Complete Mixture Research Articles

High-Throughput Viability Testing of Microbial Communities in a Probiotic Product Using Flow Cytometry

There is growing scientific and commercial interest in multi-species probiotic products due to their potential benefits in maintaining gut health. Determining the viability of probiotic microorganisms in these products is essential to ensure that they confer maximal health benefits. The gold standard for enumerating probiotic viability is the plate count method. However, this may be inaccurate for enumerating mixed probiotic populations, with recognised limitations including difficulty measuring metabolically active yet unculturable, very slow growing microbes, microencapsulated, enteric coated microbes, or multi-strain formulations that require differing growth media. Here, we developed a flow-cytometry-based approach using SYTOXTM Green dye to assess the viability of probiotic microorganisms in a multi-species, fibre-containing probiotic product and compared this to the traditional plate count method. This method was suitable for enumerating both total bacterial cells and the viable cell fraction in the complete product mixture, and could also be used to assess how stressors, such as gastric digestion and exposure to bile acids, affect bacterial cell viability. Flow cytometry measurements routinely detected higher viable cell counts than plate counting. This work demonstrates that flow cytometry assays can be established as a suitable method for rapid enumeration of viable cells in complex, multi-species probiotics.

Non-equilibrium CFD simulation of the wet-to-dry expansion of the siloxane MM in a converging–diverging nozzle

Wet-to-dry organic Rankine cycles could generate 30% higher power outputs in the temperature range of 150 to 250 °C compared to existing single-phase cycles. Since the expansion is only partially wet, turboexpanders could potentially be applied provided that the wet portion of the expansion is confined to the stator to avoid erosion in the rotor. To assess the feasibility of achieving complete evaporation in the stator, two-dimensional non-equilibrium numerical simulations of the wet-to-dry expansion of siloxane MM in a covering–diverging nozzle are performed for the first time. The simulation setup is first validated against published experimental data, and a sensitivity study is conducted concerning the selected interphase models. The model is then applied to simulate expansions from inlet pressures ranging from 478 to 1250 kPa and vapour qualities from 0.1 to 0.5. Moreover, the droplet number density was varied between 1010 and 1014. The results show that the evaporation rate, the extent of non-equilibrium effects and the flow’s spatial uniformity are predominantly dependent on the droplet size. Expansions beginning with droplets smaller than 20 μm resulted in complete mixture evaporation and negligible non-equilibrium effects in almost all investigated cases. For larger droplets, ranging from 40 to 100 μm, full evaporation could only be achieved for inlet pressures above 750 kPa and inlet qualities above 0.3, whereas for lower pressures, the outlet vapour quality varied between 80 and 90%. For droplets larger than 200 μm, there is a significant delay in evaporation resulting in outlet quality typically between 40 and 70%. Larger droplet flows are characterised by substantial velocity slip, temperature difference, phase separation and lateral velocity variations. Having said this, droplet breakup analysis indicates that droplets larger than 100 μm are likely to undergo breakup, which could enhance the evaporation rate; however, this requires further investigation. In conclusion, high inlet pressures and high inlet qualities are preferred from the perspective of ensuring dry-vapour conditions at the nozzle outlet.

Microbiological Quality of Feed

Background: In most countries, the microbiological quality of complete feed mixtures, grains, silages and hay is sadly a much-underrated aspect of official feed control. Monitoring the microbiological quality of feeds downgrades any of the poor quality feeds and stimulates feed mills to produce better quality feeds, therefore, enforcing the prominence of high-quality feeds on the market. Objectives: To collect the results of the microbiological feed quality, done over a period of one year, all of which originate from Croatia, Slovenia, and Switzerland. Furthermore, identify the presence of feedingstuffs with poor microbiological quality in some parts of the European market and therefore have the most impact on animal health and welfare. Methods: Feed quality was assessed through a single Verband deutscher landwirtschaftlicher Untersuchungs - und Forschungsanstalten (VDLUFA) method based on a systematic approach, which categorizes feed into categories from 1 to 4 according to bacteria, moulds, and yeasts content, and their ecology and hazard significance. Results: Although the most analyzed samples of feed belong to the most desirable quality level 1, it should be emphasized that almost all feed types can be found samples of quality level 4, unacceptable for feed. Conclusion: The obtained results give an overview of the advantages of monitoring the microbiological quality of feeds for governmental authorities, producers, and consumers alike and potentially provide more information concerning the new aspects of the risk assessment of certain types of feeds or their raw materials.

