Animal Residues Research Articles

Current Trends in Biological Valorization of Waste-Derived Biomass: The Critical Role of VFAs to Fuel A Biorefinery

The looming climate and energy crises, exacerbated by increased waste generation, are driving research and development of sustainable resource management systems. Research suggests that organic materials, such as food waste, grass, and manure, have potential for biotransformation into a range of products, including: high-value volatile fatty acids (VFAs); various carboxylic acids; bioenergy; and bioplastics. Valorizing these organic residues would additionally reduce the increasing burden on waste management systems. Here, we review the valorization potential of various sustainably sourced feedstocks, particularly food wastes and agricultural and animal residues. Such feedstocks are often micro-organism-rich and well-suited to mixed culture fermentations. Additionally, we touch on the technologies, mainly biological systems including anaerobic digestion, that are being developed for this purpose. In particular, we provide a synthesis of VFA recovery techniques, which remain a significant technological barrier. Furthermore, we highlight a range of challenges and opportunities which will continue to drive research and discovery within the field. Analysis of the literature reveals growing interest in the development of a circular bioeconomy, built upon a biorefinery framework, which utilizes biogenic VFAs for chemical, material, and energy applications.

Livestock waste management practices to strengthen the farm profitability

“Livestock waste” means livestock manure, unconsumed feed and associated bedding materials or litter and animal carcasses from normal mortalities of livestock on a farm. Waste management includes the activities and actions required to manage waste from its inception to its final disposal. Livestock wastes if not manage properly it may lead to fecal contamination of waters receiving agricultural runoff. The danger to humans lies in the possibility of these fecal organisms entering water and food supplies. Groundwater and surface waters may harbor pathogens originating from animal fecal deposits. Animal waste contains many beneficial constituents that if recycled effectively, can be used as fertilizer for crops, fodder for animals and to produce energy. There are a number of methods of livestock waste management to enhance farm profitability. Which are composting, biogas production, rotator drum composting, vermicomposting, biodynamic fertilizer etc. Composting is an accelerated bio-oxidation of organic matter passing through a thermophilic stage, where microorganisms liberate heat, carbon dioxide and water. Biogas is clean environment friendly fuel that can be obtained by anaerobic digestion of animal residues and domestic and farm wastes, abundantly available in the countryside. Biogas is bacterial conversion of organic matter in to gases under anaerobic conditions. The earthworm eats the organic matter and excretes little pelleted material called “vermicompost”. During vermicomposting, the important plant nutrients, such as N, P, K, and Ca present in the organic waste are released and converted into forms that are more soluble and available to the plants. Among all advance methods biogas production and vermicomposting are most common in India. Livestock waste contains significant amounts of micro-organisms which make it a source of major risk to the public. Risks of nutrients, organic material and pathogens containing water bodies and food products are common with increased livestock waste spread.

Variations in Methods for Quantification of Crude Ash in Animal Feeds.

Crude ash is categorized as an empirical method playing an important role in the nutritional interpretation of animal feeds, allowing indirect estimation of total organic matter (OM). Our objective was to evaluate variations in laboratory procedures for crude ash quantification regarding physical parameters (i.e., time, temperature) and ashing aids and their influences on crude ash, repeatability, and discrimination power among feeds. The "control" method was based on a simple ignition time of 3 h at 550°C. The variations are briefly described: increasing ashing time to 6 h; increasing temperature to 600°C; and using two 3 h ignition cycles at 550°C with ashing aids inclusion between them: fresh air supply, fresh air supply plus distilled water, and fresh air supply plus hydrogen peroxide. A color evaluation was also performed using a colorimetric technique. Twenty-four study materials from eight different feed types were evaluated. The crude ash results differed among the method variations, but a consistent decrease in the estimates was observed when liquid aids were applied, which also improved repeatability. Ash residues did not present a consistent color pattern among methods, but the residues were darker when the control method was applied. The method of obtaining ash residues in animal feeds based on 550°C × 3 h does not have enough robustness and may overestimate crude ash in some feeds. Adjustments in either ignition time or temperature might improve crude ash test results, but the best test results are obtained using liquid ashing aids between two ignition cycles. The recommended method is based on the use of 550°C and two 3 h ignition cycles with water added to the ash residue between cycles.

