Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Unit Feed and Feed Additives, Berlin, Germany.
Department of Veterinary Medicine, Freie Universität Berlin, Institute of Animal Nutrition, Berlin, Germany.
J Sci Food Agric. 2019 Nov;99(14):6649-6654. doi: 10.1002/jsfa.9963. Epub 2019 Sep 2.
This study evaluated the degradation of pyrrolizidine alkaloids (PAs) from eastern groundsel (Senecio vernalis) in grass silage prepared with different inoculants. Silages were produced from ryegrass with 230 g kg dry matter (DM) content and mixed with eastern groundsel (9:1; w/w fresh matter basis) containing 5.5 g kg DM PA. Treatments were: CON (untreated control), LP (3.0 × 10 cfu g Lactobacillus plantarum DSMZ 8862/8866) or LBLC (7.3 × 10 cfu g Lactobacillus buchneri LN40177 / Lactobacillus casei LC32909), and each of the treatments in combination with 30 g kg molasses. Silages were prepared in glass jars and opened after 3, 10, and 90 days. Fermentation characteristics were determined and the PAs analyzed.
Although the levels of fermentation acids differed between treatments, results indicated good quality of all silages during 90 days. Significant time (P < 0.001) and treatment (P < 0.001) effects were observed for PAs. Concentrations of senecionine and seneciphylline decreased with molasses, declined over time, and were negatively correlated with lactic, propionic, and butyric acid, or with lactic and butyric acid in case of seneciphylline. In all silages, seneciphylline and senecionine N-oxides were undetectable after 3 days, whereas senkirkine, the most abundant PA, remained stable.
Silage prepared from grass contaminated with eastern groundsel still contained high PA levels, and was hence a potential health hazard. Molasses supplementation reduced concentrations of senecionine and seneciphylline, while the bacterial inoculants had no effect. Other potentially toxic PA metabolites were not analyzed in the present study and further research is needed. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
本研究评估了不同接种剂制备的草青贮饲料中千里光（Senecio vernalis）中吡咯里西啶生物碱（PAs）的降解情况。青贮饲料由含 230 g kg 干物质（DM）的黑麦草制成，并与含有 5.5 g kg DM PA 的千里光（9：1；w/w 新鲜物质基础）混合。处理方法为：CON（未处理对照）、LP（3.0×10cfu g 植物乳杆菌 DSMZ 8862/8866）或 LBLC（7.3×10cfu g 布氏乳杆菌 LN40177/L 干酪乳杆菌 LC32909），每种处理方法均添加 30 g kg 糖蜜。青贮饲料在玻璃罐中制备，分别在 3、10 和 90 天后打开。测定发酵特性并分析 PAs。
尽管处理之间的发酵酸水平不同，但结果表明所有青贮饲料在 90 天内均具有良好的品质。PAs 表现出显著的时间（P<0.001）和处理（P<0.001）效应。与对照相比，添加糖蜜降低了 senecionine 和 seneciphylline 的浓度，随着时间的推移而下降，与乳酸、丙酸和丁酸呈负相关，或与 case 中的 seneciphylline 呈负相关。在所有青贮饲料中，3 天后均未检测到 seneciphylline 和 senecionine N-氧化物，而含量最高的 PA senkirkine 则保持稳定。
受千里光污染的草青贮饲料仍含有高浓度的 PA，因此存在潜在的健康危害。糖蜜的添加降低了 senecionine 和 seneciphylline 的浓度，而细菌接种剂则没有效果。本研究未分析其他潜在毒性的 PA 代谢物，需要进一步研究。
