[Analytical Method for Melengestrol Acetate in Livestock Products Using LC-MS/MS].

The present study verified that it is possible to analyze melengesterol acetate using the existing multi-residue method. Melengestrol acetate was extracted from livestock products using acidic acetonitrile acidified with acetic acid in the presence of n-hexane and anhydrous sodium sulfate. The crude extracts were cleaned up using an octadecylsilanized silica gel cartridge column. Separation by HPLC was performed using an octadecylsilanized silica gel column with linear gradient elution of 0.1 vol% formic acid and acetonitrile containing 0.1 vol% formic acid. For the determination of the analyte, tandem mass spectrometry with positive ion electrospray ionization was used. In recovery tests using four livestock products fortified with maximum residue limits levels of melengestrol acetate (0.001-0.02 mg/kg), the truenesses ranged from 82% to 100%, and the repeatabilities for the entire procedure ranged from 0.5 RSD% to 5.6 RSD%. In recovery tests using 11 livestock products fortified with 0.0005 mg/kg of melengestrol acetate, the truenesses ranged from 88% to 99%, and the repeatabilities ranged from 1.3 RSD% to 5.4 RSD%. The limit of quantification for melengestrol acetate in livestock products was 0.0005 mg/kg.

Development and validation of a sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry method for quantitative analysis of bambermycin in livestock and aquatic products: Implications for food safety control and regulatory enforcement.

A sensitive and accurate analytical method was developed and validated to detect bambermycin, a commonly used antibiotic in animal feed and livestock. The presence of bambermycin residues in food products can pose health risks to consumers, emphasizing the need for a sensitive and accurate analytical method. A reversed-phase analytical column was utilized with a mobile phase comprising 0.005 mol/L ammonium acetate in 5% acetonitrile (A) and 0.005 mol/L ammonium acetate in 95% acetonitrile (B) to achieve effective chromatographic separation. Quantitative determination of bambermycin in various samples, including beef, pork, chicken, milk, eggs, flatfish, eel, and shrimp, was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry. Sample extraction involved a mixture of methanol and a 25% ammonium hydroxide solution, followed by low-temperature purification and phospholipid removal utilizing a Phree cartridge. The method exhibited a satisfactory recovery rate ranging from 69% to 100%. Validation results demonstrated the reliability, robustness, and accuracy of the method, exhibiting good linearity, precision, and recovery. This validated method can be applied for routine analysis of bambermycin residues, assisting in the development of effective monitoring and control measures to ensure the safety of livestock and aquatic products.

[Determination of Flubendazole and Metabolite in Livestock Products Using LC-MS/MS].

This study proposes a method to determine flubendazole and metabolite R35475 in livestock products using tandem mass spectrometry coupled with positive ion electrospray ionization. Acetone is used to extract flubendazole and metabolite R35475 from the livestock samples. These extracts were purified using an SCX cartridge column (500 mg). Furthermore, high-performance liquid chromatography was performed on an Inertsil ODS-4 column with a gradient formed using methanol and water, both of which contain 5 mmol/L of ammonium acetate. The recovery tests using bovine muscle, fat, liver, milk, and egg fortified at the maximum residue limits of analytes or 0.005 mg/kg revealed that the trueness (n=5) of flubendazole and metabolite R35475 ranged from 89.4 to 106.4% with a repeatability rate of 1.7-7.8%.

Multiclass Method for the Determination of Anthelmintic and Antiprotozoal Drugs in Livestock Products by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

The objective of this study was to establish a multi-residue quantitative method for the analysis of anthelmintic and antiprotozoal drugs in various livestock products (beef, pork, and chicken) using ultra-high-performance liquid chromatography-tandem mass spectrometry. Each compound performed validation at three different levels i.e., 0.5, 1, and 2× the maximum residue limit according to the CODEX guidelines (CAC/GL 71-2009). This study was conducted according to the modified quick, easy, cheap, effective, rugged, and safe procedure. The matrix-matched calibrations gave correlation coefficients >0.98, and the obtained recoveries were in the range of 60.2%-119.9%, with coefficients of variation ≤32.0%. Furthermore, the detection and quantification limits of the method were in the ranges of 0.03-3.2 and 0.1-9.7 µg/kg, respectively. Moreover, a survey of residual anthelmintic and antiprotozoal drugs was also carried out in 30 samples of beef, pork, and chicken collected in Korea. Toltrazuril sulfone was detected in all three samples. Thus, our results indicated that the developed method is suitable for determining the anthelmintic and antiprotozoal drug contents in livestock products.

