Cow's milk with active immunoglobulins against Campylobacter jejuni: effects of temperature on immunoglobulin activity.

Adult Holstein cows were injected with an antiserum against Campylobacter jejuni and immunoglobulin activities in vitro were determined in blood and milk several weeks after injection. The immunoactivity of immunoglobulins in milk was measured by an ELISA after different temperature-time treatments (60-91°C and 4-3600 s) at laboratory and pilot-plant scales. Kinetic and thermodynamic parameters were determined. An increase in immunoglobulin activity in milk was detected several days after injection. Optical densities increased by three- to seven-fold in this period. The activity started to decay 4-5 weeks after injection. Immunoglobulins maintained most of their in vitro activity under pasteurisation conditions (72°C and 15 s) and were denatured following first-order kinetics. The injection protocol applied allows milk with specific immunoglobulins against Campylobacter jejuni to be obtained. Traditional pasteurisation did not reduce this activity.