Investigation and assessment of natural radioactivity in commercial animal feeds in Texas.

Commercial animal feed in Texas was characterized by determining natural gamma emitters including 40K,137Cs, and Uranium (235U and 238U) and Thorium (232Th) series to obtain basic radioactivity values. The measured activity concentration of natural radionuclides in animal feed was low enough for safe consumption by animal and largely depended on the type of animal feed.40K was the predominant radionuclide showing the highest activity concentration in animal feed. The radioactivity concentration of 214 Bi and 214Pb in 238U decay series was 1.39 and 1.33 Bq/kg in corn, respectively, lower than in other animal feed types. On the other hand, the vitamin/mineral mix samples showed higher concentrations of 214 Bi (9.04 Bq/kg) and 214Pb (10.19 Bq/kg). Beef cattle feed, poultry feed, and vitamin/mineral mix exhibited higher activity concentration of 228Ac and 212Pb in 232Th decay series. Gamma radionuclides appeared to be highly and significantly correlated within each decay series. 235U was present at low levels in all feed samples while the anthropogenic radionuclide of 137Cs was not detected irrespective of the type of animal feed. This study highlights an importance of establishing a current baseline of radioactivity concentration in animal feed in Texas in which the largest animal feed consumption in the US exists.

Field validation as a means for continual monitoring of approved test kit's fitness for purpose in the commercial market.

Testing accuracy of a chemical contaminant requires use of a testing platform that conforms to validation criteria outlined in quality literature and standards. This study explores the application of commercial field data measured by qualified analysts using a United States Department of Agriculture - Federal Grain Inspection Service approved kit for measuring fumonisin in maize to augment method validation procedures. Analysts from seven grain testing facilities were qualified in official USDA sampling, sample preparation, and testing methodology using the Charm LF-FUMQ-WETS5. A duplicate sample was tested in the Office of the Texas State Chemist (OTSC) laboratory using UPLC-MS-MS. Data were subject to four statistical techniques using continuous and categorical methodology. This approach enabled researchers to explore if a single test or multiple comparisons were best suited to assess a field kit's fitness for purpose across facility, toxin level, and year. The study concluded that a paired t-test and correlation analysis provided a quick and meaningful evaluation of kit performance. The correct placement of samples within the correct bin (violative versus non-violative) aligns well with market forces and regulatory compliance. The results of this study also provide a useful tool to assess all field kits' performance at the beginning of the harvest season and subsequent years. The combination of statistical techniques presented in this research is an important tool in assessing mycotoxin field test kits fitness for purpose and represents a key step in a continuous improvement-quality systems process meant to protect the feed and food supply.

Enhancing maize safety: the role of co-regulation as a regulatory strategy to manage fumonisin risk.

This study explores the implementation of the One Sample Strategy (OSS), a co-regulation program aimed at managing mycotoxin risk in Texas maize. Fumonisin-contaminated cereals and oilseeds that contain greater than 5 mg kg-1 of the toxin (B1, B2, and B3) are a risk for equids and rabbits, and levels greater than 60 mg kg-1 are a risk to ruminants. The OSS, previously successful in managing aflatoxin risk in Texas maize, was evaluated for its effectiveness in handling fumonisin risk in maize, specifically as it relates to ruminants. In 2017, 25 analysts across seven firms qualified to participate in the program. To ensure greater accuracy in testing, working control samples were provided to the participating OSS firms with the requirement that their results fall within +/- 20% of the target concentration. Ninety-four percent of the working controls met this specification. The capability to grind maize to the OSS prescribed particle size was met by 100% of participants. To verify testing accuracy, file samples collected from each OSS firm were analysed by UPLC-MS/MS. The 177 fumonisin verification samples analysed by Office of the Texas State Chemist (OTSC) were correlated (r = 0.93) with co-regulation laboratories. Results were plotted in an operating curve to depict type I and type II errors. Error analysis revealed a type I error rate of 13% and type II error rate of 2% for the 5 mg kg-1 guidance level, and 6% and 8%, respectively, for the 60 mg kg-1 guidance level. For 2017, 994 official reports of analysis for fumonisin in whole maize in the Texas High Plains were issued by the seven laboratories that employed 25 OTSC-credentialed analysts. The OSS co-regulation program, supported by a quality systems approach and government regulations, has proven effective in managing fumonisin risk in Texas maize, enhancing both market confidence and livestock safety.

