Abstract: Colostrum is quite different from normal milk,which is a milk secreted during the first few days after calving,and its importance for the health of calves has been known for a long time.Colostrum contains not only nutrients like proteins,carbohydrates,fat,vitamins,and minerals but also bioactive components like growth factors,antimicrobial factors,and sialyloligosaccharides.The most abundant and well-characterized factors in colostrum are nonpeptide trophic factors,hormones,cytokines,growth factors,epidermal growth factor receptor ligand family,epidermal growth factor,transforming growth factor,transforming growth factor β family,insulin-like growth factors,somatomedins,and their binding proteins,platelet-derived growth factor,vascular endothelial growth factor,lactoferrin,growth hormone and its releasing factor and immunoglobulins and so on.This article is a review about the characteristics of colostrums,the important roles of these factors,their applications,separations,and researches.

Key words: colostrum, bioactive factor, cytokine