This study evaluated the efficacy of a wild boar repellent (Repellent A) consisting of tannins and plant oils (castor oil, garlic oil, and cinnamon oil). Sixty farmed wild boars (4-8 months old) were divided into three groups: the normal control group (NC, n=20), the experimental group (EP, n=20), and the comparative experimental group (C-EP, n=20), which used Repellent B consisting of guaiacol, eugenol, menthol, thymol, and indole. EP and C-EP were equipped with four repellents per feeder, while no repellents were installed in the NC feeder. The feed intake and the number of feeding approaches were measured for one week in all groups. The number of approach of wild boars in feeders was monitored daily using a CCTV camera. The daily feed intake per farmed wild boar in EP and C-EP was significantly decreased compared to NC (p<0.05), and EP was significantly decreased compared to C-EP (p<0.05). In the average number of daily approaches, EP and C-EP were significantly decreased compared to NC (p<0.05), and EP was significantly decreased compared to C-EP (p<0.05). In conclusion, Product A has been confirmed to have excellent repellent effects on wild boars, and it could be used to prevent wild boars from approaching pig farms.

From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for tiamulin (TML) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with TML at the concentration of 25 g/L (TML-1, n=24) and 50 g/L (TML-2, n=24) for 5 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 1, 2, 3 and 5 days, respectively. According to the previously established analysis method, residual TML concentrations in poultry tissues were determined using LC-MS/MS. In TML-1, TML in all tissues was detected less than LOQ at 2 days after drug treatment. In TML-2, TML in liver and kidney was detected more than LOQ at 2 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of TML-1 and TML-2 in poultry tissues were established to 0 and 2 days, respectively. In conclusion, the estimated WT of TML in poultry tissues is shorter than the current WT recommendation of 5 days for TML in broiler chickens.

This study was conducted to reset the maximum residue limit (MRL) for didecyldimethylammonium chloride (DDAC) in broiler chickens. The disinfectant containing DDAC (10%, w/w) was diluted 160 times and evenly sprayed on the bodies of twenty-four broiler chickens at a rate of 15 mL per day per bird for 7 days. After the disinfectant treatment, tissue samples were collected from six broiler chickens at 0.25, 1, 3 and 5 days, respectively. Residual DDAC concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 2.0~10.0 μg/kg), recoveries (86.9~118.6%), and coefficient of variations (<19.98%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In all tissues except for liver, DDAC was detected more than LOQ at 5 days after the disinfectant treatment. In liver tissues, DDAC was detected more than LOQ at 3 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal period of DDAC in poultry tissues was established to 26 days. In conclusion, the developed analytical method is sensitive and reliable for detecting DDAC in poultry tissues. When DDAC disinfectant is sprayed on a poultry house in the presence of broiler chickens, it is necessary to keep the disinfectant from contacting the body of the livestock.

Ischemic stroke causes severe neuronal damage. Chlorogenic acid is a phenolic substance present in fruits and coffee. It also exerts neuroprotective effects against various brain injuries. The 14-3-3 family protein perform a variety of functions including metabolism, signal transduction, cell differentiation, and apoptosis. The purpose of this study is to investigate whether chlorogenic acid regulates the expression of 14-3-3 protein in stroke animal models. Ischemic stroke was induced by middle cerebral artery occlusion (MCAO) surgery. Phosphate buffered saline (PBS) or chlorogenic acid (30 mg/kg) were intraperitoneally injected to adult male rats 2 h before MCAO surgery. Adhesive-removal test was performed 24 h after MCAO surgery and cerebral cortical tissues were collected for further study. MCAO damage caused severe neurological impairment and chlorogenic acid treatment ameliorated this disorder. Our proteomic approach showed a decrease in 14-3-3 expression in MCAO animals with PBS. The decrease in 14-3-3 expression alleviated in MCAO animal with chlorogenic acid. We confirmed changes in various 14-3-3 protein isoforms, including beta/alpha, zeta/delta, gamma, epsilon, eta, and tau through reverse transcription-PCR. These results explained that chlorogenic acid regulates the expression of 14-3-3 protein in MCAO-induced cerebral ischemia. 14-3-3 is considered to be an important protein for cell survival through binding to pro-apoptotic proteins. The maintenance of 14-3-3 levels is an important event in neuroprotection against ischemic injury. Therefore, we can demonstrate that the 14-3-3 protein contributes to the neuroprotective effect of chlorogenic acid in stroke animal models.

