Swine Feed Samples Research Articles

Quantitative determination of tetracyclines in medicated feed for food-producing animals by HPLC–DAD

Tetracyclines are a group of antibiotic substances largely administered through medicated feed to control diseases in food-producing animals. Fine dosing of antibiotics contained in medicated feed is crucial for the success of the treatment as well as minimising potential threats such as the spread of antimicrobial resistance and the transfer of antibiotic residues in food. A rapid analytical method based on HPLC with diode array detection (HPLC–DAD) was developed to quantify oxytetracycline, chlortetracycline and doxycycline in medicated feed. The reported method underwent in-house validation and was found to be suitable for the quantification of three target tetracyclines within the concentration range of 40–1000 mg kg−1 in official routine analysis. The method was applied to 103 official samples in the framework of the Italian National Plan on animal feed during the years 2021–2023 and nine non-compliant concentrations were identified in swine and fish feed samples.

Occurrence of mycotoxins in swine feed from South Korea.

To update recent information on contamination levels of mycotoxins in South Korea. A total of 208 samples sourced from the feeds of swine farms were collected. The contamination levels of mycotoxins, which are aflatoxin (Afla), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN), fumonisin (FUM), and T-2 toxin, were investigated by enzyme-linked immunosorbent assays (ELISAs). The detection levels of the total samples were 78.91% for DON, 75.24% for Afla, 47.02% for ZEN, 68.31% for FUM, and 5.94% for OTA and T-2, which were not detected at all. Most of the analyzed mycotoxins showed significant high occurrences in 47.02%-78.91% of the swine feed samples. 11 of the 152 alfa-positive samples exceeded the maximum residue limit (MRL) of Afla proposed by the Korean regulation. In the analysis of mycotoxin detection levels by growth stage, ZEN was found in the nursery stage at a remarkably high concentration level (126.46 ± 63.76 ppb), exceeding the MRL of ZEN for piglets proposed by the European Commission. This mycotoxin was also found in the samples from the gestation barn (89.04 ± 46.05 ppb) and the farrowing house (105.58 ± 94.12) at a high concentration level. Afla was found in the nursery stage at a high concentration (8.00 ± 2.22 ppb), approaching the MRL (10 ppb) of Afla proposed by the Korean regulation. These results indicate that many swine farms in South Korea are still exposed to mycotoxin risk, and special attention and surveillance are necessary for these mycotoxin risks in swine farms.

Analysis of virginiamycin M1 in swine feed, muscle and liver samples by quantum dots-based fluorescent immunochromatographic assay

Based on a highly sensitive and specific monoclonal antibody (mAb) against virginiamycin M1 (VIR M1), a quantum dots-based fluorescent immunochromatographic assay (QDs-ICA) for quick and sensitive analysis of VIR M1 was established for the first time. The mAb showed a half-maximal inhibitory concentration (IC50) of 0.5 ng/mL and cross-reactivity (CR) values below 0.1% for other three analogues when used in enzyme-linked immunosorbent assay (ELISA). The mAb was conjugated to ZnCdSe/ZnS (core/shell) QDs with maximum emission wavelength of 610 nm (orange-red) which was selected as fluorescent probe to increase QDs-ICA sensitivity. The cut-off value of QDs-ICA was 12.5 ng/mL. QDs-ICA showed a linear range from 0.7 to 14.5 ng/mL with a limit of quantification of 0.7 ng/mL. Compared with existing methods for the analysis of VIR M1, the QDs-ICA exhibited higher sensitivity. For analysis of VIR M1 concentrations spiked into swine feed, muscle and liver samples, recovery rates ranged from 94.0% to 111.6% with the highest coefficient of variation (CV) of 6.7% for intra-assay, and for inter-assay ranged from 94.7% to 107.6% with the highest CV of 9.4%. In conclusion, the QDs-ICA could be a potential method for analyzing VIR M1 in animal feed and animal-derived food.

