On the composition of ergot and the effects of feeding two different ergot sources on piglets

It was one purpose of the study to obtain actual data on the composition of ergot (Claviceps purpurea), especially concerning the variation of the content of toxic alkaloids and the alkaloid pattern. For this reason 13 ergot batches, sorted out of naturally infected rye from different origins in Central Europe, were analysed for their crude nutrient, fatty acid, amino acid and alkaloid contents. The mean concentrations of crude protein, fat and fibre amounted to 223, 350 and 287 g/kg dry matter (DM). The concentration of the ergot specific ricinoleic acid was 14.4 g/100 g fatty acids on average. The mean total ergot alkaloid content (sum of ergometrine, ergotamine, ergocornine, α-ergocryptine, ergocristine, ergosine and their -inine isomers analysed by a high performance liquid chromatography (HPLC) method) was 738 mg/kg DM and showed a high variation (24–1569 mg/kg DM). The alkaloid pattern was variable as well but Ergotamine, Ergocristine and Ergosin represented the main alkaloids with average contents of 20, 24 and 15 g/100 g total alkaloids. Especially due to the high variation of the alkaloid content in ergot, the analysis of the toxic alkaloids in feed is more useful to evaluate potential risks at feeding instead of the determination of the ergot content in grain, which is current practice in the European Union up until now.Additionally, a 35-day experiment with 80 crossbred piglets from 9.2 to 24.4 kg body weight (BW), which were allocated into 5 groups, was conducted to determine the critical alkaloid contamination level in feed and to study the effect of different alkaloid patterns. Therefore, two ergot sources were used, which were characterized by different alkaloid patterns, and standardised on equal total alkaloid contents in two concentrations at 5.6 and 11.2 mg/kg diet. The alkaloid pattern had no effect on growth performance and serum biochemical parameters (P>0.05). However, the extent of the dietary amount of alkaloids had an influence since the cumulative body weight gains of the high supplemented groups were significantly decreased as compared to the control (P<0.05) and showed significant linear dose–response effects (P<0.05). The serum protein content was significantly decreased at P<0.05 as well. The evaluation of the total or key alkaloid contents (sum of ergometrine, ergotamine, ergocornine, α-ergocryptine and ergocristine) in grain or feed seems to be practicable to evaluate the feeding hazard without special consideration of the respective alkaloid pattern. The critical contamination level in the present experiment was determined to be 3.57 mg total alkaloids/kg feed (=1.89 mg key alkaloids/kg feed) for piglets.