Mycotoxin Occurrence in Feeds and Raw Materials in China: A Five-Year Investigation

Mycotoxins are ubiquitously present in feeds and raw materials and can exert toxicity on animals and humans. Therefore, mycotoxin occurrence should be monitored. We report here a multi-mycotoxin survey of feed samples in China from 2017 to 2021. Concentrations of aflatoxins, trichothecenes type B, fumonisins, and zearalenone were determined in a total of 9392 samples collected throughout China. Regional differences and year-to-year variation of mycotoxin occurrence were also assessed in new-season corn. Generally, Fusarium mycotoxins were prevalent, while mycotoxin contamination in each feed commodity showed a distinct pattern, e.g., wheat and bran were typically affected by trichothecenes type B, peanut meals were highly susceptible to aflatoxins, and finished feeds exhibited a comparatively high prevalence of all mycotoxins. In new-season corn, trichothecenes type B and fumonisins were most prevalent, with positive rates of 84.04% and 87.16%, respectively. Regions exhibited different patterns of mycotoxin occurrence. The Anhui and Jiangsu provinces of East China exhibited a high prevalence and concentrations of aflatoxins with a positive rate and a positive average of 82.61% and 103.08 μg/kg, respectively. Central China obtained high fumonisins levels of 4707.84 μg/kg. Trichothecenes type B and zearalenone occurred more frequently in temperate regions of Northeast China, and their positive rates reached 94.99% and 55.67%, respectively. In these regions, mycotoxin concentrations in new-season corn exhibited pronounced year-to-year variations and this could be due to the unusual changes of rainfall or temperature during sensitive periods of corn growing. A large fraction of new-season corn samples contained multiple mycotoxins with two to three classes (75.42%), and the most frequently observed co-contaminants were the combination of trichothecenes type B and fumonisins (73.52%). Trichothecenes type B and zearalenone concentrations were highly positively correlated with a coefficient of 0.775. In conclusion, mycotoxins contamination and co-contamination of feeds are common. Mycotoxin contamination in new-season corn exhibited regional patterns and year-to-year variations, with climate and weather conditions as determinant factors.

60 Occurrence of Mycotoxins in US Corn Gluten Products and Wheat Middlings

Secondary fungal metabolites which may affect animal health and productivity are known as mycotoxins. These naturally occurring metabolites are often detected in a variety of feed ingredients. Mycotoxin occurrence and contamination levels in corn gluten products and wheat middlings or “midds” were monitored in this study. Samples submitted from the US were screened via LC-MS/MS for six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A (OTA). The presence of clinical health or performance concerns on-farm was reported for each sample. Results from samples without clinical concerns that were above the limit of detection for each respective mycotoxin group were included in the study. Out of 14 corn gluten product samples reported as 2021 crop year, 100% were positive for both B-Trich and FUM, while 71% were positive for some amount of ZEN. These mycotoxin groups were also the most frequently detected in 2020. Mean contamination levels (parts per billion, ppb) for 2021 were 1,314 ppb, 443 ppb, and 132 ppb, respectively. Of the 24 samples of 2021 wheat midds, B-Trich were detected in 92% while 54% were positive for OTA with mean contamination levels of 665 ppb and 3 ppb, respectively. Ergot alkaloids were not screened for in the current year, however, previous analyses have identified these metabolites frequently occur in wheat midds samples. Although represented by limited data sets to date, analysis of 2021 corn gluten products and wheat midds indicate mycotoxins frequently occur in these by-product feeds. High feed costs may drive increased feeding of alternative feeds, including these and other by-products, in addition to established routine usage in pelleted feeds and other diets. Therefore, continued screening is suggested to assess mycotoxin exposure in livestock diets.

