A new study from Penn State University quantifies the environmental strides the industry has made.That's the sort of basic error that should be used to check models. If you're creating pollution where it can't be (or in this case, more than the target could possibly make), it's time to revise it.
“We have more efficient birds now that are utilizing those nutrients a lot better,” said Erica Rogers, the graduate assistant who conducted the research.
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The new figures will replace outdated book values that don’t do the industry justice, said Paul Patterson, a Penn State poultry scientist and Rogers’ adviser.
Rogers’ data could be used in The Penn State Agronomy Guide and the Chesapeake Bay model, which tracks how much progress farmers have made in reducing nitrogen and phosphorus pollution in the watershed.
Many of the numbers those sources currently use are at least 20 years old and don’t reflect more recent advances in housing systems or feed efficiency.
In one dataset used to guide the Chesapeake Bay Program, pullets are listed as excreting 50 pounds of manure per bird.
“They don’t even eat that much in their life cycle,” Rogers said.
With the cooperation of poultry integrators, Rogers visited more than 70 farms, collecting samples from random points and at varying depths throughout manure stacks.Ah, the life of a graduate student!
“I climbed a lot of manure piles,” Rogers said.