Rickets and Metastatic Mineralization in Broilers Associated with Excess Dietary Calcium and Phosphorous

Area of Science:

• Avian pathology
• Poultry nutrition
• Veterinary medicine

Background:

• Elevated mortality and culling observed in 7-day-old UK broilers.
• Clinical signs included weakness, lameness, and wet litter.

Purpose of the Study:

• Investigate the cause of early-onset lameness and mortality in broilers.
• Determine the underlying pathology and contributing nutritional factors.

Main Methods:

• Necropsy and histopathology of affected chicks.
• Bacteriologic examination of samples.
• Feed analysis of starter ration.

Main Results:

• Histopathology revealed tibial dyschondroplasia and osteodystrophy.
• Mineralization identified in gizzard, kidneys, and proventriculus.
• Feed analysis showed excessive calcium and phosphorus levels, with an imbalanced ratio.

Conclusions:

• The case presented as early rickets with metastatic visceral mineralization.
• Nutritional imbalance in the starter ration was the primary cause.
• High mortality and culling rates were associated with these findings.