Mary Beth,
Yep, those Aggies like to get down to the nitty-gritty of food chemistry. I wish I knew more about that area of science, but I do know this:
Similar to humans evolving on a diet of paleo foods, the ancient ancestors of cattle did not develop their digestive systems while eating neolithic food/feed, (namely grains). They evolved on a diet of grass and forbs, and they would never have developed 4 stomachs, if they had evolved on a grain-based diet. In fact, grains cause all sorts of digestive system problems for cattle, which have to be carefully monitored by feedlot operators, who supplement their diet as necessary, in order to minimize those issues. It doesn't take much thought to recognize that the flesh of grass-fed cattle will more closely resemble the flesh of paleo period ungulates, since grain-fed cattle are eating an unnatural diet, by definition. The amino acid profile of the protein in such beef would obviously have to be significantly altered, from the natural configuration of grass-fed beef.
http://www.ajcn.org/cgi/content/abstract/79/6/1207S
Even Dr. Mercola has jumped on the Conjugated Linoleic Acid, (CLA), bandwagon.
http://www.mercola.com/beef/cla.htm
Thanks for the links,
Tex