Calf's Choice Total Colostrum is made only from natural, premium quality bovine colostrum. It is an excellent source of IgG (over 85% in the form of IgG1), colostral fat, growth factors, and nutrients needed to improve calf survival, health, growth, and long term performance. Not a manufactured formula based on blood serum, whey, eggs, vegetable fats or other ingredients not naturally found in colostrum. High Immunity • IgG molecules are readily absorbed for maximum immune protection. • Over 85% IgG1, the antibody most effective in protecting calves against diarrhea and pneumonia. High in Colostral Fat • Colostral fat is an important energy source required by calves immediately after birth.