Concentration of key elements in North American meat & bone meal

Meat & bone meal (MBM) and related rendered protein commodities have potential for use in applications other than animal feed, including use as a fuel or a phosphorus fertilizer. In order to develop these applications, data on the elemental composition are required; the currently available elemental composition data have important limitations. To generate more appropriate and reliable data, MBM samples were collected from 17 North American rendering plants, carefully prepared and analyzed for 20 elements. Preliminary studies showed that the sample preparation process artificially increased levels of sulfur and nickel in a manner that was correctable. Concentrations of many elements were found to agree with previously published values, but concentrations of potassium, magnesium and copper were significantly different from the most authoritative reference. Concentrations of heavy metals tested for were low, and arsenic and cadmium were not detected in any sample. Among the elements tested, there were a number of pairs of elements whose concentration was correlated with high significance, which in some cases was due to the varying proportions of soft tissue and bone in the MBM. The data presented should allow the development of non-feed applications for MBM to proceed with increased confidence.