Feasibility of the J-PET to monitor the range of therapeutic proton beams

PURPOSE

The aim of this work is to investigate the feasibility of the Jagiellonian Positron Emission Tomography (J-PET) scanner for intra-treatment proton beam range monitoring.

METHODS

The Monte Carlo simulation studies with GATE and PET image reconstruction with CASToR were performed in order to compare six J-PET scanner geometries. We simulated proton irradiation of a PMMA phantom with a Single Pencil Beam (SPB) and Spread-Out Bragg Peak (SOBP) of various ranges. The sensitivity and precision of each scanner were calculated, and considering the setup's cost-effectiveness, we indicated potentially optimal geometries for the J-PET scanner prototype dedicated to the proton beam range assessment.

RESULTS

The investigations indicate that the double-layer cylindrical and triple-layer double-head configurations are the most promising for clinical application. We found that the scanner sensitivity is of the order of 10-5 coincidences per primary proton, while the precision of the range assessment for both SPB and SOBP irradiation plans was found below 1 mm. Among the scanners with the same number of detector modules, the best results are found for the triple-layer dual-head geometry. The results indicate that the double-layer cylindrical and triple-layer double-head configurations are the most promising for the clinical application, CONCLUSIONS:: We performed simulation studies demonstrating that the feasibility of the J-PET detector for PET-based proton beam therapy range monitoring is possible with reasonable sensitivity and precision enabling its pre-clinical tests in the clinical proton therapy environment. Considering the sensitivity, precision and cost-effectiveness, the double-layer cylindrical and triple-layer dual-head J-PET geometry configurations seem promising for future clinical application.

Discrete symmetries tested at 10-4 precision using linear polarization of photons from positronium annihilations

Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of 10-4 signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation.

Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators

BACKGROUND

Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for constructing a Total-Body PET scanner based on plastic scintillators.

METHODS

For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configurations (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), different cross sections of plastic scintillator, and multiple numbers of plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Siemens' Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1 mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm.

RESULTS

With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance ([Formula: see text] 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body with additional gain on its sides and provides the possibility for high-quality brain imaging.

CONCLUSION

Taking into account not only the sensitivity but also the price of Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.

The Effect of a Bacillus-Based Probiotic on Sow and Piglet Performance in Two Production Cycles

The aim of this study was to assess the impact of Bacillus-based probiotic diets on reproduction performance, fecal scores, microflora, and economic factors in lactating sows and suckling piglets across two productive cycles. A total of 96 sows, reared in a continuous farrowing system for two full cycles, were divided into two groups: a control group and an experimental group. Sows were fed a basal diet without the probiotic or a diet supplemented with viable bacterial spores. At seven days of age, control group piglets were offered standard creep feed, whereas piglets in the experimental (probiotic) group received a diet containing the probiotic fed to their dams. Sows receiving probiotic-supplemented diets were characterized by significantly higher (p ≤ 0.05) average daily feed intake in lactation, lower (p ≤ 0.01) body weight (BW) loss during lactation, and reduced loss of backfat thickness as well as higher body condition score after lactation. Dietary probiotic supplementation increased (p ≤ 0.01) birth weight, total creep feed consumption, litter weight gain, and piglet weaning weight. The probiotic also improved (p ≤ 0.01) overall fecal scores, decreased total E. coli count on day seven and Clostridium perfringens count (trend) in sucking piglets. The total feed cost per weaned piglet was lower in the experimental (probiotic) group. Supplementing the diet with a probiotic containing Bacillus strains improved the reproductive performance of sows and the performance and health of piglets.

Transformation of PET raw data into images for event classification using convolutional neural networks

In positron emission tomography (PET) studies, convolutional neural networks (CNNs) may be applied directly to the reconstructed distribution of radioactive tracers injected into the patient's body, as a pattern recognition tool. Nonetheless, unprocessed PET coincidence data exist in tabular format. This paper develops the transformation of tabular data into n-dimensional matrices, as a preparation stage for classification based on CNNs. This method explicitly introduces a nonlinear transformation at the feature engineering stage and then uses principal component analysis to create the images. We apply the proposed methodology to the classification of simulated PET coincidence events originating from NEMA IEC and anthropomorphic XCAT phantom. Comparative studies of neural network architectures, including multilayer perceptron and convolutional networks, were conducted. The developed method increased the initial number of features from 6 to 209 and gave the best precision results (79.8) for all tested neural network architectures; it also showed the smallest decrease when changing the test data to another phantom.

Detection of range shifts in proton beam therapy using the J-PET scanner: a patient simulation study

OBJECTIVE

The Jagiellonian PET (J-PET) technology, based on plastic scintillators, has been proposed as a cost effective tool for detecting range deviations during proton therapy. This study investigates the feasibility of using J-PET for range monitoring by means of a detailed Monte Carlo simulation study of 95 patients who underwent proton therapy at the Cyclotron Centre Bronowice (CCB) in Krakow, Poland. 
Approach: Discrepancies between prescribed and delivered treatments were artificially introduced in the simulations by means of shifts in patient positioning and in the Hounsfield unit to the relative proton stopping power calibration curve. A dual-layer, cylindrical J-PET geometry was simulated in an in-room monitoring scenario and a triple-layer, dual-head geometry in an in-beam protocol. The distribution of range shifts in reconstructed PET activity was visualised in the beam's eye view. Linear prediction models were constructed from all patients in the cohort, using the mean shift in reconstructed PET activity as a predictor of the mean proton range deviation. 
Main results: Maps of deviations in the range of reconstructed PET distributions showed agreement with those of deviations in dose range in most patients. The linear prediction model showed a good fit, with coefficient of determination r^2 = 0.84 (in-room) and 0.75 (in-beam). Residual standard error was below 1 mm: 0.33 mm (in-room) and 0.23 mm (in-beam). 
Significance: The precision of the proposed prediction models shows the sensitivity of the proposed J-PET scanners to shifts in proton range for a wide range of clinical treatment plans. Furthermore, it motivates the use of such models as a tool for predicting proton range deviations and opens up new prospects for investigations into the use of intra-treatment PET images for predicting clinical metrics that aid in the assessment of the quality of delivered treatment.&#xD.

