Essential Nutritional Information on Grass Fed Beef you must read..
Total Fat and Calories
Beef from pasture-fed cattle has a lower fat content and has less calories than beef from grain-fed cattle. If the meat is very lean, it can have one third as much fat as a similar cut from a grain-fed animal. As you can see by the graph below, grass-fed beef can have the same amount of fat as skinless chicken, wild deer, or elk. Research also shows that lean beef actually lowers your "bad" LDL cholesterol levels.
Meat from grass-fed animals has two to four times more omega-3 fatty acids than meat from grain- fed animals. Omega-3s are called "good fats" because they play a vital role in every cell and system in your body. Of all the fats, they are the most heart-friendly. People who have ample amounts of omega-3s in their diet are less likely to have high blood pressure or an irregular heartbeat. Remarkably, they are 50 percent less likely to suffer a heart attack. Omega-3s are essential for your brain as well. People with a diet rich in omega-3s are less likely to suffer from depression, schizophrenia, attention deficit disorder (hyperactivity), or Alzheimer's disease.
Conjugated Linoleic Acid (CLA)
Meat and dairy products from grass-fed ruminants are the richest known source of another type of good fat called "conjugated linoleic acid" or CLA. When ruminants are raised on fresh pasture alone, their products contain from three to five times more CLA than products from animals fed conventional diets. (A steak from the most marbled grass-fed animals will have the most CLA ,as much of the CLA is stored in fat cells.)
In addition to being higher in omega-3s and CLA, meat from grass-fed animals is also higher in vitamin E. The graph below shows vitamin E levels in meat from: 1) feedlot cattle, 2) feedlot cattle given high doses of synthetic vitamin E (1,000 IU per day), and 3) cattle raised on fresh pasture with no added supplements. The meat from the pastured cattle is four times higher in vitamin E than the meat from the feedlot cattle and, interestingly, almost twice as high as the meat from the feedlot cattle given vitamin E supplements.  In humans, vitamin E is linked with a lower risk of heart disease and cancer. This potent antioxidant may also have anti-aging properties.
Grass-fed meat has a similar fat profile to wild game
When cattle are free to forage on their natural diet of grass, their meat is almost as lean as wild game. The graph below shows that grass-fed beef has an overall fat content similar to wild animals such as deer.