Economic benefit of co-regulation to manage aflatoxin risk in maize.

Aflatoxins are toxic fungal metabolites that occur naturally in the field among cereals, oilseeds, and nuts that may increase during storage. Texas grown maize, commonly referred as corn, has some of the highest aflatoxin levels in the US. In 2011, the Office of the Texas State Chemist (OTSC) collaborated with the Risk Management Agency (RMA) of the United States Department of Agriculture (USDA) and the Texas grain industry to implement the state's first co-regulation governance option to manage aflatoxin risk. Co-regulation is a form of risk management that relies upon a government-private partnership in regulation; utilizing government-backed codes of practice that result in a more connected and transparent marketplace. To measure the economic benefit of co-regulation to manage aflatoxin risk, interviews were conducted among twenty-seven participants in the OTSC aflatoxin co-regulation program who represented 31% of the grain companies that handled maize contaminated by aflatoxin according to Texas Commercial Feed Rules. A comparative approach was used by gathering evidence from 2010 to 2018, in order to evaluate the results before and after the OTSC implemented its co-regulation strategy. The results were evaluated by using the data gathered from the interviews to measure the specific costs and benefits incurred by producers and grain handlers. The findings were modeled in the form of an income statement. From the income statement, the total economic benefit of the One Sample Strategy in 2018 was $14,572,180. This study provides a more realistic characterization of cost drivers associated with aflatoxin risk management and counters exaggerated economic losses associated with aflatoxin in maize from prior studies.

Rapid Detection of Single- and Co-Contaminant Aflatoxins and Fumonisins in Ground Maize Using Hyperspectral Imaging Techniques.

Aflatoxins and fumonisins, commonly found in maize and maize-derived products, frequently co-occur and can cause dangerous illness in humans and animals if ingested in large amounts. Efforts are being made to develop suitable analytical methods for screening that can rapidly detect mycotoxins in order to prevent illness through early detection. A method for classifying contaminated maize by applying hyperspectral imaging techniques including reflectance in the visible and near-infrared (VNIR) and short-wave infrared (SWIR) regions, and fluorescence was investigated. Machine learning classification models in combination with different preprocessing methods were applied to screen ground maize samples for naturally occurring aflatoxin and fumonisin as single contaminants and as co-contaminants. Partial least squares-discriminant analysis (PLS-DA) and support vector machine (SVM) with the radial basis function (RBF) kernel were employed as classification models using cut-off values of each mycotoxin. The classification performance of the SVM was better than that of PLS-DA, and the highest classification accuracies for fluorescence, VNIR, and SWIR were 89.1%, 71.7%, and 95.7%, respectively. SWIR imaging with the SVM model resulted in higher classification accuracies compared to the fluorescence and VNIR models, suggesting that as an alternative to conventional wet chemical methods, the hyperspectral SWIR imaging detection model may be the more effective and efficient analytical tool for mycotoxin analysis compared to fluorescence or VNIR imaging models. These methods represent a food safety screening tool capable of rapidly detecting mycotoxins in maize or other food ingredients consumed by animals or humans.

Detection of aflatoxins in ground maize using a compact and automated Raman spectroscopy system with machine learning.

