Response and recovery of gibel carp from subchronic oral administration of aflatoxin B1

A 16-week feeding trial was conducted to evaluate the effect of dietary aflatoxin B-1 (AFB(1)) on growth, physiological responses, histological changes, and accumulation in gibel carp (Carassius auratus gibelio), and the recovery when the fish were fed basal diet without supplemental chemical AFB(1). Triplicate groups of gibel carp with initial body weight of 10.33 +/- 0.19 g were fed seven semipurified diets (Diets 1 to 7) designed to contain 0, 10, 20, 50, 100, 200, 1000 mu g AFB(1) kg(-1) diet (determined level was 3.2, 11.3, 20.2, 55.2, 95.8, 176.0, 991.5 mu g AFB(1) kg(-1) diet, respectively) for 12 weeks. Subsequently, all fish were fed Diet 1 for another 4 weeks. The results showed that, after 12 weeks of AFB(1) exposure, average body weight in fish fed Diet 4 was 1123% of that of the control group (Diet 1), but there was no significant difference between other groups and the control group. No external changes, unusual behavior or significant difference in mortality were observed in the fish fed with various levels of AFB(1). There was no significant difference in feeding rate (FR) between the control and experimental groups. Specific growth rate (SGR) and feed efficiency (FE) of the fish fed with Diet 4 was significantly higher than that fed the control diet during the first exposure period (weeks 0-4) while there were no significant difference during the second exposure period (weeks 5-12). Fish fed with various levels of AFB(1) showed no significant differences in activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), superoxide dismutase (SOD), total protein, total serum cholesterol, and hematocrit compared to the control group. No significant histological lesions were identified between the control and increasing AFB(1) treatments. Low AFB(1) residues were found in muscles, whereas high residues of AFB(1) were determined in hepatopancreas (above the safety limitation of 5 mu g kg(-1)), which was logarithmically related to the dietary AFB(1) levels. Our results indicate that gibel carp is a less susceptible species to AFB(1) exposure up to approximately 1000 mu g AFB(1) kg(-1) diet, at least for 12 weeks. The fish also showed strong clearance ability of AFB(1) during recovery period. (C) 2011 Elsevier B.V. All rights reserved.