Molecular Identification of Bacteria Involved in Lameness in Broiler

Lameness is one of the main metabolic diseases related to fast growth in broiler. It is a significant problem in the poultry industry resulting in hundreds of millions of dollars in lost revenue annually. In commercial broilers, the most common cause of lameness is bacterial chondronecrosis with osteomyelitis (BCO). Dr. Wideman has developed a model to induce lameness in commercial broilers. The model includes raising chicken on a wire pen flooring resulting in a sharp increase in the incidence of lameness. Our research entails the collection of femoral as well as tibial heads from clinically lame birds, culturing bacteria from these sites, and PCR sequencing the 16S ribosomal DNA for species identification.    Preliminary work has shown that most cases of lameness in a single floor pen are primarily infected with a single species of bacteria.  Surprisingly, the species we identified is not normally associated with poultry.  There are two ways through which bacteria can enter the blood stream; either through the respiratory or gastrointestinal tract. We hypothesize that blood-borne bacteria then settle in microfractures in the proximal femoral and tibial heads causing lameness. Knowing the exact bacterial species causing lameness and the route of transmission to broilers will lead to the development of measures for mitigating BCO and ultimately reducing the economic losses.