Porphyrin Accumulation and Biliary Lithiasis Causing Diffusely Black Livers in Broiler Chickens

Area of Science:

• Veterinary Pathology
• Poultry Science
• Biochemistry

Background:

• Black liver discoloration in broiler chickens is an uncommon post-mortem finding.
• Previous cases have lacked detailed etiological investigation.

Purpose of the Study:

• To investigate the cause of uniformly black livers observed in two broiler chickens.
• To characterize the nature of the observed liver lesions.

Main Methods:

• Gross post-slaughter examination of affected broiler chickens.
• Histopathological and ultrastructural examination of liver tissues.
• Liquid chromatography assay for porphyrin identification.

Main Results:

• Grossly normal carcasses with uniformly black livers in affected birds.
• Microscopic examination revealed globoid, dark brown to green-brown, birefringent concrements within hepatocytes and bile canaliculi.
• Ultrastructural analysis showed radially arranged electron-dense crystal spicules within the concrements.
• Liquid chromatography confirmed the presence of protoporphyrin IX in the affected liver tissue.

Conclusions:

• The black liver discoloration in these broiler chickens was attributed to the accumulation of protoporphyrin IX concrements.
• This condition represents a specific type of porphyrin accumulation disorder in poultry.
• Further research is warranted to determine the underlying cause and prevalence of this condition.