Abstract
In this study eighteen of Egyptian native sheep and goats were tested for their ability to degrade and metabolize aflatoxin B1 (AFB1) in other less toxic metabolites aflatoxin B2a (AFB2a), aflatoxin M1 (AFM1), and aflatoxicol (AFRo) in three in vitro trial sets. One set trial evaluated the a kin B1 degradation ability of different rumen fluid donors (sheep vs. goats) by incubating whole rumen fluid (WRF) with three different AFB1 concentrations 5, 10 and 20 mu g/ml WRF for 12h. Another set examined AFB1 degradation by collecting WRF at five different times (0, 2, 4, 6 and 12 h) after feeding and incubated for 12h with AFB1 5 mu g/ml WRF. For the third set AFB1 at 5 mu g/ml WRF, was incubated for 12h with intact rumen fluid (WRF) or fractions of rumen protozoa (RP) and bacteria (RB) from sheep and goats. AFB1 and their metabolites were determined by HPLC. All animals under investigation were fed a 70% concentrated diet and 30% roughage with free access to water. Results showed that rumen fluid from the Egyptian native goats demonstrated higher (p < 0.05) AFB1 degradability than Egyptian native sheep (AFB1 content decreased by an average of 48.5% in case for baldy goats). However, differences in sheep types had no significant influence on degradability. The capacity of rumen fluid to degrade aflatoxin B1 decreased 3 h after feeding, but this activity was gradually increased till 12 h feeding time. Also, protozoa were more active than bacteria. In addition, AFB1 was cleaved into none or less toxic metabolites by rumen contents from all tested animals. It was concluded that aflatoxin degradation was depending upon aflatoxin concentration, rumen fluid source and collection time after feeding, as significant differences were observed.