Relationships between immunoglobulin M and immunoglobulin G or A in colostrum of Japanese black multiparous cows

This study was conducted to clarify the relationships among immunoglobulin (Ig)M, IgG, IgA, β‐carotene, vitamin A and α‐tocopherol contents in colostrum of 24 Japanese Black multiparous cows in order to evaluate the role of IgM on colostral IgG and IgA production. Compared with colostral IgG, colostral IgM and IgA were very low but varied widely. There was positive correlation between colostral IgM and IgG, but colostral IgM was not related with colostral IgA. There was no relationship between colostral IgM and age of cows, although colostral IgG was increased with aging. There were positive correlations among colostral β‐carotene, vitamin A and α‐tocopherol and these vitamins were positively correlated with colostral IgM and IgG. These results indicate that fat‐soluble vitamins may affect colostral IgG and IgM in cows and colostral IgG increases with the increase of colostral IgM.