Compositions and Methods for Altering Gene Expression

A pet food composition comprising:

• about 5 to about 70% protein,
• about 0.5 to about 1.6% methionine,
• about 50 to about 200 ppm manganese,
• about 0.1 to about 0.5% DHA.
• about 0.1 to about 0.7% EPA.
• about 1200 to about 7500 ppm choline,
• about 1000 to about 2000 ppm taurine,
• about 2.5 to about 6% linoleic acid,
• about 1 to about 3% total n-3 fatty acids,
• about 50 to about 1200 IU/kg vitamin E.
• about 50 to about 500 ppm vitamin C,
• about 50 to about 500 ppm carnitine, and
• about 2.5 to about 7 g lysine/1000 kcal.