Feed Material Research Articles

The Effect of Graphene Addition on the Microstructure and Properties of Graphene/Copper Composites for Sustainable Energy Materials

Graphene is a single thin layer (mono layer) of a hexagon-bound carbon atom and is an allotropic carbon in the form of a hybrid atomic plane, with a molecular bond length of 0.142 nm. Graphene is the thinnest and lightest material with 0.77 mg square meters, which exhibited excellent electricity and heat conductor. However, the perfect uniform microstructure, strength and optimum thermal properties of copper-graphene composites cannot be achieved because the amount of graphene does not reach the optimum level. In order to solve this problem, copper-graphene composites were produced by metal injection molding method (MIM) with various percentage of graphene, specifically 0.5%, 1.0% and 1.5% in the composite, to compare the physical and mechanical properties of these samples. MIM process involves the preparation of feed materials, pre-mixing process, mixing process, mold injection process, binding process and sintering processes. Feeding materials were used are copper and graphene, which have the powder loading of 62% with a mix of binder comprising 73% polyethylene glycol (PEG), 25% polymethyl methacrylate (PMMA), and 2% stearic acid (SA). Densification and tensile test were conducted to determine the mechanical properties. Scanning electron microstructure (SEM) was performed to obtain the microstructure of the composites. From the research, the result revealed that the 0.5% graphene content had the optimum parameter, which the hardness and tensile stress values were at 94.2 HRL and 205.22 MPa.

Review: Composition and utilisation of feed by monogastric animals in the context of circular food production systems.

Food production has a major impact on environmental emissions, climate change and land-use. To reduce this impact, the circularity of future food production systems is expected to become increasingly important. In a circular food system, crop land is primarily used for plant-based food production, while low-opportunity cost feed materials (LCF), i.e. crop residues, co-products of the food industry, grass from marginal land and food waste form the basis of future, animal feeds. Animal diets thus contain much less cereals and soybean meal and include a higher proportion of diverse co-products, residues and novel human-inedible ingredients. These diets are characterised by a lower starch content, and a higher content of fibre, protein, fat, and phytate compared to present diets. In this review, possible consequences of the development towards a more circular food system for the type, volume and nutritional characteristics of feed materials and complete feeds are addressed and related research questions in the area of animal nutrition, physiology and metabolism are discussed. Additional attention is given to possible effects on intestinal health and gut functionality and to (bio)technological processing of LCF to improve their suitability for feeding farm animals, with a focus on the effects in pigs and poultry. It is concluded that an increased use of LCF may limit the use of presently used criteria for the efficiency of animal production and nutrient utilisation. Development of characteristics that reflect the efficacy and efficiency of the net contribution of animal production in a circular food system is required. Animal scientists can have an important role in the development of more circular food production systems by focussing on the optimal use of LCF in animal diets for the production of animal-source food, while minimising the use of human-edible food in animal feed.

Concentrations of chemical elements in the leaves of Populus suaveolens Fischer and Betula pendula Roth at the facilities of the gold deposit of Eastern Transbaikalia

The concentration of 50 chemical elements in the leaves of Populus suaveolens Fischer and Betula pendula Roth growing in tailings dumps and dumps of gold deposits in Eastern Transbaikalia (Baley) was studied. It was found that the highest concentration of most elements was in the leaves of plants growing at the ZIF-2 tailings dump, and the lowest was on the sands of the thorium tailings dump and sand–pebble soil at the dredge gold mining site. Populus suaveolens differed from Betula pendula by a higher concentration of most chemical elements. A feature of the elemental composition of birch was a significant concentration of Mn and Ba in relation to poplar. The concentration of a number of chemical elements significantly exceeded the clark of terrestrial plants, as well as the maximum permissible levels of concentration of elements established for feed and medicinal plant raw materials.

