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Aims To determine the fermentation quality, aerobic stability, and chemical composition of Italian ryegrass silage prepared with Lactobacillus plantarum (LP), caproic acid (CA), and their combination during ensiling and feed-out phase. Methods and results Six treatments: control (CON), LP, 0.15% caproic acid (LCA), 0.2% caproic acid (HCA), LCA + LP, and HCA + LP were employed for 30 days ensiling and an 8-days aerobic stability test. LP had similar pH value and lactic acid content with LCA + LP, while the contents of NH3-N and total VFAs in LCA + LP were significantly lower than those in LP and CON, and the fermentation quality of LCA + LP performed best among all silages. As air-exposure extended, contents of water-soluble carbohydrates (WSC), lactic, and acetic acids decreased, while pH, and NH3-N content increased significantly. The population of lactic acid bacteria gradually decreased in contrast to increased counts of aerobic bacteria and yeasts. Compared with LCA, 0.2% CA delayed the aerobic deterioration as judged by a slower increase in pH and high residual of WSC and lactic acid, and negligible ethanol content and anaerobe spores counts remained in HCA at the end of air exposure. Compared with CON (73 h), LP showed less aerobic stability (38 h), whereas HCA and HCA + LP prolonged aerobic stability for 210 and 152 h, better than LCA (109 h) and LCA + LP (146 h). Conclusions Lactobacillus plantarum apparently improved the fermentation quality, and combined with CA exhibited greater efficiency in inhibiting undesirable microorganism during ensiling. CA at 0.2% optimally extended the aerobic stability. [ABSTRACT FROM AUTHOR]

BACKGROUND: The present study aimed to investigate the relationship between the phyllosphere microbiota of Italian ryegrass (Lolium multiflorum Lam.) harvested at heading (H) [> 50% earing rate or 216 g kg−1 fresh weight (FW)] and blooming (B) (> 50% bloom or 254 g kg−1 FW) stages and in‐silo fermentation products, and the composition, abundance, diversity and activity of bacterial community. In total, 72 (4 treatments × 6 ensiling durations × 3 replicates) laboratory scale (400 g) silages of Italian ryegrass were prepared: (i) irradiated heading stage silages (IRH) (n = 36) were inoculated with phyllosphere microbiota inoculum (2 mL) eluted from fresh Italian ryegrass at either heading (IH) (n = 18) or blooming (IB) (n = 18) stages; (ii) irradiated blooming stage silages (IRB) (n = 36) were inoculated with either IH (n = 18) or IB (n = 18). Triplicate silos of each treatment were analyzed after 1, 3, 7, 15, 30 and 60 days of ensiling. RESULTS: In fresh forage, Enterobacter, Exiguobacterium and Pantoea were the three major genera at heading stage, and Rhizobium, Weissella and Lactococcus were the most abundant genera at blooming stage. Higher metabolic activity was found in IB. After 3 days of ensiling, the large amounts of lactic acid in IRH‐IB and IRB‐IB can be attributed to the higher abundances of Pediococcus and Lactobacillus, 1‐phosphofructokinase, fructokinase, l‐lactate dehydrogenase and glycolysis I, II and III. CONCLUSION: The composition, abundance, diversity and functionality of the phyllosphere microbiota of Italian ryegrass at different growth stages could remarkably affect silage fermentation characteristics. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of fibrolytic enzymes, cellulolytic fungi and lactic acid bacteria on the fermentation quality, structural carbohydrate composition and in vitro digestibility of rice straw silage. This experiment followed a completely randomised block design; four treatments were designed: (1) distilled water (control, CON); (2) fibrolytic enzymes (2.0 g/kg fresh weight (FW), E); (3) Trichoderma reesei (4400 U/kg FW, F); (4) Enterococcus faecium Y83 (1 × 106 cfu/g FW, Y83). All additives were diluted with distilled water and sprayed onto the rice straw (20 mL/kg FW). The rice straw was placed into a laboratory silo (10 L) after uniformly mixing and stored at ambient temperature (17–22 °C) ensiling for 3, 7, 14, 30 and 60 days. The fermentation quality in treated silages was improved compared to the CON, as indicated by lower pH, propionic acid, acetic acid and ammonia nitrogen (NH3-N) contents. Furthermore, Y83 had the lowest (p < 0.05) pH and highest (p < 0.05) lactic acid content after 60 days of ensiling. Y83 significantly (p < 0.05) decreased the neutral detergent fibre content compared with CON, E and F. In addition, E and Y83 had significantly (p < 0.05) higher in vitro dry matter digestibility and in vitro neutral detergent fibre digestibility than CON and F. Overall, Y83 can be used as a promising inoculant for improving the fermentation quality of rice straw silage. