The inheritance of tibial dyschondroplasia in broilers

Area of Science:

• Animal Science
• Genetics
• Poultry Science

Background:

• Tibial dyschondroplasia (TD) is a significant skeletal defect in broiler chickens.
• Developing lines with high TD incidence is crucial for understanding its genetic and environmental basis.

Purpose of the Study:

• To describe a breeding program aimed at increasing TD incidence in Australian broiler chickens.
• To investigate the genetic and environmental factors influencing TD inheritance.

Main Methods:

• Selection was applied to an Australian broiler stock over four generations.
• Incidence of TD was monitored without a control flock.
• Heritability and maternal/dominance effects were estimated.

Main Results:

• Rapid increase in TD incidence was achieved through selection.
• Circumstantial evidence suggested a major sex-linked gene with a recessive allele increasing TD.
• Realised heritability estimates exceeded 1.00, indicating favorable environmental trends.
• A significant maternal or dominance genetic component was observed in the final generation.

Conclusions:

• Selective breeding can effectively increase TD incidence in broiler populations.
• A sex-linked gene and maternal/dominance effects likely play roles in TD inheritance.
• Environmental factors linked to the female parent line may influence TD occurrence in broilers.