Dairy Test May Support Grass-Fed Milk Mislabeling Claims

Iowa State University researchers have reportedly developed an inexpensive method to test whether milk was produced by grass-fed cows. Fluorescence spectroscopy, which measures light to identify the amount of chlorophyll metabolized by cows, may help regulators enforce organic milk standards requiring cows to eat a minimum of 30 percent foraged grass. The researchers reportedly found that cows fed grass only had about three times as many chlorophyll metabolites as grain- and silage-fed cows, while the organic milk samples they tested had about twice as many chlorophyll metabolites as the grain- and silage-fed cows.