Bacterial Chondronecrosis and Osteomyelitis (BCO lameness) is caused by bacterial infection of the femoral head, which can result in femoral head necrosis. The translocation of potential pathogens from the gut to the joints through the gut barrier is one reason for this disease.
Worldwide surveys confirm the widespread problem of lameness. A common disease, BCO lameness affects both long-life birds and fast growing birds worldwide.
About 10-15% of broilers suffer from subclinical BCO, a condition that appears first in younger birds (Thorp et al., 1993). BCO increases mortality due to culling and selection, and results in lower body weight gain and higher FCR as affected birds suffer impaired mobility and are unable to move towards feeders and drinkers as frequently as they should.
Mycotoxins can exacerbate the problem by increasing the permeability of the gut wall and hence, the passage of pathogens into the blood stream.
The colonization of the gut with beneficial microflora can help reduce the translocation of pathogens into the blood stream (competitive exclusion). The immunomodulation effect of the beneficial microflora helps the birds counteract this problem more efficiently.