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.

Combination of emulsifier and xylanase in triticale-based broiler chickens diets

The current study aimed to investigate the effect of supplementing an emulsifier, xylanase or a combination of both on the growth performance, digestibility of nutrients, microflora activity and intestinal morphology in broiler chickens fed triticale-based diets. A total of 480 one-day-old male Ross 308 broiler chicks were randomly assigned to four dietary treatments: control (CON), control with an added emulsifier (EMU), control with added xylanase (ENZ) and control with emulsifier and xylanase (EMU+ENZ). Xylanase supplemented groups had diminished feed intake (FI) and enhanced body weight gain (BWG) only within the starter period (p ≤ 0.05), while the feed conversion ratio (FCR) in the ENZ and ENZ+EMU groups was lower than CON during the whole experiment period. There was significant ENZ and EMU interaction in apparent metabolisable energy corrected to N equilibrium (AME_N) as well as NDF and DM retention. The viscosity of ileum digesta was the lowest in groups with enzyme addition. Interactions show that caecal galactosidase-α activity was higher in the CON group compared to EMU supplementation, but similar to ENZ and EMU+ENZ (p < 0.05). Activity of glucosidase-α was higher in the CON group related to inclusion of EMU or ENZ alone (p < 0.05) but did not differ from the combined supplementation of EMU+ENZ, whereas the glucosidase-β activity was higher in the CON group compared to all supplemented diets (p < 0.05). Caecal C2 concentration was greater in the CON group than supplemented diets (p < 0.05). The expression of FATP1, PEPT1 and SGLT1 in the ileum was downregulated after emulsifier addition (p ≤ 0.05). The addition of emulsifier and xylanase indicates a mutual effect on broiler chickens' performance and nutrient digestibility in triticale diets with palm oil during the first nutritional period. Additionally, concomitantly additives usage influenced intestinal microbiome activity, as well.

Nano-Sized Selenium Maintains Performance and Improves Health Status and Antioxidant Potential While Not Compromising Ultrastructure of Breast Muscle and Liver in Chickens

The poultry industry is looking for the most effective sources of selenium (Se) for commercial use. Over the past five years, nano-Se has attracted a great deal of attention in terms of its production, characterisation and possible application in poultry production. The objective of this study was to evaluate the effects of dietary levels of inorganic and organic Se, selenised yeast and nano forms of selenium on breast meat quality, liver and blood markers of antioxidants, the ultrastructure of tissue and the health status of chickens. A total of 300 one-day-old chicks Ross 308 were divided into 4 experimental groups, in 5 replications, with 15 birds per replication. Birds were fed the following treatments: a standard commercial diet containing inorganic Se in the form of inorganic Se at the level of 0.3 mg/kg diet and an experimental diet with an increased level of Se (0.5 mg/kg diet). The use of other forms of Se (nano-Se) versus sodium selenate significantly influences (p ≤ 0.05) a higher collagen content and does not impair physico-chemical properties in the breast muscle or the growth performance of the chickens. In addition, the use of other forms of selenium at an increased dose versus sodium selenate affected (p ≤ 0.01) the elongation of sarcomeres in the pectoral muscle while reducing (p ≤ 0.01) mitochondrial damage in hepatocytes and improving (p ≤ 0.05) oxidative indices. The use of nano-Se at a dose of 0.5 mg/kg feed has high bioavailability and low toxicity without negatively affecting the growth performance and while improving breast muscle quality parameters and the health status of the chickens.

Efficiency determination of J-PET: first plastic scintillators-based PET scanner

BACKGROUND

The Jagiellonian Positron Emission Tomograph is the 3-layer prototype of the first scanner based on plastic scintillators, consisting of 192 half-metre-long strips with readouts at both ends. Compared to crystal-based detectors, plastic scintillators are several times cheaper and could be considered as a more economical alternative to crystal scintillators in future PETs. JPET is also a first multi-photon PET prototype. For the development of multi-photon detection, with photon characterized by the continuous energy spectrum, it is important to estimate the efficiency of J-PET as a function of energy deposition. The aim of this work is to determine the registration efficiency of the J-PET tomograph as a function of energy deposition by incident photons and the intrinsic efficiency of the J-PET scanner in detecting photons of different incident energies. In this study, 3-hit events are investigated, where 2-hits are caused by 511 keV photons emitted in [Formula: see text] annihilations, while the third hit is caused by one of the scattered photons. The scattered photon is used to accurately measure the scattering angle and thus the energy deposition. Two hits by a primary and a scattered photon are sufficient to calculate the scattering angle of a photon, while the third hit ensures the precise labeling of the 511 keV photons.

RESULTS

By comparing experimental and simulated energy distribution spectra, the registration efficiency of the J-PET scanner was determined in the energy deposition range of 70-270 keV, where it varies between 20 and 100[Formula: see text]. In addition, the intrinsic efficiency of the J-PET was also determined as a function of the energy of the incident photons.

CONCLUSION

A method for determining registration efficiency as a function of energy deposition and intrinsic efficiency as a function of incident photon energy of the J-PET scanner was demonstrated. This study is crucial for evaluating the performance of the scanner based on plastic scintillators and its applications as a standard and multi-photon PET systems. The method may be also used in the calibration of Compton-cameras developed for the ion-beam therapy monitoring and simultaneous multi-radionuclide imaging in nuclear medicine.

Cannabidiol affects breast meat volatile compounds in chickens subjected to different infection models

No study has demonstrated the use of dietary Cannabis-derived cannabidiol (CBD) to alter the stress response in chickens or examined its effects on meat volatile compounds (VOCs). Here, we subjected chickens to dysbiosis via C. perfringens infection or Escherichia coli lipopolysaccharide (LPS) treatment and investigated the potential link between meat VOCs and cecal bacterial activity and the ameliorative effect of CBD. The cecal bacterial production of short-chain fatty acids (SCFAs) was closely correlated with meat VOCs. CBD supplementation reduced the formation of breast meat spoilage VOCs, including alcohols, trimethylamine and pentanoic acid, in the challenged birds, partly by decreasing cecal putrefactive SCFA production. Meat VOC/cecal SCFA relationships differed according to the challenge, and CBD attenuated the effects of C. perfringens infection better than the effects of LPS challenge on meat VOCs. These findings provide new insights into the interactions among bioactive agent supplementation, gut microbiota activity and meat properties in birds.

