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Background: This study aimed to investigate the effect of phenyllactic acid as an additive on silage fermentation and bacterial community of reed canary grass (RCG, Phalaris arundinacea L.) on the Qinghai Tibetan Plateau. At the heading stage, RCG was harvested, chopped and ensiled in small bag silos. The silage was treated without (control, 1.0 g/mL sterile water, on a fresh matter basis (FM)) or with phenyllactic acid (PLA, 3 mg/mL, FM), antimicrobial additive (PSB, a mixture of potassium sorbate and sodium benzoate, 2%, FM), lactic acid bacteria inoculant (LABi, L. plantarum + L. curvatus, 1 × 106 cfu/g, FM) and PLA + LABi, and then stored in a dark room at the ambient temperature (5 ~ 15 °C) for 60 days. Results: Compared with control, PLA decreased lactic acid, acetic acid and ammonia-N contents, and subsequently increased CP content of RCG silage. PLA enhanced the growth of lactic acid bacteria and reduced the count of yeasts (P < 0.05) in RCG silage, with reduced bacterial richness index (Chao1), observed operational taxonomic units and diversity index (Simpson). In relative to control, moreover, PLA and PLA + LABi increased the relative abundance of Lactococcus in RCG silage by 27.73 and 16.93%, respectively. Conclusions: Therefore, phenyllactic acid at ensiling improved nutritional quality of RCG silage by advancing the disappearance of yeasts and the dominance of Lactococcus. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the silage quality of forage soybean‐corn stover silage in the south of China. Forage soybean were combined manually with corn stover by ratios of R1 (25:75), R2 (50:50) and R3 (75:25) in fresh weight (FM) and ensiled in bag silos for 60 days at room temperature (20–25°C). All silages were treated without (control) or with lactic acid bacteria (LAB) inoculant (G, Lactobacillus plantarum and Lactobacillus buchneri, 105 cfu/g, of FM), cellulase (C, 0.02% of FM) and C + G. R1 silage had appropriate V‐score value with high lactic acid content and low pH value and ammonia‐N (NH3‐N) content, undetectable levels of propionic acid (PA) and butyric acid (BA). C and C + G reduced undesirable microorganisms of aerobic bacteria, yeasts and molds, resulting in improved nutritive value of R2 silage, as indicated by lower neutral detergent fiber and acid detergent fiber contents, and higher crude protein content, in vitro ruminal dry matter digestibility, gross energy and metabolizable energy values as compared to the control. Additives did not improve the quality of R3 silage with high pH value and NH3‐N content, BA and PA contents and undesirable microorganism counts. These results confirmed that high‐quality silage produced from mixtures (25:75) of forage soybean and corn stover in the south of China; additives (especially for C + G) could enhance the silage quality of forage soybean‐corn stover (50:50); and high proportion (>75%) of forage soybean was difficult to ensile. [ABSTRACT FROM AUTHOR]

In practical of silage production, variations in the fermentation parameters of silage might be attributable to changes in weather data, especially for ambient temperature. The objective of this study was to investigate how the changed temperature of outside weather condition affects distributions of pH and fermentation products in large round bale silage. The bale silages (1.22 m × 1.25 m ø; density, about 168.9 kg dry matter [DM]/m3) were produced by BR6090 Combi from New Holland Agriculture, wrapped with six layers of stretch film, stored at ambient temperature (2–20°C) and constant temperature (10°C; 15°C; 25°C) for 3, 9, 15, 45 and 90 days. Compared with other silages, silage stored at 25°C had higher (p < 0.05) lactic acid content, lower (p < 0.05) pH, butyric acid content and ammonia‐nitrogen (N) ratio of total N. Fluctuant storage temperature limited lactic acid fermentation process with delayed pH decline and continuous butyric production and crude protein (CP) degradation. The differences of pH, lactic acid, propionic acid and ammonia‐N were considerably less evident in the centre of silages stored at different temperatures, and they increased towards the boundaries. The data shows that fluctuant storage temperature had undesirable effect on the fermentation quality of silage, especially for the external part of silo; relatively high and stable storage temperature for initial stage of ensiling process was necessary, but did not promote a positive response to the homogeneous distributions of pH and fermentation products in large round bale silage. [ABSTRACT FROM AUTHOR]

Effects of lactic acid bacteria ( LAB) and formic acid ( FA) on silage quality of ultraviolet ( UV)-radiated Siberian wildrye ( Elymus sibiricus L.) were studied on the Qinghai-Tibetan plateau. Siberian wildrye seeds were sown in early April, 2012 and harvested in 2013, 2014 and 2016. Fresh forage was radiated for 0, 4 and 8 h under ambient/laboratory UV radiation conditions during the wilting process, and then mixed with LAB inoculant (105 cfu g−1 fresh matter [ FM]) and FA (3 mL kg−1 FM), respectively, no additives treatment as control. After additive treatments, chopped Siberian wildrye plants were packed in 30 cm × 40 cm polythene bags and stored in a dark room at ambient temperature (<15°C) for 90 days. Silages of UV-radiated Siberian wildrye had higher ( P < 0.05) pH and ammonia-nitrogen (N) content, lower ( P < 0.05) acetic and propionic acid content and in vitro ruminal dry matter digestibility. Compared with control, treatments with additives (especially for inoculant LAB) enhanced pH decline, increased ( P > 0.05) acetic acid content, decreased ( P < 0.05) butyric acid and ammonia-N content of silages of UV-radiated Siberian wildrye. It was concluded that the application of FA and inoculant LAB at ensiling could reduce the negative effects of extended UV radiation on the process of wilting. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of grape pomace ( GP) with different adding levels (0%, 5%, 10% and 15%, fresh matter basis), alone ( GP- LAB) or in combine with an inoculant LAB ( GP+ LAB), on the fermentation quality and aerobic stability of sweet sorghum silage. After 90 days of ensiling in vacuumized mini-silos, silages were subject to a 7-day aerobic stability test, in which chemical, microbial and polyphenol composition were measured. In the GP- LAB group, adding GP decreased ( P < 0.05) concentrations of water-soluble carbohydrate ( WSC) and butyric acid in silage. In the GP+ LAB group, adding GP increased ( P < 0.05) concentrations of lactic acid, WSC and crude protein, decreased ( P < 0.05) final pH value, NH3-N ratio and butyric acid concentration in silage. Polyphenol level was reduced ( P < 0.05) after silage fermentation. During aerobic exposure, the fungi count, pH value and silage temperature increased ( P < 0.05), the levels of lactic acid, acetic acid and polyphenols (quercetin 3-O-glucoside and quercetin 3-O-glucuronid) decreased ( P < 0.05) in silage. GP+ LAB treated silage had a lag phase for aerobic spoilage. When the fermentation products, microbial counts, chemical and polyphenol composition were considered, the use of 10% GP+ LAB at ensiling could provide a valuable source for improved fermentation quality and aerobic stability of sweet sorghum silage. [ABSTRACT FROM AUTHOR]

