Chickens and turkeys in Virginia will get a new diet in coming years under agreements signed by state officials and poultry industry representatives aimed at slashing phosphorus levels in poultry litter by 2010.

Under the agreements signed Nov. 14, the state's largest poultry integrators will optimize the use of the enzyme phytase in poultry feed to strive for a 30 percent phosphorus reduction in poultry litter.

That should result in less runoff into local streams-and the Bay-when the litter is used as fertilizer.

Representatives from Cargill Turkey Production LLC, Perdue Farms Inc., Tyson Foods Inc., Pilgrim's Pride Corp., Virginia Poultry Growers Cooperative Inc. and George's Foods LLC signed the agreement.

All have used phytase since about 2000, when the state provided matching grants to the companies to purchase equipment that mixes the enzyme into the feed.

"This agreement builds on these previous efforts for the benefit of the industry and Virginia's waters," said Joseph Maroon, director of the state Department of Conservation and Recreation, who signed the agreements for the state.

Since then, the additive has achieved a Virginia industrywide average phosphorus reduction of 20 percent in poultry litter. But research at Virginia Tech shows that reductions of up to 37 percent may be possible without harming animal health.

The 30 percent goal stems from a 2005 Bay Program strategy for managing surplus manure in the watershed. The strategy concluded that a 30 percent reduction was realistic for large-scale production facilities.

The Virginia agreement essentially commits the industry to continue working to further optimize its use of phytase in feed to achieve the goal.

"This agreement reflects the poultry industry's longstanding commitment to proactive, environmental stewardship," said Virginia Poultry Federation President Hobey Bauhan. "Along with other voluntary initiatives, our industry has demonstrated a meaningful commitment to Virginia's water quality objectives, including the commonwealth's Chesapeake Bay goals."

Although the phytase goal is voluntary, the DCR will monitor phosphorus levels in poultry litter and meet periodically with industry representatives to discuss progress.

Industry participation is critical because the poultry processors own the chickens and produce their feed. The chickens and feed are distributed to individual farmers to grow under contract. The growers, though, are left with the chicken litter-and its phosphorus.

"This is one thing the integrators can do to help their contract growers," said Russ Perkinson, assistant division director for the DCR's nonpoint source programs.

"The contract grower doesn't have any control over what is in the feed, or really what comes out in the manure, because the feed determines a significant amount of that," he said.

The stomachs of chickens and turkeys poorly absorb phosphorus, so their diets often require extra phosphorus to ensure they get enough of the nutrient.

But that also means poultry litter has high concentrations of phosphorus relative to the amount of nitrogen. If enough poultry litter is applied as fertilizer to meet the nitrogen needs of crops, the land can eventually become saturated with phosphorus, exacerbating runoff problems.

At that point, litter has to be hauled to new fields, farther away, to be applied. That's become a growing problem in many parts of the Bay watershed where large numbers of poultry are raised.

By incorporating phytase in the diet, the amount of phosphorus in the litter-and the ratio of phosphorus to nitrogen-can be reduced.

The agreement was the latest in a series of actions the state is taking to reduce the impact of poultry waste on water quality.

Earlier in November, the DCR and the Virginia Poultry Federation announced a new, jointly funded program that would offer farmers across the state $600,000 over the next three years to help pay the transportation cost of importing litter from major poultry-producing regions.

The program offers farmers conservation payments of either $5 or $12 per ton to transport litter from Rockingham or Page counties, the state's leading poultry-producing counties, and to use it outside other primary poultry counties as stipulated in a nutrient management plan. The higher incentive level is available if litter is transported out of the Bay watershed. The purchase and transport of poultry litter can typically cost $25 to $35 per ton.

The Virginia State Water Control Board is considering potential amendments to the state's poultry waste management regulations to better address concerns with litter that is transferred from grower farms. Right now, farms that grow chickens are required to have nutrient management plans to guide their fertilizer use. But those requirements do not apply to other farms that import litter as fertilizer.

State officials and poultry industry representatives say the transport incentive program should help to generate new markets for poultry litter and may reduce the impact of any new regulations on transferred poultry manure.