Simultaneous Determination of Ergot Alkaloids in Swine and Dairy Feeds Using Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Ergot alkaloids (EAs) are mycotoxins mainly produced by the fungus Claviceps purpurea. EAs are known to affect the nervous system and to be vasoconstrictors in humans and animals. This work presents recent advances in swine and dairy feeds regarding 11 major EAs, namely ergometrine, ergosine, ergotamine, ergocornine, ergocryptine, ergocristine, ergosinine, ergotaminine, ergocorninine, ergocryptinine, and ergocristinine. A reliable, sensitive, and accurate multiple mycotoxin method, based on extraction with a Mycosep 150 multifunctional column prior to analysis using UHPLC-MS/MS, was validated using samples of swine feed (100) and dairy feed (100) for the 11 targeted EAs. Based on the obtained validation results, this method showed good performance recovery and inter-day and intra-day precision that are in accordance with standard criteria to ensure reliable occurrence data on EA contaminants. More than 49% of the swine feed samples were contaminated with EAs, especially ergocryptine(-ine) (40%) and ergosine (-ine) and ergotamine (-ine) (37%). However, many of the 11 EAs were not detectable in any swine feed samples. In addition, there were contaminated (positive) dairy feed samples, especially for ergocryptine (-ine) (50%), ergosine (-ine) (48%), ergotamine (-ine), and ergocristine (-ine) (49%). The mycotoxin levels in the feed samples in this study almost complied with the European Union regulations.

Prevalence of mycotoxins in feed and feed ingredients between 2015 and 2017 in Taiwan.

Contamination of feed by mycotoxins is a global epidemic that has a sizeable impact on animal health and causes economic losses. Mycotoxins, including aflatoxins (AFs), zearalenone (ZEN), fumonisins (FUMs), deoxynivalenol (DON), and ochratoxin A (OTA), lead to acute and chronic adverse effects in pigs. Animal feed and feed ingredients are commonly contaminated by one or more mycotoxins worldwide; however, the prevalence of mycotoxin contamination in feed and feed ingredients in Taiwan remains unclear. A total of 820 cornmeal and corn-based swine feed (pregnancy and nursery diets) samples provided by feed and animal producers were analyzed using the enzyme-linked immunosorbent assay method between January 2015 and December 2017 to determine the presence of mycotoxins. The results revealed that the most prevalent mycotoxin in Taiwan was DON, with 91.4% of positive samples between 2015 and 2017, followed by ZEN, AFs, and FUMs, with 70.2%, 58.0%, and 50.4% of positive samples, respectively. A similar prevalence of mycotoxins was observed in cornmeal and corn-based swine feed. Furthermore, 7.7% of the analyzed feed samples contained one mycotoxin, and 91.3% contained multiple mycotoxins. DON was the most prevalent mycotoxin in cornmeal and corn-based swine feed in Taiwan. Moreover, a high incidence of contamination by multiple mycotoxins was observed in swine feed. Awareness of mycotoxin presence in feed and development of mycotoxin detoxification strategies are unmet needs.

Colorimetric detection of the β-agonist ractopamine in animal feed, tissue and urine samples using gold–silver alloy nanoparticles modified with sulfanilic acid

ABSTRACTA highly sensitive, selective and simple method was proposed for colorimetric detection of ractopamine on the basis of the interaction between ractopamine and sulfanilic acid-modified gold–silver alloy nanoparticles (AuAgNPs). The AuAgNPs were prepared by the reduction of HAuCl4 and AgNO3 with sodium citrate in aqueous medium and further modified by sulfanilic acid. The interaction of ractopamine with sulfanilic acid induced rapid aggregation of sulfanilic acid-modified AuAgNPs along with an optical colour change, leading to precise quantification which could be detected by absorptiometry. Under the optimum conditions, the absorbance ratio (A600/A435) of sulfanilic acid-modified AuAgNPs exhibited a linear relationship with the concentration of ractopamine in the range of 4.5–31.6 ng/mL. The detection limit of ractopamine was 1.5 ng/mL. The established novel colorimetric detection method showed high selectivity towards ractopamine. The method was successfully applied to detect ractopamine in spiked pork, swine feed and swine urine samples with excellent recoveries from 94.4% to 112.5%. These results demonstrated that the proposed new method has a good potential for practical applications.