Barley, Triticale, or Rye? The Type of Grain Can Affect the Growth Performance and Meat Quality of Sustainable Raised Pigs.

The effect of high level of barley, triticale, or rye as base of complete mixtures for growing-finishing pigs on growth performance, carcass traits, meat quality, and fatty acid profile in meat and backfat was investigated. The 100-day experiment involved 72 pigs, assigned into three groups (24 animals each). Pigs of each group were kept in six pens (two gilts and two barrows per pen). Diets offered to pigs differed in the proportion of cereals as the leading ingredients in the mixture formulation: I-barley, II-triticale, III-rye. The results showed diversified grain influence on the production results and meat quality. Triticale- and barley-based diets ensured better weight gain and lower carcass fatness than rye (p ≤ 0.05). The basic nutrients digestibility of mixtures containing triticale was comparable to that containing barley and higher than that of rye (p ≤ 0.05). The meat and backfat of pigs receiving diet with triticale or barley was characterized by more favorable fatty acids profile in respect to the health-promoting indicators (atherogenicity and thrombogenicity indexes; hypocholesterolemic/hypercholesterolemic ratio). The cholesterol level in various tissues was the lowest in pigs fed with rye diet, and their meat characterized by better water holding capacity and more SFA. Higher fat saturation indicate better resistance to oxidation during storage and longer meat shelf life. It seems that the supplementation of triticale to diet may improve the growth efficiency of pigs and the health-promoting value of meat, while the supplementation of rye may be better for the production of traditional or long-matured meat products.

Improvement of the design of the feed mixer and analysis of its performance

BACKGROUND: It has been proven by science and practice that feeding animals with complete feed mixtures can increase the productivity of feed. The preparation of loose feed mixtures has become most widespread. The analytical review of scientific and research works in the field of machinery and technology for the preparation of complete feed mixtures showed the advantage of using batch feed mixers. This is related to the fact that due to the circulation of feed components in a mixer, high quality of feed mixtures is achieved. At the same time, the issue of research and selection of reasonable parameters for improved ideological options in the direction of reducing energy and resource costs remains relevant.
 AIMS: Improvement of the design of a vertical batch mixer, elimination of cases of delay in unloading the finished mixture, which negatively affects productivity and the energy, labor and material costs associated with it.
 METHODS: The object of the research is the technology and design of a batch feed mixer. The cyclic and hourly average productivity of the mixer is studied. Mathematical expressions that describe the dependence of the loading and unloading duration on the mixer tankage are given. The influence of the mixer tankage on the mixer performance, expressed with a special coefficient, is analyzed. The coefficient range, which positively affects the performance of the facility, has been determined.
 RESULTS: It has been established that with the constructive and technological improvement of mixers and ensuring the proper operation, the tankage does not serve as the main factor for productivity increase.
 CONCLUSIONS: The maximum productivity of the vertical batch mixer is mainly ensured with the number of cycles of the auger and with the periodic forced supply of the mixture, whereas the quality of mixing depends on the angle of the vane opener.

