Today’s animal agriculture is continually changing, and national guidelines on handling animal manure should reflect those changes.

That’s where a group of animal scientists and agricultural engineers from land-grant universities enter the picture. They are rewriting guidelines to provide a science-based reference point for livestock producers with concentrated-animal-feeding operations, as well as the state and federal environmental agencies that regulate them.

The revised standards are a joint project of the American Society of Agricultural Engineers and the Federation for Animal Science Societies.

New manure and air-emission standards are long overdue, says Todd Applegate, a Purdue University Extension poultry specialist, who’s involved in the ASAE/FASS project.

“The standards haven’t been updated since the 1970s,” he notes. “Modern animal facilities use more high-tech equipment today. Also, improvements in animal genetics and nutrition have shortened production time, as well as reducing total manure volume.”

The new ASAE/FASS guidelines will attempt to fill those information gaps.

Although CAFOs are regulated, little is known about the potential threat that the facilities pose to human health. Air emissions are a highly misunderstood area. If enough data is accumulated, it would allow the ASAE/FASS team to “develop recommendations that regulators can use as they try to develop air-quality policies,” says Al Sutton, Purdue animal scientist. “Also, it would let us provide best-management practices for producers, to help them stay in compliance.”

Sutton believes it’s only a matter of time before the U.S. Environmental Protection Agency issues regulations aimed at controlling air emissions at CAFOs. “Some states are already acting, and have some air-quality-type measurements proposed,” he notes. “That’s why we’re working to get some baseline emission values from different size operations. We also need to show how we can minimize those emissions.”

The revised guidelines could have the greatest impact on nutrient-management planning and the size of manure storage facilities, says Sutton.