Mycotoxins pose risks to ruminant health due to their varied diet. Identifying issues is challenging, given nonspecific symptoms and the multitude of factors that can potentially be involved. While rumen microbiota can metabolize some mycotoxins, others persist, like Aflatoxin M1. Mitigation requires a multifaceted approach involving agricultural practices and antibiotoxin solutions in feed for effective control.
Product Manager
MiXscience, Avril Group
Mycotoxins pose a significant threat to ruminant health and productivity. Their complex diet, comprising concentrates, forages, and silages, increases and diversifies the risk of mycotoxin exposure compared to monogastrics. Aflatoxins, fumonisins, ochratoxins, zearalenone, trichothecenes, ergot alkaloids, and patulin are the primary mycotoxins of concern in ruminants. Yet, identifying a mycotoxin issue (often termed ‘mycotoxicosis’) in ruminants is challenging, given that exposure to some mycotoxins manifests nonspecific symptoms. The consequences are typically chronic, with hidden disorders such as decreased ingestion, productivity, and fertility.
Although more and more studies are being performed, it is still difficult to uniformly assess the effects of mycotoxins on dairy cows. This is due to the many factors that must be considered such as the type and level of mycotoxins ingested, the duration of the intoxication, the presence of masked mycotoxins, the diet, the animal, the environment and the additives, all influencing the magnitude of the effect on cow health.
THE SPECIFIC CASE OF RUMINANTS
In the realm of ruminants confronting mycotoxins, the dynamics present a unique scenario. Traditionally, mycotoxin impacts have been predominantly scrutinized in monogastric animals. Ruminants, however, are perceived as more resilient to the detrimental effects of mycotoxin exposure due to the transformative abilities of their rumen microbiota, which can convert certain mycotoxins into less harmful metabolites or even inert substances. Yet, recent research has illuminated that only select mycotoxins undergo metabolism, and in some instances, this process is only partial.
Take aflatoxin, for instance. It undergoes conversion into aflatoxicol, a less toxic form compared to AFB1. Nevertheless, a portion of aflatoxin persists and is absorbed by the digestive tract, ultimately metabolizing into Aflatoxin M1 (AFM1) in the liver. While ruminants exhibit considerable resistance to aflatoxicosis, the transmission of AFM1 into milk warrants close monitoring due to its potential health risks, particularly for children with heightened milk consumption.
Conversely, some mycotoxins are converted into more potent metabolites. Zearalenone, for example, transforms into α-zearalenol, a compound exhibiting three to four times greater oestrogenic activity. This metabolite’s structural similarity to oestradiol enables it to bind to specific cell receptors, potentially leading to various reproductive complications. However, disruptions in rumen function, often attributable to high dry matter intake in cows, can impede the detoxification process by rumen microbes.
Moreover, certain mycotoxins, like patulin, possess antimicrobial or anti-protozoal properties, further hindering rumen microflora’s ability to neutralize mycotoxins, consequently facilitating their absorption into the organism.
MITIGATING RISKS
Addressing mycotoxin contamination in ruminant feed necessitates a multifaceted approach, given the pervasive nature of multi-contamination. No single method ensures foolproof mycotoxin control. Therefore, implementing a robust risk management program becomes imperative, encompassing optimal agricultural practices in cultivation (such as high-quality seed selection, crop rotation, and effective management of crop residues), during harvest (adhering to proper harvesting procedures, removal of high-moisture plant parts), and in storage (regulating moisture levels, employing humidity control measures, and incorporating chemical preservatives). Notably, as many mycotoxins maintain stability throughout storage and processing, proactive measures are essential.
Furthermore, integrating well-selected antibiotoxin solutions directly into feed presents a promising strategy to mitigate mycotoxin risks. These solutions protect the animals by providing different mode of action: adsorption of the consumed mycotoxins in the gastrointestinal tract, biodegradation, and bioprotection. This biological approach is promising because it is environmentally friendly and cost-efficient.
PROMISING RESULTS
A recent trial carried out on a commercial farm in 2021 in France showed positive results on the action of such in-feed solution. This study involved 70 lactating Holstein dairy cows fed a diet supplemented with Multiprotect Y, an anti-biotoxin solution, for 60 days.
Analysis of mycotoxin contamination in the Total Mixed Ration (TMR) revealed low but multiple mycotoxin contamination (with DON, FUM, ZEA, H-T2 toxin and tenuazonic acid) throughout the study period . Supplementation with Multiprotect Y led to improvements in inflammatory status and liver functions in dairy cows. Furthermore, supplementation with Multiprotect Y resulted in increased excretion of tenuazonic acid, indicating improved liver function. Finally, a calculated gain of 0.8 kg milk per cow per day was observed with the supplemented diet, considering milk production persistency at 93.7%.
The findings of this study demonstrate the beneficial effects of supplementing dairy cow diets with Multiprotect Y in improving immunity, sanitary status, and zootechnical performance. The results underscore the importance of monitoring biomarkers for evaluating mycotoxin exposure and understanding its effects on dairy cow health and productivity.
About Anne-Laure Tournay
Graduated with an Agricultural Engineering Master’s degree, Anne-Laure Tournay has a solid experience in marketing acquired within various international agricultural companies. She joined MiXscience in September 2019 as In Feed Solution Product Manager. She is in charge of the development and marketing of two solutions portfolios: the Rabbit range, and the Multiprotect range dedicated to issues related to biotoxins.