61 Mycotoxin Trends in US Corn Grain and Corn Distiller’s Dried Grains with Solubles

Mycotoxins are secondary fungal metabolites which may affect animal health and performance and are frequently detected in various feedstuffs. Mycotoxin occurrence and contamination levels in US corn grain and corn distiller’s dried grains with solubles (DDGS) samples were monitored in this study. Samples were analyzed via LC-MS/MS for six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A. The presence of clinical health or performance concerns on-farm was reported for each sample. Results from samples without clinical concerns that were above the limit of detection for each respective mycotoxin group were analyzed using the GLIMMIX procedure (SAS 9.4, Cary, NC) to test the effect of harvest year on mean contamination level. Results are presented in Table 1. Of the 219 samples of 2021 corn grain screened in the current data set, 69% were positive for some level of B-Trich, an increase from 58% positive in 2020. Fumonisins (61%) and ZEN (27%) were the next most frequently detected mycotoxins in 2021 samples. Although numerically lower, mean B-Trich level (parts per billion, ppb) was similar to 2020 crop while contamination with FUM was elevated (P = 0.0001) compared to the prior year. Mean ZEN levels are numerically greater, but similar to 2020 samples. Out of 35 corn DDGS samples, occurrence of B-Trich, FUM, and ZEN remained high at 100, 100, and 94%, respectively. Mean B-Trich and FUM concentrations were similar year-to-year across the study period for DDGS while current mean ZEN level was similar to 2020, but lower than 2019 (P < 0.001). Preliminary results of the 2021 US corn grain and DDGS survey suggest increased mycotoxin occurrence with comparable mean contamination levels to those observed in 2020. Continued surveillance is suggested to assess contamination in common livestock feed ingredients.

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351 Mycotoxin Trends in US Total Mixed Rations and Corn Silage

Mycotoxins are secondary fungal metabolites identified in a variety of feed ingredients and may affect animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in 2022 US total mixed ration (TMR) and 2021 corn silage samples. Corn silage samples harvested in 2021 and submitted through March 2022 and TMR samples submitted between January through March 2022 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin A. Detailed information for each sample was provided including, state of origin and whether or not clinical signs of mycotoxicosis was observed on-farm. Parameters of the main toxins found for corn silage and TMR samples were analyzed for effect of clinical concern (yes/no) and harvest year on contamination levels using LSMeans statement with Tukey's adjustment in the GLIMMIX procedure (SAS 9.4, Cary, NC). Main effects of mean contamination by harvest year are presented in Table 1, since no interactions were significant (P > 0.05). To date, 20 TMR samples from seven states have been submitted for analysis in 2022. Preliminary results show detectable amounts of B-Trich in 95% of TMR samples, with ZEN and FUM detected less frequently in 55 and 10%, respectively. Mean contamination concentrations (parts per billion, ppb) are presented on dry matter basis and were greater in 2022 compared with 2021 for B-Trich and ZEN (P < 0.05) and similar for FUM (P = 0.022). Preliminary results for 72 corn silage samples show detectable quantities of B-Trich in 90% of samples with ZEN and FUM detected less frequently in 67 and 24%, respectively. Mean contamination levels are greater than the last two years and approaching those observed in the challenging 2018 crop for B-Trich, FUM, and ZEN.

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Effects of feeding variable levels of mycotoxins with or without a mitigation strategy on growth performance, gut permeability, and oxidative biomarkers in nursery pigs

