Aflatoxins in Cattle Feed and Risk to Milk Safety

Jim Crocker
18th April, 2024

Aflatoxins in Cattle Feed and Risk to Milk Safety

Key Findings

  • In Dar es Salaam, Tanzania, 78% of cattle feed samples contained harmful aflatoxins above safe levels
  • Aflatoxin B1 in feed can transform into aflatoxin M1 in cow's milk, posing health risks to humans
  • Estimated transfer of aflatoxins from feed to milk ranged from 1.2% to 1.7%, exceeding international safety thresholds
Aflatoxins are toxic compounds produced by certain molds found in food and feedstuffs, and they pose a significant risk to both animal and human health. A recent study by researchers at Mbarara University of Science and Technology has shed light on the pervasive issue of aflatoxin contamination in cattle feed in Dar es Salaam, Tanzania, and the potential for these toxins to enter the human food chain through milk[1]. The study is particularly relevant given the widespread reliance on livestock for nutrition and economic stability in many parts of the world. The problem begins when livestock, such as dairy cows, consume feed contaminated with aflatoxins. These toxins can lead to a variety of health issues in animals, including liver damage and a decrease in productivity[2]. Moreover, aflatoxin B1 (AFB1), the most toxic of these substances, can be metabolized into aflatoxin M1 (AFM1) and excreted in the milk of these animals[3], which can then be consumed by humans. This is concerning because AFM1 is a known carcinogen and can have serious health implications, including liver cancer. The study conducted in Tanzania used advanced testing methods, including Enzyme-linked Immuno-sorbent Assay (ELISA) and High-Performance Liquid Chromatography with a Fluorescent Detector (HPLC-FLD), to detect the presence of aflatoxins in cattle feed. The findings were alarming, with 78% of the concentrate feed samples containing aflatoxins, and the mean total aflatoxins (TAFs) level was higher than the recommended limit set by the World Health Organization and the US Food and Drug Administration. Furthermore, the average level of AFB1 found in the feed significantly exceeded the international safety threshold, which suggests a high risk of this toxin carrying over into the milk produced by dairy cows fed with this contaminated feed. The study estimated that the carry-over rate of aflatoxins from feed to milk ranged from 1.2 to 1.7%, which, while it may seem small, is significant enough to raise health concerns for milk consumers. These findings from Tanzania echo the concerns raised by other studies on aflatoxin contamination in animal feed and its effects on both animal health and human food safety. For example, a study on the contamination levels of AFB1 in feed and AFM1 in milk in high-yielding dairy cows found that a considerable number of samples exceeded the European Union maximum levels for these toxins[3]. Similarly, a review of aflatoxin contamination in African staple foods highlighted the widespread nature of the problem, the economic impact, and the urgent need for effective mitigation measures[4]. The study from Mbarara University of Science and Technology adds to the body of evidence that aflatoxin contamination is not just an isolated problem but a widespread issue that requires immediate attention. It underscores the need for increased awareness and education among livestock feed chain participants, from producers to consumers, about the risks of aflatoxin contamination and the importance of monitoring and controlling these toxins in animal feed. Moreover, the study's findings could have implications for the poultry industry, as previous research has shown that the glucocorticoid receptor (GR) could play a role in fatty liver syndrome in chickens, mediated by changes in gene regulation related to fat metabolism[5]. While the current study does not directly address poultry, the broader implications for understanding how toxins in feed can affect animal health and food quality are clear. In conclusion, the research conducted by Mbarara University of Science and Technology not only adds to the growing evidence of the risks associated with aflatoxin contamination in animal feed but also highlights the potential health risks to humans through the consumption of contaminated animal products. It calls for concerted efforts to reduce aflatoxin levels in feed, which would benefit both animal welfare and public health.

HealthAnimal ScienceMycology


Main Study

1) Aflatoxins in cattle concentrate feed and potential carry-over of aflatoxin B1 into milk in Dar es Salaam, Tanzania

Published 16th April, 2024

Related Studies

2) Aflatoxins in Feed: Types, Metabolism, Health Consequences in Swine and Mitigation Strategies.

3) Field Monitoring of Aflatoxins in Feed and Milk of High-Yielding Dairy Cows under Two Feeding Systems.

4) The aflatoxin situation in Africa: Systematic literature review.

5) GR-mediated transcriptional regulation of m6A metabolic genes contributes to diet-induced fatty liver in hens.

Related Articles

An unhandled error has occurred. Reload 🗙