Investigations on the Current Sulfur and Sulfate Intake of Cattle in Germany: Are There Any Risks for a Consumption Exceeding Recommended Upper Limits?

Abstract

The primary goal of the investigation was a deeper knowledge on the current sulfur and sulfate intake of dairy cows and beef cattle fed common rations in Germany based on roughages and supplemented with concentrates (as protein and energy sources). Finally, specific feeding practices/conditions should be identified that could result in adverse effects in cattle because upper levels for sulfur intake (≥4 g/kg dry matter) were exceeded. In grass silages (especially from the 3rd/4th cut, at using S containing fertilizers) values near to 4 g S/kg dry matter were not rare; unexpectedly high contents of sulfur and sulfate were measured in compound feeds (median: 3.70 g S/kg dry matter; >40% derived from sulfates!). These high values are caused by higher proportions of components that contain higher amounts of sulfur and sulfates physiologically (like rapeseed products) or contain high sulfate levels due to diverse processes in the production (DDGS/sugar beet pulp/corn gluten feed) for example like the use of sulfuric acid or sulfur dioxide. Finally, it is recommended to test more frequently and systematically the sulfate content in grass and grass silages (indicating the S supply of plants) but also in concentrates (with an unexpected high variation of sulfur and sulfate) to identify further routes of sulfur entrance.