Antimicrobial effects of four chemical additives on fermentation quality, aerobic stability, and in vitro ruminal digestibility of total mixed ration silage prepared with local food by-products

The objective of the work is to evaluate the effects of four chemical additives on fermentation quality, aerobic stability, and in vitro ruminal digestibility of total mixed ration (TMR) silage. TMR containing 15% spent mushroom substrate, 25% soybean sauce residue, 45% napiergrass (Pennisetum purpureum (L.) Schum.), and 15% concentrate was ensiled with the following: (1) no additives (control), (2) potassium sorbate (PS, 0.1%), (3) sodium benzoate (SB, 0.1%), (4) sodium diacetate (SDA, 0.5%), and (5) calcium propionate (CAP, 0.5%) based on fresh weight. All silos (10 L) were opened for fermentation quality, in vitro ruminal digestibility analysis after 60 days of ensiling, and then subjected to aerobic stability test for 9 days. All TMR silages were well-conserved, as indicated by low pH, butyric acid, and ammonia nitrogen contents. During aerobic exposure, SDA was more stable with higher (p < 0.05) lactic acid and acetic acid contents and lower (p < 0.05) yeast counts than other TMR silages. In addition, SDA significantly (p < 0.05) increased cumulate gas production and in vitro dry matter digestibility compared with the control. Overall, SDA is recommended as additives to improve fermentation quality, in vitro ruminal digestibility, and aerobic stability of TMR silage prepared with local food by-products.