Consumption of aflatoxin-contaminated food can cause severe illness when consumed by humans or livestock. Because the mycotoxin frequently occurs in cereal grains and other agricultural crops, it is crucial to develop portable devices that can be used non-destructively and in real-time to identify aflatoxin-contaminated food materials during early stages of harvesting or processing. In this study, an aflatoxin detection method was developed using a compact Raman device that can be used in the field. Data were obtained using maize samples naturally contaminated with aflatoxin, and the data were analyzed using a machine learning method. Of the multiple classification models evaluated, such as linear discriminant analysis (LDA), linear support vector machines (LSVM), quadratic discriminant analysis (QDA), and quadratic support vector machines and spectral preprocessing methods, the best classification accuracy was achieved at 95.7% using LDA in combination with Savitzky-Golay 2nd derivative (SG2) preprocessing. Partial least squares regression (PLSR) models demonstrated a close-range accuracy within the scope of standard normal variate (SNV) and multiplicative scatter correction (MSC) preprocessing methods, with determination of coefficient values of R2C and R2V of 0.9998 and 0.8322 respectively for SNV, and 0.9916 and 0.8387 respectively for MSC. This study demonstrates the potential use of compact and automated Raman spectroscopy, coupled with chemometrics and machine learning methods, as a tool for rapidly screening food and feed for hazardous substances at on-site field processing locations.

Determination of aflatoxins in animal feeds by liquid chromatography/tandem mass spectrometry with isotope dilution.

The objective of the present study is to develop a simple, fast method for detection of aflatoxins in animal feeds. Simultaneous quantitation of four aflatoxins (AFB(1), AFB(2), AFG(1) and AFG(2)) in animal feeds was achieved in a single liquid chromatography/tandem mass spectrometry (LC/MS/MS) run. The solid-phase extraction cleanup step is eliminated with the stable isotope dilution method. Matrix effects were observed and overcome by isotope dilution. The method was tested in a variety of animal feed matrices and proved to be accurate and reliable. Method ruggedness tests resulted in recoveries of 78% to 122% with an intra-day assay precision of 2% to 15% and an inter-day assay precision of 3% to 17%. These results indicate that this method is suitable for quantitation of aflatoxins in animal feeds.

Evaluation of two liquid chromatography/tandem mass spectrometry platforms for quantification of monensin in animal feed and milk.

Monensin is an anticoccidial drug that has been used as an additive in medicated feed. The United States Food and Drug Administration (USFDA) has included monensin in the national surveillance schemes for residues in foodstuff. In this study, two simple, selective and rapid methods were developed to determine monensin content in animal feed and milk. The methods enabled the detection of monensin residues as low as 1 ppb. Moreover, the two methods were used as models to compare two common liquid chromatography/tandem mass spectrometry (LC/MS/MS) platforms; an LC linear ion trap (LC/LIT) and an LC triple quadrupole (LC/QqQ). The two instrument platforms were evaluated for their matrix effect dependence, precision and accuracy. The LC/QqQ presented a lower limit of detection and limit of quantitation (LOD and LOQ) and showed less matrix dependence as compared to the LC/LIT. The LC/QqQ instrument also demonstrated a better intermediate precision. For example, the intermediate precision standard deviation calculated for 27 analyses across three days was 4% and 11% for LC/QqQ and LC/LIT, respectively. Overall, the LC/QqQ represents a better choice for analysis of monensin with respect to LOD, LOQ, matrix interference and precision.

Rapid determination of fumonisins in corn-based products by liquid chromatography/tandem mass spectrometry.

A simple, fast, and robust method was developed for the determination of fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) in corn-based human food and animal feed (cornmeal). The method involves a single extraction step followed by centrifugation and filtration before analysis by ultra-performance liquid chromatographylelectrospray ionization (UPLC/ESI)-MS/MS. The LC/MS/MS method developed here represents the fastest and simplest procedure (<30 min) among both conventional HPLC methods and other LC/MS methods using SPE cleanup. The potential for high throughput analysis makes the method particularly beneficial for regulatory agencies and analytical laboratories with a high sample volume. A single-laboratory validation was conducted by testing three different spiking levels (200, 500, and 1000 ng/g for FB1 and FB2; 100, 250, and 500 ng/g for FB3) for accuracy and precision. Recoveries of FB1 ranged from 93 to 98% with RSD values of 3-8%. Recoveries of FB2 ranged from 104 to 108%, with RSD values of 2-6%. Recoveries of FB3 ranged from 94 to 108%, with RSD values of 2-5%.

