What’s on your label? Since January 1, 2012, USDA requires nutrition facts on beef to be available to consumers either as a poster displayed near the meat case, or on the package label. You could use the nutrition information from the USDA’s National Nutrient Database for Standard Reference.  It’s compiled from analysis of conventional beef, with a little bit of data for grass-fed beef.  But that information doesn’t necessarily apply to your grass fed/finished product.
Not to worry – here’s the solution you’re looking for.
Grass Run Farms wanted labels for grass-fed beef to reflect the quality of the product, including the difference in nutritional analysis. With help from a USDA SARE-funded project, they analyzed more than 100 samples of beef to come up with nutritional information to include on the labels for twelve different cuts.
They are sharing the results as fact sheets on the different cuts of meat that were analyzed.  Then, to help you compare the product you’re raising with the beef that was analyzed for this project, they’ve provided a break down of how the animals were raised at each of the three farms.  Check that out here. They’ve also provided step by step instructions for how to us their nutrition panels create your own labels.
I really don’t agree with all the label claims. Research shows when the beef is cooked there are no differences: http://extension.psu.edu/animals/beef/grass-fed-beef/articles/telling-the-grass-fed-beef-story