The nutritional value of meats is an important consideration for meat processors and consumers alike.  FDA regulations require meats offered in retail settings to be labeled with nutritional information that can be easily understood by the consumer.  What you don't see on these labels is the exhaustive and ongoing research into the role of meats in a healthy lifestyle.  The following resources shed some light on this:

Nutritional Values of Beef (by the National Cattlemen's Beef Association)   

Nutritional Values of Pork (by the National Pork Board)

Nutritional Values for Cuts of Meat (by USDA)