Watts Branch is a major tributary to the Middle Potomac and also provides drinking water for the Washington metropolitan area. Managing the 19.5 million tons of chicken and turkey manure produced each year by the U.S. poultry industry is no simple task, but Dr. Paul Patterson, a Penn State poultry nutritionist is looking at ways to more carefully balance chicken diets and reduce waste. Farmers can control the nitrogen content of manure by using better feed formulation, lower protein diets, and feed additives. In many cases, these approaches save money as well as control the nitrogen output of the birds. Synthetic amino acids are also cost effective and reduce nitrogen waste.
Feed additives that allow birds to better use available nutrients can also help.
Controlling excess phosphorus centers around supplying phosphorus in a form the birds can use. Feeds such as corn and sorghum contain only 19 to 22 percent bioavailable phosphorus with the rest in a chemical form difficult for the birds to digest. The phosphorus in meat or fish meal is 81 to 100 percent bioavailable so birds require less phosphorus in their feed thereby reducing the amount of phosphorus in the manure.