Corn does not make up 100% of the diet. The diet of cattle is usually a mixture of many feeds, mixed in the correct proportions to give the animal what it needs for its stage of growth or production. So to wrap it all up, yes cattle do eat corn, many other cereal grains. They love these feeds [video].
The Tongue. The tongue is a muscular organ in the mouth with several functions. It is attached to the bottom of the mouth by a membrane on its underside called the lingual frenum. The top surface of the tongue contains papillae, the tiny nodules or bumps that include the taste buds. One of the functions of the tongue is taste, but it also facilitates chewing, digesting, swallowing and speaking.
The tongue is a muscular hydrostat on the floor of the mouth of most vertebrates that manipulates food for mastication. It is the primary organ of taste (gustation), as much of its upper surface is covered in taste buds. The tongue's upper surface is also covered in numerous lingual papillae. It is sensitive and kept moist by saliva, and is richly supplied with nerves and blood vessels.