This study investigated ethopabate (EPB) residues in edible tissues of broiler chickens given in drinking water and established the withdrawal time (WT) of EPB in poultry tissues. Twenty-four healthy Ross broiler chickens were orally administered with EPB at the concentration of 3.8 mg/L for 14 days (EPB-1, n=24) and 15.2 mg/L for 7 days (EPB-2, n=24) through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3, and 5 days, respectively. EPB residue concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient values ranged from 0.9980 to 0.9998, and the limits of detection and quantification (LOQ) were 0.03~0.09 and 0.1~0.3 μg/kg, respectively. Mean recoveries in muscle, liver, kidney and skin/fat tissues were 95.9~109.8, 108.7~115.3, 89.9~96.6 and 86.7~96.8%, respectively, and coefficient of variations were less than 17.11%. At the end of the drug-administration period (0 day), EPB was detected at levels under the LOQ in all tissues from both the EPB-1 and EPB-2 groups. According to the results of EPB residue in Ross broiler tissues, withdrawal periods of both EPB-1 and EPB-2 in poultry tissues were established to 0 day. In conclusion, the developed analytical method is suitable for the detection of EPB in poultry tissues, and the estimated WT of EPB in poultry tissues will contribute to ensuring the safety of Ross broiler chickens.

From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for amprolium (APL) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with APL at the concentration of 60 mg/L (APL-1, n=24) for 14 days and 240 mg/L (APL-2, n=24) for 7 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3 and 5 days, respectively. Residual APL concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 0.3~5.0 μg/kg), recoveries (81.5~112.4%), and coefficient of variations (<15.5%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In APL-1, APL in all tissues except for kidney was detected less than LOQ at 3 days after drug treatment. In APL-2, APL in liver and kidney was detected more than LOQ at 5 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of APL-1 and APL-2 in poultry tissues were established to 3 and 2 days, respectively. In conclusion, the developed analytical method is sensitive and reliable for detecting APL in poultry tissues. The estimated WT of APL in poultry tissues is longer than the current WT recommendation of 2 days for APL in broiler chickens.

This study examined the subacute oral toxicity of Dendropanax morbiferus H.Lév leaves hot-water extracts (DMWE) using male and female Spargue-Dawley rats. Rats were orally administered the DMWE at dose levels of 0, 250, 500, 1,000, and 2,000 mg/kg body weight (BW) for four weeks. For experimental period, clinical signs and the number of deaths were examined, and feed intake and BW of all experimental animals were measured once a week for four weeks. At the end of the experiment, blood samples were collected from all rats, and all animals were euthanized and autopsies were performed to collect major organs. No dead animals were found during the experimental period. In addition, no differences were found between control and DMWE-treated groups in feed intakes, BW changes, organ weights, clinical signs, hematological parameters, and serum biochemical parameters. The results of this study provided evidence that oral administration of DMWE at the dose of 2,000 mg/kg BW is safe in rats and may not exert severe toxic effects.

This study investigated changes of milk production in dairy cows intramuscularly injected with drugs containing dexamethasone (DXM). Three types of dexamethasone formulations (Bueunde® (DXM 0.5 mg/mL), Dexason INJ.® (DXM 1 mg/mL) and Dexolone-20 inj.® (DXM 1 mg/mL)) were intramuscularly injected into sixteen healthy dairy cows each. Bueunde® was intramuscularly injected into 8 dairy cows with 5 mg (BED-1) and 10 mg (BED-2) of DXM once a day for 3 consecutive days, respectively. Dexason INJ.® was intramuscularly administered once into dairy cows with 20 mg (DXS-1, n=8) and 40 mg (DXS-2, n=8) of DXM, respectively. Dexolone-20 inj.® was intramuscularly injected once into dairy cows with 20 mg (DXS-1, n=8) and 40 mg (DXS-2, n=8) of DXM, respectively. Milk production (MP) of BED-1 and BED-2 significantly decreased during the drug administration and up to 48-hour post-drug treatment. Compared with the MP before drug administration, the MP of DXS-1 and DXL-1 was meaningfully decreased by 36 and 24-hour post-drug administration, respectively, and that in both DXS-2 and DXL-2 significantly decreased until 48-hour post-drug treatment. In conclusion, it was confirmed that the MP temporarily decreased by 48 hours after administration of DXM to dairy cows.