This study was conducted to screen dual-purpose lactic acid bacteria (LAB) from uncontrolled farm-scale silage, and then we confirmed their effects on corn silage. The LAB were isolated from eight farm-scale corn silages, and then we screened the antifungal activity against Fusarium graminearum and the carboxylesterase activity using spectrophotometer with p-nitrophenyl octanoate as substrate and McIlvane solution as buffer. From a total of 25 isolates, 5M2 and 6M1 isolates were selected as silage inoculants because presented both activities of antifungal and carboxylesterase. According 16S rRNA gene sequencing method, 5M2 isolate had 100.0% similarity with Lactobacillus brevis, and 6M1 isolate had 99.7% similarity with L. buchneri. Corn forage was ensiled in bale silo (500 kg) for 72 d without inoculant (CON) or with mixture of selected isolates at 1:1 ratio (INO). The INO silage had higher nutrient digestibility in the rumen than CON silage. Acetate was higher and yeasts were lower in INO silage than in CON silage on the day of silo opening. In all days of aerobic exposure, yeasts were lower in INO silage than CON silage. The present study concluded that Lactobacillus brevis 5M2 and L. buchneri 6M1 confirmed antifungal and carboxylesterase activities on farm-scale corn silage.

Objective: This study was conducted to confirm the effects of new inoculants producing-antifungal or esterase substances on rye silage and its rumen fermentation indices by comparing wild with mutated types.Methods: Rye harvested at dough stage was ensiled into 3 L mini bucket silo (1 kg) for 90 d in triplicate following: distilled water at 20 μL/g (CON); Lactobacillus brevis 100D8 (AT) and its inactivation of antifungal genes (AT-m) at 1.2×105 cfu/g, respectively; and Leuconostoc holzapfelii 5H4 (FD) and its inactivation of esterase genes (FD-est) at 1.0×105 cfu/g, respectively. After silo opened, silage was sub-sampled for the analysis of ensiling quality and its rumen fermentation indices.Results: Among the wild type inoculants (CON vs AT vs FD), FD inoculant had higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in rumen, while AT inoculant had higher (p<0.05) lactate, acetate, and lactic acid bacteria in silage. Silage pH and the potentially degradable fraction in rumen increased (p<0.05) by inactivation of antifungal activity (AT vs AT-m), but lactate, acetate, and lactic acid bacteria of silage decreased (p<0.05). In silage, acetate increased (p<0.05) by inactivation of esterase activity (FD vs FD-est) with decreases (p<0.05) of pH, ammonia-N, lactate, and yeast. Moreover, inactivation of esterase activity clearly decreased (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in the rumen.Conclusion: This study concluded that FD inoculant confirmed esterase activity on rye silage harvested at dough stage, while AT inoculant could not be confirmed with antifungal activity due to the absence of mold in all silages.

The present study aimed to investigate effects of dual-purpose inoculants (antifungal and carboxylesterase activities) not only on corn silage quality, but also its shelf life against mold contamination at feed-out phase. Corn forage was ensiled for 252 d with different inoculants of the following: control (CON), Lactobacillus brevis 5M2 (5M), Lactobacillus buchneri 6M1 (6M), and mixture of 5M and 6M at 1:1 ratio (MIX). After ensiling, corn silage was contaminated with Fusarium graminearum. Silages applied inoculants had positive effects by increased organic acid and lactic acid bacteria, and decreased undesirable microbes. At feed-out phase, contamination of F. graminearum into corn silage had a negative effect on aerobic stability caused by increased growth of undesirable microbes. However, silages applied inoculants had positive effects by decreased undesirable microbes and extended lactic acid bacteria and aerobic stability. Generally, MIX silage presented better effects on organic acid production, rumen degradation, inhibition of undesirable microbes, and aerobic stability than 5M silage and 6M silage. The present study concluded that application of inoculants into corn silage had positive effects on fermentation characteristics and extended shelf life against mold contamination at feed-out phase. A mixed inoculant appeared to have better effects of antifungal and carboxylesterase than a single inoculant.

