Sulfur is utilized in proteins in the form of the amino acids, methionine and cystine. Other functions of sulfate, include glutathione, taurine, heparine and chondroitin sulfate, compounds derived from sulfur-containing amino acids. Inorganic sulfur supplementation may spare some of the methionine or cystine requirements, as demonstrated with other animals. Sources of sulfur include ingredients which are high in sulfur-containing amino acids (methionine, cystine) such as fish meal, cottonseed meal, rapeseed meal and yeast. Sulfur is usually not limiting in feed formulations (Akiyama et al., 1992).