The Effect of Microbial Inoculum and Urea Supplements on Nutritive Value, Amino Acids Profile, Aerobic Stability and Digestibility of Wheat and Corn Silages

SIMPLE SUMMARY: Wheat and corn silages are common feedstuffs used in Israel. For long-term use of the feedstuffs without compromising the nutritional value, there is a need for an effective preservation method. We conducted a study to assess the effect of adding microbial inoculum (MI) and urea on the chemical composition including the amino acids profile, aerobic stability and in vitro digestibility of wheat and corn silages. The silages were subjected to four treatments: control, MI, urea and a combination of MI + urea. Silages were analyzed for quality parameters and in vitro digestibility. The results showed that additives improved the quality parameters of wheat and corn silages. The inclusion of MI produced the most aerobically stable silages, whereas the inclusion of urea compromised its aerobic stability. None of the additives affected the true CP content of silages. Additives improved in vitro cell wall carbohydrates’ digestibility in both silages and had the best production when MI was combined with urea. These results imply that additives enhance the nutritional value, aerobic stability and digestibility of silages. ABSTRACT: Wheat and corn silages are widely used as ruminant feed in Israel due to their availability and cost-effectiveness. To ensure long-term preservation without compromising nutritional quality, effective methods must be employed. The inclusion of additives during harvest and ensiling can enhance efficiency and address preservation challenges. In the current study, the effects of microbial inoculum (MI) and urea on the chemical composition, amino acid profiles, aerobic stability, and in vitro digestibility of wheat and corn silages were investigated. Samples of wheat and corn were subjected to four treatments: control, MI, urea and a combination of MI + urea. The treatments were ensiled in anaerobic conditions and opened after 1, 7, 14 or 28 days. The results showed that additives improved the quality parameters of wheat and corn silages. The inclusion of MI produced the most aerobically stable silages. The inclusion of urea in silages decreased aerobic stability. Additives improved in vitro cell wall carbohydrates’ digestibility in both silages and was the best when MI was combined with urea. These results imply that additives could be incorporated in silages to enhance their nutritional value, aerobic stability and digestibility. Nonetheless, increased CP content with additives was not accompanied with a parallel increase in amino acids’ content in corn silage.