"Blockchain technology in food safety and traceability concern to livestock products".

Livestock products share more than fifteen percent of total agri-foods traded worldwide. A global increase in food demand has increased the risk to food safety. Improvements in food quality, cold chain transit, and preservation are required for safe livestock products. Though, the food safety and regulation authorities demand complete food traceability from farm to fork, but in traditional supply chain it is ignored by fiddling with the transit paperwork and bill invoices. The process of supply chain reformation and activities linked to food recalls during food safety issues are insanely expensive and challenging. Traceability-driven food supply chain management is likely to implement novel technologies like the Internet of Things (IoT). The capability of the Blockchain era within the food sector is emerging with use cases across different regions, as shown via the growing number of studies. Credibility, efficiency, and safety are all improved when food products can be instantly traced from their point of origin through all points of contact on their way to the consumer. Blockchain assures a tamper-proof and transparent system that allows an innovative business solution, together with smart contracts. However, there are significant difficulties with the implementation of blockchain technology for food traceability. It necessitates more and more training platforms as well as trainers, who can make understanding and operability of this technology easy among ground-level participants and food entities. For the tactical application of this technology, it is essential to comprehend the legal and regulatory framework.

[An LC-MS/MS Analytical Method for Moenomycin A in Livestock Products].

A simple and sensitive method for the determination of moenomycin A residues in livestock products using LC-MS/MS was developed. Moenomycin A, a residual definition of flavophospholipol, was extracted from samples with a mixture of ammonium hydroxide and methanol (1 : 9, v/v) preheated at 50℃. The crude extracted solutions were evaporated and purified by liquid-liquid partitioning between a mixture of ammonium hydroxide, methanol and water (1 : 60 : 40, v/v/v) and ethyl acetate. The alkaline layer was taken, and cleaned up using a strong anion exchange (InertSep SAX) solid phase extraction cartridge. The LC separation was performed on an Inertsil C8 column with liner gradient elution using 0.3 vol% formic acid and acetonitrile containing 0.3 vol% formic acid. Moenomycin A was detected using tandem mass spectrometry with negative ion electrospray ionization. Recovery tests were conducted using three porcine samples (muscle, fat and liver) and chicken eggs. Samples were spiked with moenomycin A at 0.01 mg/kg and at the Japanese Maximum Residue Limits (MRLs) established for each sample. The trueness ranged from 79 to 93% and precision ranged from 0.5 to 2.8%. The limit of quantification (S/N≥10) of the developed method is 0.01 mg/kg. The developed method would thus be very useful for regulatory monitoring of flavophospholipol in livestock products.

Development and application of fruit and vegetable based green films with natural bio-actives in meat and dairy products: a review.

In recent years, foodborne outbreaks and food plastic waste accumulation in the environment have impelled a hunt for new, sustainable, novel and innovatory food packaging interventions to face microbial contamination, food quality and safety. Pollution caused from wastes generated by agricultural activities is one of chief rising concerns of the environmentalists across the globe. A solution to this problem is effective and economic valorization of residues from agriculture sector. It would ensure that the by-products/residues from one activity act as ingredients/raw materials for another industry. An example is fruit and vegetable waste based green films for food packaging. Edible packaging is a well-researched area of science where numerous biomaterials have been already explored. Along with dynamic barrier properties, these biofilms often exhibit antioxidant and antimicrobial properties as function of the bioactive additives (e.g. essential oils) often incorporated in them. Additionally, these films are made competent by use of recent technologies (e.g. encapsulation, nano-emulsions, radio-sensors) to ensure high end performance and meet the principles of sustainability. Livestock products such as meat, poultry and dairy products are highly perishable and depend largely upon the mercy of packaging materials to enhance their shelf life. In this review, all the above-mentioned aspects are thoroughly covered with a view to project fruit and vegetable based green films (FVBGFs) as a potential and viable packaging material for livestock products, along with a discussion on role of bio-additives, technological interventions, properties and potential applications of FVBGFs in livestock products. © 2023 Society of Chemical Industry.

