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Pentachlorophenol (PCP) is a persistent organic pollutant usually present in the form of sodium salts (PCP-Na) that has been banned for many years, but it can still be detected in animal food. The present study established a method of detecting PCP-Na and its metabolites—tetrachlorocatechol (TCC), pentachlorophenol acetate (PCP-acetate), and pentachloroanisole (PCA)—in swine samples (pork, fat, liver, heart, lungs and kidney), simultaneously using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) based on the modified QuEChERS pre-treatment method. The validation results exhibited a good sensitivity with limits of quantitation (LOQs) of 1 μg/kg–2 μg/kg. The recoveries of spiked samples were in the range of 60.5–119.9%, with a relative standard deviation (RSD) between replicates (n = 5) of between 0.70% and 12.06%. [ABSTRACT FROM AUTHOR]

Current diagnostic methods for wooden breast and white striping, common breast muscle myopathies of modern commercial broiler chickens, rely on subjective examinations of the pectoralis major muscle, time-consuming microscopy, or expensive imaging technologies. Further research on these disorders would benefit from more quantitative and objective measures of disease severity that can be used in live birds. To this end, we utilized untargeted metabolomics alongside two statistical approaches to evaluate plasma metabolites associated with wooden breast and white striping in 250 male commercial broiler chickens. First, mixed linear modeling was employed to identify metabolites with a significant association with these muscle disorders and found 98 metabolites associated with wooden breast and 44 metabolites associated with white striping (q-value < 0.05). Second, a support vector machine was constructed using stepwise feature selection to determine the smallest subset of metabolites with the highest categorization accuracy for wooden breast. The final support vector machine achieved 94% accuracy using only 6 metabolites. The metabolite 3-methylhistidine, which is often used as an index of myofibrillar breakdown in skeletal muscle, was the top metabolite for both wooden breast and white striping in our mixed linear model and was also the metabolite with highest marginal prediction accuracy (82%) for wooden breast in our support vector machine. Overall, this study identified a candidate set of metabolites for an objective measure of wooden breast or white striping severity in live birds and expanded our understanding of these muscle disorders. [ABSTRACT FROM AUTHOR]

Praziquantel (PZQ) is a pyrazino-isoquinoline compound with broad spectrum of activity against parasitic trematodes and cestodes, and a key veterinary drug in the parasitic disease control field. However, PZQ residues caused by non-conforming or excessive use in food-producing animals may pose a serious threat to human health. Herein, a simple, sensitive and reproducible LC-MS/MS method was developed for the simultaneous determination of praziquantel and trans- and cis-4-hydroxypraziquantel in black goat tissues to guide the reasonable use of PZQ. The mean recoveries for three target analytes were 71.2 ∼ 117.6%, and the limits of quantification were 1.0 μg/kg. Twenty-five healthy black goats were administered a single dose of praziquantel tablets at a dose of 35 mg/kg of body weight for residue elimination study, The results revealed that praziquantel and 4-hydroxypraziquantel were rapidly depleted in goat tissues and the elimination half-lives did not exceed 1 day in all tissues except for muscle and lung. It provides guidance for the establishment of maximum residue limit of praziquantel in goat. [ABSTRACT FROM AUTHOR]