Gross intestinal adaptations in relation to broiler performance during chronic aflatoxin exposure

The present trial was conducted to study some morphological, digestive, and electrophysiological variables of the small intestine during chronic exposure of broilers to aflatoxin B1 (AFB1). Ross 308 male chicks (7 d old) were randomly allotted to control (no AFB1), low AFB1 (0.07 mg of AFB1/kg), or high AFB1 (0.75 mg of AFB1/kg) diet. The high AFB1 diet resulted in reduced (P ≤ 0.002) bird performance during the first 4 wk of exposure, whereas the low AFB1 diet temporarily reduced (P = 0.034) the bird performance during wk 3 of exposure. During wk 4 of exposure, a linear (P ≤ 0.013) decrease in the unit weight of both the duodenum and jejunum was observed with increasing levels of AFB1. This reduction in unit weight appeared to progress from the proximal (duodenum) to the distal (jejunum) small intestine with increase in the length of exposure and was not accompanied by modulation of electrophysiological variables in jejunal epithelium. Response from amiloride, a specific blocker of epithelial sodium channel, was also similar among jejunal epithelia of birds under different treatments. Interestingly, a compensatory linear (P ≤ 0.002) increase in the length of the duodenum and jejunum under high AFB1 diets was noted to occur during wk 4 of exposure. Thus, retention of DM and nitrogen was not negatively affected by the AFB1 diets. These data indicate that the intestine in broilers may adapt to an ongoing dietary challenge to AFB1. © 2011 Poultry Science Association Inc.