The objectives were to determine how high levels (> 2.5 mg/kg diet) of deoxynivalenol (DON), in conjunction with other naturally occurring mycotoxins (MTX) would impact growth, intestinal integrity, and oxidative status, with or without a mitigation strategy, in nursery pigs. One-hundred and five pigs (5.5 ± 0.52 kg) were randomly allotted to 35 pens and fed dietary treatments for 45 d. Treatments were factorially arranged with the inclusion of MTX being low (L-MTX; < 1 mg/kg diet) or high (H-MTX; > 2.5 mg/kg diet) in combination with no mitigation strategy or the inclusion of a mitigation strategy (Biofix® Plus, BPL; 1.5 mg/kg diet). There was no interaction between MTX level and BPL inclusion on average daily gain (ADG) or gain to feed ratio (GF), (P > 0.10). Compared to pigs fed diets containing L-MTX, feeding pigs diets containing H-MTX decreased ADG and GF (P < 0.05). The addition of BPL had no effect on ADG (P > 0.10), but improved GF (P = 0.09). There was an interaction between MTX and BPL on average daily feed intake (ADFI), where the addition of BPL had no effect on ADFI of pigs fed L-MTX diets but improved ADFI of pigs fed H-MTX diets (P = 0.09). An interaction was detected between MTX and BPL on protein oxidation as measured by plasma protein carbonyls (PC, P = 0.01), where the inclusion of BPL decreased plasma PC in pigs fed H-MTX diets to a greater extent than pigs fed the L-MTX diets. There was no interaction between MTX and BPL, or an effect of MTX or BPL on DNA damage as measured by 8-hydroxy-2ʹdexoxyguanosine (P > 0.10). There was no interaction between MTX and BPL, or a BPL effect on lipid damage as measured by thiobarbituic acid reactive substances (TBARS, P > 0.10), but pigs fed diets containing H-MTX exhibited lower concentrations of plasma TBARS (P = 0.07) compared to pigs fed L-MTX diets. There was no interaction between MTX and BPL, or an effect of MTX or BPL on plasma lactulose and mannitol ratio as a measure of intestinal permeability (P > 0.10). In conclusion, feeding H-MTX decreased ADG and GF, decreased plasma TBARS, but did not affect plasma 8-hydroxy-2ʹdexoxyguanosine or plasma LM ratio. The inclusion of a mitigation strategy improved ADFI when pigs were fed H-MTX diets and improved GF regardless of MTX level. Addition of a mitigation strategy also reduced plasma protein damage but did not affect indicators of DNA or lipid damage or affect gastrointestinal integrity.

69 Occurrence of Mycotoxins in 2020 US Corn Grain and Corn By-product Feeds

Mycotoxins are fungal metabolites that limit animal health and performance through various negative effects including reduced feed intake, diarrhea, and compromised immune function. These toxic metabolites have been detected in a broad range of feedstuffs worldwide. This study investigated mycotoxin occurrence and contamination levels in U.S. corn grain samples marked as 2020 harvest year and corn by-product feed samples submitted since October 2020. Samples were screened via LC-MS/MS for six major mycotoxin groups including: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A. Results from samples that were above the limit of detection for each respective mycotoxin group were analyzed using the GLIMMIX procedure (SAS 9.4, Cary, NC) to test the effect of harvest year on mean contamination level. Results are presented in Table 1. Occurrence levels of B-Trich, ZEN, and FUM in 2020 corn grain are numerically lower than those from 2019. Mean B-Trich level (parts per billion, ppb) for corn grain samples harvested in 2020 was similar to 2019 crop year. Contamination levels of FUM and ZEN were similar for 2020 crop as compared to prior harvest years. Mycotoxin occurrence in corn by-product feeds continued to be high at 99, 85, and 95% for B-Trich, ZEN, and FUM, respectively. Mean B-Trich and ZEN levels in 2020 corn by-products were similar to respective contamination levels in 2018, but were lower than 2019 samples. Mean FUM contamination in corn by-products has been similar across reported years. Preliminary results of the 2020 corn grain survey indicate mean mycotoxin contamination levels are similar to those observed the past two crop years while levels of B-Trich and ZEN in corn by-product feeds are reduced from 2019. Corn-based feed ingredients may present challenges to producers due to the presence of mycotoxin contamination, therefore, continued monitoring is warranted.

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70 Occurrence of Mycotoxins in 2020 US Corn Silage and Dairy Total Mixed Rations

Mycotoxins are fungal metabolites which have been identified in many feed ingredients and ruminants have an increased risk of exposure due to the complex nature of their diets. Despite varying degrees of natural detoxification in the rumen, cattle health, productivity, and reproduction can be compromised by mycotoxins. This study investigated mycotoxin occurrence and contamination levels in 2020 U.S. corn silage and dairy total mixed ration (TMR) samples. Samples were screened via LC-MS/MS for six major mycotoxin groups including: aflatoxins, type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A. Information was collected with each submission including state of origin and whether or not clinical health or performance concerns were present. Contamination levels were analyzed using the GLIMMIX procedure (SAS 9.4, Cary, NC) to investigate the interaction of clinical concern (yes/no) and harvest year. No interaction was statistically significant for each of the toxin groups, so main effects of harvest year are presented in Table 1. Type B trichothecenes have been identified most frequently in 2020 corn silage. Although not often detected, A-Trich occurrence has increased ten percentage points from 2019 crop year. Among 236 TMR samples analyzed, B-Trich have been detected in a high percentage of samples. Mean contamination levels (parts per billion, ppb) are presented on a dry matter basis and within each data set were similar in 2020 compared to 2019 for respective toxin groups. Preliminary survey results indicate B-Trich occur frequently in both U.S. corn silage and TMR samples. Despite less frequent detection, other mycotoxin groups do occur including ZEN, FUM, and A-Trich, so the potential risk from toxin interactions due to co-contamination should be considered.

