Due to the fact that antibiotics for growth promotion are being phased out, interest is now being paid to the antibiotic power of various acids and fats. The addition of these alternatives generally makes the diet more acidic and resistant to changes of this acidity, increases gastrointestinal acidity, breakdown of proteins, promotes beneficial bacteria at the expense of harmful bacteria, and modulates many physiological processes after absorption. Four major benefits can be expected including improved health and resistance to disease, faster growth, increased efficiency of diet utilisation, and better carcass quality. Secondary affects may be achieved with certain supplemental fats (called SCFAs, or short-chain fatty acids) and nitrogen and phosphorus. Consistent responses of pigs to supplement SCFAs and their salts can be achieved by optimizing their sources, levels at proper ratios of protected to non-protected forms in diets using a more complex computerized approach. The economic feasibility of the use of SCFA can be heavily determined by the farm structure and the restrictions and costs imposed by the regional environmental and health safety policies.