| Abstract: | Transfer factor-type substances obtained from leukocytic cells and fluid portions of bovine colostrum caused effective passive transfer of delayed-type hypersensitivity responses across species barriers. Passive transfer of Brucella abortus sensitivity was obtained with equal regularity when using components derived from peripheral blood and colostrum of dams sensitized at 3 and 9 months of age. Colostral feedings to calves caused the passive transfer of delayed-type hypersensitivity as early as 2 days after parturition. The findings indicated that colostral components were important in the process of cell-mediated immunity. |