Aflatoxin Proficiency Testing and Control in Kenya.

Texas A&M AgriLife Research (hereafter AgriLife) introduced a quality systems approach to accurately measure and manage aflatoxin that resulted in improved food safety for approximately 10 million Kenyans. A quality systems approach contains elements that ensure laboratory testing competence. In this study, quality system elements included analyst training and qualification, proficiency testing, use of reference material to support analytical traceability and define analytical uncertainty, development and implementation of a food safety plan by commercial maize (Zea mays) millers, and verification of testing accuracy at the AgriLife laboratory accredited by the Kenya Accreditation Service under the International Organization for Standardization/International Electrotechnical Commission 17025:2005 standard. In 2014 and 2015, five proficiency rounds were performed, ranging in aflatoxin concentrations of 5 to 40 µg/kg. Five laboratories had a z-score of >3, and all of these were for the fifth proficiency round with an aflatoxin content of 5 µg/kg. In 2015, 31 analysts qualified to participate in the program at 15 maize mills. The analysts' qualification for seven test samples, which ranged from 3.1 to 28 µg/kg total aflatoxin, resulted in an average relative standard deviation of 19.2% across all participants and test methods. Independent testing of participating mill verification results before and after analyst implementation of the quality systems approach revealed an improvement in measure accuracy.

A rapid and convenient screening method for detection of restricted monensin, decoquinate, and lasalocid in animal feed by applying SERS and chemometrics.

The surface-enhanced activities of size- and shape-controlled gold nanoparticles (AuNPs) with superior chemical stability were investigated to explore a possible development of a simple and non-destructive spectroscopic method to help the regulatory agency's analytical services for rapid detection and characterization of selected antimicrobials in animal feeds. Feed samples spiked at different concentration ranges of antimicrobials were evaluated using AuNPs as a surface-enhanced Raman spectroscopy (SERS) agent. The collected SERS spectra were mathematically preprocessed for further analysis. The classification models obtained 100% predictive accuracy with zero or little misclassification. The first two canonical variables (p = 0.001) could explain >95% of the variability in preprocessed spectral data. Most chemometric models for predicting MON, DEC, and LAS concentrations showed a high predictive accuracy (r2 > 0.90), lower predictive error (<20 mg/kg), and satisfactory regression quality (slope close to 1.0). The statistical results showed no statistically significant difference between the reference and SERS predicted values (p > 0.05). The findings and implications from the study indicate that SERS would be a powerful and efficient technique possessing a great potential serving as an excellent monitoring and screening tool for antimicrobial contaminated samples in the on-site analysis.

Adsorbent-SERS Technique for Determination of Plant VOCs from Live Cotton Plants and Dried Teas.

We developed a novel substrate for the collection of volatile organic compounds (VOCs) emitted from either living or dried plant material to be analyzed by surface-enhanced Raman spectroscopy (SERS). We demonstrated that this substrate can be utilized to differentiate emissions from blends of three teas, and to differentiate emissions from healthy cotton plants versus caterpillar-infested cotton plants. The substrate we developed can adsorb VOCs in static headspace sampling environments, and VOCs naturally evaporated from three standards were successfully identified by our SERS substrate, showing its ability to differentiate three VOCs and to detect quantitative differences according to collection times. In addition, volatile profiles from plant materials that were either qualitatively different among three teas or quantitatively different in abundance between healthy and infested cotton plants were confirmed by collections on Super-Q resin for dynamic headspace and solid-phase microextraction for static headspace sampling, respectively, followed by gas chromatography to mass spectrometry. Our results indicate that both qualitative and quantitative differences can also be detected by our SERS substrate although we find that the detection of quantitative differences could be improved.

