Animal Manure Production and Utilization: Impact of Modern Concentrated Animal Feeding Operations

The total number of livestock and poultry animals being raised in the United States has shown some fluctuation over time. From 2012 to 2018, however, there was a consistent increase of approximately 96 million head annually. This trend was fueled by strong growth in global demand over the past decade and net exports of meat are forecast to continue to grow rapidly. Swine and poultry tend to be raised in confinement, while beef cattle tend to be raised on pastures, but then are finished in confinement, while dairy cattle are often fed and milked in confinement but are allowed on pasture periodically. The number of small animal farms have continually decreased since 1982, while the number of confined animal feeding operations (CAFOs) have increased. In the United States, as much as 1.4 billion tons of manure is produced by the 9.8 billion heads of livestock and poultry produced yearly. These manures produced are primarily used as a nutrient source for crop production. However, because of the shift toward CAFOs producing most of the meat consumed, the mismatch of manure produced to area manure is applied is leading to negative environmental impacts.