This study investigated the effects of essential oil (EO) from three Korean wormwood (Artemisia Montana) plants on in vitro ruminal digestibility, fermentation, and microbial diversity. Dried (0.5 g) soybean meal (SBM) or bermudagrass hay (BGH) were incubated in buffered rumen fluid (40 mL) for 72 h with or without EO (5 mg/kg) from Ganghwa (GA), Injin (IN), or San (SA) wormwood (Experiment 1). Both SA and IN improved (p < 0.05) dry matter digestibility (DMD) of BGH, while GA reduced (p < 0.05) total short-chain fatty acid of BGH and SBM. Besides, SA increased (p < 0.05) numbers of Ruminococcus albus and Streptococcus bovis in SBM. Experiment 2 examined different doses (0, 0.1, 1, and 10 mg/kg) of SA, the most promising EO from Experiment 1. Applying SA at 10 mg/kg gave the highest DMD (L; p < 0.01) and neutral detergent fiber (Q; p < 0.05) digestibility for BGH. Applying SA at 1 mg/kg gave the highest R. albus population (Q; p < 0.05) in SBM. Therefore, SA was better than GA and IN at improving rumen fermentation, and the 0.1 to 1 and 10 mg/kg doses improved ruminal fermentation and in vitro digestibility of SBM and BGH, respectively.

This study was conducted to estimate the temperature and microbial changes of corn silages during aerobic exposure. Kwangpyeongok (KW) and Pioneer 1543 (PI) corn hybrids were harvested at 29.7% of dry matter and chopped to 3 to 5 cm lengths. Homo (Lactobacillus plantarum; LP) or hetero (Lactobacillus buchneri; LB) fermentative inoculants at 1.2×105 colony forming unit/g of fresh forage was applied to the chopped corn forage which was then ensiled in quadruplicate with a 2×2 (hybrid×inoculant) treatment arrangement for 100 days. After the silo was opened, silage was sub-sampled for analysis of chemical compositions, in vitro digestibility, and fermentation indices. The fresh silage was continued to determine aerobic exposure qualities by recorded temperature and microbial changes. The KW silages had higher (p<0.01) in vitro digestibilities of dry matter and neutral detergent fiber than those of PI silages. Silages applied with LB had higher (p<0.001) acetate concentration, but lower (p<0.01) lactate concentration and lactate to acetate ratio than those of LP silages. The interaction effect among hybrid and inoculant was detected in acetate production (p = 0.008), aerobic stability (p = 0.006), and lactic acid bacteria count (p = 0.048). The yeast was lower (p = 0.018) in LB silages than that in LP silages. During the aerobic exposure, PI silages showed higher (p<0.05) temperature and mold than KW silages, while LP silages had higher (p<0.05) lactic acid bacteria and yeast than LB silages. The results indicated that the changes of silage temperature during aerobic exposure seems mainly affected by mold growth, while applied LB only enhanced aerobic stability of PI silages.

This study estimated the effects of oil sources on fermentation characteristics, greenhouse gas, microbial diversity, and biohydrogenation of fatty acids in the rumen. In vitro ruminal incubation was performed with 7 mg of oil source, 15 mL rumen buffer, and 150 mg of synthetic diet at 39 °C for 0, 3, 6, 12, and 24 h. Oil sources consisted of corn oil (CO; linoleic acid (C18:2n-6)), linseed oil (LSO; linolenic acid (C18:3n-3)), or Ca-salts (protected C18:2n-6). The ruminal gas was collected for CH₄ and CO₂ analysis. Incubated rumen buffer was sub-sampled for the analysis of microbial quantification, fermentation characteristics, and fatty acid profiles. The results showed that Ca-salt increased acetate (p = 0.013), while CO increased propionate (p = 0.007). Fibrobacter succinogenes, Ruminococcus flavefaciens, and R. albus increased (p < 0.05) with Ca-salt after 12 h of incubation, while Streptococcus bovis increased (p < 0.05) by LSO. The CO and Ca-salt resulted in the highest C18:2n-6 (p = 0.002), while LSO resulted in the highest C18:3n-3 (p = 0.001). The Ca-salt had the lowest C18:0 (p = 0.002), but the highest C18:1cis-9 (p = 0.004). In conclusion, Ca-salt supplementation resisted biohydrogenation to some extent, decreased methanogenic archaea and protozoa, and exerted less toxic effects on fibrolytic bacteria.