A Flow Injection Chemiluminescent Immunosensor for Ultrasensitive Detection of Brombuterol Based on Resin Beads and Enzymatic Amplification

This study described the use of a rapid and sensitive flow injection chemiluminescence immunoassay based on the specific binding of antigens and antibodies for the detection of brombuterol residues in the swine meat and feed samples. Carboxylic resin beads were used as a solid-phase carrier for supporting more coating antigens through acylamide bonds. Under the mechanism of competitive immunity, the brombuterol in solution competed with the coating antigen immobilized on the resin beads for the limited binding sites of antibody. Then, horseradish peroxidase-labeled secondary antibodies were introduced into the immunosensor to combine with polyclonal antibodies. The chemiluminescence intensity of the luminol-p-iodophenol-H2O2 system was catalyzed by horseradish peroxidase, and thus, signal amplification was achieved. Under the optimal conditions of the concentration of coating antigen, antibody and enzymatic secondary antibody, brombuterol could be detected quantitatively. The chemiluminescence intensity decreased linearly with the logarithm of the brombuterol concentration in the range of 0.001 to 300 ng mL−1. The limit of detection (3σ) and the limit of quantitation were 0.33 pg mL−1 and 1.1 pg mL−1, respectively. This method had undergone a series of test conditions and exhibited good specificity, stability, and reproducibility. The immunosensor can also detect real samples and provide prospects for the detection of other small molecule compounds, such as isoproterenol, enrofloxacin, and ofloxacin.

Molecular characterization of antibiotic resistant and potentially virulent enterococci isolated from swine farms and feed mills

A total of 108 swine feed samples were collected from six feed mills and two farms and tested for enterococcal contamination. Nearly 43% of these samples were positive for enterococci. The mean ± SE concentration of enterococci in feed samples ranged from 2.0 × 101 to 7.3 × 103 CFU/g of feed. About 38% of processed feed mill samples were contaminated with enterococci compared to 59% of swine farm samples. A total of 208 enterococcal isolates were represented by Enterococcus casseliflavus (54.8% of total isolates), E. gallinarum (17.8%), E. faecium (17.8%), E. hirae (5.8%), and E. faecalis (3.8%). These isolates were phenotypically resistant to tetracycline (48.5%), erythromycin (14.4%), streptomycin (13.4%), kanamycin (11.5%), ciprofloxacin (10.0%), ampicillin (2.8%), and chloramphenicol (1.4%). All isolates were susceptible to vancomycin and gentamicin. Tetracycline resistance was encoded by tetM gene (52.8%), tetO (14.4%), tetK (1.0%), and tetS (0.5%), whereas ermB conferred erythromycin resistance in 10.6% of all isolates. Several isolates carried genes coding for virulence factors, including gelatinase (gelE; 18.2%), an enterococcal surface protein (esp; 2.4%), and cytolysin (cylA; 2.4%). Only E. faecalis was β-hemolytic (2.9%) and gelatinolytic (3.4%). The aggregation substance gene asa1 was detected in 5 out of 8 E. faecalis isolates, of which four were phenotypically positive. The transposon Tn916/1545 was detected in 11.5% of all isolates. Mating assays revealed that 7 out of 8 E. faecalis could transfer tetM gene, and rate of transfer ranged from 2.0 × 10−3 to 1.6 × 10−5. The presence of antibiotic resistant and potentially virulent enterococci in swine farm samples and feed mill samples, though in low prevalence, raises concern and emphasizes the need for improved hygiene and quality standards on farms and in feed mills.