Effect of emulsifier and multicarbohydrase enzyme supplementation on performance and nutrient digestibility in broiler diets containing rapeseed meal

The aim of this study was to determine the effect of emulsifier and multicarbohydrase enzyme supplementation on performance, nutrient utilization, and apparent metabolizable energy-nitrogen (AME_N) value of broiler diets containing rapeseed meal (RSM) as well as their influence on the gut morphological structures, excretion of total and free sialic acid, and cecum concentration of short-chain fatty acids (SCFAs) in broiler chickens. A total of 384 male broiler chicks were assigned to four dietary treatments. The diet of the control treatment (CON) consisted of soybean, maize, and RSM (5% in starter, 7% in grower, 15% in finisher) with soybean and palm oils. The diets used for the experimental treatments were the control diet supplemented with an emulsifier (EMU), enzyme (ENZ), or both (EMU + ENZ). The duodenum (n = 10/treatment) and ileum (n = 10/treatment) digesta samples were assessed to determine nutrient digestibility: crude protein (CP), ether extract (EE), starch, Ca. Throughout the experimental period, EMU + ENZ treatment indicated the lowest total average feed intake and feed conversion ratio, with the highest average weight gain among the studied treatments (P < 0.05). The EMU + ENZ treatment also resulted in higher (P < 0.05): apparent prececal digestibility (APD) of CP, total tract neutral detergent fibre (NDF) degradation, apparent total tract digestibility (ATTD) of EE, villus height to crypt depth ratio (P < 0.1). The highest APD of EE was noted in the EMU treatment (P < 0.05). No significant differences were found in the AME_N values of the diets. A greater jejunum villi surface area was found in groups supplemented by enzyme compared to CON (P < 0.05). The EMU + ENZ treatment presented lower sialic acid excretion in the ileum and concentration of cecum SCFAs compared to the CON treatment (P < 0.05). The obtained results indicate that simultaneous usage of additives had beneficial effect on production parameters, nutrient digestibility, NDF degradation, as well as gut mucosa morphology. Based on the SCFAs concentration results, separate or simultaneous addition of emulsifier or/and enzyme did not provoke excessive fermentation activity of cecal bacteria.

ProTheRaMon - a GATE simulation framework for proton therapy range monitoring using PET imaging

OBJECTIVE

This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland.

APPROACH

The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user's needs and specific settings of a given proton therapy facility and PET scanner design.

MAIN RESULTS

ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized.

SIGNIFICANCE

We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github.

The Sarcoplasmic Protein Profile of Breast Muscle in Turkeys in Response to Different Dietary Ratios of Limiting Amino Acids and Clostridium perfringens-Induced Inflammation

In this study, the effects of the Arginine/Lysine (Arg/Lys) ratio in low- and high-methionine (Met) diets on the sarcoplasmic protein profile of breast muscles from turkeys reared under optimal or challenge (Clostridium perfringens infection) conditions were determined. One-day-old Hybrid Converter female turkey poults (216 in total) obtained from a commercial hatchery on hatching day, and on the basis of their average initial body weight were randomly allocated to 12 pens (4 m² each; 2.0 m × 2.0 m) containing litter bedding and were reared over a 42-day experimental period. Diets with high levels of Lys contained approximately 1.80% and 1.65% Lys and were offered in two successive feeding periods (days 1–28 and days 29–42). The supplemental levels of Lys were consistent with the nutritional specifications for birds at their respective ages as established in the Management Guidelines for Raising Commercial Turkeys. The experiment was based on a completely randomized 3 × 2 × 2 factorial design with three levels of Arg (90%, 100% and 110%) relative to the content of dietary Met (30 or 45%) and without (−) or with (+) C. perfringens challenge at 34, 36, or 37 d of age. Meat samples were investigated in terms of pH, color, and sarcoplasmic protein profile. The experimental factors did not influence meat quality but the dietary Arg content affected meat color. The sarcoplasmic protein profile was influenced by all studied factors, and glycolytic enzymes were the most abundant. This study evidenced strong association between the challenge conditions and the involvement of glycolytic enzymes in cell metabolism, particularly in inflammatory processes, and DNA replication and maintenance in turkeys. The results showed an effect of C. perfringens infection and feeding with different doses of Arg and Met may lead to significant consequences in cell metabolism.

Increased arginine, lysine, and methionine levels can improve the performance, gut integrity and immune status of turkeys but the effect is interactive and depends on challenge conditions

Arginine (Arg), lysine (Lys), and methionine (Met) can be used to support the health status of turkeys. The present study investigated selected performance, gut integrity, and immunological parameters in turkeys reared in optimal or challenge conditions. The experiment lasted for 28 days, and it had a completely randomized 2 × 3 factorial design with two levels of dietary Arg, Lys and Met (high or low) and challenge with Clostridium perfringens (C. perfringens), Escherichia coli lipopolysaccharide (LPS) or no challenge (placebo). Increased dietary levels of Arg, Lys and Met had a beneficial effect on turkey performance and immunological parameters, and it improved selected indicators responsible for maintaining gut integrity in different challenge conditions. Under optimal conditions (with no challenge), high ArgLysMet diets did not compromise bird performance and they improved selected performance parameters in challenged birds. The immune system of turkeys was not excessively stimulated by high ArgLysMet diets, which did not disrupt the redox balance and had no negative effect on gut integrity. High ArgLysMet diets increased the expression levels of selected genes encoding nutrient transporters and tight junction proteins. However, the influence exerted by different dietary inclusion levels of Arg, Lys and Met on gut integrity was largely determined by the stressor (C. perfringens vs. LPS). Further studies are required to investigate the role of Arg, Lys and Met levels in the diet on the immune response, gut function and performance of turkeys in different challenge conditions.