[Single-laboratory Validation Study and Surveillance Using an Improved Multiresidue Analytical Method for Veterinary Drugs in Livestock Products by LC-MS/MS].

A method for the rapid analysis of multiclass residual veterinary drugs in poultry muscle, egg, and raw milk was validated in accordance with Japanese guidelines. Using LC-MS/MS, 20 veterinary drugs, including sulfonamides, coccidiostats, and macrolides were analyzed in one injection. Analytes were extracted from the samples with acetonitrile and then dehydrated and salted out using magnesium sulfate, trisodium citrate, and sodium chloride. This method was assessed by performing recovery tests of chicken muscle, duck muscle, egg, and raw milk spiked with 20 new target analytes at concentrations of 10 and 100 µg/kg. According to this method, 17 out of 20 target analytes satisfied the guideline criteria in chicken muscle and duck muscle, and all 20 target analytes met the criteria in egg and raw milk. The limit of quantification was less than MRLs for all analytes. Residues were detected in 4 out of 99 samples and analyzed using the validated method, finding that the levels of all residues were lower than the limits of quantification. These results suggest that continuous monitoring for a new trend of veterinary drugs is necessary.

[Determination of Chlorothalonil Metabolite I in Livestock Products by LC-MS/MS].

An analytical method based on LC-MS/MS was developed for the determination of chlorothalonil metabolite I in livestock products. Chlorothalonil metabolite I in livestock products was extracted with acetone. The crude extracts were defatted by acetonitrile and n-hexane partitioning. Cleanup was carried out using a combination of ethylene diamine-N-propyl silylation silica gel (PSA) and silica gel (SI) mini columns with acidic condition. The sample solution was subjected to LC-MS/MS using an external solvent calibration curve. The average recovery (n=5) of chlorothalonil metabolite I from five types of livestock products (cattle muscle, cattle fat, cattle liver, milk and egg) spike at the maximum residue limits (MRLs) or at a uniform limit of 0.01 mg/kg was 97.1-102.9%, with a relative standard deviation of 1.4-6.8%. The limit of quantitation of the developed method was calculated to be 0.01 mg/kg.

[Determination of Quinclorac in Livestock Products by LC-MS/MS].

A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method was developed for determining quinclorac in livestock products. Quinclorac was extracted from the samples using a solution of acetone and hydrochloric acid mixed in a 99 : 1 ratio. The crude extract was purified with ethyl acetate under basic conditions, followed by quinclorac extraction with ethyl acetate under acidic conditions and analysis using LC-MS/MS. The average recoveries of quinclorac from five livestock products (n=5) fortified at the maximum residue limits or 0.01 mg/kg ranged from 85.6 to 93.5%, with the precision of repeatability ranging from 1.7 to 6.8%. The quantification limit in this analytical method was 0.01 mg/kg. These results suggest that the developed method is useful for analyzing quinclorac in livestock products.

Development of Simultaneous Analytical Method for Imidazolinone Herbicides from Livestock Products by UHPLC-MSMS.

