Abstract
A 12-wk feeding experiment was conducted to investigate the effect of supplementation with molecular or nano-clay adsorbent on growth performance and haematological indices of starter (0-56 d) and grower (56-84 d) turkeys fed diets contaminated with varying doses (0, 60, and 110 ppb) of aflatoxin B-1. Two hundred and sixteen 1-d-old male turkeys were assigned to 9 diets supplemented with no adsorbent, molecular clay adsorbent, and nano-clay adsorbent and contaminated with 0, 60, and 110 ppb aflatoxin B1 in a 3 x 3 factorial arrangement of treatments with 3 replicate pens and 8 turkeys per pen. The turkeys were housed in an open-sided, deep litter system, which was partitioned into 27 pens (2 x 1.5 m(2)) using wire mesh. As aflatoxin contamination increased from 0 to 110 ppb, feed intake and weight gain decreased and feed conversion ratio (FCR) increased in starter turkeys, but the adverse effects of aflatoxin were progressively less from those fed the diets with no adsorbent to molecular clay adsorbent and then to nano-clay adsorbent (adsorbent x aflatoxin. P < 0.044). Grower turkeys fed the diets with adsorbents consumed more feed and had better FCR than those fed the diets without adsorbent, and those fed the diets with nano-clay adsorbent had better FCR than grower turkeys fed the diets with molecular clay adsorbent (P < 0.001). The highest mortality was observed in starter and grower turkeys fed the diet with no adsorbent and contaminated with 110 ppb aflatoxin (adsorbent x aflatoxin, P=0.002). As aflatoxin increased in starter and grower turkeys fed the diets with no adsorbent, white blood cell (WBC) and lymphocyte counts increased and packed cell volume (PCV) decreased, whereas aflatoxin had no noticeable effect on those response criteria in turkeys fed the diets with molecular clay and nano-clay adsorbent (adsorbent x aflatoxin, P < 0.05). Starter turkeys fed the diets with adsorbents had a greater Hb and monocyte concentration (P < 0.001), whereas grower turkeys fed the diets with adsorbents had less heterophil and eosinophil counts (P < 0.043) than those fed the diets with no adsorbent. In conclusion, supplementation of aflatoxin-contaminated diets with clay adsorbents seemed to improve weight gain and reduce mortality, and reduce adverse effects of aflatoxin on PCV and Hb in turkeys. Grower turkeys fed the diet supplemented with nano-clay adsorbent had better growth performance than those fed the diet supplemented with molecular clay adsorbent. (C) 2015 Elsevier B.V. All rights reserved.