Copper nutrition of livestock and poultry is complex. Cattle are susceptible to copper deficiency, sheep are prone to copper toxicity and pigs benefit from high levels of copper supplementation. The copper requirements of goats are more like that for cattle than sheep, and poultry do not show the same health benefits of high copper intakes observed in pigs. In addition antagonists, primarily sulfur, molybdenum and iron greatly affect the bioavailability of copper in ruminants. Increasing amounts of distillers grains are being included in livestock and poultry diets.