Effects of formic acid and lactic acid bacteria inoculant on main summer crop silages in Korea

Abstract

To improve the fermentation quality of silage and reduce the nutrients loss of raw materials during the ensiling process, silage additives are widely used. The effect of additives on silage is also affected by the species of crop. Therefore, this study was designed to explore the effects of formic acid (FA) and lactic acid bacterial inoculant on the quality of main summer crop silage. The experiment was consisted on split-plot design with three replications. The experiment used the main summer forage crops of proso millet (“Geumsilchal”), silage corn (“Gwangpyeongok”), and a sorghum-sudangrass hybrid (“Turbo-gold”). Treatments included silage with Lactic acid bacterial Inoculant ( Lactobacillus plantarum [LP], 1.0 × 10 6 CFU/g fresh matter), with FA (98%, 5 mL/kg), and a control (C, without additive). All silages were stored for 60 days after preparation. All additives significantly increased the crude protein content and in vitro dry matter digestibility (IVDMD) of the silages and also reduced the content of ammonia nitrogen (NH 3 -N) and pH. Corn had the highest content of IVDMD, total digestible nutrients and relative feed value among silages. Compared with the control, irrespective of whether FA or LP was added, the water soluble carbohydrate (WSC) of three crops was largely preserved and the WSC content in the proso millet treated with FA was the highest. The treatment of LP significantly increased the lactic acid content of the all silage, while the use of FA significantly increased the content of acetic acid ( p < 0.05). The highest count of lactic acid bacteria (LAB) was detected in the LP treatment of corn. In all FA treatment groups, the total microorganism and mold numbers were significantly lower than those of the control and LP groups ( p < 0.05). In conclusion, both additives improved the fermentation quality and nutritional composition of the main summer forage crops. The application of FA effectively inhibited the fermentation of the three crops, whereas LAB promoted fermentation. So, both FA and LP can improve the quality of various species of silage.

Evaluation of forage production, feed value, and ensilability of proso millet (Panicum miliaceum L.)

“…[ 4 ] also reported that total dry biomass in proso millet averaged 6.43 t/ha. Data of NDF and CP concentration of these forage crops is previously reported [ 8 ]. NDF was highest in sorghum-sudangrass hybrid, intermediate in proso millet, and lowest in corn.…”

“…Silage pH was determined in the filtrate with a pH meter (AB 150, Fisher Scientific International, Inc., Pittsburgh, PA, US). A 1.5 mL portion of the filtrate was used for analysis of the organic acid concentration using high performance liquid chromatography (HPLC, Agilent Technologies, Santa Clara, CA, US) equipped with a refractive index detector [8]. Ammonia nitrogen (NH3-N) was analyzed via the method described by Broderick and Kang [14].…”

“…Calamai et al [4] also reported that total dry biomass in proso millet averaged 6.43 t/ha. Data of NDF and CP concentration of these forage crops is previously reported [8].…”

“…Changes in microbial population as a function of ensiling duration are shown in Table 4. The preensiling population of LAB, mold, and total microorganisms is presented in our companion paper [8].…”

“…Proso millet crop has the potential to remain productive in areas with marginal lands and limited agricultural inputs, where cultivation of major crops such as corn is restricted [5][6][7]. Proso millet could be a viable alternative to main summer forages in areas where cultivation of corn or sorghum-sudangrass is restricted due to a longer growing season or poor agricultural conditions [8].…”