Proximate analysis of selected agricultural waste for their nutritional potential

Background: Global food insecurity is worsening as a result of the speedily expanding human population and this is taking a huge toll on the availability of feed for livestock. Alternative food sources are urgently required as livestock feeds to reduce the stern food competition between man and livestock. Agricultural waste may be able to provide cost-effective sources of nutrients. Aim: The study determines the proximate properties of agricultural waste for their possible use as raw material for animal feed. Material and methods: Consequently, 10 samples of agricultural waste were collected from locations in Edo state where the plants are cultivated in commercial quantities. Proximate analysis was performed on the samples using standard protocols to evaluate their nutritive potentials for utilization as feedstuffs for livestock feeds. The proximate properties of the agricultural waste were compared with plantain flesh (PF Auchi and PF Benin). Results: Significant variations exist among the samples (p < 0.05) with respect to their fat, protein, nitrogen free extract (NFE) and dietary fiber content. The following samples had highest proximate values; corn cob (moisture content at 17.38%), PP Usen (ash content at 7.58%), PP Benin (fat content at 7.20%), CHI Usen (fiber content at 12.70%), PP Auchi (protein content at 19.83%) and PF Benin (Nitrogen Free Extract (NFE) at 73.43%). Plantain peels had the closest proximate properties to plantain flesh. Conclusion: The results from the analysis show that the proximate properties of the wastes compare favorably with plantain flesh and will be suitable for livestock feeds production. The production of livestock feed from agricultural waste would also serve as an effective and attractive method to manage the waste. Keywords: livestock, agricultural waste, nutrient, feeds.

Chemically Driven Oscillating Soft Pneumatic Actuation.

Pneumatic actuators are widely studied in soft robotics as they are facile, low cost, scalable, and robust and exhibit compliance similar to many systems found in nature. The challenge is to harness high energy density chemical and biochemical reactions that can generate sufficient pneumatic pressure to actuate soft systems in a controlled and ecologically compatible manner. This investigation evaluates the potential of chemical reactions as both positive and negative pressure sources for use in soft robotic pneumatic actuators. Considering the pneumatic actuation demands, the chemical mechanisms of the pressure sources, and the safety of the system, several gas evolution/consumption reactions are evaluated and compared. Furthermore, the novel coupling of both gas evolution and gas consumption reactions is discussed and evaluated for the design of oscillating systems, driven by the complementary evolution and consumption of carbon dioxide. Control over the speed of gas generation and consumption is achieved by adjusting the initial ratios of feed materials. Coupling the appropriate reactions with pneumatic soft-matter actuators has delivered autonomous cyclic actuation. The reversibility of these systems is demonstrated in a range of displacement experiments, and practical application is shown through a soft gripper that can move, pick up, and let go of objects. Our approach presents a significant step toward more autonomous, versatile soft robots driven by chemo-pneumatic actuators.

Using In Silico Approach for Metabolomic and Toxicity Prediction of Alternariol.

Alternariol is a metabolite produced by Alternaria fungus that can contaminate a variety of food and feed materials. The objective of the present paper was to provide a prediction of Phase I and II metabolites of alternariol and a detailed ADME/Tox profile for alternariol and its metabolites using an in silico working model based on the MetaTox, SwissADME, pKCMS, and PASS online computational programs. A number of 12 metabolites were identified as corresponding to the metabolomic profile of alternariol. ADME profile for AOH and predicted metabolites indicated a moderate or high intestinal absorption probability but a low probability to penetrate the blood-brain barrier. In addition to cytotoxic, mutagenic, carcinogenic, and endocrine disruptor effects, the computational model has predicted other toxicological endpoints for the analyzed compounds, such as vascular toxicity, haemato-toxicity, diarrhea, and nephrotoxicity. AOH and its metabolites have been predicted to act as a substrate for different isoforms of phase I and II drug-metabolizing enzymes and to interact with the response to oxidative stress. In conclusion, in silico methods can represent a viable alternative to in vitro and in vivo tests for the prediction of mycotoxins metabolism and toxicity.

