Occurrence of principal ergot alkaloids in swine feeding

Abstract

Ergot alkaloids (EAs) are secondary metabolites produced by fungi in the genus Claviceps that contaminate a large variety of cereals. More than 50 different EAs have been identified, being the major compounds: ergometrine (Em), ergosine (Es), ergotamine (Et), ergocornine (Eco), ergokryptine (Ekr), ergocristine (Ecr), and their corresponding epimers, ergometrinine (Emn), ergosinine (Esn), ergotaminine (Etn), ergocorninine (Econ), ergokryptinine (Ekrn) and ergocristinine (Ecrn). The ingestion of contaminated cereals might cause adverse health effects in humans and animals, as the well-known ergotism. In fact, pigs, cattle, sheep, and poultry are involved in sporadic outbreaks, although most other species are also susceptible. Their toxicity is linked to their structural similarity with dopamine, noradrenaline, adrenaline and serotonin, enabling binding to the biogenic amine receptor and the interruption of neurotransmission. European Union (EU) has established a maximum content of 1000 mg/kg of rye ergot sclerotia (Claviceps purpurea) in feed materials and compound feed containing unground cereals. Although EAs as such are still not regulated, feed industry recommends practical limits for EAs in pig feeds to reduce negative effects on health and performance. However, the absence of sclerotia does not exclude the presence of EAs. In this work, 12 EAs have been quantified in 228 feed samples intended for swine using QuEChERS as sample treatment and UHPLC-MS/MS for determination. The 12.7% of samples (29 samples) revealed contamination by at least one EA, and among contaminated samples, 65% were contaminated by more than one EA. Only 6 of 12 target EAs showed concentrations above the limit of quantification. The highest concentration was detected for Emn (with concentrations up to 145 μg/kg), while the total EA content ranged from 5.9 to 158.7 μg/kg. This study revealed scarce contamination by EAs in Spanish feed samples.