Bison

     More exotic meats like bison and venison are appearing on the market. The tendency is to assume that these animals are grass fed, but this is not always the case. Analysis has shown that meat from grass-fed bison has 3.5 times more omega-3 fatty acids than meat from grain fed bison. Grain fed animals also have higher cholesterol content in their meat than animals consuming grass. The trend is bison feeding is to raise them on grain. It is a good idea to always seek out meat and animal byproducts from animals which have been exclusively grass fed.
Reference:
Robinson, Jo., Pasture Perfect, Washington: Vashon Island Press, 2004, 47-48.