Investigation on a Sensitive Chemiluminescence System Based on Ni(IV) Complex to Determine Two β2-Agonist Drugs in Urine and Swine Feed and Their Mechanism

Veterinary drug residues, particularly traces of β2-agonists, can cause various kinds of harmful impact to the environment and public health. Here, a sensitive chemiluminescence (CL) method incorporated with a flow injection analysis is developed for the determination of two β2-agonists [i.e., salbutamol (SAL) and terbutaline (TEB)]. The system is based on the CL reaction of Ni(IV) complex with luminol in alkaline solutions, whereas SAL and TEB can significantly enhance CL intensities. Under optimum conditions, CL intensities are proportional to the SAL and TEB concentration in the range of 1.0 × 10−9 M to 5.0 × 10−7 M and 1.0 × 10−9 M to 1.0 × 10−7 M, respectively. The limits of detection (3σ) are 1.0 × 10−11 M for TEB, and 1.3 × 10−11 for SAL respectively. Relative standard deviations (n = 11) are less than 2% for 5.0 × 10−8 M SAL and TEB. Possible reaction mechanisms for the CL system are suggested based on the CL system spectra, Ni(IV) complex oxidation characteristics, and electron spin resonance (ESR) techniques. The proposed method has been applied to the analysis of urine and swine feed samples with satisfactory results.

114 Evaluation of Using Hand Held Near Infrared Spectroscopy for Pellet Fines and Moisture.

Recently the use of Near Infra-red Reflectance spectroscopy (NIR) to predict nutritional information has grown. The ability to predict chemical information around protein, oil, and carbohydrates in real time has enabled nutritionists to make decisions around feeding values and to better predict animal performance. What is generally overlooked is that NIR can be used to predict physical as well as chemical properties. In addition new NIR equipment particularly at the portable end of the market has been introduced which allows the user to get closer to the production line and to make decisions whilst the product is still in process. One such physical attribute, pellet fines, is well established as resulting in poorer FCR especially if feeder adjustment is not closely controlled leading to an increased cost of pig production. The aim of the study was to determine if using a hand held (HH) NIR instrument it is possible to determine the percent pellet fines as measured using a standard sieve methodology. This trial was set-up to measure pellet fines on 89 swine feed samples using the 2 pan sieve method and developing a calibration to determine if it is feasible to measure particle size by HH-NIR. In addition 29 samples were sent for wet chemistry analyses for moisture; this data was used to determine if the level of moisture can be predicted by NIR. Using a HH-NIR instrument (wavelength between 920nm to 1650nm) approximately 1.2 to 2.0 kg of feed sample was placed in a specialized box and scanned at 5 different locations collecting 200 spectra per scan. The resulting 1000 spectra were averaged to produce 1 spectrum per sample. The same sample was then measured by being placed on to the sieve (#6) with the pan attached to the bottom. The sieve was then shaken for 45 seconds and repeated for 15 seconds until the sample was completely sieved. Pellets and fines were then weighed and the % fines determined. Chemometric analyses showed that there was a strong calibration between pellet fines analysis and the NIR spectra (r2 = 0.93, SEP 3.1). Furthermore using a standard feed calibration provided by Aunir for this HH-NIR it showed that there is a good prediction of pellet moisture against the laboratory values (r2 = 0.93, SEP 0.708). Overall, these results confirm that HH-NIR can be used at the mill to determine pellet fines and pellet moisture.

A Decrease of Incidence Cases of Fumonisins in South Korean Feedstuff between 2011 and 2016.

