women revealed that the median date of hospital admission was the 30th gestational week, with dyspnoea, cough, and fever as the leading symptoms. The presence of diabetes and hypertension predisposed pregnant women to the severe course of illness. Lung involvement shown by CT scans on admission correlated with the greater clinical severity. The main laboratory predictors of disease progression were lymphocytopenia, hypocalcemia, low total cholesterol, low total protein levels, and high serum levels of C-reactive protein, ferritin, interleukin-6, glucose, lactate dehydrogenase, procalcitonin, and troponin I. Further research with a larger cohort of pregnant women is needed to determine the utility of these results for everyday practice.

Evaluating Ocular Symptoms and Tear Film Cytokine Profiles in Symptomatic COVID-19 Patients.

Background: This study investigated the presence and duration of ophthalmic symptoms in the early phase of COVID-19 to assess the corresponding local immune response on the ocular surface. Methods: The study included data from 180 COVID-19 patients and 160 age-matched healthy controls. The main finding was the occurrence of ophthalmological manifestations at the time of admission to the hospital and during the preceding 7 days. Tear film concentrations of TNF-α, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, GM-CSF, and IFN-γ were determined by a magnetic bead assay. Results: Among the COVID-19 patients, 12.64% had at least one ocular symptom at the time of admission, and 24.14% had symptoms within the preceding 7 days (p < 0.001 vs. controls). We found that the COVID-19 patients complained more frequently about eye tearing (p = 0.04) and eye pain (p = 0.01) than controls. A multivariate analysis of the patients and controls adjusted for age and sex revealed that COVID-19 was an independent factor associated with higher VEGF and IL-10 tear film concentrations (ß = +0.13, p = 0.047 and ß = +0.34, p < 0.001, respectively) and lower IL-1ß, IL-8, and GM-CSF levels (ß = −0.25, p < 0.001; ß = −0.18, p = 0.004; and ß = −0.82, p = 0.0 respectively). Conclusions: SARS-CoV-2 does not attract a strong local response of the conjunctival immune system; therefore, ophthalmic symptoms may not constitute a substantial element in the clinical picture of novel COVID-19 infection.

Increased proinflammatory cytokines in tears correspond with conjunctival SARS-CoV-2 positivity in symptomatic COVID-19 patients.

Tear fluid cytokine levels may serve as biomarkers of innate immune system response against SARS-CoV-2 infection. Therefore, our aim was to analyze panel of selected inflammatory cytokines in tears of COVID-19 patients in relation to presence of SARS-CoV-2 viral load in conjunctival secretions. In this study concentrations of TNF-α, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, GM-CSF, and IFN-γ were determined by a magnetic bead assay in tear film collected from 232 symptomatic COVID-19 patients. SARS-CoV-2 ocular infection was confirmed based on positive conjunctival swab-based RT-PCR testing. Viral RNA in conjunctival sac was detected in 21 patients (9%). No relation between presence and the duration of ophthalmic symptoms and SARS-CoV-2 infection detected in conjunctival secretions was found. The tear film concentrations of IFN-γ, TNF-α, IL-5, IL-8 and GM-CSF were found to be significantly greater among patients with positive conjunctival swab results as compared to the group negative for SARS-CoV-2 in conjunctival sac. Our current data depict a group of inflammatory mediators in human tears, which may play a significant role in ocular pathology of SARS-CoV-2 conjunctival infection.

Influence of Zinc and Manganese Nanoparticles on Selected Parameters of Turkey Spermatozoa Stored in a Liquid State at 4 °C.

The aim of this study was to determine the effect of semen extender supplementation with 25 or 50 µM of zinc nanoparticles (ZnNPs) or manganese nanoparticles (MnNPs) on turkey spermatozoa preserved in a liquid state. Twenty turkey ejaculates were obtained from twenty healthy males. The collected semen was preserved at 4 °C for 48 h with or without NPs. Selected qualitative and quantitative parameters of sperm (motility, plasma membrane activity, mitochondrial membrane potential (MMP) and the percentage of sperm demonstrating NO and SOD activity) were examined after 2, 24 and 48 h of storage. Sperm motility and MMP decreased in semen preserved with ZnNPs at each time point of the analysis. However, all spermatozoa remained viable throughout storage. In contrast, membrane integrity and mitochondria activity (p ≤ 0.05) increased, and the highest SOD activity (p ≤ 0.05) was observed in semen preserved with MnNPs. The addition of MnNPs to the semen extender could potentially improve the parameters of turkey semen during prolonged storage.

