IN THE SWINE INDUSTRY, MATERNAL INFECTION DURING PREGNANCY NOT ONLY HAMPERS HEALTH OF THE SOW, IT HAS THE POTENTIAL TO REDUCE OFFPSRING PRODUCTIVITY. IN TERMS OF ECONOMIC SIGNIFICANCE, INFECTIONS WITH THE PORCINE RESPIRATORY AND REPRODUCTIVE VIRUS (PRRSV) ALONE ARE ESTIMATED TO COST THE U.S. SWINE INDUSTRY IN EXCESS OF $660 MILLION ANNUALLY, OR APPROXIMATELY $4.67 PER HEAD FOR EVERY PIG MARKETED EACH YEAR. THESE DIRECT LOSSES, HOWEVER, LIKELY UNDERESTIMATE THE REDUCED GROWTH AND EFFICIENCY OF PIGLETS FROM INFECTED SOWS. ADDITIONALLY, EVEN GREATER PRODUCTION LOSSES ARE ASSOCIATED WITH CO-INFECTIONS OF PRRSV AND MYCOPLASMA HYOPNEUMONIAE (MH) AS PART OF THE PORCINE RESPIRATORY DISEASE COMPLEX (PRDC). USING NUTRITIONAL TECHNOLOGIES LIKE SOY ISOFLAVONES DURING INFECTION IS A DESIRABLE AND COST-EFFECTIVE APPROACH TOWARD IMPROVING PRODUCTION EFFICIENCY IN SWINE. OUR GOAL IS TO CHARACTERIZE THE IMPACT OF MATERNAL INFECTION IN SOWS DURING PREGNANCY ON BOTH SOW AND OFFSPRING PRODUCTIVITY. WE WILL USE ECONOMIC MODELS TO CALCULATE LOST VALUE OF MEAT FROM THESE PIGS. WE WILL ALSO SPECIFICALLY FOCUS ON MUSCLE DEVELOPMENT AND THE FACTORS THAT UNDERLIE ITS REGULATION AND THE DEVELOPMENT AND RESPONSIVENESS OF THE IMMUNE SYSTEM IN OFFSPRING. THEN, WE WILL FEED INFECTED SOWS DIETS WITH SOY ISOFLAVONES AS A POTENTIAL STRATEGY TO COMBAT THE NEGATIVE EFFECTS OF INFECTION AND INFLAMMATION. SUCCESSFUL COMPLETION OF THIS WORK WILL RESULT IN A BETTER UNDERSTANDING OF BOTH THE BIOLOGICAL AND ECONOMIC IMPACTS OF SOW INFECTIONS DURING PREGNANCY. WE ALSO EXPECT VALIDATE FOR THE SWINE INDUSTRY A NEW METHOD FOR COMBATING THOSE NEGATIVE EFFECTS--FEEDING DIETS WITH SOY ISOFLAVONES TO SOWS WITH INFECTIONS DURING PREGNANCY.