Composting Animal and Plant Residues for Improving the Characteristics of a Clayey Soil and Enhancing the Productivity of Wheat Plant Grown Thereon

Composting Animal and Plant Residues for Improving the Characteristics of a Clayey Soil and Enhancing the Productivity of Wheat Plant Grown Thereon

Synergies during hydrothermal liquefaction of cow manure and wheat straw

Agribusiness crop and animal residues constitute some of the major waste streams worldwide. Among them, wheat straw and cow manure are large contributors to the quantities generated. Both materials can be converted using hydrothermal liquefaction (HTL) for recovery of biocrude and here we investigate how combined HTL processing can be of great interest to boost biocrude production and carbon recovery. This study presents batch HTL experiments using individual and blended feedstock mixtures to build predictive models for biocrude, carbon and energy recovery. These models are validated using a continuous HTL pilot plant. The combined approach led to the nitrogen-containing compounds present in cow manure to react with lignocellulosic-derived compounds from wheat straw and divert carbon into the oil phase, the reason for which biocrude, carbon and energy yields were drastically improved. Continuous HTL pilot plant campaigns successfully demonstrated increased carbon yields from 40% to 60% when using optimal feedstock ratios. Continuous data also shows the great benefits of increasing the organic matter concentration input with combined processing, resulting in total energy efficiencies larger than 50% and energy return over investment of 2.6, compared to 1.3–1.9 for individual feedstock processing.

Review on drug residue in foods of animal origin and its public healthy importance and methods of detection in Ethiopia

Veterinary pills are utilized in Food animals now no longer handiest for remedy however additionally for manipulate of diseases, prevention and boom promoter. They have the ability to generate residues in animal derived merchandise. Common pills which can be administered to animal are antimicrobial pills, anti-parasitic compounds and boom promoters. Factors influencing the incidence of residues are age of animal, feeding, disorder status, pharmacokinetics and extra-label drug use. So, it wishes a few ideas to observe to assess protection of meals consisting of ADI, MRL and calculating withdrawal time. Veterinary drug residue in meals of animal beginning can be the purpose critical public fitness in human. These issues may also include: improvement of drug resistance, drug allergy response and carcinogenic, mutagenicity, teratogenicity, and disruption of intestinal ordinary flora. To locate and pick out antimicrobial residue in meals of animal beginning makes use of screening check and confirmatory checks used. There are one-of-a-kind screening checks utilized in latest time consisting of immunoassays, microbiological checks and Biosensors. In addition, use confirmatory checks like HPLC and TLC. Although drug residues purpose critical public fitness impacts, little is understood through the society and there may be loss of records approximately it, in order that its miles crucial to study on drug residue in meals of animal beginning to perception its public fitness importance. so, there are approaches to save you and manipulate drug residues in meals of animal beginning through carrying out the subsequent measurements consisting of the drug merchandise must be used according with the categorized directions, public consciousness must be created on the general public fitness importance of drug residue the use of one-of-a-kind media, administer all pills well and pick out all dealt with animals, use handiest pharmaceuticals with veterinary steerage and hold drug well.

Role of miR-451 in mediating cadmium induced head kidney injury in common carp via targeting cacna1ab through autophagy pathways.

