Introduction
The global food crisis is a complex problem that has intensified in recent years, driven primarily by climate change and armed conflicts. These factors have led to a substantial rise in the cost of raw materials. Consequently, cereal by-products have emerged as a practical alternative for use in animal nutrition.
Climate change has altered environmental conditions across many regions of the world, and its consequences, particularly global warming, are already becoming evident. In crop and cereal production, prolonged droughts and severe flooding have caused substantial economic losses. Moreover, changes in natural ecosystems have favoured the proliferation of mycotoxigenic fungi which, owing to their adaptability, tend to dominate crop environments (Medina et al., 2017).
According to the European Food Safety Authority (EFSA), the potential impact of climate change in Europe will vary regionally and may be either adverse or beneficial, depending on geographical location. The Mediterranean region is expected to experience rising temperatures, extreme shifts in precipitation patterns, flooding, and higher concentrations of CO2, all of which will affect the production of food and feed (Medina et al., 2017).
With respect to armed conflicts—particularly the war between Russia and Ukraine—hostilities began at a critical moment for global food markets, already characterised by rising prices driven by high global demand and supply-chain disruptions following the COVID-19 pandemic. Both Ukraine and Russia play a crucial role in the fertiliser market and collectively account for 70% of global sunflower seed trade, 30% of wheat, and 20% of maize. Many countries in Africa, Asia, and the Middle East rely on Russia for affordable staple commodities. Consequently, the war has had a negative impact on global energy markets and food security, causing fuel costs and food prices to soar. This situation poses a significant threat to global food markets and presents major challenges for businesses in the post-pandemic context (Galanakis, 2023).
Apart from climate change and armed conflicts, an additional challenge for food production is the competition between food and feed uses. It is estimated that more than one billion tonnes of cereals are allocated to animal feed, and that the demand for products of animal origin could increase by up to 70% by 2050 (Galanakis, 2023). In this context and given the many dilemmas surrounding food security and the current global situation, cereal by-products have been proposed as a viable alternative for animal nutrition.
The use of cereal by-products as an alternative in animal nutrition
Livestock production in Europe relies on nearly 475 million tonnes of feed each year to meet animals’ nutritional requirements. As a result, producers are looking for alternatives to help alleviate the increasing demand for feed ingredients. In this context, the food industry has directed its efforts towards converting cereal by-products into feed materials.
At present, around 20 million tonnes of cereal by-products are consumed annually, representing approximately 11.5% of the ingredients used in feed formulation.
Among these by-products, those derived from bioethanol production are particularly noteworthy, especially distillers’ dried grains with solubles (DDGS), which represent a high-value feed source. DDGS can also replace more costly protein ingredients, providing a cost-effective alternative for the industry (Pinotti et al., 2016).
Other relevant by-products originate from the brewing industry. Among the most common are barley rootlets, brewers’ spent grains, and surplus yeast. Barley rootlets and spent grains are valuable components in feed production due to their high protein and fibre content, as well as their relatively low cost (Pinotti et al., 2016).
Presence of mycotoxins in cereal by-products
The inclusion of by-products in feed also represents a sustainable approach within the food-processing chain, as it offers a solution for the utilisation of co-products and by-products generated during food and biofuel production, thereby contributing to waste reduction. However, the main barriers to the wider adoption of cereal by-products as feed ingredients include their high variability in nutrient composition and, above all, the persistent challenge posed by mycotoxin contamination (Pinotti et al., 2016).
Cereal by-products are an important source of mycotoxin exposure, with widespread contamination reported over the years. These toxins have a severe impact on livestock health and productivity and are therefore linked to substantial economic losses, particularly due to the additive and synergistic effects that can occur in co-contamination settings.
The mycotoxin load in distillers’ dried grains depends on the initial contamination of the grain, the processing methods, storage conditions, the fermentation process, yeast characteristics, and the year of production. It is important to note that during ethanol fermentation or the production of distillers’ dried grains, mycotoxins are not destroyed (Pinotti et al., 2016). In this context, fumonisin contamination in distillers’ dried grains has been confirmed in the United States, with the resulting economic impact on pig production estimated at more than USD 147 million per year.
Regarding barley grains and malt production, these can also be heavily affected by fungal contamination, mainly by species of the genus Fusarium, which negatively impact both the safety and quality of malt and beer (Pinotti et al., 2016). Exposure to mycotoxins in by-products derived from the brewing industry is largely attributable to the characteristics of the raw materials used and to inadequate handling during storage (Pinotti et al., 2016).
Mycotoxin contamination is a global risk that compromises the sanitary and economic status of the agricultural sector in all countries, without exception. The substantial losses generated by these contaminants are associated with reductions in crop yields, the disposal of contaminated feed and food, reduced productive performance, and increased health-related costs (Rodríguez et al., 2012).
With current agronomic practices, the ability to predict the presence or prevent the occurrence of mycotoxins during pre-harvest, storage, and food processing remains uncertain. It is estimated that between 30% and 100% of feed samples are co-contaminated with different types of mycotoxins (Rodríguez et al., 2012). In many cases, entire batches of grains such as maize, wheat, rye, barley, and oats must be destroyed, leading to economic losses ranging from hundreds of millions to several billion dollars annually (Mavrommatis et al., 2021).
Conclusion
Cereal by-products provide a sustainable and cost-effective alternative in animal nutrition amid the global food crisis. However, contamination of these by-products with mycotoxins poses a significant risk to animal health and can result in substantial economic losses. Therefore, it is crucial to implement effective control measures to ensure their safe and economically viable use.
