Proper mixing of feedstuffs is critical if predictable animal performance is to be achieved in the feedlot.  Feeds are formulated to meet nutritional needs of the target animal’s production requirements and adequate mixing provides an even distribution of nutrients to the animals that consume the feed.  Coefficient of variation (CV) is the standard deviation as a percentage of the mean and is often used as a measurement of variation in feedstuff analysis (Headley, V.E., 1967.  Salt tracers and assay methods in feed mixing. (Feedstuffs, 39, (33):60-61.).  Most grains and other feedstuffs used in feedyard diets are typically low in sodium.  Since salt (sodium chloride) is routinely added to supplements that comprise from 4 to 8% of the total ration, sodium is often used as a nutrient or marker to measure mixing efficiency and accuracy.