Growth and Development: ASAS-Emerging Roles of Gut Peptides in the Regulation of Appetite and Metabolism

Public concerns related to air quality impacts of intensive livestock and poultry operations have grown drastically over the recent years. Pollutants of concern are particulate matter, ammonia, methane, hydrogen sulfide, volatile organic compounds, and odors. However, there is a general paucity on character, amount, and dispersion of livestock air pollutants. Despite dramatic knowledge gaps, the Environmental Protection Agency (EPA), State and local air quality agencies are mandated to use best available emission factor data for their emission inventories. In serious non-attainment regions like the San Joaquin Valley, pollutants like particulate matter and ozone precursors have to be reduced significantly. New legislation forces livestock producers to reduce emissions using best available control methods that for the most part were never scientifically tested. The US Department of Agriculture (USDA) is mandated to support farmers with scientifically based emission mitigation techniques and technologies but again scientific information is scarce. Both, EPA and USDA appointed the National Research Council (NRC, 2003) to review the scientific basis for current emission estimates and emission mitigation. Major NRC findings were that current emission estimates are largely inappropriate because instead of being based on representative surveys from a class of operations (e.g., dairies) over several seasons, they are predominantly grab-sample measurements conducted on one operation at one time. The committee recommended replacing the current emission factor approach with the use of process-based modeling using nutritional mass-balance approaches. A second major NRC finding was that intensive research is needed into cost effective emission mitigation for livestock and poultry operations.