Pathological assessment. At necropsy livers were photographed by the visceral and diaphragmatic aspects for gross pathology evaluation as described previously [46] . Gross hepatic lesions were scored as: absent [2] ; mild [+] (less than 10% of hepatic surface affected); moderate [++] (10-25% of hepatic surface affected); severe [+++] (25-50% of hepatic surface affected) and very severe [++++] (more than 50% of hepatic surface affected). Tissue samples were collected from the left (6 samples) and right (2 samples) hepatic lobes, fixed in 10% buffered formalin and embedded in paraffin wax. Tissue sections (4 mm) were stained with haematoxylin and eosin (HE) for the histopathological study.