1. From the Nutritional Immunology & Molecular Nutrition Laboratory, Department of Human Nutrition Foods and Exercise (JB-R, AJG, AMN, KAR, JK, and RH), and the Department of Animal and Poultry Sciences (CMW and MA), Virginia Tech University, Blacksburg, VA, and Mead Johnson Nutritionals/Bristol Myers Squibb, Evansville, IN (DR)