Lameness in broiler chickens is a significant, emerging problem currently controlled by antibiotic use (primarily lincospectin). The condition is usually associated with Enterococcus cecorum, the cause of bacterial chondronecrosis with osteomyelitis (BCZ), in which the bacteria translocate from the intestines to the bloodstream and organs, including femoral heads, knee joints, and vertebrae. The target group for this project is broiler chicken farms, i.e., primary producers, and by extension, the broader poultry industry, including veterinarians, but also the animal feed industry, feed additive companies, and the processing industry, including supermarkets. The specific problems and challenges are as follows:

1. The sharp increase in the occurrence of BCO, caused by Enterococcus cecorum, and the associated reduction in animal welfare and rising costs associated with morbidity, mortality, and slaughterhouse condemnations.
2. The sharp increase in the use of therapeutic antibiotics to treat locomotor disorders.
3. The lack of preventive strategies for BCO, whether through management interventions, feed modifications, or other methods, including the use of slow-growing breeds, early feeding, on-farm hatching, and adjusting stocking density.

The BCO problems are such that they undermine the profitability and sustainability of intensive broiler production, contribute to the prevalence of antibiotic-resistant bacteria, and suppress consumer perception of ethically farmed and sustainable meat. The current project aims to provide solutions in various areas, leading to the following objectives:

1. Describe the prevalence of the (subclinical) disease problem
2. Identify risk factors that contribute to BCO
3. Identify factors involved in the pathogenesis of the disease
4. Provide non-antibiotic measures and strategies that prevent the occurrence of BCO, including feed additives and management interventions (such as the use of slow-growing breeds, early feeding, and on-farm hatching).