Both field studies and experimental infection studies have shown that in a given penamong a given litter only some individual pigs exhibit clinical signs of PCVDPMWS indicating that genetic factors play a role in regard to susceptibilityresistance

What is the correctly punctuated version of this sentence?
Both field studies and experimental infection studies have shown that in a given pen/among a given litter only some individual pigs exhibit clinical signs of PCVD/PMWS indicating that genetic factors play a role in regard to susceptibility/resistance.