Mycotoxins are one of the most underestimated dangers to livestock production systems. Mycotoxin contamination of grains and roughages destined for animal feed is a global occurrence, with the profile and extent of contamination being influenced by factors such as climate, weather conditions, crop cultivars, agricultural practices, and post-harvest handling and storage of crops. More than 25% of harvested cereals are contaminated by different types of mycotoxins. South African climate and farming practices increase the risk for the development of deoxynivalenol (DON), fumonisins (FUM), and zearalenone (ZEA) amongst others in commonly used feed raw materials. A focus on mycotoxin risk management involves both monitoring and controlling of mycotoxins. It is not only important to monitor raw materials frequently but also to respond to the contamination levels with an effective solution. Mycotoxins vary in size, shape, and other properties, therefore, the key to combatting mycotoxins in feed is to use a wide-spectrum solution capable of effectively targeting a range of mycotoxins.

A single mycotoxin can be produced by various moulds, or the same mould can produce different mycotoxins. South African weather and farming conditions typically lead to the presence of more than one mycotoxin in the same raw material, known as polycontamination. In the case of polycontamination, the two toxins can either have an additive effect or even an effect worse than the mycotoxins on their own. Polycontamination can thus lead to a higher risk, even if both toxins are present at levels lower than the recommended safe levels. One such example is the polycontamination of DON and FUM. DON inhibits protein synthesis, leading to shorter villi in the gut. FUM inhibits lipid synthesis, leading to a decrease in cell proliferation and less renewal of villi. The result of the polycontamination with DON and FUM leads to:

• Reduced nutrient absorption
• Damage to the gut barrier
• Impairment of immune functions
• Sub-clinical mycotoxicosis
• Less productive animals  

Sub-clinical mycotoxicosis is believed to be one of the biggest underestimated thieves when it comes to animal productivity and nutrient utilisation. In a metadata analysis of 18 Ross 308-day-old chick trials done by Kolawole et al (2020), it was found that even at sub-clinical levels below the maximum allowable levels of the European Union, there was a strong correlation with increased levels of polycontamination and poor performance measured as feed conversion ratio:

Effect of mycotoxin levels below EU guidelines

• 18 trials performed with 2200 day-old Ross 308
• All feed below guidelines: feed batches more or less contaminated

Mean concentrations of mycotoxin in broiler feed samples of the 18 successive performance trials.

Feed conversion ratio (FCR) of broiler chickens fed naturally contaminated diets of the 18 successive performance trials

(Source: Toxins 2020, 12, 433; doi:10.3390/toxins12070433)

Synergistic effect of deoxynivalenol and fumonisins on the gut

Mycotoxicosis in poultry

Chickens are considered to be less sensitive to mycotoxins as they absorbed 3 to 10 times less mycotoxins than pigs. Nevertheless, this implies that the lumen of the gastrointestinal tract (GIT) may be exposed to high concentrations of toxins.80-90% of the mycotoxin absorption occurs in the upper part of the GIT.

Effects and symptoms of mycotoxicosis in poultry

Feed contaminated with mycotoxins can cause various health-related problems in animals. It can lead to clinical symptoms and in rare cases, even death. More commonly the effects are less specific and can be associated with reduced performance and an increased disease susceptibility. Mycotoxins typically exert their effects in the following ways:

• Immune system: reduced lymphocyte activity, suppression of antibody production and reduction of macrophage function.
• Gut barrier: damage to villi, damage to tight junctions (leading to leaky gut), damage to goblet cells (reduced mucous production and exposure of gut to further damage), impairment of nutrient absorption (mainly Vitamin A, Riboflavin, Thiamine and Vitamin D).
• Liver and kidneys: several adverse conditions can result because they play a critical role in metabolism including:
  • Pale and enlarged livers
  • Swollen kidneys
• Other symptoms include:
  • Oral lesions
  • Reduced growth performance
  • Lowered egg production
  • Increase in embryo mortality – reduced hatchability

The signs can vary depending on the amount of mycotoxin ingested, the combination of toxins in the feed, the period of exposure and the interaction of various mycotoxins.

Solutions

Mycotoxin risk can only be limited to a certain extent in feeds but, it is unavoidable. At Vitam International we believe in taking a proactive approach to managing mycotoxin risk. In partnership with Olmix Animal Care we have developed a comprehensive mycotoxin risk control program focussed on evaluating the mycotoxin risk and offering expert advice and technical support both at farm and feed mill level.

MMi.S is a broad-spectrum mycotoxin binder – the only mycotoxin binder in its class capable of binding most mycotoxins, including DON, FUM, and ZEA, proven at gut level. The unique technology allows for efficient and irreversible binding of mycotoxins, irrespective of their size, shape, and other physiochemical properties, to reduce the potential contact with both the gut wall and target organs. Its innovative micro granulated form facilitates mixing into feed, ensuring effective intake and is easy to use on-farm.

Read the peer-reviewed article here: link