Natamycin as a potential silage additive: A lab trial using sugarcane to assess greenhouse gas emissions

ABSTRACT

The objective of this study was to evaluate natamycin, Lactobacillus buchneri (LB), or their combination on the chemical composition, loss, fermentative profile, and aerobic stability as well as gas production and composition of sugarcane silages. The treatments were (wet basis) no additive (control), 10 g t−1 of natamycin (N10), 5 × 104 cfu g−1 of LB, and the combination of 4 g t−1 of natamycin and 2.5 × 104 cfu g−1 of LB (NLB). Sugarcane was chopped (10 mm), treated with the additives, and ensiled in experimental silos (four replicates). The silos remained stored for 51 days. The LB inoculation, alone or in combination with natamycin, increased the acetic acid content (by 105 and 78% respectively) and decreased ethanol content (by 83 and 71% respectively) when compared to N10 treatment and the control. A decrease in both dry matter and gas losses was observed in the LB (by 72 and 78%, respectively) and N10 (by 69 and 77%, respectively) silages compared with the control, but not the combination. The N10 treatment reduced greenhouse gas (GHG) emission by 86% compared with the control silage. Control and N10 silages deteriorated to the same extent with aerobic exposure, whereas LB and NLB presented higher aerobic stability. The use of natamycin alone is not recommended when ethanol and aerobic stability are concerns. However, natamycin may be considered for the composition of blend additives to decrease greenhouse gas emission and fermentative loss in silages. Further studies must be carried out to optimize doses of natamycin in blend additives.(AU)