A Professor with the Western College of Veterinary Medicine suggests genetics, management and the environment in which an animal is raised will influence its susceptibility to and ability to resist disease challenges. In an effort to improve the health and productivity of food producing animals while reducing the use of antibiotics scientists have stepped up their focus on the factors that impact an animal's resilience in the face of disease challenges.
Dr. John Harding, a Professor with the Western College of Veterinary Medicine, says a range of factors will influence the ability of an animal to resist disease.
Clip-Dr. John Harding-Western College of Veterinary Medicine:
We think a lot of that has to do with the genetic makeup of the animal. The most obvious reason would be related to the immune response, whether that would be antibodies or cytokines or other factors that we are not completely familiar with at this point in time.
That's the most obvious reason but there could be other physiologic reasons why one pig would respond better than others or something to do with its metabolic state. Those are factors related to genetics. From a management point of view, the other obvious factors are vaccination status.
Obviously vaccinated animals will be more resilient to diseases, be able to ward off infections. The environment in which the pig is raised and the level of stress it's undergoing. Certainly stress causes immune suppression so that's a big one and then part of it really comes back down to how much of the pathogen did it receive? We call that the infectious dose and that will be intimately related with the virulence of the pathogen as well.
Source : Farmscape