Mining Candidate Genes and Identifying Risk Factors for Leg Disease in Broilers: A Mendelian Randomization Study.

Area of Science:

• Animal Science
• Genetics
• Veterinary Medicine

Background:

• Leg disease (LD) in broilers is linked to bone metabolic disruptions and altered serum indicators.
• The genetic basis for the association between bone health and LD incidence in broilers remains unclear.

Purpose of the Study:

• To identify genetic risk factors for leg disease (LD) in broilers using Mendelian randomization (MR) analysis.
• To investigate the causal relationships between various bone and serum indicators and LD incidence.

Main Methods:

• Utilized Mendelian randomization (MR) analysis on 1235 sequenced white-feathered broilers.
• Assessed associations between bone strength, bone mineral density (BMD), tibial bone dimensions, bone ash, and serum indicators (calcium, phosphorus, alkaline phosphatase, osteoprotegerin) with LD incidence.

Main Results:

• Decreased bone mineral density (BMD) and narrower tibial bone diameter (TBD) were causally linked to increased LD risk.
• Elevated serum calcium, phosphorus, alkaline phosphatase (ALP), and osteoprotegerin (OPG) were associated with altered bone parameters and LD risk.
• Specific associations found: BMD with OPG, TBD with ALP, and narrower TBD with elevated serum Ca and P.

Conclusions:

• Reduced BMD and TBD are significant genetic risk factors for LD in broilers.
• Serum markers like Ca, P, ALP, and OPG play a role in the bone metabolic disturbances leading to LD.
• Findings offer insights into LD pathogenesis in broilers and potential parallels with human conditions like osteoporosis.