Several plant pathogen Fusarium species produce fumonisins (FUMs); which can end up in food and feed and; when ingested; can exhibit harmful effects on humans and livestock. Mycotoxin intoxication by fumonisin B1 (FB1) and fumonisin B2 (FB2) can cause porcine pulmonary edema; leukoencephalomalacia in equines; esophageal cancer and birth defects by natural contamination. Herein; the occurrence of FB1 and FB2 in feedstuff (compound feed and feed ingredients) was investigated between 2011 and 2016 in South Korea. A total of 535 animal feed samples (425 compound feed samples and 110 feed ingredients) produced domestically were sampled four times between 2011 and 2016 (2011; 2012; 2014 and 2016) from feed factories in South Korea. The limit of detection (LOD) for FB1 and FB2 was 20 μg/kg and 25 μg/kg; respectively; and the limit of quantitation (LOQ) was 30 μg/kg and 35 μg/kg; respectively. The recovery range (%) was between 86.4% and 108.8%; and the relative standard deviation (RSD) (%) was 4.7–12.1%. Seven (swine feed samples) out of the 425 feed samples exceeded the European Union (EU) and South Korea commission regulations over the six-year test period; and no feed ingredients exceeded the guidelines.

Simultaneous determination of β2-agonists clenbuterol and salbutamol in water and swine feed samples by dual-labeled time-resolved fluoroimmunoassay

Lanthanide ions, the excellent fluorescence markers, have the potential to simplify the performance of multi-analytes analysis. In this work, a powerful time-resolved fluoroimmunoassay (TRFIA) based on dual-labeled format were performed for detecting clenbuterol and salbutamol simultaneously in water and swine feed samples. Europium (Eu3+)-labeled goat anti-mouse IgG and Samarium (Sm3+)-labeled goat anti-rabbit IgG were prepared and used as fluorescent probes. Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of the TRFIA were 0.263 and 0.007 ng/mL for clenbuterol, and 0.179 and 0.014 ng/mL for salbutamol, respectively. The cross-reactivities of the TRFIA between these two β2-agonists and with their analogues were negligible, thus indicated high specificity and promoted the simultaneous determination. The spiked recoveries were 72.2%–102.2% with relative standard deviations (RSDs) of 3.4–13.8% for clenbuterol and salbutamol in water and swine feed samples. Furthermore, the results of TRFIA correlated well with those obtained by HPLC. The proposed dual-labeled TRFIA was a satisfactory tool for simultaneous, sensitive, efficient and labour-saving detection of clenbuterol and salbutamol in water and swine feed samples.

Ultrasensitive and Specific Detection of Salbutamol in Swine Feed, Meat, and Urine Samples by a Competitive Immunochromatographic Test Integrated with Surface-Enhanced Raman Scattering

Salbutamol (SAL), a kind of β-agonist which can enhance the lean meat-to-fat ratio, has been inhibited as an additive used in animal feeds for livestock production in many countries due to its harmful effect to the consumers. In this study, an ultrasensitive and specific competitive immunochromatographic test (ICT) integrated with surface-enhanced Raman scattering (SERS) for the detection of SAL was described. The immunoprobe was prepared by immobilizing polyclonal antibody against SAL on the surface of Au@Ag nanoparticles in which the Raman reporter (4-mercaptobenzoic acid, MBA) had been sandwiched. After ICT procedures, the specific SERS signals generated from MBA on the test line of the ICT strip were measured for the quantitative determination of SAL. The assay was completed in 15 min. The IC50 and the limit of detection (LOD) values of the assay for SAL were 0.028 ng mL−1 and 3.0 pg mL−1, respectively. There was no cross-reactivity (CR) of the assay with other three β-agonists (clenbuterol, phenylethanolamine A, and ractopamine), showing high specificity of the assay. Spiking experiments indicated that the average recoveries (n = 3) of SAL from swine feed, meat, and urine samples were in ranges of 98.4–105.2 % with the relative standard deviations (RSDs) of 1.7–7.8 %. The results demonstrated that the proposed ICT was a feasible method for ultrasensitive and specific detection SAL in swine feed, meat and urine samples, and could be extended for the detection of other target analytes.

Development of a sensitive monoclonal antibody-based ELISA for the determination of a β-adrenergic agonist brombuterol in swine meat, liver and feed samples

A sensitive enzyme-linked immunosorbent assay (ELISA) based on a newly prepared monoclonal antibody (mAb) for the determination of a β-adrenergic agonist brombuterol in swine meat, liver and feed samples was developed.