Gut microbiota activity in chickens from two genetic lines and with outdoor-preferring, moderate-preferring, and indoor-preferring ranging profiles

Despite the existing research into the gut microbiome of meat chickens, the associations between gut microbiome composition, its activity and chicken outdoor ranging frequency remain unexplored. The aim of this study was to determine the gut microbiota composition, activity and metabolic products in chickens of 2 different lines and 3 ranging profiles. Sixty non-beak trimmed birds, either Sasso or Green-legged Partridge were housed with access to outdoor ranges from wk. 5 to 10 of age. Outdoor ranges were video recorded to obtain frequencies of the birds’ range use. The information about relative abundance of selected bacterial groups in the ceca including Lactobacillus spp., E. coli, Bifidobacterium spp., and Clostridium spp. was obtained with the PCR method. Gut microbiota activity was assessed based on the glycolytic activity of bacterial enzymes including, α-glucosidase, β-glucosidase, α-galactosidase, β-galactosidase, and β-glucuronidase as well as based on the concentration of short-chain fatty acids (SCFA) in the caecal digesta. Statistical analysis was conducted by generalized linear mixed models, applying the breed and ranging profile as fixed effects and pen as a random factor. The lowest relative abundance of Bifidobacterium spp. was found in the cecal content of indoor-preferring Sasso birds (0.01 ± 0.001), as compared to all other birds in the experiment (ranging from 0.03 ± 0.01 to 0.11 ± 0.07; P = 0.0002). The lowest relative abundance of E. coli was identified for all outdoor-preferring birds and indoor- preferring Sasso birds (0.01 ± 0.001; P = 0.0087). Cecal activity of: α-glucosidase, β-glucuronidase and β-galactosidase was higher in Green-legged Partridges, as compared to Sasso (P = 0.013; P = 0.008; P = 0.004). Valeric acid concentrations were higher in moderate Green-legged Partridges than in Sasso of the same ranging profile (2.03 ± 0.16 vs. 1.5 ± 0.17; 0.016). The majority of the current results confirmed an effect of genotype and ranging profile on the various analyzed parameters. In outdoor-preferring birds, the consumption of pasture originating feed sources as a supplement to the indoor accessible cereal-based diet likely caused the positive effects on the birds’ microbial profile.

Immune Parameters in Chickens Treated with Antibiotics and Probiotics during Early Life

The aim of the study was to compare the effect of the administration of antibiotics or probiotics on chickens in their first week of life, on selected parameters of humoral and cellular immunity, and on the bursa of Fabricius and spleen indices. The experiment was carried out on 90 one-day-old male broilers. The control group received no additive in the drinking water; the group GP received a probiotic providing Enterococcus faecium and Bacillus amyloliquefaciens; and the group GA received 10% enrofloxacin in the drinking water on the first five days of life. Administration of the antibiotic enrofloxacin or a probiotic containing E. faecium and B. amyloliquefaciens strains to chickens in their first week of life exerts pronounced immunomodulatory effects on humoral and cellular defense mechanisms in these birds. The changes in the subpopulations of B and T cells immediately following early administration of enrofloxacin or the probiotic were not observed at the age of 35 days. Early administration of enrofloxacin can pose a risk of suppression of humoral immunity, as indicated by the significant decrease in the total IgY concentration in the plasma of the chickens.

Bacillus-based probiotics affect gut barrier integrity in different ways in chickens subjected to optimal or challenge conditions

Dietary supplementation with spore-forming Bacillus-based probiotics represents an efficient means to improve gut health while maintaining good broiler performance. This study investigated the potential of two probiotic products in chickens subjected to optimal (Experiment 1) and Clostridium perfringens-challenged (Experiment 2) conditions. The treatments in Experiment 1 were as follows: (i) CON (no probiotic additive), (ii) One-strain Pro (supplemented with Bacillus licheniformis) or (iii) Multi-strain Pro (supplemented with a multistrain Bacillus-based probiotic). The treatment groups in Experiment 2 received the same diets as those in Experiment 1 but were subjected to C. perfringens challenge. Both experiments lasted 35 days. Both products marginally affected broiler performance in the optimal or challenge conditions. In Experiment 1, Multi-strain Pro upregulated the mRNA expression level of 11 out of 15 selected genes, whereas in Experiment 2, this was less evident, and One-strain Pro was more effective. The multistrain probiotic was effective in maintaining gut morphostructure indices and increasing gut wall thickness, which was particularly evident in challenged birds. Neither additive induced bacterial activity (assessed by measuring enzymatic activity and short-chain fatty acid production) in the cecum, and Multi-strain Pro maintained the cecal butyrate concentration in challenged birds as in the challenged CON treatment, in which butyrate concentration was significantly higher than in the One-strain Pro treatment. Our findings indicated that the activity of these single- and multistrain probiotic products varies depending on rearing conditions, and the effect is highly strain- and product-specific. However, the multistrain probiotic apparently had more beneficial effects than the one-strain probiotic in the maintenance of gut functional status under optimal and challenge conditions.

Selenium and the health status, production results, and product quality in poultry

A Selenium (Se) is an element belonging to the nonmetallic group. It was first discovered in 1817 by J.J. Berzelius. Until the 1950s, it was considered to be toxic to animals. However, with increasing research conducted on laboratory animals, it is now clear that Se is necessary for the proper functioning of both plants and animals. Recent studies indicate that Se is necessary for the proper functioning of metabolic pathways in animals. It was evidenced that Se is a component of about 100 proteins involved in the immune system, antioxidant homeostasis, or release of an inflammatory mediator. Therefore, it is of key interest to find the appropriate dosage for the supplementation of Se in the diet of farm animals and thereby eliminate physiological disorders in the body associated with Se imbalance. In this study, we present a literature review on the importance and appropriate dosage of Se in the diet of poultry concerning their health status, production results, and the quality of animal-origin products.

