Effects of low-dose zearalenone-contaminated diets with or without montmorillonite clay adsorbent on nutrient metabolic rates, serum enzyme activities, and genital organs of growing-laying hens

We investigated the effects of the mycotoxin zearalenone (ZEA) on nutrient availability, serum enzyme activities, and genital organ indices of growing-laying hens, and the mitigating effects of a montmorillonite clay adsorbent Calibrin-A (CA) was also evaluated. The experiment was conducted for 49 d using 720 70-day-old Hy-Line Brown growing-laying hens. Hens fed a corn-soybean meal-whey basal diet or ZEA-contaminated diets with or without CA. The treatments were as follows: (1) (Control); (2) Control + 0.15% CA; (3) ZEA0.4; and (4) ZEA0.4 + 0.15% CA. Zearalenone contaminated diet had no effect (P > 0.05) on apparent metabolic rate. In hens fed the ZEA0.4 diet, serum aspartate amino transferase (AST) and alkaline phosphatase (ALP) activities had significantly increased compared with control (P < 0.05). Relative oviduct weight and relative ovary weight were heavier in hens fed the ZEA0.4 diet than in the control group (P < 0.05). Degeneration and atrophy of the ovarian tissues was also found in hens fed the ZEA0.4 diet. The result reflects granular film of developing follicles in ovarian follicular wall portion and the intima separate theca folliculi. Addition of clay adsorbent in the ZEA0.4 diet showed a positive protective effect on ZEA toxicity. In hens fed a basal diet with clay alone, there was no significant impact (P > 0.05) on any variable compared to the control. In conclusion, feeding a 0.4 mg/kg ZEA0.4 diet for 49 days might result in deleterious effects on growing-laying hens, and the addition of CA can effectively neutralize the detrimental effects of ZEA.