It was found that feeding a composition including activated growth factor(s) increases feed to gain ratio, increases overall weight gain, reduces necessary antibiotic or electrolyte therapy and reduces mortality in animals. The composition is derived by first separating growth factor(s) from a source such as whey or blood, then subjecting the factor to an activation process, and then providing the activated growth factor to the animal A feed additive comprising activated growth factors in appropriate amounts, shows results that are an improvement over standard therapies of supplementation. Application of activated growth factors may be by topical, injection or oral application.