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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. [ABSTRACT FROM AUTHOR]

Mycotoxins are harmful secondary fungal metabolites central to food and feed safety management. These toxins are detrimental to animal health and even at low levels can compromise performance. Focus on clinical signs like decreased feed intake and vomiting overlook significant impacts of mycotoxicosis, including increased disease incidence and severity, immune dysfunction, inflammation, and modulation of the gastrointestinal environment. The objective of this study was to determine the effect of harvest year on five major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), and zearalenone (ZEN) in corn and corn DDGS samples. For each mycotoxin group within ingredient, 2019 harvest (329 corn and 20 corn DDGS) were compared with 2020 harvest (27 corn and 21 corn DDGS). Data were analyzed using GLIMMIX procedure of SAS with harvest year as fixed effect and sample as the experimental unit. Average B-Trich and FUM contamination levels in corn are significantly (P < 0.05) affected by harvest year. However, B-Trich levels remained consistent, whereas FUM decreased (P < 0.05) from 2019 to 2020. Contamination levels in corn for Afla, A-Trich, and ZEN have remained consistent (P > 0.05) from 2019 to 2020. In corn DDGS, B-Trich contamination level was decreased (P < 0.05) from 2019 to 2020, whereas FUM and ZEN contamination levels remained similar (P > 0.05). The 2020 crop risk profile is likely to change as the sample pool expands. A combination of hot weather, storm events, and drought during the 2020 growing season resulted in crop stress and damage, ultimately leading to grain quality and mycotoxin contamination concerns. Due to the continued risk of mycotoxin co-occurrence, expanding mitigation strategies beyond adsorption by mycotoxin deactivation with biotransformation and additional support of immune and liver function is essential. [ABSTRACT FROM AUTHOR]

Phytogenic feed additives that contain anti-inflammatory and antioxidant properties may have potential to reduce inflammation and oxidation observed during bouts of heat stress. The trial objective was to determine the effects of a phytogenic feed additive on markers of stress in heifers subjected to diurnal heat stress (dHS). Eighteen Holstein and four Jersey heifers (5-6 months of age; d1 BW=205±9 kg) were assigned to two dietary treatments (n = 11) based on breed and age; 1) a basal TMR diet (CTL), 2) CTL supplemented with 0.25 g/head/d of a proprietary blend of phytogenics (PFA; BIOMIN America, Inc., Overland Park, KS). Heifers were housed individually and fed their respective treatments for 14d prior to dHS (d-14-1), subjected dHS (d1-7), and followed through a recovery period (d8-11). Weights were collected at d1 (baseline), d7 (end of dHS), and d11 (end of recovery). The temperature set point was assigned at 33°C from 0900 to 2100 h and allowed to equilibrate with outside temperature during night (24°C) for a total of 7d dHS. Total DMI (tDMI) and DMI from 0900 to 2100 h (hsDMI) were recorded daily. Serum was collected at d1, 2, 7 and 11 to determine effect of treatment on markers of oxidation, inflammation, and stress. Treatment effects were analyzed using PROC MIXED in SAS with treatment and time as fixed effects and heifer as a random effect. Temperature humidity index during dHS was greater during the day (84.5) versus night (73.3). There were no treatment differences (P>0.05) in d 0-11 on ADG, ADFI, or GF between treatments. However, PFA numerically increased hsDMI, reduced (P< 0.05) haptoglobin and tended to reduce (P< 0.10) lipopolysaccharide binding protein compared with CTL. Overall, dietary PFA may be a potential strategy to mitigate the stresses that heifers experience during dHS. [ABSTRACT FROM AUTHOR]

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]