Metabolic Challenges: Past, Present, and Future

Metabolic disorders have been recognized for 50 yr, and yet most still affect the poultry industry. Before 1950, several disorders as described in the literature were most likely because of incomplete knowledge regarding requirements for certain vitamins and some trace elements. The first classical description of a metabolic disorder was that of cage layer fatigue, recognized in 1955. Since that time, some 15 to 20 disorders have been documented, and with few notable exceptions, none have been completely eliminated. Metabolic disorders can be categorized as chronic, which usually affect a small percentage of a flock, and acute, which invariably involve more birds but is sporadic in occurrence. When of sufficient economic significance, it may be possible to reduce the effect of a certain disorder by genetic selection. In the future, for both meat birds and layers, it is predicted that disorders related to skeletal integrity will pose limits to ever-increasing production efficiency.