Sulfur is a necessary dietary component that can be toxic at excessive concentrations. Animal bodies are about 0.15% sulfur by weight ([NRC, 1988] and [NRC, 1998]). Sulfur is incorporated into many essential molecules, including biotin, chondroitin sulfate, cartilage mucopolysaccharides, co-enzyme A, fibrinogen, glutathione, heparin, lipoic acid, mucins, and thiamine ([NRC, 1988], [NRC, 1996] and [NRC, 1998]). In addition to these biologically active compounds, sulfur is an intricate component of sulfur containing amino acids, such as methionine, cysteine, cystine, homocysteine, and taurine. With the exception of thiamine and biotin, all sulfur containing compounds in the body can be synthesized from methionine (NRC, 1996). Thus, thiamine, biotin, and methionine are essential nutrients in the diet of monogastric animals, but ruminant microbes can synthesize these compounds from inorganic sulfate in the diet (Block et.al., 1951). Species differences are such that cats cannot synthesize taurine from methionine, making it an essential nutrient in their diets. Recommended daily dietary intakes of sulfur are 0.15%, 0.14–0.26%, 0.15–0.2%, and 0.2–0.25% of the diet for horses, sheep, beef cattle, and dairy cattle, respectively ([NRC, 1985], [NRC, 1988], [NRC, 1989] and [NRC, 1996]).
Hall, J. 2007. Sulfur In: Veterinary Toxicology 465-469.