Cadmium (Cd) is a common environmental pollutant, which leads to Cd residue in aquatic animals. The Cd in aquatic animals will be enriched into the human body through the food chain and seriously harm human health. The research aims to investigate the molecular mechanism of Cd poisoning in common carps. Our previous studies have confirmed that 23 differentially expressed miRNAs were potential biomarkers for Cd exposure in common carp head kidney lymphocytes. Herein, based on the prediction of the website and previous studies, miR-451 and cacna1ab were selected and their targeting relationship was verified again by dual-luciferase. Subsequently, we established the miR-451 overexpression/knockdown models and miR-451 inhibitor, cacna1ab co-knockdown models in common carp head kidney lymphocytes respectively. Immunofluorescence staining, MDC staining, calcium staining, qRT-PCR (Quantitative Real-time PCR) and western blot were used to detect the levels of autophagy. Our results demonstrated that Cd significantly decreased the expression of miR-451, miR-451 suppression thereby induced increased cacna1ab and the expression of ATG5, LC3-I, LC3-II and Beclin 1, while significantly inhibiting the expression of mTOR, P62 and Bcl-2, which indicated that autophagy was triggered. Moreover, the miR-451 knockdown group activated the expression of autophagy related factors as well as the Cd group. However, cacna1ab knockdown can reduce autophagy activation induced by miR-451 knockdown. Our results indicated that Cd induced autophagy in head kidney lymphocytes through the inhibition of miR-451 and the excitation of cacna1ab.

A Universal LC-MS/MS Method for Simultaneous Detection of Antibiotic Residues in Animal and Environmental Samples.

Detecting and monitoring the usage of antibiotics is a critical aspect of efforts to combat antimicrobial resistance. Antibiotic residue testing with existing LC-MS/MS methods is limited in detection range. Current methods also lack the capacity to detect multiple antibiotic residues in different samples simultaneously. In this study, we demonstrate a methodology that permits simultaneous extraction and detection of antibiotic residues in animal and environmental samples. A total of 30 different antibiotics from 13 classes could be qualitatively detected with our methodology. Further study to reduce analytes’ matrix effect would allow for quantification of antibiotic residues.

Sequential removal of chromium (VI) and prednisolone by nanobiochar- enriched-diamine derivative

Biochars are biosorbents made from a wide range of agricultural or animal residues that involve functional groups to enable binding with different species. In the current work, pyrolysis of artichoke leaves was done to generate nanobiochar (NanoBch) and enriched with ethylenediamine (EDA) as nitrogen-rich derivative to yield (NanoBch-EDA). This was characterized by different techniques and compared with NanoBch. The evaluated NanoBch-EDA showed promising removal performance under optimized conditions of contact time, nanosorbent dosage, initial concentration of Pn and Cr(VI), pH, temperature, and interfering ions. The elimination processes of Pn and Cr(VI) onto (NanoBch-EDA) by four isotherm models (Langmuir, Dubinin-Radushkevitch, Temkin, and Freundlich) were discussed. In Pn elimination process, the Langmuir model achieved (R2 = 0.99) as the highest correlation coefficient. Otherwise, the Freundlich (R2 = 0.98) was the applicable model in Cr(VI) elimination. The values of maximum capacity qmax (mg g−1) for adsorption of Pn and Cr(VI) onto NanoBch-EDA were 21.93 and 79.37 mg g−1, respectively. Based on the obtained R2 (0.999), the pseudo-second-order model was shown to be the superlative match for describing the elimination of Pn and Cr(VI) by NanoBch-EDA. The reaction was stated as spontaneous and endothermic based on parameters signs and values obtained from thermodynamic studies. NanoBch-EDA (60 mg) was found highly effective in extracting 95.0%, 90.0%, and 92.0% of Pn (25 mg L−1) from tap, waste, and sea water, respectively, while 20 mg of NanoBch-EDA removed 96.0%, 94.6%, and 97.3% of Cr(VI) 10 mg L−1 from tap, waste, and sea water, respectively.

Diagnosis and management of obstructive urolithiasis in miniature pigs.

