Which immunoglobulin is found in colostrum?

The immunoglobulin primarily found in colostrum is Immunoglobulin A (IgA). Colostrum, the first milk produced by mammals after giving birth, is rich in antibodies, particularly secretory IgA, which plays a crucial role in protecting the newborn's mucosal surfaces from infection. Additionally, colostrum contains other immunoglobulins like IgG and IgM, but IgA is the most abundant and significant for neonatal immunity.