Grain storage plays a critical role in poultry feed production, and improper practices can lead to mold growth and mycotoxin production. In this article, we explore the challenges associated with grain storage, the impact on mycotoxin contamination, and essential measures to ensure the quality of grains for poultry feed.
Before delving into this discussion, it is important to highlight an upcoming funding opportunity: the Efficient Grain Handling Program, set to launch in April 2024 by the Alberta government. Designed to aid primary producers, this program aims to minimize energy consumption on farms. It provides financial support for the acquisition of grain handling system components that offer substantial improvements in energy efficiency compared to conventional methods. For more details on eligibility criteria and the application process, visit the Government of Alberta website.
Mycotoxin concerns
The storage of grain plays a pivotal role in preventing mycotoxin contamination, a serious threat to poultry health. Mycotoxins can develop in grains stored in dirty silos or bins exposed to the elements. The combination of heat-conducting metal silo walls, condensation, and mold contamination creates an environment favorable to mycotoxin production. This concern is particularly relevant for young animals where feed tends to be stored for longer durations. To mitigate this risk, it is essential to maintain clean storage bins as part of a comprehensive system for mycotoxin exposure management. However, cleanliness alone is not sufficient; proper post-harvest steps and continuous monitoring are crucial components of effective grain storage. Read more about mycotoxins in our previous article.
Basic principles of grain storage: minimizing losses and ensuring quality
- Harvesting and storage challenges
Harvesting at physiological maturation restricts mechanical threshing (separation of grain from stalks and husks), leading to a critical period where grains are exposed to adverse weather conditions and pest attacks. Timely harvesting, aligned with suitable moisture content for mechanical processing, is essential to prevent quality alterations during this vulnerable phase.
- Postharvest assessment and quality maintenance
Upon entering storage units, grains may vary in moisture levels and cleanliness. Differentiating between dry and dirty, dry and clean, or moist and dirty grains is crucial for implementing appropriate postharvest steps. A thorough evaluation at reception, including correct sampling, homogenization, and assessment procedures, ensures accurate decision-making within storage units.
- Pre-cleaning, cleaning, and drying
Pre-cleaning and cleaning steps are essential in removing foreign matter and impurities, ensuring standardized grain masses. Cleaning, using air machines and sieves, is especially critical to minimize the risk of fire during drying. Drying, the process of removing moisture, is fundamental for long-term storage, reducing the likelihood of insect and microorganism development.
- Loading techniques for silos and warehouses
Efficient loading practices contribute to uniform grain masses. Avoiding the accumulation of foreign matter, impurities, and broken grains within silos is essential for effective aeration. Loading recommendations involve staged processes to maintain uniformity, with careful attention to maintaining proper distances between the grain mass and silo cover to facilitate gas exchange. The use of exhaust fans further aids in preventing condensation and supporting optimal gas exchange.
Aeration: The key to temperature and quality control
Grains, despite their inherent morphological resilience, face numerous threats from insects, mites, microorganisms, rodents, birds, and other factors. Mechanical damage, biochemical alterations, and exposure to nonenzymatic chemicals such as pesticides, herbicides, and mycotoxins contribute to quantitative and qualitative losses even before entering storage. This jeopardizes their suitability for consumption and industrialization unless effective conservation techniques are implemented. Aeration, defined as the regulated ventilation of grains, aims to reduce and maintain uniform temperature within the stored grain mass. This practice is essential to limit metabolic activities and associated organism development. Optimal control of air movement and pressure is achieved by employing fans with the right capacity and power (correctly sized fans) under suitable aeration conditions, including temperature and moisture control as well as uniform airflow. This prevents the creation of unwanted air currents and stops any negative effects on the quality of grain. Contact your grain silo provider for more information about the right fan for your silo. Inadequate aeration, especially during temperature fluctuations, can lead to heating, high humidity, and accelerated respiratory processes, posing risks to grain quality. Other helpful techniques, like using wind-powered exhaust systems, moving grain between containers, and moving grain within a container, provide more ways to ventilate grain. When these methods are used carefully during loading and storage, they help get rid of damaged grains, foreign objects, and impurities. This improves the efficiency of ventilation and overall preservation of the grain.
Changes in grain quality due to storage
Understanding the impact of storage on grain quality is crucial for poultry producers aiming to maintain optimal nutrition in poultry feed. Several key aspects, including physiological and biochemical properties, chemical composition, digestibility of starch, bioactive properties, and technological attributes of grain silos, are influenced by storage conditions.
1. Changes in chemical composition and starch digestibility
Chemical composition alterations during storage impact grains and associated microorganisms. Studies reveal that high grain moisture, prolonged storage time, and elevated temperatures negatively affect the quality of grains like wheat, maize, canola, soy, and rye. Storage conditions influence protein and lipid content in soybeans, with temperature and humidity playing crucial roles. Grains with lower fat content, like rice, beans, and maize, exhibit better stability during storage compared to high-fat content grains, such as soy and oats. Maintaining optimal storage conditions is particularly critical for preserving the value-added components like proteins and lipids in grains like soybeans.
2. Bioactive properties
While the relationship between storage and bioactive compounds, specifically phenolic compounds, is not fully established, interactions between temperature, humidity, and microorganisms may stimulate the synthesis of phenolic compounds during storage. Research indicates a reduction in total phenolics and caffeic acid in oat grains after 24 months of storage at 25 °C. These phenolic compounds are considered natural feed additives and may have a role in the antioxidant, immunity, antimicrobial, and overall production performance of poultry and swine.
3. Technological properties
Cooling the grain mass during storage proves effective in preserving grain quality by reducing water activity, respiration rates, and deterring the development of insects and microflora. Temperature influences physicochemical properties such as increased lipid acidity, changes in color and hardness. Maintaining recommended moisture levels, drying processes, and careful monitoring are essential to prevent fungal development and ensure the longevity of grains in storage.
Conclusion: prioritizing grain quality for optimal poultry nutrition
In conclusion, effective grain storage systems are essential in maintaining high-quality feed for poultry. By implementing proper management practices, minimizing storage time, adopting suitable aeration techniques to control temperature and moisture, and creating uniform airflow, you can ensure the nutritional integrity and safety of your poultry feed. By taking care of your flock’s health and well-being, these actions significantly contribute to the overall success of your poultry farming efforts.
References
Elizabeth Hines and Gino Lorenzoni. 2023. Mycotoxins and their effect on poultry and swine production. PennState Extension. (link)
Shad Mahfuz, Qinghui Shang, and Xiangshu Piao. 2021. Phenolic compounds as natural feed additives in poultry and swine diets: a review. Journal of Anim Science and Biotechnology. 12(1):48 (link)
Valmor Ziegler, Ricardo Tadeu Paraginski, Cristiano Dietrich Ferreira. 2021. Grain storage systems and effects of moisture, temperature and time on grain quality – A review. Journal of Stored Products Research. 91: 101770. (link)
