Colostrum, the fluid produced by mothers in the early stages of lactation, is rich in immunoglobulins crucial for neonatal immune defense.
Immunoglobulin A (IgA) is particularly abundant in colostrum. IgA is key to mucosal immunity, protecting the infant's gut and respiratory tract linings, which are exposed to the external environment.
IgA offers passive immunity, shielding newborns from infections as their immune systems mature.
While other immunoglobulins like IgM, IgE, and IgG are present at varying levels and have different roles, IgA is the most prevalent in colostrum.
Thus, the correct identification is: IgA.