Hepatoprotective effects of milk thistle (Silybum marianum) seed cakes during the chicken broiler fattening

Abstract

The objective of this work was to verify the hepatoprotective effects of Silybum marianum seed cakes in feed mixtures used for the fattening of chicken broilers to heavier weights. Part of the experiment was to verify the preventive effect of such modified feed mixtures with the use of chlortetracycline medication. The experiment was carried out on 180 ROSS 308 broiler chickens. The chickens were fed complete feed mixtures containing 0.0% (K), 0.2% (P1 and 1.0% (P2) of Silybum marianum seed cakes. The cakes used contained 2.95% of silymarin. On the 44th day of fattening half of the chickens from every group were supplied with chlortetracycline medicated water at a dose of 2 g·kg1 live weight. The selected biochemical indices were observed: cholesterol (Chol), glutamyl transferase (GMT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). On the 52 nd day of the test, six chickens from each group were euthanized and their liver was taken for histological examination. Adding Silybum marianum seed cakes resulted in a non-significant decrease in the chickens' live weight and in the feed conversion in both experimental groups compared to the control group. The cholesterol levels were highly significantly lower (p < 0.01) on the 43rd day in group P2, and significantly lower (p < 0.05) on the 52nd day in group P1 when compared to the control group (K). Also the ALT and AST activity was lower (p < 0.01) in both experimental groups on the 22nd day of the experiment. On the 52nd day the lower activity (p < 0.01) was found only for AST in both experimental groups. In the chlortetracycline medicated group P2, cholesterol level (p < 0.05) as well as ALT activity and AST activity decreased (p < 0.01), compared to the medicated control group. Results of biochemical analyses were also confirmed by histological examination of the liver. Administration of silymarin reduced (p < 0.01) the content of lipids and increased the content of glycogen in the liver of both experimental groups.