Effects of Dietary Milk Thistle (Silybum marianum) Supplementation in Ducks Fed Mycotoxin-Contaminated Diets

SIMPLE SUMMARY: Previous experiments have shown that the medicinal plant milk thistle (Silybum marianum) can be a potential feed additive protecting farm animals against the deleterious effects of various mycotoxins. The main objective of our study was to investigate the health protective effects of dietary milk thistle seed (0.5%), oil (0.1%), and seed cake (0.5%) in ducks fed diets naturally contaminated with deoxynivalenol (3.43–3.72 mg/kg feed) and zearalenone (0.46–0.50 mg/kg feed). The feeding of experimental diets did not result in mortality cases, clinical signs of mycotoxicosis, or in differences of clinical chemistry values of blood serum but led to histopathological alterations. The positive effects of milk thistle oil on histopathology parameters exceeded those of the seed and seed cake (vacuolar hepatocyte degeneration) or all of the treatments showed similar effectiveness (solitary cell death and infiltration of lympho- and histiocytes in the liver, lymphocyte depletion in the spleen and bursa of Fabricius). Based on our results, the applied milk thistle supplements have been proven effective in the prevention of histopathological changes caused by deoxynivalenol and zearalenone. ABSTRACT: The medicinal plant milk thistle (Silybum marianum) has been widely used due to its hepatoprotective properties. The main objective of our study was to investigate the health protective effects of dietary milk thistle seed (MS), oil (MO), and seed cake (MSC) in ducks fed diets naturally contaminated with deoxynivalenol (DON; 3.43–3.72 mg/kg feed) and zearalenone (ZEN; 0.46–0.50 mg/kg feed). Female White Hungarian ducks were randomly allocated to four dietary treatments consisting of the control diet (C), the control diet supplemented with 0.5% MS, 0.5% MSC, or 0.1% MO. The feeding of experimental diets did not result in mortality cases, clinical signs of mycotoxicosis, or in differences of clinical chemistry values of blood serum. The positive effect of MO on vacuolar hepatocyte degeneration exceeded that of the MSC on d14 and both MS and MSC on d42. Each treatment was equally effective in the decrease of the severity of solitary cell death and infiltration of lympho- and histiocytes in the liver on d28 as well as in the prevention of lymphocyte depletion in the spleen and bursa of Fabricius on d14. In conclusion, the applied treatments have been proven effective in the prevention of histopathological changes caused by DON and ZEN.