Does it make a difference what the animals eat? It certainly does, Grass fed animals are shown to be higher in Omega 3’s and CLA (Conjugated Linoleic Acid) fatty acids, and that's good for your body.
CLA is a naturally occurring, free fatty acid found mainly in meat and dairy products in small amounts. It is known to be an anti-carcinogen , and CLA is also known for its body weight management properties, which include reducing body fat and increasing lean muscle mass.
The most abundant source of natural CLA is in meat and dairy products of grassfed animals. Research shows that grazing animals have 35 times more CLA than animals fattened on grain in feedlots. Simply switching from grainfed to grassfed products can greatly increase the intake of CLA.
Omega 3 is an essential fatty acid for human growth and development. Grassfed beef is a great source for this essential nutrient. The source of Omega 3 is the green leaves of plants. When cattle eat their natural diet, beef becomes a great source of Omega 3. Grain is not a rich source of Omega 3. So grain feeding practices cause the Omega 3 level to decrease dramatically.