Increased humidity in broiler feed storage environments does accelerate the oxidative degradation of vitamins. This phenomenon is closely related to the chemical properties of the vitamins in the feed, microbial activity, and the hygroscopicity of the carrier. Vitamins in broiler feed are key nutrients for maintaining healthy animal growth, but their stability is susceptible to environmental factors, with humidity being the primary disruptor.
High humidity directly destroys the molecular structure of vitamins. Fat-soluble vitamins (such as vitamins A, D, and E) and water-soluble vitamins (such as vitamin C and B vitamins) in broiler feed contain unsaturated chemical bonds, which readily react with oxygen in humid conditions, leading to oxidative degradation. For example, the lattice structure of vitamin A is weakened in the presence of moisture, significantly increasing its permeability to oxygen and accelerating the oxidation process. Furthermore, water-soluble vitamins such as vitamin C are more susceptible to hydrolysis in high humidity, producing inactive metabolites and losing their nutritional value.
Increased humidity also indirectly accelerates vitamin degradation through microbial activity. High humidity creates favorable conditions for the growth of microorganisms such as mold and bacteria. These microorganisms secrete acids or enzymes during their metabolism, directly destroying vitamin molecules. For example, organic acids produced by mold can esterify with B vitamins, rendering them inactive. Furthermore, microbial growth consumes oxygen in the feed, creating localized hypoxic environments that promote anaerobic degradation of vitamins, further exacerbating nutrient loss.
The hygroscopicity of carrier materials in broiler feeds is also a significant factor in vitamin degradation. Ingredients commonly used in premixes, such as choline chloride and mineral carriers, are highly hygroscopic. When humidity exceeds 65%, these materials absorb moisture from the air, creating high-humidity zones within the microenvironment. Under these conditions, the rate of chemical reactions between vitamins and carriers increases significantly. For example, when vitamin E comes into contact with choline chloride, its antioxidant capacity decreases significantly due to moisture absorption, weakening its protective effect. Furthermore, moisture absorption by the carrier can cause feed to clump, hindering oxygen flow and creating localized anaerobic environments, accelerating anaerobic degradation of vitamins.
The synergistic effects of light and humidity further exacerbate vitamin destruction. In a humid environment, light (especially ultraviolet light) stimulates the production of free radicals. These highly active free radicals can attack unsaturated bonds in vitamin molecules, leading to a chain oxidation reaction. For example, vitamin A oxidizes faster under light and high humidity than under light or high humidity alone. This synergistic effect exponentially increases vitamin degradation.
To mitigate the damage caused by humidity to vitamins in broiler feed, storage conditions must be optimized. First, feed should be stored in a cool, dry place, avoiding exposure to the open air or direct contact with the ground to prevent condensation. Second, sealed packaging or the addition of desiccants can be used to reduce internal humidity. Furthermore, carriers and protective agents with low humidity sensitivity should be selected. For example, vitamin microparticles treated with cross-linking technology can form an airtight and watertight protective layer, effectively resisting corrosion in high humidity environments.
Broiler feed manufacturers also need to improve vitamin stability through process improvements. For example, adding antioxidants (such as BHA and BHT) during premix production can slow the oxidation and rancidity of fatty acids, thereby indirectly protecting the vitamins. At the same time, optimizing the pelleting process and reducing the exposure time to moisture and heat during production can also reduce the risk of vitamin degradation. Through these comprehensive measures, the shelf life of vitamins in broiler feed can be significantly extended, ensuring the healthy growth of broilers.
