Mycotoxins in Cattle Feed and Feed Ingredients in Brazil: A Five-Year Survey.

Mycotoxins are toxic secondary metabolites produced by a variety of fungi, which when ingested can cause several deleterious effects to the health of humans and animals. In this work, the detection and quantification of six major mycotoxins (aflatoxins-AFLA, deoxynivalenol-DON, fumonisins-FUMO, ochratoxin A-OTA, T-2 toxin-T-2 and zearalenone-ZON) in 1749 samples of feed and feed ingredients for cattle, collected in Brazil between 2017 and 2021, was carried out using enzyme-linked immunosorbent assay (ELISA). In total, 97% of samples were contaminated with at least one mycotoxin, yet, very few samples exceeded the lowest European Union guidance values for cattle, and the estimated daily intake also showed a low risk for the animals. However, co-occurrences were widely observed, as 87% of samples contained two or more mycotoxins at the same time, and the presence of more than one mycotoxin at the same time in feed can lead to interactions. In conclusion, the contamination of feed and feed ingredients for cattle with mycotoxins in Brazil is very common. Hence, the monitoring of these mycotoxins is of significant importance for food safety.

Liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (QTOF/MS) assay for quantification of protodioscin in Brachiaria grasses.

This work aimed to develop and validate a method to detect and quantify protodioscin in Brachiaria grasses using ultraperformance liquid chromatography (UPLC) coupled to high-resolution quadrupole time-of-flight mass spectrometry. Samples were extracted by acetonitrile-water 50:50 v/v mixture and ultrasonication. The mobile phase consisted of 5 mM ammonium acetate in water-methanol and acetonitrile containing 0.1% formic acid. The parameters used to validate the method for determining protodioscin comprised determination of the selectivity, ionization suppression/enhancement (matrix effect), linearity of the calibration curve, the limit of detection (LOD), the lower limit of quantitation (LLOQ), and the precision and accuracy of the method. The LLOQ of protodioscin was determined as 0.1 µg mL-1, and the LOD was 0.03 µg mL-1. The developed method was applied for determining protodioscin levels in B. decumbens collected from three pastures where sheep showed clinical signs of photosensitization. The obtained values ranged from 0.71% to 1.12%. Thus, the developed method for determining protodioscin in Brachiaria grasses by LC coupled to high-resolution quadrupole time-of-flight mass spectrometry showed high accuracy, precision, and sensitivity.