Activ Active Acquired Immunity Case Study

A cow’s ability to avoid and fight infection largely depends on a range and strength of her defence which are collectively called immunity.
Immunity includes:
I. Physical barriers, such as skin, or a teat seals
II. Chemical immunity, such as from antibodies and inflammatory substances
III. Cells which actively seek and destroy pathogens
Acquired immunity This is a delayed response second-line defence. It involves cells which either produce antibodies which neutralise the pathogen, or killer cells which directly destroy the pathogen, by surrounding the foreign body and consuming it. This type of immunity recalls the pathogens the body has encountered before and has already developed antigens against that particular pathogen. Antibodies passed on to calves via colostrum are an important defence system and is called passive acquired immunity because the animal didn’t make the antibodies itself. …show more content…
Some pathogens have the ability to change and mutate so the body cannot develop antibodies against it. This is why the body can be attacked by the same bacteria over and again. Moreover, successful pathogens have evolved ways of avoiding the body’s immune defences and this is why chronic infections can occur, such as TB, Johne’s disease and some mastitis. For instances some mastitis pathogens generally don’t stimulate an adaptive immunity, so re-infection with the same bacteria can occur time and again (Morrisans,