This study aims to establish a modified analytical method with sensitivity and reliability for streptomycin (STP) and dihydrostreptomycin (DHS) of residues level in pig tissues, plasma and urine by LC-MS/MS on the basis of previous studies. The mass parameters of quantitative and qualitative ions for STP and DHS were optimized using multiple reaction monitoring in positive mode. The separation of compounds was conducted using BEH Amide column according to material’s characteristics. The analytes in plasma were extracted with only organic solvents. In muscle and kidney, KH2PO4 buffer solution containing 2% CCl3COOH and EDTA-Na was used as extraction solvent. The WCX cartridege was selected as SPE cartridge in considering high recoveries for STP and DHS. The analytes in urine were extracted by organic solvents with acid and addition of EDTA. The limits of detection (LODs) in STP and DHS ranged 0.45~3.66 μg/kg and 0.22~0.78 μg/kg, respectively. The limits of quantification (LOQs) were 1.35~11.10 μg/kg in STP and 0.66~2.36 μg/kg in DHS. The recoveries (%) were 94.29~104.5% in STP and 92.32~108.45% in DHS except for plasma with lower values (61.45/68.5%, respectively). In the precision evaluation, the coefficient of variation (CV, %) of STP showed <10.50% on intra-day and <18.04% on inter-day. The CV (%) of DHS showed <8.42% on intra-day, whereas <17.98% on inter-day. The modified method is reliable for continuous residual monitoring in pig to ensure food safety for consumer’s health. In addition, this method could be used in study relation to residue depletion and pharmacokinetics of veterinary drug.

The Korean National Residue Program (KNRP) use three plans for the sampling of domestic meats: monitoring, surveillance, and exploratory testing. We analyzed the results of monitoring and surveillance for residual veterinary drugs and pesticides in meat during 2012 and 2013. KNRP targets food-producing animals including cattle, pigs, chickens, ducks, sheep (goats), and horses. Sampling mainly focuses on veterinary drugs and pesticide residues found in tissues such as muscle, kidney, and liver. A total of 548 residue violations occurred between 2012 and 2013, mainly in pigs (427 violations) and cattle (113 violations). The most commonly found compounds were antimicrobials such as penicillins, fluoroquinolones, aminoglycosides, tetracyclines, sulfonamides, and macrolides. Pig residue violations were mainly for the presence of penicillins (34%) and fluoroquinolones (28%), while most residue violations in cattle were due to the presence of penicillins (32%) and aminoglycosides (27%). The overall rates of violations were 0.21% in 2012 and 0.10% in 2013. A major cause of violations was the failure to follow the appropriate withdrawal periods (68.8%). The results of the KNRP were analyzed to provide information on agricultural chemical residues that are of public health concern and to help control and prevent residue violations for ensuring food safety.

Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FMB1), ochratoxin A, T2 toxin, and zearalenone, are found in numerous vegetables. Mycotoxin accumulation in food and feed poses serious health risks to humans and animals because of carcinogenic, mutagenic, teratogenic, and toxic properties. In addition, mycotoxins cause large economic losses in commercial crop production, food and feed processing, and animal husbandry worldwide. In this study, an analytical method for the simultaneous analysis of the levels of AFB1, DON, and FMB1 in cow blood with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. AOZTM and Myco6in1TM multitoxin immunoaffinity columns and an OasisTM reversed-phase solid-phase extraction Hydrophilic-Lipophilic-Balanced columns were used to purify and concentrate the blood samples. Extracts that contained AFB1, DON, and FMB1 had average recovery of 64.0%, 98.0%, and 89.9%, respectively. In conclusion, we used LC-MS/MS to detect several important toxicological mycotoxins in cow blood. The multimycotoxin method, which detected and quantified the levels of AFB1, DON, and FMB1 can be used in animal pilot studies to monitor simultaneous exposure to major mycotoxins.

The efficacy of chemical disinfectants is reduced owing to the inactivation of active ingredients after dilution. This study investigated the effect of time on the efficacy of six different disinfectants, after dilution, against avian influenza virus. When used at the recommended concentration, most disinfectants showed efficacy at a high concentrations in the presence of organic materials immediately after dilution, while sodium dichloroisocyanurate-based products, after dilution, showed reduced efficacy over time at low concentrations in the absence of organic materials. Most disinfectants were neutralized by organic materials; however, this could be compensated for by increasing the product dosage. For successful decontamination in farms, disinfectants should be used at high concentrations in accordance with the manufacturers’ recommendations. Furthermore, the presence of organic materials must be taken into consideration, and diluted disinfectant solution should be prepared no more than a day before use.

Blood from livestock is a common by-product which is obtained in industrial slaughterhouses. Blood is mainly composed of three fractions, red blood cells (RBCs), white blood cells (WBCs) and plasma. Plasma contains about 8% proteins, which is mainly composed of albumin, globulins and fibrinogen. Hemoglobin is the major protein within whole blood including RBC. These proteins isolated from animal blood have been used in variety of industry such as food, medical, pharmaceutics, animal feed and laboratory. Initially, blood is sterile in healthy animals thus adequate blood collecting system helps to minimize the risk of contamination. In Europe, closed-draining systems are adopted and a high-quality blood product is produced. European Union lays down health rules as regard animal by-products and derived products called Regulation (EC) No 1774/2002 which is improved to No 1069/2009. This regulation lays down strict animal and public health rules for the blood collection, transport, storage, handling, processing and use or disposal of all animal by-products. In spite of the significant using of blood from livestock, almost blood from slaughtering is considered a waste except only small part for use and causes a serious environmental pollution in Korea. Because of the environmental pollution by blood from slaughterhouse, the great expense is loosed, and blood-related products are small and are imported from foreign countries in Korea. For successful blood utilization, suitable infrastructure facilities are needed to control microbial contamination of blood from slaughterhouses and more specific plans on animal blood control may be established at the same time.