Nutritive Value of Silage from Two Genotypes of Sugarcane Associated with Calcium Oxide and Sodium Hydroxide as Chemical Additives

Brazil is the world’s largest producer of sugarcane, and its processing residues have potential as feed for ruminants; however, treatments are required to improve their digestibility. This study evaluated the chemical composition, carbohydrate fractionation, and ruminal degradability of sugarcane silages from two genotypes treated with alkaline additives—calcium oxide (CaO) and sodium hydroxide (NaOH). A 2 × 4 factorial design was used, comprising two genotypes and four treatments (no additives, 1% CaO, 1% NaOH, and 0.5% CaO + 0.5% NaOH). A significant interaction (p < 0.05) between genotype and additive was observed for dry matter, ether extract, fiber components, lignin, cellulose, non-fiber carbohydrates, total digestible nutrients, and phosphorus. The IAC-862480 genotype without additives exhibited higher values for most variables compared with CTC-3. Interactions were also detected for total carbohydrates and fractions A + B1 and C, except in silages treated with 1% CaO or the combined 0.5% CaO + 0.5% NaOH, where genotypes did not differ. Overall, alkaline additives improved the nutritional quality of sugarcane silages. Treatments with 1% CaO or 0.5% CaO + 0.5% NaOH were the most effective in hydrolyzing structural carbohydrates and enhancing dry matter and neutral detergent fiber degradability, especially in the CTC-3 genotype.