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effects of different additives on the fermentation quality and bacterial community of silage prepared from fresh-cut whole-plant quinoa (WPQ). Fresh-cut WPQ without wilting process was directly ensiled with one of the following additives: (i) untreated (control); (ii) fibrolytic enzyme (E); (iii) molasses (M); (iv) LAB inoculant (L); (v) a combination of fibrolytic enzyme and LAB inoculant (EL); and (vi) a combination of molasses and LAB inoculant (ML). The fermentation quality and bacterial community after 60 days of ensiling were analysed. The results showed that control silage was dominated by enterobacteria (>50%), with high pH value (5.25), acetic acid (77.9 g/kg DM) and NH3–N production (261 g/kg TN). Adding E, EL and ML shifted the fermentation pattern towards increased intensity of lactic acid production, as indicated by increased lactic acid content (>62.4 g/kg DM), lactic/acetic acid ratio (>1.12) and relative abundance of Lactobacillus (>62.0%), and decreased pH value (<4.73), contents of acetic acid (<60.7 g/kg DM) and NH3-N (<179 g/kg TN) and the relative abundance of enterobacteria. The results suggested that treatments of E, EL and ML could be the feasible solutions for improving the fermentation quality and protein preservation of silage prepared from fresh-cut WPQ. The results of this study could be beneficial for producing high-quality WPQ silage in aeras where wilting is hard to conduct before ensiling. WPQ silage was prone to acetic acid-type fermentation dominated by enterobacteria. Adding E, EL and ML improved the lactic acid fermentation and protein preservation of fresh-cut WPQ silage. This study provided feasible solutions for producing high-quality WPQ silage under adverse climate conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND To investigate the contributions of chemical and microbial diurnal variations in fermentation characteristics and bacterial community of Napier grass silage, gamma‐ray irradiated Napier grass harvested at 07.00 h (AM), 12.00 h (M) and 17.00 h (PM) was inoculated with the microbiota derived from Napier grass harvested at AM, M and PM in a 3 (irradiated forage: AMG, MG and PMG) × 3 (microbiota: AMM, MM and PMM) design and then ensiled for 14 and 60 days. RESULTS: Napier grass harvested at various times had different chemical compositions and epiphytic microbiota prior to ensiling. For silages inoculated with the same microbiota, the pH values, residual water soluble carbohydrates and dry matter contents increased, and lactic acid, acetic acid, propionic acid, butyric acid, ethanol and volatile fatty acids contents decreased in PMG and MG silages compared to AMG silages. MM and PMM inoculum promoted lactic acid fermentation as indicated by higher lactic acid contents and lactic/acetic acid ratios in MM and PMM‐inculated silages compared to those in AMM‐inoculated silages after 60 days of ensiling. During ensiling, epiphytic microbiota affected the Chao1 index, operational taxonomic units (OTUs) number and Shannon index, as well as the abundances, of more than half of the top 10 abundant genera, whereas chemical composition did not affect any of the bacterial diversity and richness indices and only showed significant impacts on the abundances of two genera. CONCLUSION: The results indicated that chemical diurnal variation exerted an influence mainly on the extent of fermentation, whereas microbial diurnal variation affected more the bacterial community and fermentation types during Napier grass ensiling. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Aims: This work evaluated the effects of epiphytic microbiota and chemical components on fermentation quality and microbial community of ensiled oat. Methods and Results: Oat harvested at the heading stage (HS) and the milk stage (MS) was sterilized by gamma‐ray irradiation and inoculated as the following: (1) HS epiphytic microbiota + sterilized HS (H‐H); (2) MS epiphytic microbiota + sterilized HS (M‐H); (3) MS epiphytic microbiota + sterilized MS (M‐M); and (4) HS epiphytic microbiota + sterilized MS (H‐M). After 60‐day fermentation, silages inoculated with the epiphytic microbiota of HS had higher acetic acid content than those inoculated with MS. Silage made from sterilized MS had lower pH, ammonia nitrogen and butyric acid contents and higher dry matter, water‐soluble carbohydrates and lactic acid contents than that made from sterilized HS. The microbial communities of oat silages were similar, and they were mainly Lactobacillus. Conclusions: The chemical component rather than the epiphytic microbiota at harvest exerted more effects on oat silages. Significance and Impact of the Study: This work reveals the different effects of chemical and microbial factors on the fermentation of silage, which is instructive for us to produce quality silage. [ABSTRACT FROM AUTHOR]

Aims: To enrich lignocellulolytic microbial consortia and evaluate whether a combination of these consortia and Lactobacillus plantarum can facilitate degradation of structural carbohydrates and improve fermentation quality of high‐moisture alfalfa silage. Methods and Results: Two novel microbial consortia (CL and YL) with high lignocellulolytic potential were enriched, and had higher enzyme activities at slightly acidic conditions (pH 3.5–6.5). Two consortia were inoculated with and without combined L. plantarum (LP) to alfalfa for up to 120 days of ensiling. The two consortia alone or combined with LP significantly (p < 0.05) increased lactic‐to‐acetic acid ratios and decreased contents of volatile organic acids and NH3‐N as compared to the control. Treatments that combining microbial consortia and LP further resulted in the higher contents of lactic acid (LA), water soluble carbohydrates (WSC) and crude protein, dry matter (DM) recovery, and lower neutral detergent fibre, acid detergent lignin and cellulose contents, with YLP silage showing the lowest pH (4.41) and highest LA content (76.72 g kg−1 