The pig either converts them to energy, or stores them directly in his body fat. The fat and oils are the most dense source of energy that can be fed to pigs. On average, fats and oils will provide about 2 to 2.5 times as much energy as carbohydrates. Under most situations, feeding of animal fat to growing-finishing pigs will improve feed efficiency, but the improvement does not offset the higher diet costs. Lipids, carbohydrates, and some protein are the dietary energy sources used by the pig.
Energy is measured as either digestible energy or metabolizable energy.
Proteins Proteins are a large group of organic compounds made up of 22 amino acids. The amino acids are linked together in different combinations to form very long chains. The sequence of amino acids determines the function of each protein. For example, the proteins in muscle cells are much different from the protein that makes up growth hormone. On a quantitative basis, the proteins form most of the soft tissues of pigs, being part of muscle and collagen.