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336 Occurrence of Mycotoxins in 2020 US Pasture Grasses and Harvested Hay Feed Ingredients

Mycotoxins are harmful secondary fungal metabolites which limit animal health and performance through various negative effects such as reduced feed intake, diarrhea, and compromised immune and reproductive function. These metabolites are found in a variety of feedstuffs worldwide. This study monitored mycotoxin occurrence and contamination levels in fresh pasture grasses and harvested dry hay from across the US. Samples were screened for six major mycotoxin groups: aflatoxins, type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A via LC-MS/MS. Samples that were above the limit of detection for each mycotoxin group were analyzed using the GLIMMIX procedure of SAS (SAS 9.4, Cary, NC) to test the effect of harvest year on average contamination level. Results are presented in Table 1. Zearalenone and B-Trich contamination prevalence for fresh grass samples was lower in 2020 compared to the previous two years. A-Trich tested positive in 34% of samples which was greater in 2020 compared to 2018 and 2019. Mean concentration levels (parts per billion, ppb) for B-Trich, ZEN, A-Trich were not different in 2020 compared to the previous two years. Prevalence of mycotoxin contamination for dry harvested hay samples for B-Trich and ZEN decreased in 2020 compared to the previous two years, but 64 and 28% of samples tested positive, respectively. A-Trich prevalence was greater than the last two years and resulted in 17% of samples testing positive compared to 0 and 6% in 2018 and 2019, respectively. Mean B-Trich levels in 2020 were similar to levels seen in 2018 and lower than 2019 (P = 0.005). Mean ZEN and A-Trich concentration levels averaged 1,612 ppb and 796 ppb, respectively. Mycotoxin analysis of pasture grasses and harvested hay forages is warranted to identify potential sources of mycotoxin contamination in ruminant diets.

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269 Mycotoxin Mitigation Strategy to Improve Nursery Pig Performance During Natural Mycotoxin Challenge

Mycotoxins (MTX) such as deoxynivalenol (DON), fumonisins (FUM), and zearalenone (ZEN) are a few of the most prevalent mycotoxins in livestock feed. Effects of MTX can vary based on contamination and type, but include losses in performance, immune function and reproduction impacting profitability. Effectiveness of mitigation strategies for MTX can greatly vary depending on type and contamination level. Therefore, the trial objective was to evaluate an in-feed mitigation strategy [Biofix® Plus (BPL), 1.5 kg/MT inclusion, BIOMIN America, Inc., Overland Park, KS] on nursery pig performance during a natural mixed MTX challenge. A total of 105 newly weaned pigs (BW = 5.5 ± 0.2 kg) were allotted to 1 of 4 treatments in a 2 × 2 factorial design with 2 MTX contamination levels [low (L-MTX) and high (H-MTX); Table 1] and 2 BPL levels [without (Control) and with (BPL)] with 3 pigs per pen and 8 to 9 pens per treatment for a 5-week trial. Data were analyzed using the GLIMMIX procedure of SAS with main effects of MTX and BPL and their interaction. There was no interaction of MTX and BPL on any of the cumulative 5-week performance metrics, therefore only main effects will be discussed. Average pig BW at 5-week was reduced (P < 0.05) in H-MTX compared with L-MTX diets (21.5 vs 18.5 kg, respectively). Similarly, ADG and ADFI were reduced (P < 0.05) in H-MTX pigs compared with L-MTX pigs. Feed efficiency was numerically reduced (P = 0.050) in H-MTX pigs compared with L-MTX pigs. However, BPL fed pigs had increased (P < 0.05) feed efficiency compared with pigs not fed BPL. Thus, MTX did effect BW, ADG, and ADFI and BPL was able to increase feed efficiency regardless of MTX level suggesting that BPL should be considered as a mitigation strategy to address mixed MTX challenges.

