Swine Production Infection Chain Dr. David Baumert, Swine Practitioner, talks about the infection chain concept as it relates to Mycoplasma hyopneumonia (Mhp). The infection chain concept is the movement of infectious disease agents from breeding herds to the offspring production flows (with resulting production losses up to and including the market swine phase). Dr. Baumert closes with note that control of 'Infection Chain Disease' at the gilt source level can control significant economic loss throughout the production chain.