Transcriptome and Proteome Analysis Revealed Key Pathways Regulating Final Stage of Oocyte Maturation of the Turkey (Meleagris gallopavo).

In birds, the zona pellucida (ZP) matrix that surrounds the ovulated oocyte-called the inner perivitelline layer-is involved in sperm-zona interaction and successful fertilization. To identify the important genes and proteins connected with the final step of egg development, next-generation sequencing and two-dimensional electrophoresis, combined with mass spectrometry, were used for the analysis of mature oocytes at the F1 developmental stage. A total of 8161 genes and 228 proteins were annotated. Six subfamilies of genes, with codes ZP, ZP1-4, ZPD, and ZPAX, were identified, with the dominant expression of ZPD. The main expression site for ZP1 was the liver; however, granulosa cells may also participate in local ZP1 secretion. A ubiquitination system was identified in mature oocytes, where ZP1 was found to be the main ubiquitinated protein. Analysis of transcripts classified in estrogen receptor (ESR) signaling indicated the presence of ESR1 and ESR2, as well as a set of estrogen-dependent genes involved in both genomic and nongenomic mechanisms for the regulation of gene expression by estrogen. Oxidative phosphorylation was found to be a possible source of adenosine triphosphate, and the nuclear factor erythroid 2-related factor 2 signaling pathway could be involved in the response against oxidative stress. Oocyte-granulosa cell communication by tight, adherens, and gap junctions seems to be essential for the final step of oocyte maturation.

The problem of Lyme borreliosis infections in urban and rural residents in Poland, based on National Health Fund data.

INTRODUCTION AND OBJECTIVE: Some fragmentary studies show that the incidence of Lyme borreliosis in Poland is increasing. It has been generally accepted that the most affected are forestry workers and farmers. The aim of the study is to compare the incidence of borreliosis in urban and rural residents in 2008-2016. MATERIAL AND METHODS: Databases on Lyme borreliosis from the National Health Fund and Central Statistical Office in Poland were analyzed. For each patient, ambulatory or discharged from every hospital, the diagnosis was compulsorily reported as encoded following the International Classification of Diseases. RESULTS: A steadily increasing number of patients with borreliosis in Poland was found, which doubled in 2008 - 2016. The incidence was similar in urban and rural residents. In all the provinces in Poland, an increase in incidence of borreliosis was observed, although there were big differences between them. The highest frequency of borreliosis was in Podlasie and Warmia-Masuria provinces. The lowest incidence of borreliosis was noticed in Wielkopolska province. In the most provinces the increase in the incidence of borreliosis was steady, except Warmia-Masuria, where it was very low in 2008, and soaring since 2011. The number of cases per year between 2008 - 2016 increased in both in males and females. CONCLUSIONS: The results suggest the need for higher awareness of the risk of Lyme borreliosis in urban residents, because the incidence of Lyme borreliosis is growing independently of the place of residence. Prompt measures to prevent tick bites and appropriate education are urgently needed.

Characterization and biological role of cysteine-rich venom protein belonging to CRISPs from turkey seminal plasma†.

Turkey semen contains cysteine-rich secretory proteins (CRISPs) that belong to the dominant seminal plasma proteins. We aimed to isolate and characterize CRISP from turkey seminal plasma and evaluate its possible involvement in yellow semen syndrome (YSS). YSS, which is well characterized, causes reduced fertility and hatchability. The protein was purified using hydrophobic interaction, gel filtration, and reverse phase chromatography. It then was subjected to identification by mass spectrometry, analysis of physicochemical properties, and specific antibody production. The biological function of the isolated protein was tested and included its effects on sperm motility and migration and sperm-egg interactions. Sperm motility was measured with the CASA system using Hobson Sperm Tracker. The reproductive tract of turkey toms was analyzed for gene expression; immunohistochemistry was used for protein localization in the male reproductive tract, spermatozoa, and inner perivitelline layer. The isolated protein was identified as cysteine-rich venom protein-like isoform X2 (CRVP X2; XP_010706464.1) and contained feature motifs of CRISP family proteins. Turkey CRVP X2 was present in both spermatozoa and seminal plasma. The extensive secretion of CRVP X2 by the epithelial cells of the epididymis and ductus deferens suggests its involvement in post-testicular sperm maturation. The internally localized CRVP X2 in the proximal part of the sperm tail might be responsible for stimulation of sperm motility. CRVP X2 on the sperm head might be involved in several events prior to fusion and may also participate in gamete fusion itself. Although the mechanisms by which CRVP X2 mediates fertilization are still unknown, the involvement of complementary sites cannot be excluded. The disturbance of CRVP X2 expression can serve as an etiologic factor of YSS in the turkey. This study expands the understanding of the detailed mechanism of fertilization in birds by clarifying the specific role of CRVP X2.