A bibliometric approach to understanding the recent development of self-sufficient fish feed production utilizing agri-food wastes and by-products towards sustainable aquaculture

The global agri-food industry generates a large volume of waste annually, which causes both environmental and economic problems. Recently, there has been a growing interest in the use of agri-food wastes and by-products to produce self-sufficient fish feed. This study aimed to analyze the intellectual structure of the recent research on the utilization of agri-food wastes and by-products as self-sufficient fish feed materials based on 922 Scopus-indexed core collection documents from 252 journals written by 4420 authors from 73 countries with an annual growth rate of 18.65% over the last four years (2019–2022). This bibliometric study implemented knowledge domain visualization (KDV) using VOSViewer and Biblioshiny in the Bibliometrix R-package to investigate the basic scientometric profile of the selected fields. The results showed that Dawood M.A.O., with PageRanks of 0.0732, 19 total publications, 695 global citations from 2019 to 2022, and closeness values of 0.25, was the most productive author within the field. Subsequently, China was determined to be the most productive country (93 valid documents) and have the strongest collaboration network. Major research hotspots in the field included aquaculture and sustainable aquaculture, fish feed with agri-food waste, rainbow trout species, the development of a circular economy, probiotic applications, and cell signaling cytokines and peptides. This bibliometric study provides comprehensive information on the intellectual domain and research landscape on self-sufficient fish feed and also shows how interest in this research topic and similar ones is growing.

Investigation of Doping Processes to Achieve Highly Doped Czochralski Germanium Ingots

Highly doped germanium (HD-Ge) is a promising material for mid-infrared detectors, bio-sensors, and other devices. Bulk crystals with a doping concentration higher than 1018 cm−3 would be desirable for such device fabrication technologies. Hence, an effective method needs to be developed to dope germanium (Ge) ingots in the Czochralski (Cz) growth process. In this study, a total of 5 ingots were grown by the Cz technique: two undoped Ge ingots as a reference and three doped ingots with 1018, 1019 , and 1020 atoms/cm3 respectively. To obtain a uniform p-type doping concentration along the crystal, co-doping of boron-gallium (B-Ga) via the Ge feed material was also attempted. Both B and Ga are p-type dopants, but with a large difference in their segregation behavior (contrary segregation profile) in Ge, and hence it is expected that the incorporation of dopants in the crystal would be uniform along the crystal length. The distribution of the dopants followed the Scheil-predicted profile. The etch pit density maps of the grown crystals showed an average dislocation density in the order of 105 cm−2. No increase in the overall etch pit count was observed with increasing dopant concentration in the crystal. The grown highly doped Ge crystals have a good structural quality as confirmed by x-ray diffraction rocking curve measurements.

Production and optimisation of used cooking palm oil into protected fat calcium salts by fusion method using response surface methodology (RSM)

Used cooking oil (UCO) is a waste, and creates environmental issues due to its hydrophobic property. UCO, with its high content of fatty acid, can be used as source material for animal feed. However, high unsaturated fatty acid in UCO is harmful to the ruminant’s microflora. This can be resolved by transforming UCO into functional product such as ruminant’s protected fat (PF). In the present work, the production of used cooking oil protected fat (UCOPF) using fusion method via saponification process was investigated. Response surface methodology (RSM) was used to evaluate the effect of calcium oxide concentration (CaO), initial temperature (iTemp.), and percentage of water (H2O) on the solidification score and free fatty acid (FFA) content of PF. Results showed that all the studied parameters significantly affected the responses. The coefficient of determination (R2) for solidification score and FFA were high at 0.9433 and 0.9599, respectively. The optimum condition to produced UCOPF by fusion method was CaO (20%), iTemp. (80°C), and percentage of water (30%), which yielded solidification score and FFA of 5.33 ± 0.53 and 0.85 ± 0.07%, respectively. The FFA content of the optimised PF was lower than permitted; thus, it can be used as animal supplement. In conclusion, the UCO can be converted into PF by using calcium fusion method. However, the property and stability of the produced PF should be assessed prior to commercialisation.

