Screening of Aflatoxins and Zearalenone in feedstuffs and complete feeds for pigs in Southern Vietnam

Abstract

A survey ofaflatoxins and zearalenone (ZEA) in 120 samples, including cassava chip (12), maize (12), rice bran (24), broken rice (24), and complete feeds for growing pigs (24) and sows (24) was carried out in southern Vietnam. Aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) were determined by an HPLC method using an immunoaffinity column for clean-up. Zearalenone was analysed by Enzyme-Linked Immunosorbent Assay (ELISA) AgraQuant. High incidences of aflatoxins and ZEA in feedstuffs and pig feeds (83.3%-100%) were detected. Aflatoxins and ZEA were detected in all commodities analyzed. Aflatoxin B1 was found in 100, 92, 92, 83, 100 and 96%, respectively, of samples of cassava chip, maize, rice bran, broken rice, and complete feeds for growing pigs and sows, with mean concentrations of 0.86, 77.5, 1.3, 1.6, 4.7 and 7.5 microg/kg, respectively. AFB2 and AFG1 were found in low concentrations and co-occurred with AFB1 in all samples where they were found. ZEA was detected in 8%, 33%, 36%, 21%, 67% and 67%, respectively, of the samples of cassava chip, maize, rice bran, broken rice, and complete feeds for growing pigs and sows, with average concentrations of 10.0, 163.5, 83.1, 31.4, 86.0 and 101.4 microg/kg, respectively. The high incidence of mycotoxins found in feedstuffs highlights the need for periodic monitoring and prevention ofmycotoxins, not only in feeds, but also in food for human consumption.

A survey of aflatoxin B1 in maize and awareness of aflatoxins in Vietnam

“…Another study from southern Vietnam showed that positive rate for AFB 1 in maize was 91.7% (11/12), ranging from 0.4 µg/kg to 555 µg/ kg (median: 77.5 µg/kg) which was higher than our results (Thieu et al, 2008). Overall, µg/kg levels for mean, median and range were relatively low compared with the previous studies (Thieu et al, 2008;Trung et al, 2008;Wang et al, 1995). It might be possible that improved techniques or facilities for storing maize have played a role in mitigating aflatoxins over time or it might be related to timing of sampling depending on the areas.…”

“…However, our study showed a relatively low positive rate and low µg/kg levels were detected for feed in Hanoi. Another study from southern Vietnam showed that positive rate for AFB 1 in maize was 91.7% (11/12), ranging from 0.4 µg/kg to 555 µg/ kg (median: 77.5 µg/kg) which was higher than our results (Thieu et al, 2008). Overall, µg/kg levels for mean, median and range were relatively low compared with the previous studies (Thieu et al, 2008;Trung et al, 2008;Wang et al, 1995).…”

“…Another study in North Vietnam found that 14 out of 15 samples were positive for AFB 1 , ranging between 9.4 and 96 µg/kg (Wang et al, 1995). In Southern Vietnam, a study showed that the positive rate for AFB 1 was 91.7% (11/12) in maize for growing pigs and sows, with a mean concentration of 77.5 µg/kg (Thieu et al, 2008). However, those studies may not have had large enough sample sizes to properly evaluate the level of AFB 1 .…”

“…In particular, aflatoxin B 1 (AFB 1 ) is commonly detected in a wide range of food commodities (Goto et al, 1996;Klich et al, 2000). Maize and peanuts are at high risk for aflatoxin contamination (Bennett and Klich, 2003;Roebuck and Maxuitenko, 1993;Rustom, 1997;Thieu et al, 2008). Aflatoxins have been associated with both carcinogenic and hepatotoxic effects, depending on the level and duration of exposure (Lewis et al, 2005).…”

The role of mycotoxins in pig reproduction: a review

“…Aflatoxins are mainly produced by Aspergillus flavus and Aspergillus parasiticus and are present in many frequently used feedstuffs (Thieu et al, 2008). Four aflatoxins are described, according to their fluorescence at chromatography: blue (B1, B2) or green (G1, G2).…”