Estimated intestinal absorption of phosphorus and its deposition in chosen tissues, bones and feathers of chickens receiving chromium picolinate or chromium nanoparticles in diet.

The aim of the study was to determine whether the level and form of Cr in the diet of chickens influences its accumulation in tissues as well as intestinal absorption of P and its deposition in tissues. The experiment was carried out on 405 one-day-old male Ross 308 chickens that were randomly divided into five treatment groups. Control group was fed the diet without supplemental chromium; experimental groups were fed the diet with 3 or 6 mg/kg chromium picolinate (Cr-Pic) and with 3 or 6 mg/kg chromium nanoparticles (Cr-NP). Chromium was found to accumulate in the tissues of the ileum, liver, breast muscle, bones skin and in feathers of chickens. Chromium deposited in the ileum of chickens does not affect the ex vivo estimated intestinal absorption of P. The use of Cr in the diet of chickens carries the risk of lowering P levels in femur.

Transcriptome analysis of turkey (Meleagris gallopavo) reproductive tract revealed key pathways regulating spermatogenesis and post-testicular sperm maturation.

The application of transcriptomics to the study of the reproductive tract in male turkeys can significantly increase our current knowledge regarding the specifics of bird reproduction. To characterize the complex transcriptomic changes that occur in the testis, epididymis, and ductus deferens, deep sequencing of male turkey RNA samples (n = 6) was performed, using Illumina RNA-Seq. The obtained sequence reads were mapped to the turkey genome, and relative expression values were calculated to analyze differentially expressed genes (DEGs). Statistical analysis revealed 1,682; 2,150; and 340 DEGs in testis/epididymis, testis/ductus deferens, and epididymis/ductus deferens comparisons, respectively. The expression of selected genes was validated using quantitative real-time reverse transcriptase-polymerase chain reaction. Bioinformatics analysis revealed several potential candidate genes involved in spermatogenesis, spermiogenesis and flagellum formation in the testis, and in post-testicular sperm maturation in the epididymis and ductus deferens. In the testis, genes were linked with the mitotic proliferation of spermatogonia and the meiotic division of spermatocytes. Histone ubiquitination and protamine phosphorylation were shown to be regulatory mechanisms for nuclear condensation during spermiogenesis. The characterization of testicular transcripts allowed a better understanding of acrosome formation and development and flagellum formation, including axoneme structures and functions. Spermatozoa motility during post-testicular maturation was linked to the development of flagellar actin filaments and biochemical processes, including Ca2+ influx and protein phosphorylation/dephosphorylation. Spermatozoa quality appeared to be controlled by apoptosis and antioxidant systems in the epididymis and ductus deferens. Finally, genes associated with reproductive system development and morphogenesis were identified. To the best of our knowledge, this is the first genome-wide functional investigation of genes associated with tissue-specific processes in turkey reproductive tract. A catalog of genes worthy of further studies to understand the avian reproductive physiology and regulation was provided.

Antioxidant Status and Liver Function of Young Turkeys Receiving a Diet with Full-Fat Insect Meal from Hermetia illucens.

We hypothesized that full-fat insect meal from Hermetia illucens (HI) larvae can be an acceptable source of protein and energy in the diet of young turkeys, in an amount adapted to the nutritional needs of these birds, and at the same time can improve their antioxidant status and metabolism. The turkeys were fed a control diet (HI0) without the insect meal, and three diets with increasing HI content of 5%, 10% and 15% (treatments HI5, HI10 and HI15, respectively). The use of 10% or 15% HI in the diet of young turkeys, while beneficially raising levels of P, Fe and Hb, has a negative effect on lipid metabolism, increasing TC levels, lipid oxidation, and fat deposition in the liver. The inclusion of 5% HI in the diet of young turkeys has no adverse effect on the lipid status and histology of the liver, but it does not improve antioxidant status. To conclude, the level of HI meal in the diet of turkeys should not exceed 5%. However, as similar studies on turkeys have not yet been published, overly general conclusions should not be drawn from the results of the present study, and further research is necessary.

Transformation of a large multi-speciality hospital into a dedicated COVID-19 centre during the coronavirus pandemic.