Complexes Formed by Hydrophobic Interaction between Ag-Nanospheres and Adsorbents for the Detection of Methyl Salicylate VOC.

Surface-enhanced Raman spectroscopy (SERS) has been widely investigated in many applications. However, only little work has been done on using SERS for the detection of volatile organic compounds (VOCs), primarily due to the challenges associated with fabricating SERS substrates with sufficient hotspots for signal enhancement and with the surface interfacially compatible for the VOCs. This study investigated the phase transfer of Ag-nanospheres (AgNSs) from the aqueous phase to the non-aqueous phase by electrostatic interaction induced by cationic surfactants, and the feasibility of the transferred AgNSs as SERS substrates for the determination of methyl salicylate VOC. Results indicated that one of three cationic surfactants, tetraoctylammonium bromide (TOAB) dissolved in organic solvent showed successful phase transfer of the AgNSs confirmed by several characterization analyses. The complex formed by hydrophobic interaction between the transferred AgNSs and Tenax-TA adsorbent polymer was able to be utilized as a SERS substrate, and the volatile of methyl salicylate could be easily determined from SERS measurements at 4 h static volatile collection. Therefore, the proposed new techniques can be effectively employed to areas where many VOCs relevant to food and agriculture need to be analyzed.

Evaluation of Coregulation as a Governance Option To Manage Aflatoxin Risk in Texas Maize.

Coregulation as a form of risk management relies upon a government-private partnership in regulation using government-backed codes of practice or action plans. In Texas, implementation of coregulation to manage aflatoxin risk has been practiced since 2011 and operates under the program title One Sample Strategy (OSS). Aflatoxin-contaminated cereals and oilseeds that contain greater than 20 µg/kg of the toxin (B1, B2, G1, and G2) are adulterated as defined by the Texas Commercial Feed Rules and regulated by the Texas Feed and Fertilizer Control Service of the Office of the Texas State Chemist. The present study was intended to evaluate the implementation and effectiveness of the coregulation program for 3 years based on selected evaluation criteria aiming to improve aflatoxin risk management and thus reduce market and food safety risk in Texas. In 2013, 124 analysts qualified to participate in the program at 23 grain elevators. During the 2013 harvest, use of control samples to ensure testing accuracy revealed that the average relative standard deviation among all participants was 14.5%. In 2014 and 2015, 129 and 151 analysts, respectively, qualified to measure aflatoxin, and the average relative standard deviation values for the working control across the 29 and 30 participating firms were 16.2 and 13.7%, respectively. All firms demonstrated the capability to grind maize to the OSS-prescribed particle size (70% passing through a 20-mesh sieve) in all 3 years. The Texas Feed and Fertilizer Control Service verified testing accuracy of OSS participants analyzing 612, 693, and 482 retained samples in 2013, 2014, and 2015, respectively. Results were plotted in an operating curve to depict type I and type II errors. The implementation of the OSS built upon a quality system-based code of practice successfully managed aflatoxin risk in Texas by using coregulation as a governance option.

Corroborative study on maize quality, dry-milling and wet-milling properties of selected maize hybrids.

A corroborative study was conducted on the maize quality properties of test weight, pycnometer density, tangential abrasive dehulling device (TADD), time-to-grind on the Stenvert hardness tester (SHT), 100-kernel weight, kernel size distribution, and proximate composition as well as maize dry- and wet-millability by six participating laboratories. Suggested operating procedures were given to compare their measurements and provide the variance structure within and between laboratories and hybrids. Partial correlation coefficient among maize quality properties varied among laboratories. The repeatability and reproducibility precision values were acceptably low for the physical quality tests, except for TADD and SHT time-to-grind measurements. The yields of dry- and wet-milled products and their correlation with maize quality properties were dependent on the collaborating laboratory. This paper highlights the importance of laboratory variation when considering which maize hybrids are best suited for dry-milling and wet-milling.