DETERMINATION OF YIELD AND QUALITY CHARACTERISTICS OF COMMON REED (Phragmites australis (Cav.) Trin. Ex Steud) HARVESTED AT DIFFERENT GROWTH STAGES

Common Reed (Phragmites australis (Cav.) Trin. Ex Steud, which is remained inactive and grown in saline
 drainage channels, has been seen as an important potential to reduce the roughage deficit needed in animal nutrition. For this purpose, some yield, fermantation, chemical and nutritional characteristics of P.australis herbage and silage obtained from the end of the vegetative stage (EVS), the beginning of panicle (BP) and the full panicle stage (FPS) were determined. The study was carried out in 2021-2022 in Igdir, which is located in the North-East of Turkey. The results showed that the forage yield characteristics increased as the development period progressed and also that high lactic acid, low pH, acetic, propionic and butyric acid contents desired in silo feeds were obtained from the cuttings at FPS. In addition, ammonia production was low in silages at BP and FPS, but high the fleig score. It was observed that the dry matter digestibility, metabolic energy and relative feed value were higher while dry matter and crude protein ratio, acid detergent fibre and crude ash content of herbage according to silage were lower. On the other hand, the desired chemical and nutritional values in both herbage and silage were determined during the most suitable BP. As a result, it was determined that the common reed was appropriate to harvest in FPS for a silo feed with high yield and fermentation properties. In addition, it was concluded that the herbage and silage harvested at BP produced a higher quality feed material in terms of nutritional and chemical composition, respectively.

Hibiscus sabdariffa natural dye extraction process with central composite design for optimal extract yield

This study reports optimization of Hibiscus sabdariffa natural dye extraction process parameters with response surface methodology, which is aimed at developing a more suitable and standardized technique to extract active components from plant materials. Hibiscus sabdariffa dye extraction process parameters (temperature, time and feed materials) were optimized for high yield. The dye was extracted using locally fabricated combined dye extractor and dryer machine with throughput capacity of 4 g/min machine and extraction efficiencies of 78.61% and 63.77% respectively using solvent as the medium. Central Composite Design (CCD) of Response Surface Methodology (RSM) was employed to optimize the process parameters that resulted in optimal yield. Liquid chromatography revealed components typical of natural dye extracts. The equations and models generated from RSM revealed experimental correlation between the dependent and independent variables. The fitted quadratic model's analysis of variance (ANOVA) with F-value of 14.78 for the model indicates its significance as there is only a 0.01% probability that such a big F -value is attributable to noise. Additionally, this analysis shows significant model terms as P-values less than 0.05 was obtained. The FTIR result showed a characteristic plant dye absorption pattern with wavenumbers that ranged from 3377 to 1032 cm−1. Optimal extract yield of 68% was attained at the temperature of 100 °C for 60 min and 1 kg feed material through RSM. This study revealed that extraction temperature and time had a significant effect, while the amount of feed material had a slight effect on the yield. Therefore, natural dyes can be extracted from Hibiscus sabdariffa for a sustainable natural color dyeing approach practiced in the textile industries. The study created a sustainable method of using bioresources for economic growth and development. The findings on this study provided a foundation for the use of Hibiscus sabdariffa dye extract as alternative to conventional dyes that can serve as functional colors for the textile, food and pharmaceutical industries.

Determination of eleven total amino acids including cyst(e)ine by HPLC-DAD/FLD in complete dry and wet pet foods and their feed materials

