Neurotoxicity and secondary metabolic problems associated with low to moderate levels of exposure to excess dietary sulphur in ruminants: a review.

Problems associated with a low to moderate excess in dietary sulphur (S) intake in ruminants are being increasingly recognized. Comparing more recent reports with older data, there is an evident decrease in tolerance of cattle and sheep for even moderately elevated levels of dietary S, and an apparent drastic change in the clinical picture of chronic dietary S toxicoses. Outbreaks of polioencephalomalacia (PEM) in ruminants in association with excess dietary S have been reported in recent years throughout the world. Excessive levels of S-containing compounds in domestic ruminant animals' rations, and clinical problems associated with low to moderate levels of exposure to dietary S may be more common than previously thought. This review presents a comprehensive evaluation of the problems associated with excessive levels of S in ruminants' rations. Emphasis is placed on the recently increasing incidence of S-induced PEM. Secondary metabolic disorders associated with excessive intake of S are also discussed.