Whey contains proteins with a variety of functional properties and biological activities. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to separate the whey proteins in bovine colostrum and bovine milk. The results showed significant differences in the whey protein composition between colostrum and normal milk, and 290 and 325 types of proteins were identified in whey from bovine colostrum and bovine milk, respectively. According to the gene ontology (GO) annotations, bovine colostrum whey proteins exhibited a slightly higher impact on the establishment of cellular localization and the cellular localization than normal milk whey proteins. Enzyme inhibition was the main molecular function of whey proteins from bovine colostrum and normal milk. Regarding cellular composition, bovine colostrum whey proteins were involved in the extracellular region and extracellular space, and bovine milk whey proteins showed a similar result. The Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis suggested that whey proteins from both bovine colostrum and normal milk were involved in the reaction pathways of coagulation and complement cascades. This study of the whey protein composition in bovine colostrum can not only promote the utilization of bovine colostrum, but also provide theoretical foundations for future production of dairy products using whey protein as a raw material.
