Evaluation of inoculants addition on corn silage nutritional value

Utilization of chemical or biological additives to optimize ensiling process is focused into an improvement of the nutritional fractions of forages. In this fashion, Silo-King® would act in stabilizing pH, reducing silage temperature and dry matter loss, improving organic matter digestibility, and, overall, an increased nutrient availability. Harvested corn was treated according to the experimental protocol: the first portion was treated with 10 mg/kg solution of inoculant (T2), the second one with 6 mg/kg solution (T1), while the third one with de-ionized water at 10 mg/kg (C). From every treatment, 42 samples (0.9 to 1.0 kg weight) were randomly collected, pressed in mini-silos and sealed. At 0, 15, 30, 60, 90, 120, 180 and 240 days of ensiling, replicates per each treatment were opened and analyzed for dry matter, ashes, aNDFom, ADF, ADL, NDIP, ADIP, SolP, ammonia, starch digestibility at 7h, sugars and in vitro aNDFom digestibility at 24, 48 and 240 hours. All data were analyzed with statistical software via factorial ANOVA. Dry matter and ash content were not different among treatments. Averaged values of CP were statistically different for T2 vs. T1 and C, (9.27, 8.89, 8.92% respectively P≤0.05), while no differences were found for ADIP and NDIP. Ammonia was higher in control samples, with significance at 120, 180 and 240 days (0.68, 0.9 and 1.58% for T2, T1 and C respectively at 240d. P≤0.05). Results about fibrous fractions suggest no impact of the treatment. Values of aNDFom were similar among different thesis (~37-40, % on DM basis), and in line with the expected. No differences were observed for ADF or ADL. in vitro NDF digestibility at 24 and 48 hours, showed higher values for T2 and T1 compared to C (P≤0.05). After 180 days of ensiling, observed values were 36.9, 38.9 and 31.9 % at 24h, 53.9, 50.6 and 42.9% at 48h, for T2, T1 and C, respectively. Sugar content decreased as the ensiling process, while starch digestibility resulted differently among treatment, being higher for treated samples compared to control after different ensiling points (82.7, 65.2 and 57.1% at 180d for T2, T1 and C. P≤0.05). Present study demonstrates that inoculants led to higher amount of soluble protein preserved, resulting in less ammonia formation, and to an increased fiber and starch digestibility. From a nutritional point of view, Silo-King® improved energetic yield of the treated substrate, for both nitrogen source and carbohydrates.