A single-step analytical method for the simultaneous determination of eleven amino acids (Arginine, Histidine, Threonine, Tyrosine, Cystine, Valine, Methionine, Phenylalanine, Isoleucine, Leucine, Lysine) materials was developed and validated in complete pet food and feed. Samples were hydrolysed, purified using a polytetrafluorethylene (PTFE) syringe filter, and then analysed by high-performance liquid chromatography (HPLC), equipped with photodiode array (DAD) and fluorometric (FLD) detectors, after an online pre-column derivatisation with o-phthalaldehyde. The use of two detection systems allows the simultaneous identification and quantification of different amino acids by a single chromatographic with high sensitivity and specificity. The chromatographic separations were carried out using an Advance Bio AAA column under a gradient mode with a mobile phase of acetonitrile, methanol, water (45:45:10), and a phosphate buffer solution. Linearity, precision, recovery, specificity, limit of detection (LOD) and limit of quantification (LOQ) were assessed. Linearity was evaluated over the range of 4–250 µM with diode array detector and 4–100 µM with the fluorometric detector. Method validation was carried out using certified reference materials; each analyte recovery ranged from 71% to 111% with a precision (CV%) less than 5%. Ninety one samples (ie, n = 30 dry and wet complete pet foods and n = 61 feed materials) were analysed using the validated method to define the nutritional quality of feed materials and to verify the completeness of complete pet foods for dogs and cats. All complete pet food samples complied with the minimum recommended levels of amino acids.

Material flow path and extreme thermomechanical processing history during additive friction stir deposition

With significant interest from the aerospace and defense industry, additive friction stir deposition (AFSD) is an emerging solid-state metal additive process that can result in fully-dense material with fine equiaxed grains and forged-like mechanical properties. Vital to quality control, the thermal and deformation history of the feed-rod governs the resulting microstructure and properties; however, such history has remained elusive due to experimental constraint. By leveraging both theoretical and experimental efforts, here we develop an experimentally-informed modeling framework that unravels the three-dimensional material flow path and quantifies the thermal and deformation history by tracing the temperature and effective strain rate along the flow path. We show that the feed material undergoes extreme thermomechanical processing during AFSD. Take an Al-Mg-Si alloy for example: the temperature is maintained high within a narrow range during AFSD (e.g., 75–80 % of the melting temperature); the peak strain rate is on the order of 101–102 s−1; the total accumulated strain is on the order of 102. Within the feed-rod, the edge and intermediate voxels are more rapidly deformed than the center voxel, but the values of the Zener-Hollomon parameter and flow stress are comparable among all voxels. This suggests a uniform grain structure distribution after continuous dynamic recrystallization, which is validated experimentally via microstructure mapping.

Effect of Infill Pattern on Impact Toughness, Microstructure, and Surface Roughness of Inconel 625 Built via Filament-Based Material Extrusion Additive Manufacturing

Filament-based material extrusion additive manufacturing (FMEAM) is an additive manufacturing technique that uses 3D printing. Additive manufacturing could build parts with infill variations. Solid or triangular infill pattern could be selected as needed. The solid pattern will have the maximum material volume, while the triangular pattern will contain a triangular lattice structure that fills the voids in the volume so the material requirement is reduced. This is valuable in optimizing the requirements of metallic materials for mechanical properties without changing the surface shape. The alloy Inconel 625, which is very popular in the aerospace industry have been developed as a feed material of FMEAM. However, for developing rotating parts, such as turbine blades, impact toughness, surface roughness and microstructure need to be investigated. This research was conducted to determine the effect of the infill pattern on the impact toughness, morphology of surface fracture, microstructure of side surface and surface roughness with Inconel 625 material built using FMEAM. The Charpy impact test, s ASTM 23, with v-notch testing method and SEM with EDS were performed. The results showed that the impact toughness for solids was higher than the value for the triangular infill pattern. It was discovered that the cavities in the triangular lattice structure within the specimen reduced the impact toughness to 57.6%. Micropores and residual polymer trapped on the surface reduce impact toughness. However, the same surface shape on solid and triangular infill patterns with surface roughness of 2.44 and 10.03 µm is still feasible for manufacture.