The effect of different dietary ratios of lysine, arginine and methionine on protein nitration and oxidation reactions in turkey tissues and DNA

An assumption was made in the study that the optimal inclusion levels and ratios of lysine (Lys), arginine (Arg) and methionine (Met) in diets with Lys content consistent with National Research Council (NRC) recommendations (1994) contribute to stimulate the antioxidant defense system and prevent disorders resulting from the oxidation and nitration of biologically important molecules. The experiment was carried out on 864 one-day-old Hybrid Converter turkeys divided into six experimental groups (8 replicates per group and 18 birds per replicate) receiving different levels of Arg and Met. Chickens from group Arg₉₀Met₃₀ received 90% Arg and 30% Met relative to Lys; Arg₉₀Met₄₅ - 90% Arg and 45% Met relative to Lys; Arg₁₀₀Met₃₀ - 100% Arg and 30% Met relative to Lys; Arg₁₀₀Met₄₅ - 100% Arg and 45% Met relative to Lys; Arg₁₁₀Met₃₀ - 110% Arg and 30% Met relative to Lys and Arg₁₁₀Met₄₅ - 110% Arg level and 45% Met level relative to the content of dietary Lys. In comparison with turkeys fed diets with moderate Arg content (100% of Lys content), a decrease in dietary Arg level (90% of Lys content) led to a decrease in plasma 3-nitrotyrosine (3-NT) concentration (163.6 vs. 141.0), whereas an increase in dietary Arg level (110% of Lys content) led to an increase in plasma 3-NT concentration (163.6 vs. 202.6). In comparison with turkeys fed diets with moderate Arg content (100% of Lys content), the lowest dietary Arg level (90% of Lys content) decreased superoxide dismutase (SOD) activity in the intestinal wall (19.68 vs. 17.41) and in the liver (11.51 vs. 7.94), increased SOD activity in the blood (507.6 vs. 961.4) and in breast muscles (6.26 vs. 7.43) and increased the concentration of malondiadehyde in breast muscles (1.10 vs. 1.50). An increase in dietary Met content from 30 to 45% of Lys content caused a decrease in plasma protein carbonyl concentration (4.33 vs. 3.8) and catalase activity in breast muscles (54.70 vs. 49.66), and an increase in SOD activity in the liver (8.90 vs. 10.41). The highest dietary Arg level (110% of Lys content) did not induce the oxidation of lipids, proteins or DNA, but it increased the risk of protein nitration. The lowest dietary Arg level (90% of Lys content) deteriorated the antioxidant status of turkeys. Regardless of dietary Arg levels, an increase in Met content from 30 to 45% of Lys content stimulated the antioxidant defense system of turkeys.

Oxidative and Epigenetic Changes and Gut Permeability Response in Early-Treated Chickens with Antibiotic or Probiotic

The aim of this study was to compare the effect of the use of enrofloxacin and a probiotic containing Enterococcus faecium and Bacillus amyloliquefaciens strains in the first week of life of chickens on oxidative and epigenetic changes in molecules and intestinal integrity. The three treatments were as follows: the control group received no additive in the drinking water (GC); the second group (GP) received a probiotic preparation in the drinking water during the first five days of life, providing E. faecium strain 4a1713 at 1.0 × 107 CFU/L water and B. amyloliquefaciens 4b1822 at 1.0 × 107 CFU/L water, the third group (GA) received an antibiotic (enrofloxacin 0.5 mL/L water) in the drinking water during the first five days of life. The use of both enrofloxacin and a probiotic containing E. faecium and B. amyloliquefaciens strains in chickens' first week of life improved intestinal integrity and reduced inflammation and oxidative and epigenetic changes in the small intestine. This effect was evident both at 6 days of age and at the end of the rearing period.

Emulsifier and Xylanase Can Modulate the Gut Microbiota Activity of Broiler Chickens

Simple Summary

Modern broiler nutrition, due to widely accepted goals of sustainable production, is concerned with the improvement of nutrient utilization. To achieve this, in our study, we used feed additives that improve the value of feed components. Due to the significant amounts of non-starch polysaccharides (which are not digested under broiler intestinal tract conditions and negatively affect broilers performance) in popular feed components like wheat, enzymes are needed. Furthermore, the use of emulsifiers to improve fat digestion is necessary, as young birds do not secrete sufficient enzyme and bile salts. Previous studies have shown that an additional increase in carbohydrate digestibility can be obtained by using an emulsifier containing xylanase in the feed. Presumably, the increase in carbohydrate digestibility occurred after adding the emulsifier. In our study, we aimed to investigate the effect of xylanase, emulsifier, and a combination of both in wheat diets with high level of tallow on the gastrointestinal tract microbiota activity of 480 one-day-old male ROSS 308 broiler chickens. The simultaneous usage of both additives in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Abstract

In this study, we aimed to investigate the effect of xylanase (XYL), emulsifier (EMU), and a combination of both (XYL + EMU) in wheat diet with a high level of tallow on gastrointestinal tract microbiota activity, excretion of sialic acids, and selected gut segments morphology of 480 one-day-old male ROSS 308 broiler chickens. The activities of bacterial enzymes in the ileal digesta were lower in experimental groups compared to the control (CON) group. Enzyme activity in the cecum was significantly higher than in the ileum. The additives did not affect the excretion of sialic acid. The number of duodenum goblet cells on the villi decreased in all of the experimental groups (p < 0.05). The simultaneous use of XYL + EMU deepened the ileum crypts (p < 0.05). The total short-chain fatty acid (SCFA) concentration in the cecal digesta was higher in experimental groups. The abundance of Bifidobacterium, Lactobacillus, and Escherichia coli did not change among experimental groups. The relative abundance of Clostridium was significantly (p < 0.05) lower in groups with emulsifier addition. In conclusion, the simultaneous usage of EMU and XYL in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Cannabis-derived cannabidiol and nanoselenium improve gut barrier function and affect bacterial enzyme activity in chickens subjected to C. perfringens challenge

Revealing the multifocal mechanisms affecting cross-talk between Clostridium perfringens pathogenesis and the host response is an urgent need in the poultry industry. Herein, the activity of Cannabis sativa-derived cannabidiol (CBD) and selenium nanoparticles (Nano-Se) in modulating the host response to Clostridium perfringens challenge was investigated in broiler chickens subjected to a mild infection model. The infected chickens exhibited no clinical manifestations, confirming the potential hazard of pathogen transmission to the food chain in the commercial sector. However, both CBD and Nano-Se affected the responses of chickens to C. perfringens challenge. The beneficial actions of both agents were manifested in the upregulated expression of genes determining gut barrier function. Both CBD and Nano-Se promoted shifts in gut bacterial enzyme activity to increased energy uptake in challenged chickens and upregulated potential collagenase activity. There was no opposite effect of CBD and Nano-Se in mediating the host response to challenge, whereas an additive effect was evidenced on the upregulation of gene determining gut integrity. Collectively, these findings indicate that understanding the action mechanisms of CBD and Nano-Se is of great interest for developing a preventive strategy for C. perfringens infection in broilers.