INTRODUCTION: The article describes the process of converting a large multi-specialized hospital into one dedicated to COVID-19 patients, and present established standards of work organization in all the wards and training system of the medical and supporting staff. The several weeks pandemic of the COVID-19 disease has forced the healthcare systems of numerous countries to adjust their resources to the care of the growing number of COVID-19 patients. Managers were presented with the challenge of protecting the healthcare workers from transmission of the disease within medical institutions, and issues concerning the physical and psychological depletion of personnel. MATERIAL AND METHODS: Based on analyses of the structure and work processes in Central Clinical Hospital (CCH) reconstructive strategic plan was developed. It included: division of existing wards into observation and isolation wards; installing locks; weekly plan for supplying personal protection equipment (PPE); designating new access to the hospital and communication routes; training of medical and supporting staff. The plan was implemented from the first days of conversion of the hospital. RESULTS: The wards of the CCH were converted for observation and isolation, and each one was fitted with sanitary locks. There was a big improvement in the supply of PPE for the medical staff. Separation of the 'dirty' and 'clean' parts of the CCH were attained, and widespread intensive training not only protected personnel against infections, but also diminished unrest which was discernable at the beginning of conversion. CONCLUSIONS: The transformation efforts will ultimately be appraised at the end of the epidemic, but the data looks encouraging. Two weeks after conversion, the testing of hospital Staff was started and by the end of April, 459 tests were had been conducted, of which only 11 were positive.

Habitat and seasonality shape the structure of tench (Tinca tinca L.) gut microbiome.

Tench (Tinca tinca L.) is one of the most valued species of the Cyprinidae. This species is commercially important and has been intensively domesticated in recent years. To avoid excessive production losses, the health of farm fish must be maintained. Characterization of the tench gut microbiome can help achieve this goal, as the gastrointestinal microbiome plays an important role in host health. As part of this characterization, investigating the influence of the environment and season will help to understand the interrelationship between host and gut microbiota. Therefore, our aim was to use high-throughput 16S rRNA gene amplicon sequencing to profile the gut microbiome of tench. We studied two populations in summer and autumn: wild tench living in a lake and tench living in a pond in a semi-intensive fish farm. We found that, in the gut microbiome of all fish, the most abundant phylum was Proteobacteria, followed by Firmicutes, Bacteroidetes and Actinobacteria. Together, these phyla constituted up to 90% of the microbial communities. The abundance of Candidatus Xiphinematobacter differed significantly between lake and pond fish in summer, but not in autumn. In pond tench, Methylobacterium abundance was significantly lower in summer than in autumn. Mean Shannon, Chao1 indices and observed OTU's indicated that microbial biodiversity was greater in the gut of lake fish than in that of pond fish. Beta-diversity analysis showed significant divergence between groups with both weighted and unweighted UniFrac distance matrices. Principal coordinates analysis revealed that more of the variance in microbial diversity was attributable to environment than to season. Although some of the diversity in lake tench gut microbiota could be attributable to feeding preferences of individual fish, our results suggest that environment is the main factor in determining gut microbiome diversity in tench.

The Effect of Chromium Nanoparticles and Chromium Picolinate in the Diet of Chickens on Levels of Selected Hormones and Tissue Antioxidant Status.

: We have postulated that supplementation with Cr can increase serotonin levels and improve the antioxidant status of chickens, with no adverse effect on the secretion of other hormones. The study aimed to determine what form and dose of Cr more favorably affect the level of selected hormones (insulin, glucagon, serotonin, dopamine, noradrenaline, histamine, T3 and T4) and the antioxidant status (level of malondialdehyde and lipid peroxides, activity of superoxide dismutase and catalase) of chicken tissues. The experiment was carried out on chickens randomly divided into five treatment groups. The basal diets (control group) were supplemented with two levels of Cr (3 and 6 mg/kg) and two Cr sources: Cr-picolinate (Cr-Pic) and Cr-nano (Cr-NP) to obtain four experimental diets: 3 mg/kg Cr-Pic, 6.0 mg/kg Cr-Pic, 3.0 mg/kg Cr-NP. and 6.0 mg/kg Cr-NP. The addition of Cr in both forms increased the level of serotonin at a dose of 3 mg/kg and, at the same time, reduced the level of noradrenaline. The addition of Cr at 3 mg/kg, irrespective of the form used, regulated the level of hormones of carbohydrate metabolism (increasing insulin levels and reducing glucagon levels) and had an adverse effect on the antioxidant status of the liver and breast muscle. Due to the adverse effect of Cr at 3 mg/kg on the antioxidant status of chickens, this level of Cr should not be considered in both forms Cr-Pic and Cr-NP as a feed additive for broiler chickens. In the future, studies on the potential beneficial effects of Cr on the organism should take into account doses lower than 3 mg/kg.