A simultaneous analytical method, which used LC/MSMS for imidazolinone herbicides from livestock products (egg, milk, beef, pork, and chicken) for monitoring, was developed with a QuEChERS preparation. A weighed sample (5 g) in a 50 mL conical tube was added to 0.1 M potassium phosphate dibasic solution (5 mL) and shaken for 10 min. After shaking, 0.5 mL of 6 N HCl and 5 mL of acetonitrile were added, and this solution was shaken for 10 min. Additionally, QuEChERS extraction salts (original method, 4 g MgSO4, 1 g NaCl) were added to the sample in a 50 mL conical tube. The mixture was strongly shaken for 1 min and centrifuged at 3000× g for 10 min. The acetonitrile layer was purified with dSPE (150 mg MgSO4, 25 mg C18) and was centrifuged at 13,000× g for 5 min. The supernatant was filtered with a membrane filter (pore size: 0.2 µm) before analysis. The ME (%, matrix effect) range for almost all analytes was −6.56 to 7.11%. MLOD (method limit of detection) and MLOQ (method limit of quantitative) values were calculated by the S/N ratio. MLOQs were 0.01 mg/kg. The linear correlation coefficients (R2) were >0.99 with the range of 0.5~25 µg/kg for all of the imidazolinone herbicides. The recoveries (of imidazolinone herbicides) were in the range of 76.1~110.6% (0.01 mg/kg level), 89.2~97.1% (0.1 mg/kg level), and 94.4~104.4% (0.5 mg/kg level). These are within the validation criteria (to recover 70−120% with RSD <20%). The method demonstrated the simple, rapid, high throughput screening and quantitative analysis of imidazolinone herbicide residues for monitoring in livestock products.

Antimicrobial Activity of Propolis Extract and Their Application as a Natural Preservative in Livestock Products: A Meta-Analysis.

This study aimed to evaluate the effectiveness of propolis extract as a natural preservative for livestock products in term of chemical and microbiological characteristics by meta-analysis. The stages carried out in this study were identification, selection, checking suitability, and the resulting selected articles were used in the meta-analysis. The selection results obtained a total of 22 selected journal articles consisting of 9 articles for analysis of the antimicrobial activity of propolis extract and 13 articles for analysis of the chemical and mirobiological characteristics of livestock products. The articles were obtained from electronic databases, namely Science Direct and Google Scholar. The model used in this study is the random-effect model involving two groups, control and experimental. Heterogeneity and effect size values were carried out in this study using Hedge's obtained through openMEE software. Forest plot tests and data validation on publication bias was obtained using Kendall's test throught JASP 0.14.1 software. The results showed that there is a significant relationship between propolis extract with the results of the antimicrobial activity (p<0.05). In addition, the results of the application of propolis extract on the livestock products for the test microbes and the value of thiobarbituric acid reactive substances (TBARs) showed significant results (p<0.05). Conclusion based on the random-effect model on the effectiveness of antimicrobial activity of propolis extract and their apllication as a natural preservative of the chemical and microbiological characteristics of livestock products is valid by Kendall's test (p>0.05). Propolis in this case effectively used as natural preservatives in livestock products.

Measuring self-reported food loss in primary production: Survey-based insights from Central and Eastern Europe.

Food loss and waste occur along the whole food supply chain and need to be addressed by dedicated strategies. Among all the stages of the food supply chain, food loss in primary production has been the least studied to date. In order to address this gap, this paper focuses on on-farm food loss, using Lithuania as a case study. The research comprises eleven crop products and five livestock products prevailing in Lithuanian agricultural production. A survey-based method is utilized to collect primary data from farmers. The final data set consists of 408 completely answered questionnaires. The survey-based data are merged with those from the Farm Accountancy Data Network in order to devise an effective framework for estimating self-reported on-farm food loss. The results show that there exists substantial variation in on-farm food loss rates ranging from less than 1% for milk to slightly more than 20% for beets. Environmental factors and those related to consumer and buyer requirements are the main reasons for losses of crop products, while diseases appear as the main causes of death for animals. The food loss and waste reduction measures are derived based on the results of the survey.

Simultaneous Analysis of Fenpropimorph and Fenpropimorph Acid in Six Different Livestock Products Using a Single-Sample Preparation Method Followed by Liquid Chromatography-Tandem Mass Spectrometry.

Pesticides in livestock products must be measured to ensure food safety. We developed a single-sample preparation method followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneous determination of fenpropimorph and fenpropimorph acid in six different livestock products. The extraction method was a modification of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and was validated according to the CODEX guidelines. The matrix-matched calibration curves for fenpropimorph and fenpropimorph acid exhibited good linearity, with coefficients of determination (R2 values) higher than 0.998. The limit of detection (LOD) and the limit of quantitation (LOQ) were 1.25 and 5.0 µg kg-1, respectively. The average recovery values ranged from 61.5% to 97.1% for samples fortified to the LOQ, 2 × LOQ, and 10 × LOQ. The method fully complied with the CODEX guidelines and was successfully applied to real samples obtained from domestic markets.