Development and implementation of hazard analysis and critical control point plans by several U.S. feed manufacturers.

The commitment to consumer food safety, global trade, and proposed new regulations by the U.S. Food and Drug Administration Center for Veterinary Medicine has led to increased adoption of hazard analysis and critical control point (HACCP) by the U.S. feed industry. A project supported by the U.S. Department of Agriculture Integrated Food Safety Initiate titled "Development and Implementation of a Voluntary HACCP Program for the US Feed Industry" enabled faculty from three land grant universities to assist individuals from 14 feed companies that collectively manufacture 15 million metric tons of feed in 100 facilities to develop HACCP plans. The process flow in these plans averaged 20 steps, and the most detailed plan included 60 process steps. Chemical hazards were more commonly identified in HACCP plans (average of four hazards per plan) than were biological hazards (average of one per plan). The most prevalent chemical hazards were cross-contamination of type A medicated articles and type B medicated feeds, aflatoxin, and wrong ingredient inclusion in feed. The most common biological hazard was mammalian protein contamination of feed ingredients and finished feed for cattle. An assessment of time and costs associated with developing HACCP plans revealed that approximately 29% of the companies needed additional personnel or additional equipment to implement a HACCP plan, and on average 268 additional person hours were needed to develop and implement a HACCP plan. Plan design, compliance monitoring, and record keeping were the three most time-consuming activities needed for developing and implementing a HACCP plan. The average cost of additional equipment needed to implement a HACCP plan was $250.

Physical and biochemical properties of maize hardness and extrudates of selected hybrids.

Protein and starch determinants of maize kernel hardness and extruded products were characterized to better define the role of endosperm texture during extrusion. Maize physical properties were correlated with total proteins and zein subclasses (p < 0.01). The extrusion process significantly altered protein solubility and increased protein fragmentation as measured by RP-HPLC and size exclusion chromatography. Harder grits and extrudates demonstrated higher amylose content, lower degree of starch damage, and fragmentation at different screw speeds than softer grits and extrudates. Differences in extrudate expansion ratio, water absorption index, water solubility index, oil absorption capacity, and breaking stress between harder and softer hybrids were related to protein aggregation and fragmentation as well as starch damage and fragmentation.

Evaluation of Selected Nutrients and Contaminants in Distillers Grains from Ethanol Production in Texas.

This article contains the results of the evaluation of distillers grain (DG) coproducts from different ethanol plants around the United States and supplemented in animal diets in Texas, based on samples analyzed from 2008 to 2014. The samples were assessed for concentration, occurrence, and prevalence of selected nutrients and contaminants. Protein and sulfur contents of DG were largely different between maize and sorghum coproducts, as well as wet distillers grain with solubles (WDGS) and dried distillers grain with solubles (DDGS), indicating a significant effect of grain feedstock and dry grind process stream on DG composition and quality. Salmonella was isolated in 4 DDGS samples of a total of 157 DG samples, a percentage (2.5%) that is lower than the percentage of Salmonella -positive samples found in other feed samples analyzed during the same period. A small amount of virginiamycin residue was found in 24 maize DDGS, 1 maize WDGS, and 2 sorghum DDGS samples of 242 samples in total. One sorghum DDGS sample of 168 DG samples was contaminated with animal protein prohibited for use in ruminant feed and was channeled to poultry feed. The concentrations of aflatoxin and fumonisin DG coproducts averaged 3.4 µg/kg and 0.7 mg/kg, respectively. Among contaminated maize DG samples, five DDGS samples for aflatoxin contained a higher concentration than the U.S. Food and Drug Administration (FDA) minimum action level of 20 µg/kg for use in animal feed, whereas no sample for fumonisin was found above the action level of 5 mg/kg. The study provides the most current results involving DG coproducts and associated hazards that will assist development of food safety plans required by the FDA in their September 2015 rule titled "Current Good Manufacturing Practice Hazard Analysis and Risk Based Preventive Controls for Food for Animals."

