Colostrx is the colostrum supplement brand ranchers have trusted for more than 30 years made with whole bovine colostrum, Colostrx CS delivers the guaranteed quality and quantity of immunoglobulins that calves need for the best start. Colostrx is a valuable necessity for increasing newborn calf immunity to disease and illness when natural colostrum is limited or of low quality. Licensed by the USDA as a veterinary biologic proving safety, purity, potency, and efficacy.