Nutritional composition, antioxidant activity and gossypol level of Nazilli glandless cottonseed, cottonseed kernel and their cold-pressed meal

BackgroundThe study was conducted to determine the nutrient composition and gossypol levels of glandless cottonseed (GCS), glandless cottonseed kernel (GCSK) glandless cottonseed meal (GCSM) and cottonseed kernel meal (GCSKM) obtained by cold pressing of cotton seeds and kernels (Glandless Nazilli variety) as a raw material of compound feed industry.ResultFeed and dry matter (DM)-based nutrient analyses showed significant differences (p < 0.05) in DM, OM (organic matter), CP (crude protein), EE (ether extract), ash and NFE (nitrogen-free extract) contents between GCS and GCSK. The DM-based K, P, S, Mg, Ca, Na, Fe, Cu, Zn and Al contents were significantly different (p < 0.05) between GCS and GCSK. The concentrations of nonessential heavy metals (Cd, Pb, Ni and Al) in GCS, GCSK, GCSM and GCSKM samples were below the permissible limits. The linoleic acid (C18:2; ω6) was the main component (55.55%) among the 20 fatty acids identified in GCS oil. The level of unsaturated fatty acids (70.78%) was higher than that of saturated fatty acids (29.22%). Total phenolics concentrations of GCS, GCSK, GCSM and GCSKM samples were 7.87, 2.18, 5.86 and 1.91 mg gallic acid equivalents (GAE)/g, respectively. Free and total gossypol levels of GCS and GCSK were 294 and 440, and 521 and 706 mg/kg, respectively.ConclusionThe results revealed that nutritional properties of Nazilli GCS with low gossypol and high linoleic acid content were relatively higher compared to the other meals investigated. The antioxidant activity of phenolic compounds, albeit at low levels in Nazilli GCS and GCSM, may contribute to animal health and production efficiency when used in animal rations.

Physical Characteristics Content Evaluation of Feed Containing Termite as a Potential Alternative for Fish Feed

Termite flour is very promising as a raw material for snakehead feed to substitute fish meals. The good raw material and composition will produce quality artificial feed with a high level of water stability, preferred and safe for fish. The purpose of this study was to evaluate the quality of snakehead feed at various levels of substitution of fish meal with termites based on physical tests. The treatments given were the subtitution 0, 9, 6, 12% of fish meal with termite flour. The feed physical test results include water stability, homogeneity level, bouyancy, attractability, and storability. The results showed that the substitution of fish meal with termite flour was able to maintain water stability for more than 24 hours, the level of feed homogeneity was quite uniform in all treatments, the pungent aroma of feed preferred by snakehead was proven by the results of the feed allureness test which showed that the feed was eaten by snakehead in less than 5 seconds. The test results showed that the level of substitution of fish meal with termite flour with different levels resulted in feed with relatively the same quality in all treatments.

Exploring the Health Benefits of Yeast Isolated from Traditional Fermented Foods in Korea: Anti-Inflammatory and Functional Properties of Saccharomyces and Non-Saccharomyces Strains.

Traditional yeast (Saccharomyces cerevisiae) has been used for its benefits in various fermentation processes; the benefits of non-Saccharomyces yeast as a material for food, feed, and pharmaceuticals have been studied recently. This study evaluated the anti-inflammatory activity and extracellular functional characteristics of wild-type yeasts isolated from traditional fermented foods (doenjang (common name: soybean paste) and nuruk) in Korea. The viability of the yeast and lipopolysaccharide (LPS)-stimulated RAWBlue™ cells was improved, similar to unstimulated RAWBlue™ cells, and the isolates demonstrated NF-κB inhibitory activity. Yeast suppressed the nitric oxide production in LPS-stimulated RAWBlue™ cells, which was attributed to the inhibition of iNOS or COX-2 mRNA expression depending on the strain. Although there were differences depending on the strain, the production of anti-inflammatory cytokines was reduced in the yeast and LPS-stimulated RAWBlue™ cells, some of which were demonstrated at the mRNA level. In addition, the isolates exhibited high antioxidant and antihypertensive activities (similar to the positive control), which varied depending on the strain. This suggests that yeast can be used for fermentation with enhanced antioxidant and antihypertensive activities. Furthermore, the isolates inhibited the growth of pathogenic Gram-negative bacteria, indicating that yeast can inhibit food spoilage and the growth of pathogenic bacteria during fermentation. Consequently, utilizing raw materials to cultivate yeast strains could be a promising avenue for developing functional foods to prevent and treat inflammatory reactions; such foods may exhibit antioxidant, antihypertensive, and antibacterial properties.