This article provides information to assist practitioners in the diagnosis, medical, and surgical management of obstructive urolithiasis in miniature pigs. The article focuses primarily on pigs managed as pets because production swine rarely undergo intensive treatment for urolithiasis. As much as possible, the information in this article is based on published literature, but given the limited number of publications addressing obstructive urolithiasis in pigs, some information is based on the authors' clinical experience. Medical and surgical management of obstructive urolithiasis of pigs is often similar to management in ruminant and small animal species, but differences in swine anatomy, handling, and temperament create unique challenges. Pigs tend to be more difficult to restrain and examine than other livestock and often require heavy sedation or anesthesia to facilitate physical examination and basic diagnostic procedures. Because pigs are monogastrics, some oral treatments used in small animals may be used effectively in pigs. Clinicians should follow AMDUCA and consult the Food Animal Residue Avoidance Databank prior to extralabel drug use because pet pigs are still considered a major food-producing species in the United States.

An Interactive Generic Physiologically Based Pharmacokinetic (igPBPK) Modeling Platform to Predict Drug Withdrawal Intervals in Cattle and Swine: A Case Study on Flunixin, Florfenicol, and Penicillin G.

Violative chemical residues in edible tissues from food-producing animals are of global public health concern. Great efforts have been made to develop physiologically based pharmacokinetic (PBPK) models for estimating withdrawal intervals (WDIs) for extralabel prescribed drugs in food animals. Existing models are insufficient to address the food safety concern as these models are either limited to 1 specific drug or difficult to be used by non-modelers. This study aimed to develop a user-friendly generic PBPK platform that can predict tissue residues and estimate WDIs for multiple drugs including flunixin, florfenicol, and penicillin G in cattle and swine. Mechanism-based in silico methods were used to predict tissue/plasma partition coefficients and the models were calibrated and evaluated with pharmacokinetic data from Food Animal Residue Avoidance Databank (FARAD). Results showed that model predictions were, in general, within a 2-fold factor of experimental data for all 3 drugs in both species. Following extralabel administration and respective U.S. FDA-approved tolerances, predicted WDIs for both cattle and swine were close to or slightly longer than FDA-approved label withdrawal times (eg, predicted 8, 28, and 7 days vs labeled 4, 28, and 4 days for flunixin, florfenicol, and penicillin G in cattle, respectively). The final model was converted to a web-based interactive generic PBPK platform. This PBPK platform serves as a user-friendly quantitative tool for real-time predictions of WDIs for flunixin, florfenicol, and penicillin G following FDA-approved label or extralabel use in both cattle and swine, and provides a basis for extrapolating to other drugs and species.

Effects of Glycyrrhiza Polysaccharides on Chickens' Intestinal Health and Homeostasis

The overuse of antibiotics in poultry farming causes the accumulation of drug residue in animals' bodies and the occurrence of antibiotic-resistant bacteria, which not only compromise animals' health but ultimately endanger human health. Thus, there is an urgent need for a novel poultry feed additive to substitute for excessive antibiotics. Glycyrrhiza polysaccharides (GPS) derived from Chinese licorice have shown promising immunomodulatory effects in previous studies. The present study investigated the pharmacological effects of GPS on poultry intestines to assess whether it can be used as a feed additive. The results show that GPS can increase production of sIgA, promote the secretion activity of goblet cells, alter the gut microbial composition and lead to changes in short-chain fatty acids. GPS also elevated both Th1 and Th2 immune responses by facilitating the expression of IL-2, IL-4, IL-1β, and IFN-γ while increasing the proportion of both CD4+ and CD8+ cells in the intestine. Moreover, the results of 16S rRNA gene sequencing showed that GPS could significantly change intestinal microbiota composition in the intestine, evidenced by the increased proportion of Bacteroides, Butyricicoccus and Eisenbergiella, as well as a decreased portion of Erysipelatoclostridium, leading to a healthier intestinal microbiota composition for the host. Taken together, it can be concluded that GPS is safe to use as a novel feed additive that can be used as an alternative to prophylactic antibiotics in poultry feeding.

