Influences of Corn Storage Conditions and Storage Time on Grain Quality, Mycotoxin Contamination, Feed Nutritional Properties and Broiler Nutrient Metabolism

The study evaluated the effects of corn grain deterioration under different storage conditions in processed feeds and broiler digestibility. The corn grains were stored in chambers (quality corn and contaminated corn) at different storage temperatures and relative humidity (10 °C and 90%, 30 °C and 40%), and the evaluations were carried out at five storage times (zero, three, six, nine, and twelve months). After feed formulation (zero, six, and twelve months of corn stored), the broilers (504 animals) were fed for up to 14 days. The excreta collection was done twice per day for metabolism analysis. The 10 °C and 90% RH conditions influenced the loss of dry matter; the physical quality of corn grain was lower for the 30 °C and 90% RH conditions. When we obtained lower dry matter losses, the microbiological and mycotoxin levels were directly influenced by the loss of dry matter in corn. The storage time increased the risk of fungi (8.5 × 107 CFU g−1), bacteria (7.5 × 106 CFU g−1), and aflatoxins (64.96 µg kg−1), reaching levels above acceptable limits for the corn quality and interfering with digestibility and animal metabolism. In addition, the storage time was the determining factor in the nutritional loss of corn quality, feed, and animal digestibility. Furthermore, the storage time reduced the levels of crude protein (5%), gross energy in the feed (3200 kcal kg−1), metabolizable energy (3000 kcal kg−1), and animal digestibility (3100 kcal kg−1) after six months of storage. Based on the results of this study, the feed processing industry should pay close attention to the origin of stored corn and the associated environmental conditions, as these factors led to significant changes in grain quality, directly impacting animal nutrition and production. Therefore, it is recommended that the production chain invest more in the sector—specifically in adequate infrastructure and grain storage monitoring and control systems—to provide higher-quality raw materials to the processing industry.