It is difficult to quantify "healthy" pigs, but pigs of a high health status gain weight more rapidly and are more efficient in feed utilization than pigs that have clinical or subclinical disease conditions. Healthy pigs will more nearly reach their genetic potential for growth. High-health-status pigs gain lean more rapidly, but they also deposit fat at a faster rate. The inclusion of antibiotics or antibacterial agents in the diets of market pigs has consistently shown a growth and feed conversion improvement. Generally, grower pigs show a greater benefit than finisher pigs when antibiotics are added to their diets.