Effects of faba bean extrusion and phytase supplementation on performance, phosphorus and nitrogen retention, and gut microbiota activity in broilers

BACKGROUND

Faba bean (FB) can be used in poultry diets as a protein source alternative to soybean meal. This study evaluated the effect of extrusion of low-tannin FB and phytase supplementation on performance, phosphorus (P) and nitrogen (N) retention, and gut microbiota activity in broiler chickens. Raw or extruded FB meal was included in broiler diet at 300 g kg^-1 . The experimental treatments additionally differed in nutrient level (adequate, or calcium, P, and protein reduced) and phytase supplementation.

RESULTS

Broiler performance was not affected by the dietary treatments. Extrusion and a reduced nutrient content did not affect P and N retention coefficients, but they increased when the reduced diets were supplemented with phytase. In the ileal digesta, FB extrusion increased the activities of bacterial α- and β-glucosidase, β-galactosidase, and β-glucuronidase, but acetate and total short-chain fatty acids (SCFAs) concentrations were higher only in birds fed extruded FB supplemented with phytase. In the cecal digesta, FB extrusion increased the activities of bacterial α- and β-glucosidase, α-galactosidase and β-glucuronidase, and phytase supplementation decreased β-glucosidase and β-glucuronidase activities, but acetate, butyrate and valerate and total SCFA concentrations were lower in birds fed extruded FB.

CONCLUSION

Good performance of broilers could be obtained using diets containing 300 g kg^-1 raw FB. The extrusion process does not improve FB nutritive value and may negatively affect the activity of cecal microbiota. Phytase supplementation allows lowering calcium, inorganic P, and protein level in diets with FB, and reduces P and N excreted in droppings, with a positive effect on the environment. © 2020 Society of Chemical Industry.

The effect of different dietary ratios of lysine, arginine and methionine on biochemical parameters and hormone secretion in turkeys

We postulated that the use of optimal levels and proportions of Lys, Arg and Met in compound feed allows for optimal exploitation of the growth potential of contemporary slaughter turkey hybrids and reduces metabolic disorders. The aim of the study was to determine the effect of different proportions of Lys, Arg and Met in diets whose Lys content is in accordance with NRC recommendations, that is a low level, on selected parameters of protein, lipid and carbohydrate metabolism and on hormone secretion in turkeys. The lowest Arg content (90% Lys) in the diet resulted in an increase in plasma total cholesterol levels in the turkeys as compared to higher Arg content (100% or 110% of Lys), (2.50 vs. 2.09 vs. 1.83). Plasma HDL and creatinine concentration increased in turkeys fed diets with higher Arg content (100% and 110% Lys) compared to turkeys receiving the diet with the lowest Arg content (90% Lys). Compared to turkeys receiving the lowest and intermediate Arg content (90% and 100% Lys), the diet with the highest content of this AA (110% Lys) resulted in an increase in the plasma T4 level (71.21 vs. 86.60 vs. 128.2). The varied Arg and Met levels relative to Lys did not affect the secretion of neurotransmitters or hormones regulating glucose metabolism. At low levels of Met in the diet, an decrease in Arg relative to Lys from 100% to 90% caused a growth depression of turkeys (10.68 vs. 10.21 kg), which was not noted in the case of the higher Met content. When using the Lys level recommended by NRC in the turkey diet, the optimal Arg level is 100% and Met is 45% compared to Lys.

Dietary Phytogenic Combination with Hops and a Mixture of a Free Butyrate Acidifier and Gluconic Acid Maintaining the Health Status of the Gut and Performance in Chickens

Additives with bioactive properties can improve chickens' gut health. This study investigated the physiological status of the gut, including its morphological structure and microbiome activities in chickens fed diets supplemented with phytogenic ingredients with hops (Anta^®Phyt) or a mixture of a free butyrate acidifier and gluconic acid (PreAcid). In this study, 1155 broilers were distributed to three dietary treatments with 5 replicate pens per treatment, 77 birds each. Anta^®Phyt was added at 400/300/200/200 mg/kg diet whereas PreAcid was added at 3/2/1/1 g/kg starter/grower I/grower II/finisher diet respectively. Dietary treatments did not compromise body weight in different growth periods. In the birds fed PreAcid-supplemented diet, higher gut concentration of butyric acid was observed, particularly in the early stage of growth, while the profile of the short-chain fatty acids was maintained among the treatments. Neither additive significantly affected cecal bacterial enzyme activities. Feeding the birds with Anta^®Phyt and PreAcid had beneficial effects on gut morphostructure indices, including intestinal wall thickness, crypt depth and the villus height to crypt depth ratio, in 35- and 42-day old birds. In conclusion, the feeding Anta^®Phyt- or PreAcid-supplemented diet exerted beneficial effects on the indices determining the physiological status of the gut and maintained good performance of birds of different ages.

Effects of different levels of arginine and methionine in a high-lysine diet on the immune status, performance, and carcass traits of turkeys

We postulated that the use of appropriate levels and proportions of arginine (Arg) and methionine (Met) in compound feed with high lysine content (Lys) would make it possible to fully exploit the growth potential of modern fattening turkey crossbreds, without compromising their immune system. The aim of this study was to determine the effect of different ratios of Arg and Met in diets with high Lys content on the performance and immune status of turkeys. The turkeys were assigned to 6 groups with 8 replicates per group and 18 birds per replicate. Six feeding programs, with 3 dietary Arg levels (90, 100, and 110%) and 2 dietary Met levels (30 and 45%) relative to dietary Lys content, were compared. During each of 4 feeding phases (weeks 0–4, 5–8, 9–12, and 13–16), birds were fed ad libitum isocaloric diets containing high level of Lys, approximately 1.83, 1.67, 1.49, and 1.20%, respectively. The dietary treatments had no effect on daily feed intake or body weight at any stage of the study. The protein content of the breast meat was higher in the treatments with the highest Arg level (110%) compared with the lowest Arg level (90%). Similarly, protein content was higher in the treatments with the higher Met level compared with the lower Met level. Higher plasma levels of tumor necrosis factor, interleukin 6 (IL-6), and immunoglobulin Y were found in turkeys fed diets with the lowest Arg content. An increase in Met content resulted in a decrease in plasma content of IL-6. In growing turkeys fed diets high in Lys, an Arg level of 90% relative to Lys can be used without negatively affecting production results and immune system. Regardless of dietary Arg levels, an increase in Met content does not stimulate the immune defense system and shows no effect on growth performance of turkeys in current trial.