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PSII-22 Trends in Mycotoxin Contamination in United States Corn

Mycotoxins are harmful secondary fungal metabolites and are of key concern to food and feed safety globally. These toxins are detrimental to animal health and can compromise animal performance even at low levels. Classic signs such as decreased feed intake and vomiting used as indicators for exposure overlook other costs of mycotoxicosis, including increasing the frequency and severity of disease via immune suppression, inciting inflammation, and modulating the gastrointestinal environment. This survey examines initial samples of the 2019 crop with previous year trends. New crop corn samples were submitted from September 2019 and consisted of corn (46%), corn silage (50%), and corn byproduct (4%). Samples were analyzed utilizing the liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for six major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin-A (OTA). Data are presented for major mycotoxin classes in Table 1. Fewer samples are available thus far compared to the fall of 2018 (50 samples in 2019 vs. 135 samples in 2018), thus risk profile of this crop year is likely to change as the sample pool expands. Co-occurrence (≥ 2 mycotoxins) has decreased compared to 2018. The prevalence of B-Trich decreased compared with previous years, but levels are similar to 2018. Prevalence and levels of ZEN decreased from 2018, and are similar to 2017, while FUM is similar in prevalence to 2018, but average ppb numerically increased. As of yet, no Alfa has been detected; however, corn stored with higher moisture content has increased the risk for storage toxins. Mycotoxin risk of this harvest season is still coming into focus as harvest delays have affected sample submission. Due to continued risk of multi-mycotoxin contamination, multiple mitigation strategies are needed beyond just adsorption, including biotransformation, support of the immune system and liver function.

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67 Occurrence of Mycotoxins in Forage-Based Feeds from US and Canada

Mycotoxins are secondary fungal metabolites that contaminate a variety of feedstuffs and are detrimental to animal health and productivity. The risk of broad-spectrum mycotoxin exposure is elevated for ruminants due to the complexity of their diets. This study investigated the occurrence and contamination levels of mycotoxins in forage-based feeds including corn silage, haylage (including various cuttings of multiple forage sources), and straw samples from across the US and Canada. Samples were screened for the six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A via LC-MS/MS technique. Samples submitted for clinical health or performance concerns were excluded from the data set. The B-Trich occurred most frequently (95% positive) among 92 corn silage samples harvested in 2019 followed by ZEN (34%) and FUM (9%). Mean contamination levels (parts per billion, ppb) on dry matter basis were 2,788 ppb, 456 ppb, and 194 ppb, respectively. Only 4% of silage samples were below the limit of detection (LOD) for all mycotoxins evaluated. Among 20 haylage samples from 2019 crop year, B-Trich were the most frequently detected, with 50% of samples positive at a mean concentration of 3,222 ppb. Twenty-one 2019 straw samples were submitted for analysis, with 100% testing positive for some level of B-Trich (mean 2,001 ppb) and 81% ZEN positive with an average of 640 ppb. Seventy-one percent of straw samples were positive for both B-Trich and ZEN. Preliminary mycotoxin survey results from US and Canada suggest B-Trich and ZEN are the most frequently occurring major mycotoxins in 2019 forage-based feed samples. Based on the frequency and levels of mycotoxin contamination identified in the current data set, continued analysis of forage-based feeds is warranted as mycotoxins pose a potential risk to the health, performance, and reproductive success of ruminants.

