Effect of Saccharomyces cerevisiae addition to feed contaminated with aflatoxin B1 on the health and performance indices of tambaqui (Colossoma macropomum) fingerlings

Abstract

The objective of this study was to evaluate the effects of the addition of Saccharomyces cerevisiae to feed contaminated with aflatoxin B1 (AFB1) on the performance and health of tambaqui fingerlings. A fully randomised study design was used, represented by four treatments: (T1) with 0.0 μg/kg of AFB1 and 0.0 colony forming unit (cfu)/g of yeast (control); (T2) with 0.0 μg/kg of AFB1 and 106 cfu/g of yeast; (T3) with 100 μg/kg of AFB1 and 0.0 cfu/g of yeast and (T4) with 100 μg/kg of AFB1 and 106 cfu/g of yeast, with four repetitions per treatment. Over a period of 34 days, 192 fingerlings with an initial weight of 2.9±0.2 g and length of 26.1±1.3 mm were used, distributed in 16 tanks with 12 fish per experimental unit. The following parameters were evaluated: water quality, zootechnical performance, histopathological analysis, counting and isolation of yeasts from the feed and intestine. No significant differences were observed (P>0.05) in the initial weight, initial length, final length, specific growth rate, mean length gain, Fulton condition factor (K Factor) or survival rate of the tambaqui fingerlings during the trial period. Statistical differences (P<0.05) were found between the treatments with respect to fingerling final weight, mean weight gain and average feed intake. Histopathological changes in the liver and kidney tissues from tambaqui fingerlings were more pronounced in T3 and T4. Based on histopathological findings, the yeast was unable to reduce the characteristic effects of aflatoxicosis in tambaqui fingerlings fed with 100 μg/kg AFB1. The S. cerevisiae A8L2 strain was able to colonise the intestine of tambaqui fingerlings, however, its addition in conjunction with 100 μg/kg AFB1 to fingerling feed did not promote improvements in performance indices or the histopathological parameters of these animals.