Curled toes and perosis-like leg abnormalities in cage reared broilers

Area of Science:

• Animal Science
• Poultry Nutrition
• Avian Pathology

Background:

• Perosis, a leg disorder characterized by curled toes, frequently affects broiler chicks.
• This condition has been observed in chicks reared in both cage and floor pen systems.
• The disorder appears within 5-7 days when chicks are fed a standard corn-soybean meal diet.

Purpose of the Study:

• To investigate the high incidence of perosis-curled toe leg disorder in broiler chicks.
• To evaluate the effectiveness of dietary manganese and vitamin B-2 supplementation in preventing the disorder.
• To assess the impact of environmental factors, including housing and photoperiod, on perosis development.

Main Methods:

• Male broiler chicks of two genetic strains were fed a nutritionally complete corn-soybean meal diet.
• Rations were modified with additional manganese (50 ppm) or vitamin B-2 (0.5 mg/kg).
• Chicks were reared in both cage and floor pen environments with varying photoperiods (24 hr/day vs. 12 hr/day).

Main Results:

• A high incidence of perosis-curled toe disorder was observed within 5-7 days in chicks fed the basal diet.
• Supplementation with manganese or vitamin B-2 did not prevent or reduce the incidence of the leg problem.
• Floor pen rearing (12-13% incidence) showed a lower perosis rate compared to battery rearing (20-60% incidence).
• Reduced photoperiod (12 hr/day) decreased leg disorder incidence but also reduced growth rate.
• A positive correlation was noted between weight gain rate and the severity of leg abnormalities.

Conclusions:

• The standard corn-soybean meal diet promotes rapid growth but is associated with a high incidence of perosis-like leg disorders.
• Dietary manganese and vitamin B-2 are not solely responsible for preventing this specific perosis condition.
• Environmental management, particularly housing type and photoperiod, plays a significant role in mitigating leg disorder development in broiler chicks.
• The basal diet serves as a suitable model for studying perosis-like leg problems in broilers.