Organochlorine and Organophosphorus Pesticides Residues in Commercial Poultry Feed Samples in Lagos State, Nigeria

Pesticides are among Persistent Organic Pollutants (POP) used in agricultural practices to increase production efficiency. They enter the food chain, bioaccumulate and are toxic to human, animals and the environment. The presence of pesticide residues in animal feeds has been rarely monitored and reported in Nigeria. This study evaluated the levels of pesticide residues in different brands and types of poultry feeds that are produced, marketed and used in Lagos, Nigeria. Five types of five commonly used commercial brands (25 samples) of poultry feeds were purchased from animal feed markets in Lagos, Nigeria. Simultaneous detection and quantitation of selected thirteen (13) OCPs and eight (8) OPs residues in the feeds was carried out using Gas Chromatography-Electron Capture Detector (GC-ECD) and Gas Chromatography-Flame Ionization Detector (GC-FID) respectively. Results revealed that all the feed samples had multiple pesticide residues levels which ranged from 0.10 - 1.83 mg/kg for OCPs and 0.25 - 6.04 mg/kg for OPs. These values were above the Maximum Residual Limit (MRL). The detected pesticide residues order of violation of the MRL was Methoxychlor > Dieldrin >Endrin ketone for OCPs, and Trichlorfon > Malathion > Diazinon for OPs. There was no significant (p>0.05) differences in the pesticide residues levels among the brands and types of the samples. Present study indicates extensive and unwholesome use of pesticides in the agro industry in Nigeria suggesting need to enforce Good Agricultural Practices (GAP), Good Storage Practices (GSP), Good Manufacturing Practices (GMP) and constant monitoring of pesticide residues thereby implementing the Good health and Wellbeing (Goal 3) of the 2030 Sustainable Development Goal.

Effects of early florfenicol exposure on glutathione signaling pathway and PPAR signaling pathway in chick liver

Florfenicol (FFC) is a common antibiotic for animals. The nonstandard and excessive use of FFC can cause veterinary drug residues in animals, pollute soil and marine environment, and even threaten human health. Therefore, it is necessary to study the toxicity and side effects of FFC on animals. Our previous studies have proved that FFC can cause liver injury in chicks, but there are few in-depth studies on the mechanism of FFC causing liver injury at the level of signaling pathway in chicks. Therefore, transcriptome and proteome sequencing were performed and combined analysis was performed. Sequencing results showed that 1989 genes and 917 proteins were significantly changed in chick livers after FFC exposure. These genes and proteins are related to redox, glutathione transferase activity and lipid metabolism. There are 9 significantly different genes and 7 significantly different proteins in glutathione signaling pathway. Oxidative stress may occur in the liver of chicks through the change of activation state of glutathione signaling pathway. And there are 13 significantly different genes and 18 significantly different proteins in PPAR signaling pathway. The changes of PPAR signaling pathway may induce lipid metabolism disorder in liver. The verification results of qPCR and PRM were consistent with the sequencing results. We also detected GSH-Px, GSH, GST, TG, TC and ANDP levels in liver. These changes of biochemical indicators directly confirmed oxidative stress and lipid metabolism disorders were occurred in the livers of chicks treated by FFC. In conclusion, FFC could induce liver injury in chicks by regulating the expression levels of significantly different genes and proteins in glutathione signaling pathway and PPAR signaling pathway.

Organic residue analysis reveals the function of bronze age metal daggers

The article discusses results of organic residue analysis performed on ten copper-alloy daggers from Bronze Age Pragatto, Italy, c.1550–1250 BCE. Metal daggers are widespread in Chalcolithic and Bronze Age Europe, yet their social and practical roles are still hotly debated. Are they symbolic or functional? Are they tools or weapons? How were they used? For what tasks and on what materials? The research addresses these questions through a novel application of biochemical staining and SEM–EDX analysis. The method has proved successful in extracting and identifying animal residues located on cutting edges including bone, muscle, and tendons. These are interpreted as evidence of prehistoric carcass butchering and carving. Further residues were observed on blade faces and hafting plates or tangs; these are interpreted as remnants of bone handles and sheaths, the latter made of either wood fibers or processed hide and fur. The readings proposed in the article are validated by original experiments with replica daggers, as detailed in the Supplementary Materials. The analysis and experiments shed new light on Bronze Age metal daggers, showing that they were fully functional tools (and perhaps tool-weapons) primarily utilized for the processing of animal carcasses. This original research result contributes significant knowledge towards interpreting an under-studied, yet socially salient, prehistoric metal artifact.