Spatial and Temporal Evolution of Particle Migration in Gap-Graded Granular Soils: Insights from Experimental Observations

This study presents physical observations and insights into particle migration characteristics throughout the suffusion process. Using a purpose-built coaxial permeameter cell, suffusion experiments were conducted on idealized internally unstable gap-graded granular soils at varying fines content and hydraulic loading conditions. The specimens were prepared with a mixture layer comprising finer and coarser fractions underlying a coarse layer composed of the coarser fraction alone. This enabled the finer fraction within the mixture layer to migrate through the coarse layer with upward seepage flow. The local porosity profile along the specimen was determined using spatial time-domain reflectometry and an inversion algorithm, which enabled the development of a novel field map of the difference in porosity from the initial condition. This field map provided a visual guide of the spatial and temporal variation in porosity and enabled particle migration internally within the specimen to be quantitatively characterized from onset to progression to washout. The limiting onset condition identified from the field map was shown to be comparable to that obtained using conventional approaches, thereby providing strong validation for the application of porosity-based field maps. As suffusion progressed, the height of infiltrating finer particles into the coarse layer increased linearly with time, while the overall rate of particle migration from the mixture layer to the coarse layer evolved in a non-linear manner with the rate of migration increasing as the specimen reached a complete mixture condition, where the finer fraction infiltrated the entire coarse layer. The attainment of a complete mixture condition was dependent on the fabric of the gap-graded soil. Specimens with an underfilled fabric showed a gradual migration process, while specimens with a transitionally underfilled fabric resulted in minimal particle migration followed by a very rapid formation of the complete mixture.

Occurrence of zearalenone in dairy farms – A study on the determinants of exposure and risk assessment

The Azorean dairy industry is based on a semi-intensive model. Due to the few storage facilities and the large climatic fluctuations that characterize the Azores, the complete feed mixture (total mixed ration - TMR) is susceptible to the proliferation of a variety of fungi and mycotoxin contamination. Thus, chronic ingestion of these xenobiotics may lead to increased susceptibility to disease, loss of reproductive performance and, in the case of dairy cattle, decreased productivity and quality of milk produced. Since it is impossible to eliminate completely the presence of mycotoxins, it is essential to ensure the implementation of strategies to reduce their concentration in products intended for food and feed, as well as to monitor and control the levels present in food.This study aimed to evaluate the occurrence zearalenone (ZEA) in feed (TMR) in four dairy cattle farms on the Azorean Island of São Miguel and relate it to the occurrence of this mycotoxin in the milk produced, by associating several production and health indicators translated by the monthly milk contrast. To this end, the monthly milk contrast data, the determination of ZEA in the ingested feed and the (individual) milk samples from the four farms included in the study were used. Eighty-three (98.8%) of the milk samples under study had detectable ZEA levels (1.56 ± 1.36 μg/L), higher than reported in previous similar studies. Although ZEA concentration was not significantly associated with any production indicator analyzed (days in milk, age at calving, milk yield, protein content, butyrate content, somatic cell concentration and urea), it was found that the production regime and type of feed management is a major factor in the exposure of animals to high mycotoxin contents.Further studies are recommended to ensure continued monitoring and reduction of the risk associated with exposure of animals and humans to ZEA.

Analysis of energy characteristics of vibration mixing of multicomponent mixtures of agricultural raw materials

