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The objective of this project was to examine the effectiveness of feeding a kaolin and yeast-based feed additive on the performance of feedlot cattle. Seventy-five steers (initial BW; 545 ± 42.4 kg) were blocked by BW and randomly allocated into 25 blocks of 3 steers (n = 25 per treatment) in a randomized complete block design with 3 treatments including control, low (10 g/day) and high (15 g/day) kaolin and yeast-based feed additive (FA) supplementation. The steers were fed a finishing diet consisting of 7% corn silage, 1% straw, and 92% corn-based concentrate (DM basis). The duration of the feeding period was 120 days. Supplementation of high grain finishing diet with FA did not affect feed intake (average, 12.4 kg/d), final BW (average, 768 kg), averaged daily gain (average, 1.77 kg/d), carcass traits, and abscessed livers. However, increasing the feeding of FA (0, 10, 15 g/d) to finishing steers linearly (P = 0.05) improved feed efficiency from 0.139 to 0.143 and 0.148 kg gain/kg feed and linearly (P = 0.06) improved net energy for maintenance from 2.05 to 2.10 and 2.15 Mcal/kg and net energy for growth from1.39 to 1.43 and 1.47 Mcal/kg, respectively. Fecal IgA concentration linearly (P = 0.06) increased from 15.0 to 22.7 and 30.1 μg/g with increasing FA addition, suggesting an improvement in nutrient absorption, and potentially better gut health. The increasing addition of FA also linearly (P = 0.03) increased plasma lipopolysaccharide binding protein (LBP) concentration from 46.3 to 56.2 and 64.7 μg/mL but decreased blood total antioxidants from 0.282 to 0.251 and 0.204 mM. These results suggest that the addition of FA may support gut health. [ABSTRACT FROM AUTHOR]

The aim of this survey was to compare the occurrence and contamination levels of six major mycotoxin categories found in corn and corn by-product feed ingredients harvested in the United States from 2018 through 2022. Mycotoxins are secondary fungal metabolites that can negatively impact animal health and performance and have been routinely found in a variety of feedstuffs including, but not limited to, cereal grains, by-products, silages, dry hays and pasture grasses. Mycotoxin categories evaluated in this survey included: aflatoxins (AFLA), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A (OTA). This study includes data from corn samples labeled as 2022 harvest and corn b-product feed ingredients submitted from October 2022 through March 2023 and were analyzed for 17 different metabolites via the Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) method. Samples that tested above the limit of detection for each mycotoxin group were analyzed using the generalized linear mixed model procedure of SAS (SAS 9.4, Cary, NC) using harvest year as a fixed effect. The effect of harvest year on average contamination level for each mycotoxin is presented in Table 1. For 2022 harvest year, 260 corn samples and 66 corn by-product samples have been evaluated to date. Mean B-Trich, ZEN, FUM and AFLA levels (parts per billion, ppb) for corn grain samples were similar in 2022 as previous years (P > 0.05). However, for corn grain samples, FUM prevalence and concentration were numerically greater in 2022 than in 2021 and 2020. In the 66 samples of corn by-products, FUM was found in all the samples (100%) and B-Trich were found in the majority of the samples (97%). Mean concentration of FUM in 2022 corn by-product samples was greater (P < 0.001) compared with 2021. Preliminary results of this survey suggest mycotoxin occurrence and contamination remains similar to previous harvest years except for greater mean FUM concentration levels in corn and corn by-products feed ingredients. [ABSTRACT FROM AUTHOR]

Phytogenic feed additives (PFA) have been shown to provide anti-inflammatory, anti-microbial and antioxidant properties across many species including livestock and can positively influence animal performance. The objective of this study was to evaluate the effects of feeding a PFA to growing and finishing beef steers on growth performance, feed efficiency, carcass traits, and liver abscesses. Forty-five crossbred steers (initial BW; 272 ± 20.5 kg) were housed in individual pens and used in a randomized complete block design including a 110-d growing period followed by a 120-d finishing period. The steers were blocked by BW and randomly allocated to 1 of 3 treatments: control (CON) basal diet without PFA or monensin; basal diet with a phytogenic feed additive (PFA; 500 mg· animal-1·/day-1) or basal diet with monensin (MON; 300 mg/head/d). The growing diet consisted of 60% silage and 40% concentrate, while the finishing diet consisted of 10% silage and 90% of concentrate (DM basis). In the growing period, dry matter intake (DMI) did not differ; whereas, final BW (415 vs. 403 kg; P = 0.10) and average daily gain (1.31 vs. 1.20 kg/d; P = 0.12) was numerically greater with PFA than CON, respectively, with no difference from MON. Feed efficiency (gain:feed) in the growing period was greater (P = 0.04) with MON (173 g/kg) than PFA (161 g/kg) and CON (156 g/kg). In the finishing period, growth performance, feed efficiency, carcass traits did not differ among treatments; whereas, DMI was numerically less (P = 0.11) with PFA (10.2 kg/d) than CON (10.8 kg/d), but there was no difference between PFA and MON (9.8 kg/d). The percentage of abscessed livers did not differ between PFA and CON, but the proportion of abscessed livers tended (P = 0.09) to be greater with MON compared with PFA and CON, without difference in severely abscessed livers among treatments. These results indicate that feed efficiency of growing steers was not improved by PFA to the level with MON. However, supplementation of PFA or MON resulted in similar finishing performance and feed efficiency. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [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]