Medicinal Earthworm: Speciation and Bioaccessibility of Arsenic and Its Potential Health Risks.

Arsenic in environmental health has caused public concerns all over the world. However, high levels of arsenic residues in medicinal animals have not received enough attention. Medicinal earthworms are consumed widely in China, but its arsenic potential health risks to humans are unknown. This work investigated the total concentration, bioaccessibility, and speciation of arsenic in earthworms by ICP-MS and HPLC-ICP-MS to evaluate its potential health risks to humans. Arsenic was found in all earthworms at concentrations ranging from 0.4 to 53.6 mg kg−1. The bioaccessibility of arsenic (bAs) varied significantly and ranged from 12.1 to 69.1%, with inorganic arsenic (iAs, including As(III) and As(V)) as the predominant species. Furthermore, a small amount of arsenobetaine (AB) was found. The estimated daily intake dose (EDI), hazard quotient (HQ), and carcinogenic risk (CR) of arsenic in most of the samples exceeded the safe threshold level. Results from this study indicated that the potential health risks by the consumption of earthworms may not be negligible. Herein, recommendations for the use of earthworms and regulatory recommendations for arsenic limit standards were proposed. This study reminds us that more control and monitoring of arsenic in medicinal animals should be carried out.

Hydrothermal synthesis of similar mineral-sourced humic acid from food waste and the role of protein

Food waste is a challenging biomass resource due to its high moisture content, low calorific value, and complex composition. Natural humification of animal and plant residues is highly related to microorganism activity, but natural hydrothermal conditions are also speculated to play a significant role. In this work, a novel method for the conversion of food waste into artificial humic acid (HAa) under hydrothermal conditions is proposed. The results revealed that an optimum HAa yield of 43.5% from food waste was successfully obtained at 215 °C for only 1 h. Detailed analyses, including elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectroscopy, showed that the produced HAa had similar structures and compositions with natural HA extracted from minerals. Moreover, the proteins contained in the food waste significantly promoted HA formation through the reaction of saccharides with amino acids, in which Maillard-like reactions were the key steps. These results not only provide experimental evidence for verifying the role of hydrothermal reactions in transforming food waste into humic acid but also provide insight into effective resource utilization of food waste.

