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

摘要

To improve the fermentation quality of silage and reduce the nutrients loss ofraw materials during the ensiling process, silage additives are widely used. Theeffect 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. Theexperiment used the main summer forage crops of proso millet(“Geumsilchal”), silage corn (“Gwangpyeongok”), anda sorghum-sudangrass hybrid (“Turbo-gold”). Treatments includedsilage with Lactic acid bacterial Inoculant (Lactobacillusplantarum [LP], 1.0 × 106 CFU/g fresh matter),with FA (98%, 5 mL/kg), and a control (C, without additive). All silages werestored for 60 days after preparation. All additives significantly increased thecrude protein content and in vitro dry matter digestibility(IVDMD) of the silages and also reduced the content of ammonia nitrogen(NH3-N) and pH. Corn had the highest content of IVDMD, totaldigestible nutrients and relative feed value among silages. Compared with thecontrol, irrespective of whether FA or LP was added, the water solublecarbohydrate (WSC) of three crops was largely preserved and the WSC content inthe proso millet treated with FA was the highest. The treatment of LPsignificantly increased the lactic acid content of the all silage, while the useof FA significantly increased the content of acetic acid (p< 0.05). The highest count of lactic acid bacteria (LAB) was detected inthe LP treatment of corn. In all FA treatment groups, the total microorganismand mold numbers were significantly lower than those of the control and LPgroups (p < 0.05). In conclusion, both additivesimproved the fermentation quality and nutritional composition of the main summerforage crops. The application of FA effectively inhibited the fermentation ofthe three crops, whereas LAB promoted fermentation. So, both FA and LP canimprove the quality of various species of silage.