Ensuring the efficiency of the use of nutrients of grain, protein, vitamin and mineral feeds in the composition of complete feed mixtures in animal husbandry and crop production, as well as the corresponding reduction in the cost of manufacturing of these products, is the relevance of the presented research and prospects for their development. Therefore, the purpose of the study is to substantiate the effective regime parameters for the preparation of premixes of feed mixtures based on the assessment of the energy parameters of the vibration mixing process. This assessment was carried out by comparing the results of applying vibration, blade, and vibroblade technological operations. Under the conditions of low-frequency vibrations, a decrease in the working resistance of the loosened layer of the mixture is observed, which provided the effect of reducing energy consumption in this process. Therefore, in comparison with conventional vibrating mixers have a higher specific productivity of 5-6 times, provide a reduction in the mixing time by 2-3 times, metal consumption – by 17%, energy consumption – by 30%, capital costs for manufacturing – by 18%, and drive power – by 30-35%, which leads to a reduction in total energy consumption by 3-4 times. As a result, the zone of minimal energy consumption was substantiated, in which the reduction of the resistance of the technological medium allowed radically reducing the friction forces during mixing, while ensuring uniform distribution with the concentration of the components of the mixture required by technological requirements. An increase in the oscillation amplitude is accompanied by a quadratic increase in power consumption, which is conditioned by an increase in energy dissipation in the mass of the mixture in the form of heat. The implementation of reasonable operating mixing modes allowed reducing the energy consumption of the proposed vibro-blade mixing by 2.0-2.5 times compared to conventional blade processing. The practical value of these developments includes the use of vibro-blade working bodies and the vibration-free operation of the drive shaft, which, together with the minimisation of energy consumption for the process, reduces dynamic loads on the support units of the developed mixer

A feed enrichment strategy targeting the tricarboxylic acid cycle for increasing monoclonal antibody production and alleviating ammonia accumulation in Chinese hamster ovary cell culture

In this study, we demonstrated a simple strategy for increasing mAb production by enriching an existing feed with TCA cycle intermediates and precursors. TCA cycle intermediates/precursors were tested individually and as mixtures, termed as ‘Enriched Feeds’. The enriched feed mixtures were tested in two compositions comprising: (i) only TCA intermediates/precursors that individually increased mAb titre (EF_Partial) and, (ii) all TCA intermediates/precursors (EF_Complete). These mixtures were also tested for initiation at two phases: (i) from Day 3 (start of exponential phase) and, (ii) from Day 6 (start of stationary phase), and at two concentration levels (high and low). Our results showed that the EF_Partial mixtures were more efficient in increasing mAb titre as compared to the EF_Complete mixtures. The EF_Partial_D6_Low mixture gave the highest titre increase of 55 %, as compared to the control culture. Additionally, a decrease in ammonia production was observed immediately upon the supply of the enriched feeds. In the individual assessment, succinate supplementation resulted in a superior cell growth profile and also exhibited the most significant reduction in ammonia. The individually tested TCA compounds and mixtures also did not impact mAb quality. Therefore, in this study, we demonstrate that a simple approach of enriching feeds with TCA cycle intermediates/precursors effectively increases mAb production by > 50 % without affecting quality attributes.

On Analogies in Proton-Transfers for Pyrimidine Bases in the Gas Phase (Apolar Environment)—Cytosine Versus Isocytosine

Inter- and intra-molecular proton-transfers between functional groups in nucleobases play a principal role in their interactions (pairing) in nucleic acids. Although prototropic rearrangements (intramolecular proton-transfers) for neutral pyrimidine bases are well documented, they have not always been considered for their protonated and deprotonated forms. The complete isomeric mixtures in acid-base equilibria and in acidity–basicity parameters have not yet been examined. Taking into account the lack of literature and data, research into the question of prototropy for the ionic (protonated and deprotonated) forms has been undertaken in this work. For the purposes of this investigation, two isomeric pyrimidine bases (C—cytosine and iC—isocytosine) were chosen. They exhibit analogous (symmetrical) general acid-base equilibria (intermolecular proton-transfers). Being similar polyfunctional tautomeric systems, C and iC possess two labile protons and five conjugated tautomeric sites. However, positions of exo groups are different. Consequently, structural conversions such as prototropy, rotational, and geometrical isomerism of exo groups (=O/−OH and =NH/−NH2) and their intramolecular interactions with endo groups (=N−/>NH) possible in neutral C and iC and in their ionic forms lead to some differences in compositions of isomeric mixtures. By application of quantum–chemical methods to the isolated (in vacuo) species, stability of all possible neutral and ionic isomers has been examined and the candidate isomers selected. The complete isomeric mixtures have been considered for the first time for di-deprotonated, mono-deprotonated, mono-protonated, and di-protonated forms. Protonation–deprotonation reactions have been analyzed in the gas phase that models non-polar environment. The gas-phase microscopic (kinetic) and macroscopic (thermodynamic) acidity–basicity parameters have been estimated for each step of acid-base equilibria. When proceeding from di-anion to di-cation in four steps of protonation–deprotonation reaction, the macroscopic proton affinities for C and iC differ by less than 10 kcal mol−1. Their DFT-calculated values are as follows: 451 and 457, 340 and 339, 228 and 224, and 100 and 104 kcal mol−1, respectively. Differences between the microscopic proton affinities for analogous isomers of C and iC seem to be larger for the exo than endo groups. Owing to variations of relative stabilities for neutral and ionic isomers, in some cases they are even larger than 10 kcal mol−1.