Revisit soil organic matter

<p indent="0mm">The accurate and comprehensive understanding of the molecular composition, source, and stabilization mechanism of soil organic matter (SOM) is vital for soil management and the preservation of organic carbon. Currently, a series of key scientific issues concerning the formation and stabilization of SOM is highly contentious. This review summarized the advances in the sources and molecular structure of SOM, and presented a systematic analysis of the different views, conflicts, and problems concerning soil humic substances in the past decades. The traditional view of soil science believes that SOMs are mainly composed of humic substances which are macromolecular compounds and are derived from plant and animal residues through a series of mineralization and humification processes. Soil enzymes and minerals, including phenol oxidase, laccase, peroxidase, iron oxide, manganese oxide, promote the polymerization of organic molecules through additive nucleophilic reactions and free radical catalyzation. ¹³C-NMR and FT-ICR-MS analyses supported the existence of humic substances in soils based on the structure and the molecular composition of SOM. However, with the application of biomarker analysis, high-resolution mass spectrometry, spatial resolution spectroscopy, and other advanced techniques, there is an emergence of new perspectives on the source and the structure of SOM. HPLC-SEC showed the average molecular weight of Aldrich humic acid was significantly smaller than previously thought and the aggregation of humic substances was affected by acetic acid, pH and ionic strength. These evidences suggest that humic substances are aggregates of small organic compounds with a molecular weight of hundreds to thousands of Daltons, rather than macromolecules of tens to hundreds of thousands of Daltons. Furthermore, <italic>in situ</italic> observation of soil particles by STXM revealed significant heterogeneity of SOM at <sc>50 nm</sc> spatial resolution. In terms of the origin of SOM, model calculations and biomarker analysis have indicated that microbial necromass is the major constituent of SOM which accounts for ~33%–62% of SOM in different ecosystems. Collectively, microbial residues may contribute predominantly to the SOM pool and traditional concept “humification” may not occur in the soil. These new findings are contrary to the traditional theory of soil chemistry and soil biochemistry and subvert our understanding of SOM. Therefore, it is imperative to perform further in-depth studies to fill the knowledge gaps regarding the sources, formation processes, and molecular structures of humus. However, further intensive investigations on SOM are restricted by the lack of efficient and reliable extraction procedures. In addition, the conversion coefficients from biomarker to necromass are not accurate and mass spectrometry could not provide a comprehensive analysis on the whole organic molecules in the soil. The studies on enzymatic reactions and microbial synthesis were mainly performed in simple suspension systems, which could not simulate the complex soil matrix. Consequently, future studies are needed to improve the efficiency and accuracy of the extraction and analysis of SOM and to develop a real-time study platform for the interfacial reactions among minerals, organic matters and microorganisms. Meanwhile, <italic>in situ</italic> characterization techniques and modeling should be employed and combined to clarify the sources and the underlying mechanisms of SOM stabilization at molecular level.

Hormones residues in bovine animals: Sampling, analysis and health risk assessment

The use of hormones for breeding animal livestock has been banned since 1981 under the Council Directive 81/602/EC. So far, each country should monitor the use of anabolic hormones in animal production to protect the consumer's health against these unwanted residues. This paper presents the research results on steroid and non-steroid hormones residues carried out in Lebanon from 2018 to 2020. Using a newly developed and validated LC-MS/MS method, the detection and the quantification of hormones in bovine matrices were done. The targeted matrices were muscle, liver, kidney, and bile. A total of two-hundred and forty-seven samples were collected from different slaughterhouses located in six different cities in Lebanon. Interestingly, only four hormones were found: testosterone, progesterone, epitestosterone, and 6 propyl 2thiouracil. Based on the obtained data, the estimated daily intake, hazard quotient, and hazard index were calculated to evaluate an exposure assessment.

Multi residue determination of 96 veterinary drug residues in domestic livestock and fishery products in South Korea

This study was to develop a multi-residue quantification method for determination of 96 veterinary drugs in livestock products (beef, pork, chicken, milk, egg) and fishery products (flatfish, eel, and shrimp) using liquid chromatography-tandem mass spectrometry. In addition, the purpose of this study was to verify the identification of veterinary drug residues by applying this analytical method to livestock and aquaculture animals. The coefficient of determination (r2) was more than 0.98 at the matrix-matched calibration curve. The proposed method was validated according to the CODEX guidelines (CAC/GL-71-2009), and most target compounds were found to be in acceptable quantities under the requirements of the validation guidelines. The limit of detection and limit of quantification ranged from 0.3 to 19.7 μg kg−1 and 1 to 65 μg kg−1. Samples (n = 581) were collected and analyzed to investigate the residues in target animal derived foods and 131 samples were detected (22.5%). In addition, only one rockfish sample exceeded the Korean MRL for sulfadiazine (523 μg kg−1; MRL: 100 μg kg−1) and trimethoprim (195 μg kg−1; MRL: 50 μg kg−1). The most frequently detected veterinary drugs were flumequine followed by oxytetracycline, enrofloxacin, trimethoprim, ciprofloxacin, and mebendazole. These results showed that we developed an acceptable analytical method of 96 veterinary drugs in animal derived foods and it will be useful for the safety management of veterinary drugs in livestock products, fish, and shrimp.