Prevalence of Nontyphoidal Salmonella and Salmonella Strains with Conjugative Antimicrobial-Resistant Serovars Contaminating Animal Feed in Texas.

The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.0%) were recovered from three of six medicated feed types. Three of these isolates derived from the medicated feed, Salmonella Newport, Salmonella Typhimurium var. O 5- (Copenhagen), and Salmonella Lexington var. 15+ (Manila), displayed antimicrobial resistance. Susceptibility testing revealed that only 3.0% (12) of the 365 isolates displayed resistance to any of the antimicrobial agents. These 12 isolates were recovered from unmedicated dry beef feed (n = 3), medicated dry beef feed (n = 3), cabbage culls (n = 2), animal protein products (n = 2), dry dairy cattle feed (n = 1), and fish meal (n = 1). Only Salmonella Newport and Salmonella Typhimurium var. O 5- (Copenhagen) were multidrug resistant. Both isolates possessed the IncA/C replicon and the blaCMY-2 gene associated with cephalosporin resistance. Plasmid replicons were amplified from 4 of 12 resistant isolates. Plasmids (40 kb) were Salmonella Montevideo and Salmonella Kentucky. Conjugation experiments were done using 7 of the 12 resistant isolates as donors. Only Salmonella Montevideo, possessing a plasmid and amplifying IncN, produced transconjugants. Transconjugants displayed the same antimicrobial resistance profile as did the donor isolate. Three isolates that amplified replicons corresponding to IncA/C or IncHI2 did not produce transconjugants at 30 or 37°C. The results of this study suggest that the prevalence of antimicrobial-resistant Salmonella contaminating animal feed is low in Texas. However, Salmonella was more prevalent in feed by-products; fish meal had the highest prevalence (84%) followed by animal protein products (48%). Ten of the 35 feed types had no Salmonella contamination. Further investigation is needed to understand the possible role of specific feed types in the dissemination of antimicrobial resistant bacteria.

Evaluation of Selected Nutrients and Contaminants in Distillers Grains from Ethanol Production in Texas.

This study evaluated distillers grain (DG) by-products produced in different ethanol plants and supplemented in animal diets in Texas, based on samples analyzed from 2008 to 2014. The samples were assessed for concentration, occurrence, and prevalence of selected nutrients and contaminants. Protein and sulfur contents of DG were largely different between corn and sorghum by-products as well as wet distillers grain with solubles and dry distillers grain with solubles (DDGS), indicating a significant effect of grain feedstock and dry-grind process stream on DG composition and quality. Salmonella was isolated in 4 DDGS samples out of a total of 157 DG samples, a percentage (2.5%) that is much lower than the percentage of Salmonella-positive samples found in other feed samples analyzed during the same period. A small amount of virginiamycin residue was found in 24 corn DDGS, 1 corn wet distillers grain with solubles, and 2 sorghum DDGS samples out of 242 samples in total. One sorghum DDGS sample out of 168 DG samples was contaminated with bovine spongiform encephalopathy, but the transmission route of the bovine spongiform encephalopathy agent could not be clearly defined. The concentrations of aflatoxin and fumonisin DG by-products averaged 3.4 µg/kg and 0.7 mg/kg, respectively. Among contaminated corn DG samples, five DDGS samples for aflatoxin contained a higher concentration than the U.S. Food and Drug Administration action level for use in animal feed, whereas no sample for fumonisin was found above the action level. The study results raised some important issues associated with the quality and use of DG by-products, suggesting several approaches and strategies for their effective and safe use as a feed ingredient to promote animal and human health and welfare.