Abstrakt: |
Comparison of colostrum-induced immunities in calves was made by challenge exposure with Escherichia coli. These calves were delivered of cows which were vaccinated intramuscularly or deep subcutaneously (in the region of the mammary lymph nodes) with strain B44 E coli bacterin during the last trimester of pregnancy. The calf of each cow was allowed to nurse colostrum naturally after birth. Cows vaccinated by either route of administration were capable of providing increased resistance to their calves, via the colostrum, when compared with nonvaccinated cows. |