Using a tobit regression model to analyse risk factors for foot-pad dermatitis in commercially grown broilers

Area of Science:

• Veterinary Medicine
• Animal Science
• Agricultural Economics

Background:

• Foot-pad dermatitis (FPD) is a significant welfare issue in broiler chickens.
• Understanding local and regional risk factors is crucial for effective FPD management.
• Previous research has not extensively applied advanced statistical models to FPD in broilers.

Purpose of the Study:

• To develop and apply a statistical model to identify factors influencing FPD prevalence in Swedish broilers.
• To analyze the impact of local (slaughterhouses, feed suppliers) and regional factors on FPD.
• To investigate interactions between identified risk factors and time.

Main Methods:

• Utilized a two-year dataset on broiler foot-health in Sweden.
• Employed Tobit regression analysis, a censored data model, for statistical analysis.
• Included variables such as week of slaughter, bird age, slaughterhouses, feed suppliers, and regions.

Main Results:

• Week of slaughter (p < 0.001) and bird age (p < 0.01) were significantly associated with total foot-pad score.
• Five slaughterhouses (p < 0.01), three feed suppliers (p < 0.05), and four regions (p < 0.01) were significant risk factors.
• Significant interactions were found between time and slaughterhouses, feed suppliers, and regions (p < 0.001).

Conclusions:

• The developed Tobit model effectively identified key local and regional risk factors for broiler FPD.
• Slaughter timing, bird age, specific facilities, feed sources, and geographical areas influence FPD.
• Findings will inform modifications to the Swedish broiler foot-health program for improved animal welfare.