• Oat silage is inoculated with low temperature tolerant lactic acid bacteria (LAB). • Main present of Clostridia reduces silage fermentation and bacterial diversity. • Low temperature tolerant LAB shifts silage bacterial community. • Low temperature tolerant LAB enhance the silage quality. The objective of this study was to investigate the effect of a low temperature tolerant lactic acid bacteria (LAB) inoculant on the fermentation characteristics and bacterial community of oat silage. Oats were harvested at the flowering stage and wilted to dry matter content of approximately 270 g/kg fresh weight. Wilted and chopped oats were used to make mini round bale silages. Silages were prepared without (control) or with a low temperature tolerant LAB inoculant including Lactobacillus plantarum BP18, Pediococcus pentosaceus HS1 and L. buchneri LP22 and then separately stored at different geographic locations (L, Chengdu Plain; H, Qinghai Tibetan Plateau) for 120 days. High contents of water soluble carbohydrate (WSC), crude protein (CP), neutral detergent fiber (aNDF) and acid detergent fiber (ADF) were found in LAB inoculated silage. Inoculation with LAB increased (P < 0.05) lactic acid and acetic acid contents, and decreased (P < 0.05) the final pH of silage stored at the H location. However, LAB inoculation reduced (P < 0.05) the bacterial operational taxonomic units (OTUs), richness index (Chao 1) and diversity index (Shannon) of silage stored at the L location. The dominant genera from silage samples were Lactobacillus , Leuconostoc and Clostridium , with a total relative abundance of 71∼93 %. LAB inoculation increased the abundance of desirable Lactobacillus and inhibited the growth of undesirable Clostridium in silage. Therefore, inoculation of low temperature tolerant LAB at ensiling could stimulate favorable fermentation and reconstruct the bacterial community for better preservation of high moist oat silage nutrients. [ABSTRACT FROM AUTHOR]

• SBP is utilized as an additive in silage making. • Addition of SBP advances silage fermentation process. • Addition of SBP enriches the growth of Lactobacillus and Lactococcs. • Addition of SBP + LP shows best performance. To effectively preserve nutrients, alfalfa silage was treated without (control) or with Lactobacillus plantarum (LP) and their mixture (LP + SBP). Results showed that SBP decreased (P < 0.05) final pH value and ammonia-N of total N, increased (P < 0.05) lactic, acetic and propionic acid contents, resulting in more residual water soluble carbohydrate and crude protein contents and less fiber content in relative to control. Moreover, SBP decreased (P < 0.05) the number of observed species, richness index of ACE and diversity index of Shannon at early stage of ensiling, while Lactobacillus plantarum , Lactococcus lactis , and/or Lactobacillus brevis dominated in silages. In particular, LP + SBP enhanced the growth of Lactococcus lactic at early stage and Lactobacillus plantarum at late stage of ensiling, resulting in higher lactic and acetic acid contents and lower propionic acid content as compared with LP. These confirmed that SBP could be used as an additive for improving silage quality of alfalfa. [ABSTRACT FROM AUTHOR]

Highlights • This is the first study of bur clover and annual ryegrass ensiled with additives. • Untreated silages have a broad microbial diversity resulting in poor fermentations. • Additives reduced microbial diversity and improved silage fermentation. • Additives enrich the relative abundance of Lactobacillus species during ensiling. • Clostridium species produce butyric acid, resulting in poor quality of silage. Abstract The objective of this study was to evaluate the silage fermentation and bacterial community of bur clover, annual ryegrass and their mixtures in south of China. Bur clover, annual ryegrass and their mixtures were ensiled without additive (control), or with lactic acid bacteria inoculant (LABi, 106 cfu/g of fresh weight) and formic acid (FA, 3 mL/kg of fresh weight) for 60 d of fermentation. Untreated bur clover displayed high bacterial diversity resulting in a poor fermentation. LABi and FA reduced bacterial diversity and enriched the relative abundance of Lactobacillus , Pediococcus or Sporolactobacillus species during ensiling, resulting in improved silage fermentation. Annual ryegrass contained relative abundance of Proteobacteria and Clostridium species, and produced more butyric acid. This study confirmed that LABi and FA could reduce microbial diversity and improve silage quality; and Clostridium species produced butyric acid which caused a poor fermentation. [ABSTRACT FROM AUTHOR]