[Determination of Albendazole Metabolite in Livestock Products Using LC-MS/MS].

A method for determining albendazole metabolite (metabolite I) in livestock products using LC-MS/MS was proposed. Livestock samples were hydrolyzed with 6 mol/L HCl at 110℃ for an hour and defatted with ethyl acetate and n-hexane (1 : 1, v/v) mixture. Metabolite I was extracted with acetonitrile from the sample, and the extracts were salted out under basic conditions, allowing the acetonitrile layer to separate. The acetonitrile solution was cleaned up using a cartridge column packed with divinylbenzene-N-vinylpyrolidone copolymer bearing sulfo groups. The HPLC separation was conducted on an Inertsil ODS-4 column with a gradient formed from water containing 0.05% (v/v) formic acid and acetonitrile containing 0.05% (v/v) formic acid. To detect metabolite I, tandem mass spectrometry with positive ion electrospray ionization was used. Truenesses (n=5) of metabolite I from cattle meat, fat, liver, and milk spiked at the maximum residue limits or the 0.01 mg/kg were in the range from 83.6 to 97.9%, and the relative standard deviations were from 1.6 to 6.1%.

[Determination of Asulam in Livestock Products by LC-MS/MS].

An analytical method based on LC-MS/MS was developed for the determination of asulam in livestock products. Asulam in livestock products was extracted with acetone. The crude extracts were defatted by acetonitrile and n-hexane partitioning. Cleanup was carried out using a combination of ethylene diamine-N-propyl silylation silica gel (PSA) and octadecyl silylated silica gel (C18) mini columns with acidic condition. The sample solution was subjected to LC-MS/MS using an external solvent calibration curve. The average recovery (n=5) of Asulam from four types of livestock products (bovine muscle, bovine fat, bovine liver and milk) spike at the maximum residue limits (MRLs) or at a uniform limit of 0.01 mg/kg was 92.7-98.7%, with a relative standard deviation of 3.1-11.6%. The limit of quantitation of the developed method was calculated to be 0.01 mg/kg.

[Analytical Method for Fipronil and Fipronil Sulfone in Livestock Products Using LC-MS/MS].

A rapid and sensitive method for the simultaneous determination of fipronil and fipronil sulfone (metabolite B) in livestock products was developed. The analytes were extracted from samples with acidic acetonitrile. The crude extracts were subjected to clean-up step using neutral alumina cartridge column. The HPLC separation was performed on a C18 column with isocratic elution of acetonitrile and ammonium formate solution. For the determination of the analytes, a tandem mass spectrometry with negative ion electrospray ionization was used. In the recovery tests using 6 livestock products fortified with MRLs levels of analytes, the truenesses for fipronil and fipronil sulfone were 95 to 115 and 94 to 101% with the repeatabilities of 0.8 to 4.1 and 0.9 to 5.1 RSD%, respectively. The limits of quantification for both analytes were estimated to be 0.001 mg/kg. The developed method is considered suitable for regulatory analysis of fipronil and fipronil sulfone.

Trust in trade: a global perspective on health certification.

Trade in livestock and livestock products can bring about great benefits, but also substantial risk to animal and human health with high economic, social and environmental impacts. Livestock products are also especially vulnerable to food fraud. In order to mitigate risk and prevent fraud, most animal trade requires health certification by a competent authority, backed by systems and processes that create trust and confidence in importers. Among Veterinary Services which have undergone a structured assessment of performance, most find the need to improve their authority and/or capability for health certificates and for transparent disease reporting. Health certification is trusted when it is legal, carried out by an adequately performing authority, implemented by competent persons, supported by technical evidence, and validated by third parties and when the process is transparent, predictable and free from conflict of interest. The large and growing trade in animals and their products is a testimony to the effectiveness of the current process and the trust of importers. Nonetheless, there is considerable scope for further improvement especially by improving the legal framework, building capacity of Veterinary Services, increasing trust in signing authorities, validating the certification process, and making the process of certification more efficient and predictable.