The effect of different dietary ratios of lysine and arginine in diets with high or low methionine levels on oxidative and epigenetic DNA damage, the gene expression of tight junction proteins and selected metabolic parameters in Clostridium perfringens-challenged turkeys

Two experiments were performed to investigate the effect of different ratios of arginine (Arg) to lysine (Lys) in diets with low (30% Lys; Experiment 1) and high (45% Lys; Experiment 2) methionine (Met) levels on selected metabolic parameters, oxidative and epigenetic DNA damage, and the mechanisms underlying intestinal barrier integrity in turkeys challenged with Clostridium perfringens. In each experiment, 108 one-day-old Hybrid Converter female turkeys were placed in 6 pens (18 birds per pen) and reared for 42 days. At 34, 36 and 37 days of age, half of the birds were subjected to C. perfringens challenge. A 3 × 2 factorial design with three levels of Arg relative to Lys (90, 100 and 110%; Arg₉₀, Arg₁₀₀ and Arg₁₁₀, respectively) and C. perfringens infection (-, +) was employed. Challenging birds with C. perfringens increased lipid oxidation and the oxidation and methylation of DNA of intestinal mucosa, and down-regulated the activities of DNA-repairing enzymes. Neither the dietary treatment nor the challenge affected the markers of liver function or metabolism. Arg₁₁₀ diets with the high Met level induced DNA oxidation and methylation whereas these processes were downregulated in birds fed Arg₉₀ diets. The results indicate that Arg₉₀ diets with high Met levels have a beneficial influence on the indicators of intestinal barrier integrity in turkeys with necrotic enteritis (NE). Despite the analyzed amino acid ratios interacted with the systems responsible for the maintenance of gut integrity in the host organism, this dietary intervention probably enabled birds to cope with NE.

The potential of acetylsalicylic acid and vitamin E in modulating inflammatory cascades in chickens under lipopolysaccharide-induced inflammation

Distinct enzymes, including cyclooxygenase 1 and 2 (COX-1 and COX-2), lipoxygenase (LOXs), and cytochrome P450 monooxygenase (CYP450), produce different stress mediators and mediate inflammation in birds. Bioactive agents such as acetylsalicylic acid (ASA) and vitamin E (vE) may affect enzyme activities and could be used in poultry production to control the magnitude of acute phase inflammation. Here, we characterized COX, LOX, and CYP450 mRNA expression levels in chicken immune tissues in response to Escherichia coli lipopolysaccharide (LPS) challenge and investigated whether ASA and vE could alter gene expression. Additionally, for the first time in chickens, we evaluated oxygen consumption by platelet mitochondria as a biomarker of mitochondria function in response to ASA- and vE. LPS challenge compromised bird growth rates, but neither dietary ASA nor vE significantly ameliorated this effect; however, gradually increasing dietary vE levels were more effective than basal levels. ASA regulated arachidonic acid metabolism, providing an eicosanoid synthesis substrate, whereas gradually increasing vE levels evoked aspirin resistance during challenge. Gene expression in immune tissues was highly variable, indicating a complex regulatory network controlling inflammatory pathways. However, unlike COX-1, COX-2 and CYP450 exhibited increased mRNA expression in some cases, suggesting an initiation of novel anti-inflammatory and pro-resolving signals during challenge. Measuring oxygen consumption rate, we revealed that neither the ASA nor vE levels applied here exerted toxic effects on platelet mitochondria.

Effects of pea extrusion and enzyme and probiotic supplementation on performance, microbiota activity and biofilm formation in the broiler gastrointestinal tract

1. The effects of supplementation of broiler chicken diets with pea meal, carbohydrase enzymes and a probiotic were investigated for potential performance improvement. 2. Raw or extruded pea meal (cv Model, grown in Poland) was included in a wheat-soybean meal-based diet at 250 g/kg. The diets were unsupplemented (control) or supplemented with either carbohydrase enzymes (200 U/kg xylanase and 10 U/kg β-glucanase in feed) or a probiotic (Bacillus subtilis), or both. The diets were fed to Ross 308 broilers aged 9-28 days. 3. After two additional days, chick gastrointestinal tracts were excised and analysed for the presence of Bacillus subtilis biofilm; and the ileal and caecal digesta were analysed for bacterial enzyme activities and to determine the concentration of short-chain fatty acids (SCFAs). 4. Feeding the pea-based diet supplemented with the probiotic compromised feed utilisation, due to higher feed intake. The addition of enzymes to the raw, but not the extruded, pea containing diet partially ameliorated this effect (pea form × additives; P < 0.002). 5. In the ileal digesta, interactions between the dietary treatments were observed for the activities of all bacterial glycolytic enzymes and for SCFA concentrations. β-glucosidase, α-galactosidase and β-glucuronidase were highest in birds fed the diet containing extruded pea supplemented with the probiotic and enzymes (pea form x additives; P = 0.018 to P < 0.006). In the caecal digesta, interactions were observed for bacterial enzyme activities, but not for total SCFA concentration. Biofilm formation in the caecum indicated that the probiotic strain was metabolically active in the broiler gut. 6. In conclusion, supplementation of diets containing raw or extruded pea meal with enzymes and a Bacillus subtilis spore-based probiotic modulated microbiota activity but had no clear effects on broiler performance. Probiotic administration did not cause excessive fermentation in the ileum and caecum but enhanced Bacillus subtilis spp. biofilm formation in the caecum, which may be indicative of a beneficial effect on gut health.

