Fermentation quality, aerobic stability and in vitro gas production kinetics and digestibility in total mixed ration silage treated with lactic acid bacteria inoculants and antimicrobial additives

The objective was to evaluate the effectiveness of lactic acid bacteria (LAB) inoculants and chemical additives on the fermentation quality, aerobic stability and in vitro gas production kinetics and digestibility of total mixed ration (TMR) silage. Total mixed ration (568 g/kg dry matter (DM)) was ensiled with six experimental treatments: (1) no additives (control); (2) Lactobacillus buchneri (LB; applied at 1 x 10(6) cfu/g fresh weight (FW)); (3) Lactobacillus casei (LC; applied at 1 x 10(6) cfu/g FW); (4) calcium propionate (CAP; applied at 0.5% FW); (5) sodium diacetate (SD; applied at 0.5% FW); (6) potassium sorbate (PS; applied at 0.1% FW). All silos (18 L) were opened for fermentation quality, in vitro gas production kinetics and digestibility analysis after 90 days of ensiling, and then subjected to aerobic stability test for 14 days. All the TMR silage was well-preserved with low pH (4.36 similar to 4.66) and acceptable levels of butyric acid (1.02 similar to 2.51 g/kg DM) and ammonia nitrogen (86.3 similar to 107 g/kg total nitrogen). All the groups were steady during 14 days of aerobic exposure, while SD group was more stable with lower (p < 0.05) yeast (4.60 vs. 5.17 similar to 5.77 log(10) cfu/g FW) and mould (3.33 vs. 4.12 similar to 4.64 log(10) cfu/g FW) populations than other treated groups on day 14. Moreover, SD group had the highest (p < 0.05) in vitro digestibility of dry matter (67.8 vs. 56.6 similar to 63.5%) and neutral detergent fibre (61.7 vs. 50.5 similar to 57.4%) among all groups. Overall, SD is recommended as additive to improve fermentation quality, in vitro ruminal digestibility, and aerobic stability of TMR silage.