Sensitive immunoassay for the β-agonist ractopamine based on glassy carbon electrode modified with gold nanoparticles and multi-walled carbon nanotubes in a film of poly-arginine

We are presenting an electrochemical immunosensor for the determination of the β-agonist and food additive ractopamine. A glassy carbon electrode (GCE) was modified with gold nanoparticles and a film of a composite made from poly(arginine) and multi-walled carbon nanotubes. Antibody against ractopamine was immobilized on the surface of the modified GCE which then was blocked with bovine serum albumin. The assembly of the immunosensor was followed by electrochemical impedance spectroscopy. Results demonstrated that the semicircle diameter increases, indicating that the film formed on the surface hinders electron transfer due to formation of the antibody-antigen complex on the modified electrode. Under optimal conditions, the peak current obtained by differential pulse voltammetry decreases linearly with increasing ractopamine concentrations in the 0.1 nmol•L−1 to 1 μmol•L−1 concentration range. The lower detection limit is 0.1 nmol•L−1. The sensor displays good stability and reproducibility. The method was applied to the analysis of spiked swine feed samples and gave satisfactory results.

Development of an immunoaffinity chromatography column for selective extraction of a new agonist phenylethylamine A from feed, meat and liver samples

Phenylethanolamine A (PA) is a new emerged β-adrenergic agonist that has been illegally used as an animal feed additive for growth promotion in China. In this study, an immunoaffinity chromatography (IAC) column for selective extraction of PA from swine feed, meat and liver samples was developed. The IAC column was constructed by covalently coupling specific polyclonal antibody (Ab) against PA to CNBr-activated Sepharose 4B and packed into a common solid phase extraction (SPE) cartridge. The extraction conditions including loading, washing and eluting solutions were carefully optimized. Under optimal conditions, the IAC column was characterized in terms of maximum capacity, selectivity, extraction recovery and stability. The maximum capacity of the ICA for PA extraction was found to be 239.4ng. For selectivity testing, 100ng of other three β-adrenergic agonists (clenbuterol, ractopamine and salbutamol) was separately loaded onto the column, and it was observed that the tested compounds could not be captured on the column, e.g. the column could only selectively recognize PA. The recovery of the IAC for PA extraction was found within 96.47-101.98% when 10, 50 and 100ng PA were separately loaded onto IAC column. The IAC column was also applied to real sample extraction. Swine feed, meat and liver samples were collected and spiked with PA in range of 1.0-20ngg(-1). The spiked and unspiked samples were extracted by IAC column and measured by high performance liquid chromatography (HPLC). It was found that there was no detectable PA in the blank samples, and the extraction recoveries of the IAC for PA from the spiked samples were within 89.48-104.89%. The stability of the column was also tested. It was showed that after 35 times repeated usage, 60% of the maximum capacity was still remained. The proposed IAC was proven to be a feasible extraction method for PA from different matrices with the properties of high maximum capacity, selectivity, extraction efficiency and stability.

Molecularly imprinted quartz crystal microbalance sensor based on poly(o-aminothiophenol) membrane and Au nanoparticles for ractopamine determination

A molecularly imprinted quartz crystal microbalance (QCM) sensor for ractopamine (RAC) detection was developed by electrodepositing a poly-o-aminothiophenol membrane on an Au electrode surface modified by self-assembled Au nanoparticles (AuNPs). The modified electrodes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. This molecularly imprinted QCM sensor showed good frequency response in RAC binding measurements and the introduction of AuNPs demonstrated performance improvements. Frequency shifts were found to be proportional to concentration of RAC in the range of 2.5×10−6 to 1.5×10−4molL−1 with a detection limit of 1.17×10−6molL−1 (S/N=3). The sensor showed a good selective affinity for RAC (selectivity coefficient >3) compared with similar molecules and good reproducibility and long-term stability. This research has combined the advantages of high specific surface area of AuNPs, high selectivity from molecularly imprinted electrodeposited membrane and high sensitivity from quartz crystal microgravimetry. In addition, the modified electrode sensor was successfully applied to determine RAC residues in spiked swine feed samples with satisfactory recoveries ranging from 87.7 to 95.2%.

