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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]