60 Occurrence of Mycotoxins in 2019 US Corn-based Feed Ingredients

Mycotoxins are secondary fungal metabolites that are detrimental to animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in the 2019 US corn harvest, including corn grain and corn byproduct feed ingredients (distillers dried grains, gluten feed, etc.). Corn samples from the 2019 harvest and corn DDGS and other byproducts from October 2019 through April 2020 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin A. Parameters of the main toxins found were compared to the two prior harvest years using the Kruskal-Wallis Test (Prism7, GraphPad, La Jolla, CA) and are presented in Table 1. Mean toxin count per sample in corn grain was similar in 2019 as 2018, with just over two toxins per sample. Mean B-Trich level (parts per billion, ppb) was elevated in 2019 from 2017. Fumonisin contamination increased in 2019 compared to 2017, and prevalence was similar to 2018. Zearalenone contamination and prevalence were similar in 2019 compared to 2018 levels. Co-contamination in corn byproduct feeds was steady, averaging nearly three toxins per sample. Mean B-Trich contamination was higher than the 2017 crop, and FUM contamination was higher in 2019 than 2017 and 2018. Zearalenone levels in 2019 byproducts are the highest seen in the past three years. Preliminary results of the 2019 corn-based feed ingredients survey suggest mycotoxin occurrence and contamination levels are approaching those observed in the challenging 2018 crop. Furthermore, there are continued concerns for co-contamination and greater ZEN contamination that may impose negative effects on growth, health and reproductive performance in ruminants.

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10 Occurrence of mycotoxins in wheat middlings

Mycotoxins are harmful secondary fungal metabolites which can contaminate a variety of feedstuffs worldwide. Various negative effects in vivo are associated with these toxins and severity is dependent on the level, type, and duration of exposure and age, species, and health status of animals. Wheat middlings or “midds” are a by-product of flour milling and are used in a wide range of livestock rations including frequent inclusion in pelleted feeds. The objectives of the current study were to determine the occurrence of mycotoxins in wheat midds samples and to evaluate the potential risk posed to livestock. Since November 2015, 97 samples submitted from 21 states and provinces have been screened via LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins, zearalenone, and ochratoxin A (OTA) at Romer Labs (Union, MO, USA) or Activation Laboratories (Ancaster, Ontario, Canada). A subset of samples were also screened for the presence of six ergot alkaloids. Parameters of the main mycotoxins detected are presented in Table 1. On average, 1.7 mycotoxin groups were detected per sample with 91.8% of samples testing positive for at least one mycotoxin. The B-Trich deoxynivalenol was detected in 89.7% of samples (mean 1871.5 ± 157.5 ppb). OTA was also frequently detected (30.9% positive), but at low risk levels (4.2 ± 0.5 ppb). Out of 33 samples screened for ergot alkaloids, 72.7% were positive (493.3 ppb ± 68.3 ppb). Wheat midds are a commonly used feed ingredient for various livestock species. The types and concentrations of mycotoxins detected may pose challenges to livestock health, performance, and reproduction. Special consideration for young animals which are especially susceptible to mycotoxin challenges, such as calves consuming starter feeds, is warranted.

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359 Occurrence of mycotoxins in 2018 us corn-based feed ingredients

Mycotoxins are harmful secondary fungal metabolites that are detrimental to animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in the 2018 US corn harvest including corn grain, corn silage and corn by-product feed ingredients (distillers dried grains, gluten feed, etc.). Corn and corn silage samples marked as 2018 harvest from feed mills, livestock producers, and integrators and corn DDGS and other by-products from mid-August 2018 through January 2019 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin. Parameters of the main toxins found were compared to the two prior harvest years using the Kruskal-Wallis Test (Prism7, GraphPad, La Jolla, CA) and are presented in Table 1. Mean toxin count per sample in corn grain increased in 2018 versus 2017, returning to over two toxins per sample as in 2016. Mean B-Trich level (ppb) is elevated in 2018 from 2017. Although ZEN contamination does not differ from prior years, prevalence increased to 45% from 25% in 2017. Co-contamination in corn by-product feeds is steady, averaging nearly three toxins per sample. Mean B-Trich is higher than the 2017 crop, while FUM contamination is similar to 2017. ZEN levels in 2018 by-products are the highest seen in the past three years. Corn silage has increased in mean toxin count per sample and contamination levels of B-Trich and ZEN in 2018 versus 2017. Prevalence of B-trich has remained constant from year to year, while both ZEN and FUM prevalence have increased from 2017 to 2018. Preliminary results of the 2018 corn-based feed ingredients survey suggest mycotoxin occurrence and contamination levels are approaching those observed in the challenging 2016 crop with continued concerns for co-contamination.