The interactive effect of dietary n-6: n-3 fatty acid ratio and vitamin E level on tissue lipid peroxidation, DNA damage in intestinal epithelial cells, and gut morphology in chickens of different ages

Feeding chickens diets high in n-3 fatty acids (FA) increases their incorporation into tissue lipids, but leads to oxidative stress in cells. This study investigated the effect of the dietary polyunsaturated FA ratio (PUFA n-6: n-3) and vitamin E (vE) level on DNA damage and morphological changes in the gut epithelium of chickens. One-day-old female broiler chicks (n = 176) were divided into 4 groups fed for 43 d diets with a high (HR) or low (LR) PUFA n-6: n-3 ratio and supplemented with 50 or 300 mg vE kg-1. Performance was calculated for periods of d 1 to 9, d 9 to 16, d 9 to 35, and d 9 to 42, while organs were sampled at d 9, d 17, d 36, and d 43. At d 17 and d 43, DNA damage of epithelial cells in the duodenum and jejunum was measured and duodenal and jejunal morphology was analyzed. HR diets improved FCR for the periods of d 1 to 9, d 9 to 16 and d 9 to 42, whereas the increased vE level improved FCR for the period of d 9 to 16. In the jejunum DNA damage was greater in chickens fed LR than HR diets at d 17 (P < 0.001) and the increased vE level promoted DNA damage in both intestinal segments (P < 0.02) in younger birds. The morphology of the duodenum was marginally affected by the diets, whereas LR diets in the jejunum reduced villus surface area at d 17 (P = 0.022), and mucosa thickness (P = 0.029) and villus height (P = 0.035) at d 43. The results indicated that feeding birds LR diets and vE levels significantly exceeding the recommendation induced DNA damage in epithelial cells, but this effect varied depending on the intestinal segment and the age of birds.

Interactive effects of dietary lipids and vitamin E level on performance, blood eicosanoids, and response to mitogen stimulation in broiler chickens of different ages

The effects of the dietary polyunsaturated fatty acids (PUFA) n-6:n-3 ratio and vitamin E (vE) on the levels of pro-inflammatory eicosanoids, the incorporation of docosahexaenoic acid (DHA) and arachidonic acid (AA) into immune tissues, and changes in leukocyte population after phytohemagglutinin (PHA) challenge were investigated in broiler chickens of different ages. One-day-old female broilers (48 per treatment) were fed 4 different wheat-soybean-corn-based diets containing corn oil with a high PUFA n-6:n-3 ratio (HR) or a mixture of linseed and fish oils with a low PUFA n-6:n-3 ratio (LR). Diets contained either 50 mg vE kg-1 of diet (basal vE) or 300 mg vE kg-1 of diet (increased vE). At d 14 and d 34, 8 chickens per treatment were challenged with PHA, and wing web swelling (WWS) was measured. The blood concentration of leukotriene (LTB4), prostaglandin (PGE2), and thromboxane (TBX2) in 17-day-old and 43-day-old chickens was determined. The pattern of AA and DHA incorporation into bursa, spleen, and brain lipids reflected the level of their precursors in the diet. WWS was the highest in chickens fed a LR diet and in 14-day-old chickens (P < 0.01). Leukocyte proportions varied with dietary PUFA n-6:n-3 ratio and with age. The heterophil:lymphocyte ratio was the highest at 6 h post PHA challenge, and was higher in 34-day-old chickens (P < 0.001). TBX2 and PGE2 concentrations were higher in chickens fed HR diet, whereas TBX2 and LTB4 concentrations were lower at high vE level. Lower PGE2 and LTB4, but higher TBX2 concentrations were measured in younger birds (P < 0.001). The results indicated that LR increased the phagocytic cell proportion in the blood; HR promoted the incorporation of AA into the immune tissues, which increased the levels of more pro-inflammatory eicosanoids in the blood; and vE counteracts these effects to some extent. Owing to the immaturity of the immune system, dietary interventions might be promising at the early stage of chicken growth.

Development of laboratory reference material: Soil 1. Baseline and highly elevated concentrations of metals and polycyclic aromatic hydrocarbons

Reference materials play a key part in systems of inspection and quality control of results of analytical measurements. The main limitation in using certified reference materials (CRM) is their high price, which results from the long and costly process of producing the reference material. An alternative to costly CRM materials is the employment of laboratory reference materials, particularly for interlaboratory control of measurement results and procedures. Under the auspices of the Chair of Analytical Chemistry at the Chemical Department of Gdansk University of Technology, research on the development of new reference materials is being conducted. At present, the research is aimed at producing a new laboratory reference material (LRM): 'Soil 1. Baseline and Highly Elevated Concentrations of Metals and Polycyclic Aromatic Hydrocarbons' - LRM soil 1. This paper presents the production stages of the developed laboratory reference material: acquisition of raw material from soil samples taken from the environment of the Tri-city (in Polish, Trójmiasto Gdansk, Sopot, Gdynia) bypass road, homogenization and subsequent dosage into appropriate containers, tests of homogeneity of sampled material within one container and between containers, based on the results of the determination of selected parameters (total carbon, content of optional metals - Hg, Fe, Cu Zn, Mn, Mg, water content, content of PAH-group analytes). The obtained results of homogeneity tests of the proposed future laboratory reference material have confirmed the homogeneity of soil samples within a container and between containers. Currently, interlaboratory tests are being carried out to determine the reference value.

Metal-coated fused silica fibers as a support for immobilized compounds yielding a volatile analyte (C2H4)

This paper presents the results of investigations of chemically modified fibers comprising an immobilized compound that yields ethene as the analyte in generated standard gaseous mixtures. Prior to chemical modification, the fibers were coated with a thin aluminum layer to improve their mechanical strength. Commercially available Al-coated fibers were used in this work. During thermal decomposition of the immobilized compound, reproducible quantities of the analyte per unit fiber length were obtained for all the investigated fibers (fiber diameter (microm)/outside diameter (microm) of the Al-coated fiber=110/146, 220/300, and 660/830), amounting to 0.685+/-0.032, 0.8300+/-0.0081, and 1.092+/-0.010 ng cm(-1), respectively. The proposed procedure can be used successfully for the generation of measured component of matrix-free reference materials.