Enhancing Fermentation and Nutritional Quality of Total Mixed Ration Silages: The Impact of Forage‐to‐Concentrate Ratio and Microbial Inoculant Inclusion

This study aimed to determine the ideal roughage‐to‐concentrate ratio in total mixed ration (TMR) silage, with and without microbial inoculant addition, by evaluating fermentation characteristics, microbial populations, aerobic stability, nutritional composition, and dry matter (DM) loss. Sixty experimental silos (PVC, 150 mm internal diameter × 30 cm height; ≈5.3 L capacity) were used, with a packing density of 600 kg m −3 of fresh forage in a completely randomized design with a 2 × 3 factorial arrangement. Treatments consisted of two levels of bacterial (0 and 8g/ton) inoculants ( Lentilactobacillus plantarum : 4 × 10 10 CFU/g + Pediococcus acidilactici : 4 × 10 10 CFU/g) and three roughage‐to‐concentrate ratios (60:40, 50:50, and 40:60). The silos were opened after 60 days of storage. The roughage‐to‐concentrate ratio significantly affected effluent, gas, and total losses, as well as DM recovery. The addition of bacterial inoculants did not compromise aerobic stability during the evaluation period and resulted in lower pH values throughout the oxygen exposure phase compared to untreated silages. Silages treated with bacterial inoculants exhibited lower DM (604.00 vs. 538.21 g/kg), while presenting higher crude protein (CP) (158.04 vs. 182.51 g/kg). Additionally, inoculated silages showed reduced ammonia nitrogen concentrations (2.44 vs. 2.09% of total nitrogen) and increased concentrations of ethanol (0.086 vs. 0.113 g/kg DM), acetate (1.927 vs. 2.837 g/kg DM), propionate (0.021 vs. 0.037 g/kg DM), butyrate (0.030 vs. 0.045 g/kg DM), lactate (0.463 vs. 0.626 g/kg DM), and total volatile fatty acids (2.137 vs. 3.159 g/kg DM). The addition of bacterial inoculants increased anaerobic and aerobic bacterial counts while reducing fungal and mold populations. It was concluded that the 50:50 roughage‐to‐concentrate ratio, when combined with the use of a microbial inoculant, was optimal for the production of TMR silage.