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Mycotoxins in Southeast Asian aquaculture: plant-based meals and finished feeds

The awareness of mycotoxin-related issues in aquaculture industry has grown as manufacturers and producers realise the importance of mycotoxins, beyond aflatoxin, and their potential to impact production. During a period of one year (January 2016 – December 2016), 175 samples of different plant proteins, aquaculture/fishery by-products and finished aquaculture feeds, were analysed. Samples were tested for aflatoxins (aflatoxin B1, B2, G1 and G2); zearalenone; type B trichothecenes (deoxynivalenol (DON); nivalenol; 3-acetyldeoxynivalenol; 15-acetyldeoxynivalenol and fusarenon X-glucoside); fumonisins (fumonisin B1, B2 and B3); type A trichothecenes (T-2 and HT-2 toxin; diacetoxyscirpenol and neosolaniol); and ochratoxin A. All samples were sourced in Southeast Asia. Within the analysed samples, 4% were free of detectable mycotoxins. 8% of the samples had one mycotoxin and 88% of the samples were contaminated with more than one mycotoxin. The current work show similarity to previous studies, that mycotoxin occurrence in plant-meals, and consequently in finished feeds, is quite variable and confirms that aflatoxin is not the main mycotoxin in aquafeeds. Mycotoxin occurrence in fish and shrimp feeds in the present samples were higher than reported in previous studies for the same region. In samples of shrimp feed with DON detected, the mean average DON level was 882 μg/kg with a maximum level of 2,287 μg/kg. These values are within the reported sensitivity levels of white leg shrimp (Litopenaeus vannamei). Despite the limited number and short period of sampling, this inventory study helps address a knowledge gap of mycotoxin occurrence in feeds specifically destined for the aquaculture industry.

Occurrence of mycotoxins in aquaculture: preliminary overview of Asian and European plant ingredients and finished feeds

Concern about mycotoxins in aquaculture has been growing, partly due to the gradual replacement of animal-derived proteins, such as fish meal, by plant sources. Over a period of one year, 2,176 samples of different plant protein sources and 25 samples of finished aquaculture feeds were analysed. Samples were tested for aflatoxins (AF; sum of aflatoxin B1, B2, G1 and G2), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB; sum of fumonisin B1 and B2), T-2 toxin and ochratoxin A (full toxin screen). The following plant-based meals were analysed: soybean meal (SBM), wheat (WH), wheat bran (WB), maize (C), corn gluten meal (CGM), cottonseed meal (CSM), rapeseed/canola meal (R/CM) and rice bran (RB). The plant raw materials and aquaculture finished feeds were obtained from Asia and Europe. Finished feed samples from Asia were acquired from Vietnam, Indonesia and Myanmar, while from Europe they were sampled from Denmark, Austria, the Netherlands and Germany. Mycotoxins were found in most of the commodities and finished feeds analysed, showing that mycotoxins represent a risk for the development of the aquaculture sector. Generally, in Asian samples we observed that SBM, WH, WB, C, CGM, R/CM and RB were mostly contaminated with Fusarium mycotoxins (ZEA, DON and FB). CSM was contaminated primarily by AF and Fusarium toxins (ZEA and DON) at lower concentrations. European samples were contaminated mainly by Fusarium mycotoxins. The co-occurrence of mycotoxins in all commodities was high, raising the probability of co-occurrence in finished feeds. An accumulation of mycotoxins on the processed plant-based ingredients (e.g. CGM and WB) was observed when compared to the respective whole grains (C and WH, respectively). Compared to results obtained in 2014, finished feeds presented lower contamination levels, but the co-occurrence risk increased.

[Investigation of potential causes for the development of porcine ear necrosis: different study designs--comparable results?]