Pemanfaatan Tepung Lemna sp. dan Enzim Non-Starch Polysaccharides (NSPs) Pada Pakan Ikan Tambakan (Helostoma temminckii)

Lemna sp. is one of the local raw materials that can be used to substitute fish flour and soybean meal in fish feed formulation because its protein contain. However, protein plant-based in fish feed formulation need additional enzyme (exogenous) such as Non starch polysaccharides (NSP) enzyme which able to increase feed digestibility. The aim of this study is to determine the effect of NSP enzyme to Lemna sp. flour in feed formulation for kissing gouramy’s growth and feed efficiency. This research has been conducted at the Experimental Pond Laboratory, Aquaculture Study Program and Laboratory of Chemical and Microbiology of Agricultural Products, Department of Agricultural Technology, Faculty of Agriculture, Sriwijaya University. Juvenile kissing gourami 4±0,5 cm in length were used and culture in certain condition which was temperature 25-27 °C, pH 6, dissolved oxygen &gt; 2.5 mgL-1 and ammonia &lt;0.1 mgL-1. The Rovabio Excel AP10 T-Flex were used as NSP enzyme. Completely Randomized Design (CRD) was used with 4 treatments (Tn) and 3 replications, namely the addition of Lemna sp. flour 0% without enzyme (T0), addition of Lemna sp. flour 0% with enzyme (T1), addition of Lemna sp. flour 5% without enzyme (T2), addition of Lemna sp. flour 5% with enzyme (T3). NSP enzyme dose is 1 g/kg feed material. The results showed that T3 gave the best results with absolute weight growth 0.91 g, absolute length growth 0.63 cm, specific weight growth rate 1.35% day-1, specific length growth rate 0, 41% day-1, survival 100%, and feed efficiency 28.59%.

Determination of four aflatoxins in feeds by high throughput automated immunoaffinity magnetic beads purification-ultra performance liquid chromatography

