Carry-Over of Aflatoxin B1 from Feed to Cow Milk—A Review

Abstract

The conversion of aflatoxin B1 in feed consumed by cows into aflatoxin M1 in their milk poses a challenge to food safety, with milk being a popular staple food and because of the harmful effects of these compounds. This study aimed at reviewing scientific information about the extent of carry-over of AFB1 from feed to milk. A range of studies reported about correlations of carry-over with different factors, particularly with milk yield and AFB1 intake. The extent of carry-over considerably varies, being 1–2% on average, which may be as high as 6% in the case of increased milk production. Specific factors influencing transfer rates, including milk yield, somatic cell counts, aflatoxin B1 intake, source of contamination, seasonal effects, particle size of feed, and the effects of certain interventions, namely vaccination and the use of adsorbents, are identified as the most important and are discussed in this review. The different mathematical formulas describing carry-over and instances of their application are reviewed as well. These carry-over equations may lead to largely different results, and no single carry-over equation can be suggested as the best one. While the exact quantification of carry-over is difficult as the process depends on many factors, including individual variabilities between animals, the intake of aflatoxin B1 and milk yield seem to be the most important factors influencing the excreted amount of aflatoxin M1 and the rate of carry-over.

Mycotoxin Occurrence in Milk and Durum Wheat Samples from Tunisia Using Dispersive Liquid–Liquid Microextraction and Liquid Chromatography with Fluorescence Detection

“…Thus, the presence of AFM1 in milk is determined by the concentrations of AFB1 absorbed by the animal. It is estimated that approximately 5% of digested AFB1 is converted into AFM1 in the liver and excreted in the milk of dairy animals [52]. As stated before, AFM1 was not detected in any of the analyzed samples.…”

“…In our findings, although mycotoxins were present in low concentrations in the analyzed samples, the co-occurrence of both nephrotoxic OTA and genotoxic-carcinogenic AFG2 may contribute to synergic effects, thus increasing the health risk caused by these toxins when consumed by animals and/or humans [52]. For these reasons, it may be necessary to confirm the potential effects of their synergistic activity, revise the regulation of their limits in cereals, or establish legislative values for unregulated mycotoxins.…”

Aflatoxins in food: Prevalence, health effects, and emerging trends in its mitigation—An updated review

“…The different forms of AFs can undergo inter‐conversion as shown in Figure 1. The conversion of AFB 1 into AFM 1 is influenced by a number of variables, including the animal's breed, food, health, age, rumen degradation potential, rate of digestion, immunological profile, and stage of lactation (Duarte et al., 2013; Zentai et al., 2023). There have also been reports of the production of other forms of AFs, including GM 1 , GM 2 , GM 2 A, and B 3 , (Ashiq, 2015).…”

A Novel Multicellular Placental Barrier Model to Investigate the Effect of Maternal Aflatoxin B1 Exposure on Fetal-Side Neural Stem Cells

“…Global climate change is increasing the frequency of such conditions, including, for example, in countries such as China, the U.S. and Europe. Additionally, aflatoxins on moldy feed consumed by farm animals can be transferred to their tissues and consumed by humans, especially in milk [ 52 ]. Because China is a severely AFB 1 -contaminated country, studying the effects of maternal intake of AFB 1 on fetal development is essential.…”