Si les échanges internationaux d'animaux et de produits d'origine animale peuvent être très bénéfiques, ils représentent aussi un risque non négligeable pour la santé animale et publique, dont l'impact économique, social et environnemental est parfois conséquent. Il y a également un risque élevé de fraude alimentaire associé aux produits issus de l'élevage. Afin d'atténuer ces risques et de prévenir les fraudes, les échanges internationaux d'animaux et de produits d'origine animale sont généralement soumis à une certification sanitaire délivrée par l'autorité compétente et soutenue par des systèmes et des processus destinés à créer la confiance chez les importateurs. La plupart des Services vétérinaires qui ont entrepris une évaluation structurée de leurs performances ont pu constater la nécessité d'améliorer leur autorité et/ou leurs capacités en matière de certification sanitaire et de notification transparente des maladies. Plusieurs facteurs conditionnent la confiance dans la certification sanitaire : que celle-ci soit encadrée par la loi ; qu'elle soit effectuée par une autorité reconnue ; que les personnes chargées de sa mise en oeuvre soient qualifiées ; qu'elle soit soutenue par des données techniques probantes ; qu'elle soit validée par des tiers indépendants. En outre, l'ensemble du processus doit être transparent, prévisible et exempt de conflits d'intérêts. L'importance et la croissance du commerce international d'animaux et de produits d'origine animale témoignent de l'efficacité actuelle du processus et de la confiance des importateurs. Néanmoins, il subsiste encore une marge notable d'amélioration, qui concerne le cadre juridique, le renforcement des capacités des Services vétérinaires, la confiance dans les instances décisionnaires, la validation du processus de certification et l'efficience et prévisibilité du processus lui-même.

El comercio de ganado y productos ganaderos puede traer consigo grandes beneficios, pero también un importante riesgo sanitario y zoosanitario, con posibles y profundas repercusiones económicas, sociales y ambientales. Los productos ganaderos también son especialmente vulnerables al fraude alimentario. Con objeto de mitigar el riesgo y de prevenir posibles fraudes, la mayor parte de los intercambios comerciales con animales se acompañan de la exigencia de un certificado sanitario expedido por una autoridad competente y respaldado por sistemas y procesos que inspiren confianza a los importadores. La mayoría de los Servicios Veterinarios que han pasado por un proceso de evaluación estructurada de su eficacia llegaron a la conclusión de que debían dotarse de mayor autoridad y/o capacidad para expedir certificados sanitarios y notificar enfermedades con transparencia. Para que un proceso de certificación sanitaria sea digno de confianza debe ajustarse a derecho, estar en manos de una autoridad que trabaje con la debida eficacia y a cargo de personal competente, venir avalado por datos técnicos y validado por terceras partes, ser transparente y previsible y estar exento de conflictos de intereses. El enorme y creciente volumen del comercio de animales y productos de origen animal da testimonio de la eficacia del actual proceso y de la confianza que merece a los importadores. Sin embargo, aún hay mucho margen para progresar, sobre todo perfeccionando el ordenamiento jurídico, potenciando la capacidad de los Servicios Veterinarios, mejorando el nivel de confianza que inspiran las autoridades signatarias, validando el proceso de certificación y logrando que este sea más eficiente y previsible.

Informal trade in livestock and livestock products.

Informal trade in livestock and livestock products is of special concern because of the risk of spreading animal and human diseases. At the same time, informal trade can contribute to people's livelihoods and food security, especially in lowand middle-income countries. Informal trade may involve legal or illegal products. It may be domestic (or internal) or involve neighbouring countries; it may take place within a region or between distant countries. Entrepôt trade (or 're-exports') is a significant form of informal trade in livestock products. Pastoral mobility often entails movement across boundaries for trade and much of this is also informal. There are important economic, social, political, and environmental drivers for informal trade which make it difficult to eliminate. Informal livestock trade may be largely ignored by the authorities, implicitly encouraged, made less attractive, forcibly suppressed, or actively engaged with, in an attempt to mitigate its risks and enhance its benefits. To identify the optimal management approach, it is crucial to understand the importance and characteristics of informal trade, its benefits and risks, and the feasibility and cost-effectiveness of different strategies to address it. The authors describe a case study from East Africa to explore some of the issues raised by informal trade.