The study of ignition and emission characteristics of hydrogen-additive hydro-processed renewable diesel

This study was conducted to understand the effects of hydrogen (H2) addition on the combustion and emission characteristics of hydro-processed renewable diesel. Experiments were performed in a constant volume combustion chamber (CVCC) at varying H2 concentrations (0%, 5%, and 10% (by vol.)) relative to air (100%, 95%, and 90% (by vol.)), initial temperatures (Tini) of 600, 650 and 700 K, equivalence ratios (φ) of 0.5, 1.0, and 1.5 and a fixed initial pressure (Pini) of 10 bar. Overall, HRD has lower ignition delay (ID) and total ID. However, H2 addition to HRD delayed the fuel's auto-ignition due to excess H2 oxidation (H2+OHH2O + H) reaction taking place, which turns the chain reactions from branching to propagation, resulting from increasing in ID. Moreover, increasing of H2 concentrations enhanced the maximum pressure rise (Pmax) and heat release rate (HRR), whereas carbon dioxide (CO2) and unburned hydrocarbon (HC) were decreased due to the higher magnitude of the lower heating value of H2 than that of pure HRD. Since H2 itself is a carbon-free molecule, the carbon content of the fuel is reduced. H2 has the characteristics of fast combustion, resulting in a more flammable and complete mixture, which also makes HC emissions to become lower. However, the higher energy density of H2 significantly raises the combustion temperature, and subsequent nitrogen oxides (NOx) were increased. The kinetic modeling predictions revealed that the IDs for HRD-H2 were elongated due to the increased hydroperoxyl (HO2) and hydrogen peroxide (H2O2) mole fractions which led to improved stability.

Does machine learning help private sectors to alarm crises? Evidence from China’s currency market

With respect to a broad range of well-established early warning systems (EWSs) for financial crises, this study discusses the practical usefulness of currency early warning models in their service to the daily operation of private sectors. Based on 24-year daily and monthly data of China, a complete mixture of classic and emerging crisis early warning paradigms are examined at both the short and long predictive horizons. To answer the question whether and how machine learning algorithms contribute to the institutional assessment of currency vulnerabilities, the models are evaluated in terms of the out-of-sample crisis predictive power as well as the real-time improvements on the performance of currency portfolios. Evidences are found to support the potential of machine learning in outperforming canonical models. Nonetheless, it is stressed that in comparison to the selection of predictive mechanisms, the quantitative definition of crises, that addresses precision and robustness at the same time, is an equally important determinant for the success of an EWS. This study suggests that private sectors are more likely to be benefited from monitoring short-horizon market turmoils at daily frequency.

Ochratoxin Incidence in Poultry Feed Mixtures

Ochratoxin is one of the most frequently occurring mycotoxins in food and feed. In humans and animals, it is the cause of health disorders, mycotoxicosis. Monitoring the content of ochratoxin in food and feed is an important part of preventive measures. This work was focused at determining the concentrations of ochratoxin in complete feed mixtures for broilers and turkeys by ELISA analysis. The presence of ochratoxin in concentrations lower than 2 ppb was confirmed in the examined samples. The ochratoxin content limit for supplementary and complete feed mixtures for poultry, which represents a value of 100 ppb in feed with a moisture content of 12%, was not exceeded in the samples.

