A source of Mycobacterium avium subs. paratuberculosis (MAP)-free milk for calf feeding is needed to control MAP transmission to calves, and is a key component in the success of the national Johne's disease (JD) control programs. JD affects up to 30% of Ontario Dairy herds and similar rates are reported for dairy and beef herds across Canada. Calves are most susceptible to infection when they ingest the bacterium in colostrums and milk contaminated either in the mammary glands or post harvest with feces of cows with JD. At the present, installing pasteurization systems, or purchasing pasteurized and commercial milk replacers to feed calves are the only options available to producers. For producers, these options present added economic costs, since they buy commercial products while discarding readily available colostrums or waste (non-saleable) milk. In this study, raw milk cow milk and colostrum seeded with cultured clinical MAP strains was employed to investigate the following, (i) the pH necessary and the minimum contact time required to achieve log-reduction in MAP viability, (ii) whether MAP bacteria subjected to acidic treatments were actually 'killed' or could resuscitate once milk is stored, neutralized or diluted, (iii) whether acidification destroyed milk immunoglobulins. Here we discuss our results on the effect of acidification on MAP culturability. Our results show that acidification affected the recovery of MAP from milk and decreased by up to 70% the culturability of the bacterium. HPC decontamination and antibiotic treatment further decreased the culturability of MAP bacteria. In our hands, acidification significantly reduced the cfu of MAP in milk. Neutralization of the milk prior to recovery of the bacterium did not counteract the effect of acidification. It remains to be determined whether acidification affects the nutritional quality of the milk and the functions of the colostrum immunoglobulins.