During the last years two studies for the investigation of the etiology of porcine ear necrosis were carried out at the Clinic for Swine of the University of Veterinary Medicine Vienna. In study 1, parameters, which are discussed in this context, were collected by veterinary practitioners by completing specially designed questionnaires in farms with symptoms of the porcine ear necrosis syndrome. In study 2, samples of piglets and feed were collected for laboratory analysis of the most important infectious agents as well as mycotoxins. In the present manuscript, the results of both projects were compared. Even if the selection criteria of both studies differed, the affected age class was comparable (5.5 to ten weeks of life in study 1 and six to ten weeks of life in study 2). The herd-specific prevalence of the porcine ear necrosis syndrome varied considerably with percentages between 2 and 10, respectively, to 100%. The evaluation of questionnaires in study 1 showed that 51% of the farms had problems with cannibalism. Particles of plant material, which were frequently seen on the histologic slides of study 2, could have got into the tissue by chewing the ears of the pen mates or cannibalism. Whereas in study 1 the negative effect of parameters as high pig density, suboptimal climate, missing enrichment material and bad quality of feed and water were considered, in study 2 all these factors were checked at sample collection and ruled out as precursor for cannibalism. In both studies bacterial agents proved to be a crucial co-factor for the expansion of the necroses to deeper tissue layers, whereas viral pathogens were classified less important. In both projects it was not possible to estimate the direct impact of infectious agents and mycotoxins as direct trigger of the necroses as well as their participation as co-factors or precursor in the sense of an immunosuppression or previous damage of blood vessels or tissue.

Porcine ear necrosis syndrome: a preliminary investigation of putative infectious agents in piglets and mycotoxins in feed

The aim of this study was to identify the causative factors of porcine ear necrosis syndrome (PENS) in 72 pigs, 5.5-10 weeks in age housed on nine farms. Biopsy samples of ear pinnae were collected from all piglets for bacteriology, histopathology and in situ hybridization for porcine circovirus type 2 (PCV2). At the same time, serum samples were taken for serological analysis and viral PCR, and feed was sampled for mycotoxin analysis. The initial lesion of PENS seemed to be a focal epidermal necrosis. Streptococci were isolated from 44 and staphylococci from 36 pinnae. PCV2 could not be detected by in situ hybridization or qPCR. Seven piglets were positive for porcine reproductive and respiratory syndrome virus, and one for Mycoplasma suis. One piglet had antibodies against Sarcoptes scabiei var. suis. No infectious agents were found in 15 samples. Positive virology and parasitology were often found alongside positive bacteriology. Deoxynivalenol, zearalenone and ergot alkaloids were detected in feed. The findings suggest that PENS is multifactorial in origin and that although infectious agents can be involved in the development of the syndrome they are not the exclusive triggering factor.

Occurrence of mycotoxins in Southern Europe

Contamination of feed materials with mycotoxins is an important issue for farmers, as dietary exposure to these toxins may cause acute or chronic intoxication in animals, resulting in major economic losses. Although prevention methods to avoid mycotoxin contamination on the field prior to harvest, during harvesting or storage have been developed, it is currently not possible to eliminate the risk of a mycotoxin contamination entirely. Here we present a survey over a 4.5 year period that was performed to evaluate the incidence of mycotoxins in feed materials and compounded feed samples originating from Southern European countries, including Portugal, Spain, Italy, Greece and Cyprus. The 416 samples received were tested for the most relevant mycotoxins that are found in feed materials, such as aflatoxins, zearalenone (ZEA), type B trichothecenes (deoxynivalenol and acetyldeoxynivalenol), type A trichothecenes (T-2 toxin and HT-2 toxin), fumonisins and ochratoxin A (OTA), by two different methods, a commercial ELISA and by validated HPLC methods. The Fusarium mycotoxins (type B trichothecenes, ZEA and fumonisins) were the major contaminants. Average concentrations of type B trichothecenes were 365 µg/kg or 445 µg/kg analysed by HPLC or ELISA, respectively. In the case of zearalenone the average concentration was 27 µg/kg by ELISA or 32.5 µg/kg by HPLC. Fumonisin contamination was found with an average of 1,411 µg/kg by HPLC or 6,260 µg/kg by ELISA. Aflatoxins and OTA as well as the type A trichothecenes were detected less frequently and the average concentration was lower in comparison to the other mycotoxins tested. The average concentration of aflatoxins, OTA and the type A trichothecenes was 1 µg/kg or 3 µg/kg, 4 µg/kg or 2 µg/kg, 2 µg/kg or 18 µg/kg, respectively, by HPLC or ELISA analysis.