References

RE-Cycle – a profitable swine production system with zero waste

North Carolina State University Swine Nutrient Management Research from 2003. Traditionally, swine production and crop production were tightly integrated. Swine were raised on crop residues, and their manure was a valuable fertilizer. Over the past 40 years, however, both crop producers and swine producers have moved away from this integration in an effort to reduce production costs. Crop producers prefer pure fertilizers that are easy and accurate to spread, while swine producers prefer to hold animals in large groups in close proximity to feed mills and slaughter plants. Feed ingredients are often imported from distant regions making it financially prohibitive to return the highly dilute manure to the crop-growing areas. Thus, manure ends up being used locally, sometimes at application rates that exceed crop requirements.