The content of ten elements in pig feed and manure and its relationship with element concentration in earthworms on swine farms

The aim of this investigation is to determine the content of ten elements, Cr, Mn, Co, Ni, Fe, Zn, As, Cu, Se, and Cd, in pig feed, manure and earthworms (Lumbricus terrestris). Samples were collected during 2015 and 2017, on four pig farms in Serbia, and analyzed for elements by inductively coupled plasma mass spectrometry. According to the mean concentrations, the elements show the following trends: Fe > Mn > Zn > Cr > Ni > Cu > Cd > Se > As > Co in monocalcium phosphate, Zn > Mn > Fe > Cu > Co > Cr > Ni > Se > As > Cd in vitamin-mineral premixes, Fe > Zn > Mn > Cu > Ni > Cr > Se > Co > As > Cd in complete feed, and Fe > Zn > Mn > Cu > Ni > Cr > Co > Se > Cd > As in pig manure. The obtained results show that monocalcium phosphate and vitamin-mineral premixes are the main source of Mn, Zn, and Fe in complete feed mixtures. The Cd concentration in one sample of monocalcium phosphate exceeds the maximum permissible level. Only one out of six investigated complete feed mixtures was in accordance with the national and EU regulations. The presence of Fe, Zn, and Mn in earthworms reflects their concentration in pig manure, but this is not noticed for Cr, Cu, Se, As, Ni, Co, and Cd.

Topinambur (Helianthus tuberosus) ve výživě králíků

Jerusalem artichoke is crop with the possibility of a wide using. The main nutrient of this plant is a non-starch polysaccharide inulin, which is considered like prebiotic. Young rabbits after weaning lose an immunity obtained from colostrum; are stressed by weaning; pre-moult; the permanent incisors are growing and a starch digestion by an enzyme amylase is not fully developed. The aim of this study was to evaluate the effect of the dietary supplement of dried Jerusalem artichoke tuber and tops (the sources of non-starch saccharide) on growth performance and health status of broiler rabbits after weaning in view of prices and efficiency of feeding mixtures. The test was realized through experiments with a different percentage of Jerusalem artichoke tuber (25%, 10%) and top (30%, 20%, 10%). Every experiment was composed of 2 groups – the control group without a supplement of Jerusalem artichoke and an experimental group with a different percentage of Jerusalem artichoke tuber and top. Experimental animals (1095 HY PLUS broiler rabbits) were weaned at 33 - 35 days of age and were fed by complete granulated feeding mixture ad libitum for the whole feeding period. Statistical analyses were performed by using SAS 9.3 The statistical differences (P<0.05) were found in average daily gain (rabbits fed 25% Jerusalem artichoke tubers 42.37±13,96 g/day vs. control 36.42±12.91 g/day) and mortality (rabbits fed 10% Jerusalem artichoke tubers 4.17% vs. control 10.83%; rabbits fed.20% Jerusalem artichoke tops 5.26% vs. control 16.67%).

