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Pathological changes in liver and thyroid in broiler chickens fed by rapeseed cake

The aim of this study was to investigate pathological changes in liver and thyroid gland to determine the possibility of using different levels of rapeseed cake in diets for chickens. The experiment was carried out on three hundred sixty male day-old Cobb hybrid chickens which were fed on three different feeding treatments (T-0=% ; T-5=5% ; T-10=10% of rapeseed cake, “double low” cultivar Bristol). The rapeseed cake contains 2, 86 μmol/g of glucosinolate (Gls) and ratio of erucic acid was 0, 08% of total faty acids. Introduction of 5% rapeseed cake to chicken feed increased mortality, but it was still an acceptable mortality rate. The average liver mass was increased in T-5 and T-10 groups compared to the control group. Thyroid glands of treated animals showed no significant increase in weight compared to the control group. Histopathologically, liver and thyroid lesion were more prominent in treated animals compared to the control group. In treated group a significantly high rate of perivascular necrosis of hepatocytes, and perivascular mixtocellular cell infiltration in the liver was in T-5 group. In the liver, a significantly high rate of congestion, degeneration of blood vessels, vasculitis, and hydropic degeneration was in T-10 group. Thyroid glands of treated animals showed a significantly high rate scattered proliferation of follicular epithelial cells, and mild interstitial fibrosis in T-5 group. Severe interstitial fibrosis was pronounced only in T-10 group with a significantly high rate. The highest rate of follicular haemorrhages was in T-10 group, followed by T-5 group. The relation between these rapeseed cake specific changes, and how the concern with the undesirable effects specific to rapeseed cake remain to be elucidated. However, the existence of causative factor other than erucic acid and glucosinolates can not be excluded. Conclusively, introduction of 5 and 10% rapeseed cake (Bristol-“double low” cultivar) to broiler chickens causes liver and thyroid changes but these changes were not severe enough to have greater impact on production results. Key words: rapeseed cake, broiler chickens, liver, thyroid gland, pathological changes

Rapeseed Cake; Broiler Chickens; Liver; Thyroid Gland; Pathological Changes

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