The JorVet colostrumeter measures IgG content in a simple cowside test. The graduated cylinder is filled with a few ounces of Bovine colostrum. The colostrumeter is gently inserted and floats to a level indicating the colostrum IgG content. A University of Florida study found only 20 percent of colostrum contained an adequate amount of IgG for good calf health. Plastic.