NEAREST NEIGHBOR PATTERNS OF DOMINANT TREE SPECIES IN TROPICAL FORESTS, PHOU KHAO KHOUAY NATIONAL PARK, LAOS

Target-tree management is a silviculture technique that aims to achieve sustainable forest management by considering the spatial structure of forests. In this study, a new quantitative method was used to analyze the spatial structure of natural forest stands in the Phou Khao Khouay national park in Laos. The method involved mapping and measuring all individual trees with a diameter at breast height (DBH) greater than or equal to 5 cm in 32 permanent plots of 50 m × 50 m. The analysis focused on four spatial structural parameters: uniform angle index, species mingling, height dominance, and crowding. The results showed that (1) the dominant species in the three forest types had a species mingling degree ranging from medium to complete mixture; (2) the target trees were found to have a dominant height compared to their nearest neighbors; (3) the distribution patterns of trees in the stands varied from regular to clumped; and (4) the crowding index indicated a distribution density of trees from sparse to dense. Dispersal limitation and competition among neighboring trees were the main mechanisms driving the forest's spatial structure in the study area. The findings of the present study provide valuable information for proposing silvicultural measures that promote sustainable forest management in Phou Khao Khouay National Park. By understanding the spatial structure of forests, target-tree management can be used to improve forest health, increase biodiversity, and enhance the ecosystem services provided by forests.

Effects of Dietary Halloysite Supplementation on Broiler Chicken’s Blood Parameters, Carcass and Meat Quality, and Bone Characteristics: A Preliminary Study

Abstract The aim of this study was to determine the effect of halloysite supplementation to the complete diets for broiler chickens on selected blood parameters, carcass and organ characteristics, as well as bone and meat traits. The trial was conducted under experimental conditions in a large-scale poultry farm on 18,000 broiler chickens. The one-day broiler Ross 308 chicks were randomly divided into two groups: control (C) and experimental (E) in an amount of 9,000 birds per group. In each group, chicks were separated into five pens (100 m2) with 1800 chicks per pen. The birds were fed granulated complete mixtures without (C group) or with halloysite (E group) distributed in an amount of 1% (based on fresh matter) from the 11 d of life. Analysis revealed that halloysite supplementation to the broiler diet at the level of 1% showed a trend (P = 0.056) towards higher final body weight, significantly improved carcass yield (P = 0.048), and reduced the relative weights of the liver and gizzard (P&lt;0.05). No differences (P&gt;0.05) were observed either in terms of the physicochemical parameters of the broiler chickens’ breast muscles, except a significantly lower b* value of the colour parameter (P = 0.048). In turn, in the blood serum, the addition of 1% halloysite significantly decreased (P&lt;0.05) the content of triglycerides and the total cholesterol and low-density lipoprotein fraction, but did not affect (P&gt;0.05) the high-density lipoprotein fraction, calcium, phosphorus or alkaline phosphate content. Tibia and femur characteristics (weight, length, relative bone weight, bone mineral density, bone mineral content, and breaking strength) were not affected (P&gt;0.05) by the usage of halloysite. In conclusion, supplementation of broiler diet with halloysite in the amount of 1% had beneficial effects on the carcass yield and health status of the animals, without any adverse effect on the bone parameters or meat quality of the broiler chickens.

The Thyroid Hormone and Immunoglobulin Concentrations in Blood Serum and Thyroid Gland Morphology in Young Hens Fed with Different Diets, Sources, and Levels of Iodine Supply

The aim of this study was to examine the influence of the level (1, 3, and 5 mg I/kg) and source of iodine (KI, Ca(IO3)2, and KIO3) on thyroid hormone and immunoglobulin concentrations in the blood serum of laying hens alongside a histological picture of the thyroid. In the first, birds were fed grain-soybean meal mixtures, and in the second, two kinds of diets based on corn-soybean or corn-soybean-rapeseed meal were applied. In the experiments, we determined the levels of the blood serum thyroid hormones fT3 and fT4, as well as the morphological structure of the thyroid gland. In the second experiment, the concentration of immunoglobulins in blood serum was assayed. In both experiments, no influence of iodine source on thyroid hormone concentration was observed. However, increasing the iodine level in the full mixture and adding rapeseed meal in both experiments caused an increase in fT3 concentration. Increasing I-addition in both experiments led to a decrease in thyroid gland follicle diameter. Rapeseed meal inclusion (at a level of 10%) to the complete hen mixture led to an increase in thyroid gland follicle diameter. Applying KIO3 as an iodine source in both experiments caused a decrease in the thyroid gland height of follicle epithelial cells. Immunoglobulin concentrations in the serum were not affected by experimental factors. The results suggest that the methodologies of studies on the bioavailability of minerals and the corresponding analytical methods require unification. The lack of such standardization makes it impossible to engage in a satisfactory discussion of the results and exchange experiences.