Le commerce informel d'animaux d'élevage et de produits d'origine animale est un sujet particulièrement préoccupant en raison du risque de propagation de maladies animales et humaines associé à cette activité. En même temps, le commerce informel apporte aux populations des moyens de subsistance et contribue à leur sécurité alimentaire, en particulier dans les pays à revenu faible et intermédiaire. Le commerce informel peut porter sur des produits licites ou illicites. Il peut être domestique (marché intérieur) ou inclure les pays avoisinants ; il peut se dérouler dans une même région ou bien entre pays distants. La réexportation (ou recours aux entrepôts francs) constitue une modalité importante du commerce informel de produits issus de l'élevage. Le pastoralisme, qui se caractérise par sa mobilité, entraîne souvent des mouvements transfrontaliers en vue de transactions commerciales dont une grande partie est également informelle. Il existe d'importants moteurs économiques, sociaux, politiques et environnementaux qui favorisent le commerce informel et le rendent difficile à éliminer. Les réponses déployées par les pouvoirs publics face au commerce informel d'animaux d'élevage sont diverses : l'ignorer, l'encourager implicitement, le rendre moins attractif, le réprimer par la force, ou l'accompagner de manière active, le but étant d'atténuer les risques ou d'optimiser les bénéfices qui lui sont associés. Pour définir la meilleure approche de gestion, il est indispensable de bien comprendre l'importance et les caractéristiques du commerce informel, ses bénéfices et ses risques, ainsi que la faisabilité des différentes stratégies d'intervention et leur efficacité au regard de leur coût. Les auteurs décrivent une étude menée en Afrique de l'Est qui permet d'analyser certaines questions soulevées par le commerce informel.

El comercio informal de ganado y productos ganaderos suscita especial inquietud porque trae consigo el riesgo de propagación de enfermedades animales y humanas. Al mismo tiempo, puede contribuir al sustento y a la seguridad alimentaria de las personas, especialmente en los países de renta baja y de renta media. Este tipo de comercio puede tratar con productos legales o ilegales. A veces las transacciones son internas (nacionales), a veces interesan a países contiguos y otras veces tienen lugar dentro de una gran región o entre países distantes. El comercio de reexportación (o uso de puertos francos) es una de las formas importantes que reviste el comercio informal de productos ganaderos. La movilidad propia de las poblaciones que viven del pastoreo las lleva a menudo a cruzar fronteras para entablar transacciones comerciales que son mayoritariamente informales. El comercio informal obedece a importantes factores económicos, sociales, políticos y ambientales que lo alimentan y hacen difícil eliminarlo. La postura de las autoridades respecto del comercio informal de ganado es muy variable: a veces se desentienden en gran medida de él, otras veces lo alientan tácitamente, en ocasiones adoptan medidas para restarle atractivo o lo reprimen por la fuerza e incluso a veces participan activamente en él, tratando así de mitigar los riesgos que entraña y de potenciar sus beneficios. Para determinar la forma idónea de manejar el fenómeno del comercio informal es básico aprehender su importancia y características, sus ventajas y riesgos y la viabilidad y relación costo-eficacia de las distintas posturas que se pueden adoptar ante él. Los autores parten de un estudio monográfico realizado en el África Oriental para abordar algunos de los interrogantes que suscita el comercio informal.

[Determination of Hexazinone and Its Major Metabolites in Livestock Products by LC-MS/MS].

A method for the determination of hexazinone and three metabolites (hexazinone metabolite B, hexazinone metabolite C, hexazinone metabolite F) in livestock products by LC-MS/MS was developed. Hexazinone and the three metabolites were extracted from a sample with acetonitrile in the presence of n-hexane, and lipid was removed by acetonitrile/n-hexane partition. The acetonitrile extract was cleaned up using a SAX/PSA cartridge column. Average recoveries (n=5) of hexazinone and the three metabolites from cattle meat, fat, liver and milk spiked at the maximum residue limits (MRLs) or at 0.0025 mg/kg ranged from 85.6 to 96.0%, and the relative standard deviations ranged from 0.8 to 4.9%.