Infectious disease is like a set of old fashioned scales or 'a balance' or a 'see-saw'.
There is always a balance between the animals immunity / resistance level and the number of infectious agents in the animals environment.
So, to prevent disease, we must increase immunity (e.g. colostrum, vaccination) and / or reduce 'infection pressure' (e.g. disinfection, bedding, ventilation, liner changes).
We have a special range of cleaners & disinfectants to remove debris, then kill the bugs in calf pens, calving boxes, cubicle beds, lambing pens & in on wellies etc.