Influence of the low-pressure exhaust gas recirculation injection point on engine performance

The use of low-pressure exhaust gas recirculation (EGR) has been extended in spark-ignited engines in recent years due to advantages from efficiency perspective. However, the potential condensation of the water contained in the exhaust gases and eventual compressor erosion can limit the usage of such systems during engine warm-up and/or cold ambient conditions. One possibility to avoid condensation at cold ambient is to place the EGR injection close to the compressor wheel, avoiding a complete mixture of both streams, but it alters the flow distribution upstream of the compressor, potentially affecting its performance. In order to assess the impact of this phenomenon in engine operation, a detailed experimental campaign in a state-of-the-art spark-ignition engine was performed comparing this close-coupled configuration with another one where the injection point was far upstream the compressor, ensuring a perfect mixing. A previously developed and validated one-dimensional model of the variable geometry turbocharger was used to analyze in further detail the compressor and turbine operation. The results show a general deterioration of the engine pumping mean effective pressure (up to 0.02 bar) and the specific fuel consumption (up to 4 g/kWh) when applying the close configuration, higher as the EGR rate increases, which is partially due to the change in turbine operation induced by the new compressor working point.

EVALUASI NILAI NUTRISI SORGUM TERFERMENTASI Cellulomonas Sp DALAM PAKAN KOMPLIT TERNAK KELINCI

This study aims to obtain the best ration using fermented sorghum Cellulomonas Sp in complete feed through performance parameters of rabbit production. This research was carried out in 2 stages namely; 1) Sorghum fermentation test experiment using Cellulomonas Sp with determination of the best incubation time. 2) Research on biological test of treated feed (best results of phase 1) research formulated in a complete feed mixture for rabbits. The first phase of the study used an experimental method with a completely randomized design (CRD) with 4 treatments which was repeated 5 times. Treatment of incubation time (L) at room temperature was 4 levels, namely L1 = 7 days, L2 = 14 days, L3 = 21 days and L4 = 28 days. The observed variables were protein and crude fiber content. The second phase of the study used an experimental method with a randomized block design (RAK) based on the initial body weight of rabbits. The treatment feed consisted of 5 levels which were repeated in 3 body weight groups, each experimental unit filled with 2 male rabbits so that the number of rabbits used was 30. The treatment given was the level of use of sorghum in a complete feed ration made in pellet form with the following arrangement: R0 = Ration without using sorghum; R1 = Ration using 10% fermented sorghum Cellulomonas Sp; R2 = Ration using 20% fermented sorghum Cellulomonas Sp; R3 = ration using 30% fermented sorghum Cellulomonas Sp and R4 = ration using 40% fermented sorghum Cellulomonas Sp. The observed variables were feed consumption, body weight gain and feed conversion. The results of the Phase I study showed that the average protein content incubated at 7, 14, 21 and 28 days, respectively, was 7.23%, 7.50%, 8.77% and 8.80%, while the average fiber content was crude oil is 14.46%, 12.33%, 11.22% and 10.64%. Fermentation plays an important role in the process of increasing protein and decreasing crude fiber, because in the fermentation process there are microbes that can remodel the substrate. In the second stage of the study, it was seen that the highest ration consumption was found in the R3 treatment, which was 59.70 g/head/day, as well as the highest body weight gain was found in the R3 treatment, which was 15.91 g/head/day. The R3 treatment also showed the lowest conversion value of 3.75 compared to other treatments in this study. This shows that the R3 treatment is more efficient than the other treatments. Based on the results of the study, it can be concluded that the administration of 30% fermented sorghum Cellulomonas sp in a complete feed mixture showed the best results in terms of consumption parameters, body weight gain and feed conversion