Acute outbreak of polioencephalomalacia in adult beef cows on pasture associated with feeding broiler litter.

Abstract

Polioencephalomalacia (PEM) is a neurologic disorder of ruminants that can affect cattle as a result of high levels of sulfur in the diet. Sulfur can be ingested by an animal through feed or water, and the mineral status of the animal can affect how much sulfur is ultimately absorbed. Broiler (poultry) litter is sometimes used in cattle diets as an economical protein source, although it runs the risk of supplying too much sulfur to the bovine diet. Here we report a case in which 15 cows had neurologic signs before death. Initial testing ruled out other causes of acute death, and histologic findings confirmed a diagnosis of PEM. The sulfur concentration was ~0.70% of the total mixed ration (TMR), which is above the maximum tolerable dietary concentration of sulfur. The broiler litter contributed nearly all of the sulfur to this ration and was the cause of the PEM experienced in this herd. When feeding by- and co-products as part of a TMR, it is important for producers to analyze the feed to mitigate risk and ensure good health.