Osteochondrosis is a well defined clinical syndrome causing acute lamenesses of sudden onset in European swine, especially the European Landrace. It is characterized as: (1) following familial lines. (2) occurring primarily at 6-12 months of age. (3) relating to certain conformations. (4) unrelated to stress or nutritional levels of calcium, phosphorous, Vitamin A, Vitamin D, and protein. (5) occuring in fast growing swine. Those with the genetic ability to grow and/or high-energy rations.