Most common immunoglobulin secreted by mother in milk and colostrum is:

Ans. is a, i.e. IgARef. Dutta Obs. 7/e, p 148; Ghai 6/e, p 97Composition of Breast Milk:Carbohydrate - Lactose is present in high concentration in breast milk.Protein content is low, as the baby cannot metabolise a high protein diet. The proteins are mainly lactalbumin and lactoglobulin, which are easily digestible. It is also rich in the amino acids taurine and cysteine, which are necessary for neurotransmission and neuromodulation.Fats - Breast milk is rich in polyunsaturated fatty acids (PUFA) needed for myelination.Water and electrolytes - The water content is 86-87%.Immunological superiority - Breast milk contains immunoglobulins, especially IgA and IgM, lysozyme, lactoferrin (which protects against enterobacteria), bifidus factor (to protect against E. coli), PABA (which protects from malaria). "Breast milk has a high concentration of secretory IgA, IgM". -- Ghai 6/e, p 97"Colostrum -Contains antibody (IgA) produce locally". --Dutta Obs. 6/e, p 149Therefore, IgA is the option of choice.