Colostrum is a complex mixture of bioactives that promotes neonate growth. Studies show that it contains components capable of promoting bone formation and inhibiting bone resorption. Although many colostrum-based nutritional supplements have been developed as growth promotants, few studies have investigated their functional effects. A bovine colostrum 1-30 kDa fraction, Growth Protein-Colostrum (GP-C), was administered to juvenile rats as a dietary supplement to determine effects on growth and development. GP-C enhanced the growth and mineralization of the femur as evidenced by increased serum osteocalcin and bone mineral density. Increased levels of serum growth hormone and insulin-like growth factor-1 suggest that the mechanism of enhanced growth is partially controlled by endocrine factors. GP-C was also found to increase osteoblast proliferation in vitro, a finding that indicates a possible mechanism of action of GP-C, but further studies are required. Based on our findings, we hypothesize that a colostrum-based dietary supplement enhances bone growth and development in humans.