Aflatoxin (AFT) is an extremely toxic and highly toxic carcinogenic substance. This is particularly problematic due to the risk of aflatoxin contamination in raw feed materials and products during production, transportation, and storage. In this study, immunoaffinity magnetic beads (IMBs) were prepared for the purification of four aflatoxins (aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2)). The aflatoxin contents were then determined rapidly and accurately using ultra performance liquid chromatography (UPLC). More specifically, the coupling ratio of magnetic beads (MBs) to the aflatoxin monoclonal antibody was initially optimized, wherein an MB volume of 1 mL and an antibody content of 2.0 mg was found to meet the purification requirements of this method. The magnetic properties of the MBs and the IMBs were then investigated using a vibrating sample magnetometer (VSM) at room temperature. As a result, the maximum saturation super magnetizations of the MBs and the IMBs were determined to be 28.61 and 23.22 emu/g, respectively, indicating that the saturation magnetization intensity of the IMBs was reduced by coupling with a non-magnetic antibody. However, the saturation magnetization intensity remained sufficiently high to permit magnetic separation from the solution. In addition, the appearance of the IMBs was examined using a biomicroscope, and it was clear that the magnetic cores were wrapped in agarose gel. Furthermore, the reaction time between the IMBs and the aflatoxins was investigated, and the optimal reaction time for meeting the purification requirements was determined to be 2 min. The stability of the IMBs was then evaluated under refrigerated storage conditions at 4 ℃. It was found that the prepared IMBs maintained a high aflatoxin enrichment capacity for at least eight months. Through the examination of three different extraction solutions, a mixture of acetonitrile and water (70∶30, v/v) was found to be optimal for the extraction of aflatoxins from the feed samples. Moreover, five sample dilutions and purification effects were also examined, and phosphate-buffered saline (containing 0.5% Tween-20) was selected as the preferred sample dilutant. With the optimized conditions, the effectiveness of using IMB for the purification of different feed samples was investigated. The resulting UPLC chromatogram showed no spurious peaks close to the target peaks, demonstrating a good purification performance. Following matrix spiking (5, 20, and 40 μg/kg, calculated based on AFB1) of the four feed samples (i. e., soybean meal, distillers dried grains with solubles, pig feed, and chicken feed), the spiked recoveries of the four aflatoxins ranged from 91.1% to 119.4% with a relative standard deviation (RSD) of <6.9%. In addition, the inter-day precision was 4.5% to 7.5%, and the method exhibited a good reproducibility. Subsequently, the developed method was used to detect AFB1 using reference materials. The test value was 18.6 μg/kg with an accuracy of 110.3%, thereby constituting satisfactory results. Upon testing 21 randomly purchased feed samples using this method, four of these samples contained AFB1, and the test results obtained using the developed method and stable isotope dilution LC-MS/MS were comparable. It was therefore apparent that the IMB purification method combined with UPLC analysis exhibited a good accuracy for aflatoxin determination. Thus, an automatic purification system was established to facilitate the operation and use of IMBs. This system was able to purify 24 samples simultaneously in 30 min. An IMB purification kit for was also designed and produced for aflatoxin detection in feed samples. The kit contained the sample dilutant, IMBs, the washing solution, and the eluent. After extraction of the feed sample, the extraction solution was added to the sample wells provided in the kit, and the purification system automatically completed the steps of aflatoxin enrichment, impurity washing, and elution of the target toxin. It should be noted that the purification process does not require the operator to manually add the solution, thereby simplifying operation. Overall, the purification method established in this study achieved the high-throughput and automatic purification of the four aflatoxins in feed samples.

The Role of Wildlife and Pests in the Transmission of Pathogenic Agents to Domestic Pigs: A Systematic Review.

Wild animals and pests are important reservoirs and vectors of pathogenic agents that can affect domestic pigs. Rapid globalization, anthropogenic factors, and increasing trends toward outdoor pig production facilitate the contact between domestic pigs and wildlife. However, knowledge on the transmission pathways between domestic pigs and the aforementioned target groups is limited. The present systematic review aims to collect and analyze information on the roles of different wild animal species and pests in the spread of pathogens to domesticated pigs. Overall, 1250 peer-reviewed manuscripts published in English between 2010 and 2022 were screened through the PRISMA framework using PubMed, Scopus, and Web of Science databases. A total of 84 studies reporting possible transmission routes of different pathogenic agents were included. A majority of the studies (80%) focused on the role of wild boars in the transmission of pathogenic agents to pig farms. Studies involving the role of rodents (7%), and deer (6%) were the next most frequent, whereas the role of insects (5%), wild carnivores (5%), wild birds (4%), cats (2%), and badgers (1%) were less available. Only 3.5% of studies presented evidence-based transmission routes from wildlife to domestic pigs. Approximately 65.5% of the included studies described possible risks/risk factors for pathogens' transmission based on quantitative data, whereas 31% of the articles only presented a hypothesis or qualitative analysis of possible transmission routes or risk factors and/or contact rates. Risk factors identified include outdoor farms or extensive systems and farms with a low level of biosecurity as well as wildlife behavior; environmental conditions; human activities and movements; fomites, feed (swill feeding), water, carcasses, and bedding materials. We recommend the strengthening of farm biosecurity frameworks with special attention to wildlife-associated parameters, especially in extensive rearing systems and high-risk zones as it was repeatedly found to be an important measure to prevent pathogen transmission to domestic pigs. In addition, there is a need to focus on effective risk-based wildlife surveillance mechanisms and to raise awareness among farmers about existing wildlife-associated risk factors for disease transmission.