Below are several questions that have been posed regarding feeding colostrum and the importance of feeding colostrum. One of the methods that M.paratuberculosis is spread throughout the herd is by the consumption of infected colostrum. Johne's organisms may be shed into the colostrum of infected cows. Research has shown that this is one important vector of disease transmission. Research on whether pasteurizing is completely effective in killing all M.paratuberculosis is still unclear, although it appears likely that commercial pasteurization is effective in killing all M.paratuberculosis in milk.
Colostrum is another matter, however.
This makes it more difficult to raise the temperature sufficiently to ensure that all M.paratuberculosis organisms are killed. These cells carry the organisms, so it is likely that colostrum will effectively concentrate the organism. Again this makes pasteurization less effective. Many on-farm pasteurizes are not as effective as commercial firms, therefore, the risk of leaving viable organisms is significant. For these reasons, it is recommended not to feed pasteurized colostrum from Johne's positive cows.