Colorimetric detection of ractopamine and salbutamol using gold nanoparticles functionalized with melamine as a probe

A highly selective and sensitive method is developed for colorimetric detection of ractopamine and salbutamol using gold nanoparticles (AuNPs) functionalized with melamine (MA), respectively. The presence of these β-agonists induces the aggregation of gold nanoparticles through hydrogen-bonding interaction that was accompanied by a distinct change in color and optical properties, which could be monitored by a UV–vis spectrophotometer or even naked eyes. This process caused a significant decrease in the absorbance ratio (A670nm/A520nm) of melamine–gold nanoparticles (MA–AuNPs), and the color changed from wine red to blue. The systems exhibited a wide liner range, from 1×10−10M to 5×10−7mol/L with a correlation coefficient of 0.995 for ractopamine, and 1×10−10M to 1×10−5mol/L with a correlation coefficient of 0.996 for salbutamol, with measuring the absorbance ratio (A670nm/A520nm). The detection limit of these β-agonists is as low as 1×10−11mol/L. Particularly, the developed method has been applied to the analysis of real swine feed samples and has achieved satisfactory results.

Occurrence of fumonisins in feed for swine and horses

BackgroundFumonisin B1 (FB1), fumonisin B2 (FB2), and overall mycotoxins feed contamination may cause several effects on crops production and animal health. The contamination occurred predominantly in corn and corn-based foods and feeds. AimsThis survey intends to provide the occurrence of fumonisins in swine and equine mixed feeds in Portugal, making an overview from 2007 to 2010. MethodsA total of 363 samples were analyzed, 258 from swine feed and 105 from horse feed with HPLC method. The detection limit was 50μg/kg for FB1 and 100μg/kg for FB2. ResultsThe overall results were 13% of FB1 occurrence from 2007 to 2010. FB1 was detected in about 17.0% of swine feed samples, being more frequent in 2010 (32.9%). In this year (2010) levels ranged between 66.7 and 3815.5μg/kg.FB2 occurred only in 2010 in swine feed (6 samples, ranging between 104.0 to 467.2μg/kg) and in horse feed (1 sample). ConclusionsThis represents an increase in occurrence through the analyzed years, but this may not be a threat to animal health, once the values were below the recommended guidance values from European Commission.

안전 축산물 생산을 위한 가축사료 내 중금속 오염 분석에 관한 연구

The safety of animal feed was evaluated by analyzing the levels of heavy metals (Pb, Cr, Cd, As, Se and Ag) in cattle, swine, and poultry feeds and the levels of Cu, Zn and P in swine feed. Feeds used in the analysis were produced in Korea from 2004 through the first half of 2007. The results of the study revealed that, with the exception of Cd, the concentration of heavy metals were much lower than the Minimum Regulation Levels (MRLs). However, the Cd concentration exceeded the MRL in 1 of 987 swine feed samples in 2005, as well as in 4 of 1,239 swine feed samples and 1 of 778 poultry feed samples in 2006. The levels of Cu, Zn and P in swine feed were compared with the swine breeding standard. The results of this analysis revealed that the Cu concentrations in the samples exceeded the MRL for growing pigs by 0.97%, and that for finishing and breeding pigs by 9.9%. In addition, the Cu levels (80.98 ppm for piglet, 44.82 ppm for growing pigs, 19 ppm for finishing and breeding pigs) in swine feed showed higher levels compared to 3.5-6.0 ppm, which is the Cu requirement for swine. Furthermore, the results of the Zn analysis revealed that the samples exceeded the MRL for piglets, growing pigs, and finishing and breeding pigs by 5.7%, 7.7%, and 9.3%, respectively. Finally, the average concentration of P in swine feed was 0.74%, which is almost the same as the phosphate requirement for swine.