Effect of lignin supplementation of a diet contaminated with Fusarium mycotoxins on blood and intestinal lymphocyte subpopulations in chickens.

The objective of the study was to investigate the effects of lignin supplementation of a diet contaminated with the Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) on peripheral blood leukocytes and duodenal immunocompetent cells in broiler chickens. From day 1 after hatching, all chickens were fed an identical control diet for two weeks. Then chickens of Group 1 continued to be fed the control diet, whereas Group 2 was fed the same diet supplemented with lignin at 0.5% level. Simultaneously, Group 3 started to receive a diet contaminated with DON (2.95 mg kg-1) and ZEA (1.59 mg kg-1), while Group 4 received an identical contaminated diet supplemented with 0.5% lignin for further two weeks. Samples of blood and duodenal tissue were collected from 6 birds of each group at 4 weeks of age. Neither counts of white blood cells nor phagocytic function in the peripheral blood were significantly affected in the mycotoxin- and/or lignin-treated birds. As compared to the control, increased numbers of IgM-bearing cells were found in the peripheral blood in Group 3 fed the contaminated diet (P < 0.05) and in Group 4 given the contaminated diet supplemented with lignin (P < 0.01). While the contaminated diet led to reduced numbers of duodenal CD4+ cells, in Group 2 treated only with lignin the number of duodenal CD4+ cells was increased. Lignin enrichment of the contaminated diet did not eliminate the mycotoxin-induced reduction in the number of duodenal CD4+ cells. The results suggest that dietary supplementation of lignin as an indigestible compound to poultry feed may increase the density of some intestinal immunocompetent cells without exerting effects on that in the peripheral blood. However, when added to a diet contaminated with Fusarium mycotoxins, lignin did not prevent the mycotoxin-induced changes in the numbers of blood and intestinal immunocompetent cells.

Effect of lignin on oxidative stress in chickens fed a diet contaminated with zearalenone.

The effect of lignin supplementation to a diet contaminated with zearalenone (ZEA) on antioxidant status was studied in female chickens of the ISA BROWN laying strain. From the day of hatching to 2 weeks of age, four groups of chickens were fed the same uncontaminated control diet. After 14 days, Group 1 (control) continued to receive the uncontaminated diet, while Group 2 was fed an identical diet enriched with 0.5% chemically modified lignin. Simultaneously, chickens of Group 3 were switched to a diet contaminated with 7.9 mg/kg ZEA and those of Group 4 to an identical contaminated diet supplemented with 0.5% lignin. At 6 weeks of age blood and tissue samples were collected. Feeding of a diet contaminated with a high level of ZEA resulted in elevated glutathione peroxidase (GPx) activity in the duodenal mucosa and kidney tissues, and an increased γ-glutamyltransferase (GGT) activity in the plasma, indicative of oxidative stress. In the liver tissue, no mycotoxin-induced response in GPx and thioredoxin reductase (TrxR) activities occurred, and the malondialdehyde (MDA) level was even reduced. Neither the plasma levels of retinol and α-tocopherol nor the activities of superoxide dismutase in erythrocytes and GPx in blood were affected in birds fed the contaminated diet. The only effect of lignin supplemented to the contaminated feed was that it prevented the increase of GPx activity in the duodenal mucosa as an indicator of oxidative stress.

Effects of feeding diets contaminated with Fusarium mycotoxins on blood biochemical parameters of broiler chickens.

This study was conducted to investigate the effects of deoxynivalenol (DON) and zearalenone (ZEA) on some biochemical indices of broiler chickens. Twenty-four Ross 308 hybrid broiler chickens of both sexes were fed diets containing maize contaminated with Fusarium mycotoxins. The diets included a control diet (DON 0.60 mg/kg feed; ZEA 0.07 mg/kg feed), an experimental 1 diet (DON 3.4 mg kg⁻¹ feed; ZEA 3.4 mg kg⁻¹ feed), and an experimental 2 diet (DON 8.2 mg kg⁻¹ feed; ZEA 8.3 mg kg⁻¹ feed). Contaminated diets were fed from 14 days of age for 14 days. Blood samples were collected from 4-week-old birds. Chicks fed a diet containing a low level of contaminated maize (experimental 1) had decreased plasma potassium, magnesium, phosphorus, total protein, albumin, triglycerides, free glycerol concentrations and increased cholesterol and calcium levels as well as alkaline phosphatase (ALP) and aspartate aminotransferase (AST) enzyme activities as compared to the control. Feeding a diet contaminated with high levels of mycotoxins (experimental 2) resulted in decreased plasma potassium, magnesium, total protein, albumin, triglycerides, free glycerol concentrations and increased plasma ALP, alanine aminotransferase (ALT) and AST enzyme activities. The effect of mycotoxin-contaminated diets on ALP activity was dose dependent. Chloride concentration was not affected by the diets. It can be concluded that feeding diets contaminated with both levels of Fusarium mycotoxins significantly affected protein, lipid and mineral metabolism as well as AST and ALP enzyme activities in broiler chickens.

Effects of deoxynivalenol and zearalenone on oxidative stress and blood phagocytic activity in broilers.

Effects of dietary contamination with various levels of deoxynivalenol (DON) and zearalenone (ZEA) were investigated on Ross 308 hybrid broilers of both sexes. After hatching, all chickens were fed an identical control diet for two weeks. Then chickens of Group 1 received a diet contaminated with DON and ZEA, both being 3.4 mg kg(-1), while Group 2 received DON and ZEA at 8.2 and 8.3 mg kg(-1), respectively. The diet of the control group contained background levels of mycotoxins. Samples of blood and tissues were collected after two weeks. Intake of both contaminated diets resulted in a significantly decreased activity of glutathione peroxidase (GPx) and increased level of malondialdehyde (MDA) in liver tissue, while in kidneys the concentration of MDA was significantly increased only in Group 1. On the other hand, activities of blood GPx and plasma gamma-glutamyltransferase (GGT) were elevated in Group 2 only. Activities of thioredoxin reductase in liver and GPx in duodenal mucosa tissues, superoxide dismutase (SOD) in erythrocytes as well as levels of MDA in duodenal mucosa and alpha-tocopherol in plasma were not affected by dietary mycotoxins. Blood phagocytic activity was significantly depressed in Group 1 and 2. These results demonstrate that diets contaminated with DON and ZEA at medium levels are already able to induce oxidative stress and compromise the blood phagocytic activity in fattening chickens.