DM) and the conversion of WSC into LA (184.03%). Conclusions: The addition of lignocellulolytic microbial consortia (CL or YL) to alfalfa silages as attractive silage inoculants could improve fermentation quality, and that their combination with L. plantarum appeared more effective on the degradation of structural carbohydrates and conversion of soluble carbohydrates into LA. Significance and Impact of the Study: High‐moisture alfalfa is difficult to ensile due to its high buffering capacity and low readily fermentable carbohydrate contents. Microbial consortia (CL and YL) can encode a broad selection of multi‐functional CAZymes, and their combination with LP could be promising for the degradation of structural carbohydrates simultaneously with improvement fermentation quality, with high performance in LA production. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to separate the effects of chemical and microbial factors on the fermentation quality and bacterial community of ensiled Pennisetum giganteum. Methods and Results: Fresh P. giganteum of two vegetative stages (stage I, GI; stage II, GII) was treated as follows: GI epiphytic microbiota + γ‐ray presterilized GI (MICI), GII epiphytic microbiota + γ‐ray presterilized GI (MIICI), GI epiphytic microbiota + γ‐ray presterilized GII (MICII), and GII epiphytic microbiota + γ‐ray presterilized GII (MIICII). Triplicates per treatment were sampled after 30 days of ensiling for chemical and microbial analyses and high‐throughput sequencing. Silages made from CII (MICII and MIICII) had higher lactic acid concentration and the ratio of lactic to acetic acid, and lower pH and ammonia nitrogen concentration than silages produced by CI (MICI and MIICI). Species differential analyses showed that the changes of chemical composition rather than epiphytic microbiota significantly affected the relative abundance of Lactobacillus, Pediococcus and Pantoea in P. giganteum silages. Conclusion: These above results manifested that chemical composition was the main factor influencing the fermentation quality and bacterial community of P. giganteum silage in this study. Significance and Impact of the Study: The obtained results may, therefore, be the first record to provide an in‐depth understanding of the relative contributions of chemical and microbial parameters on fermentation quality and bacterial community, which is of great importance for modulating silage fermentation and improving silage quality. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the effect of different additives on the fermentation characteristics, in vitro digestibility and aerobic stability of fermented total mixed ration (FTMR) prepared with local feed resources in Tibet, China. Additives added to FTMR were Lactobacillus buchneri (1 × 106 cfu/g fresh weight (FW)), acetic acid (0.3% FW), propionic acid (0.4% FW), 1,2‐propanediol and 1‐propanol (0.5% FW). FTMR were opened after 90 days and subjected to a 14‐d aerobic stability test. The results showed that L. buchneri, 1,2‐propanediol and 1‐propanol increased (P < 0.05) pH values and acetic acid concentrations and decreased (P < 0.05) lactic acid concentrations in FTMR. Adding acetic acid decreased (P < 0.05) lactic/acetic acid ratio. FTMR treated with propionic acid had higher (P < 0.05) lactic acid, propionic acid and DM recovery compared with the other treatments. Treating FTMR with acetic acid, 1,2‐propanediol and 1‐propanol decreased (P < 0.05) yeast counts. The in vitro potential gas production tended to be lower in L. buchneri‐treated silage than other silages. During aerobic exposure, FTMR treated with propionic acid spoiled first, with marked pH increase and lactic acid decrease from days 9 to 14. Treatment with L. buchneri, acetic acid, 1,2‐propanediol and 1‐propanol markedly improved the aerobic stability, as indicated by nearly unchanged pH and lactic acid concentrations. The results suggest that L. buchneri, acetic acid, 1,2‐propanediol and 1‐propanol did not adversely affect the in vitro digestibility and could be effective additives for enhancing the aerobic stability of FTMR prepared on Tibetan plateau. [ABSTRACT FROM AUTHOR]

The experiment was conducted to investigate the effects of different levels of citric acid residue (CAR) on the fermentation quality and aerobic stability of Napier grass. Napier grass was ensiled with no additives control (CON), 1.2% CAR (C1), 3.6% CAR (C2) and 6.0% CAR (C3) on a fresh weight basis in laboratory silos for 3, 6, 9, 15 and 45 days. After opening the silos, the silages were subjected to analyzing the chemical and microbial compositions, and the residual silages ensiled for 45 days were evaluated for aerobic stability. Addition of CAR increased lactic acid/acetic acid, dry matter, lactic acid and water‐soluble carbohydrate contents, and decreased pH, acetic acid, ammonia nitrogen (NH3‐N), neutral detergent fiber, acid detergent fiber and cellulose contents as compared to the control. At the day 45 of ensiling, the C2 and C3 silages showed higher lactic acid contents and lactic acid/acetic acid, and lower NH3‐N and acetic acid contents than these of C1 silages. There was no significant difference in the aerobic stability between CAR‐treated silages and the control. Application of CAR effectively improved the fermentation quality of Napier grass, but had no obvious effects on the improvement of aerobic stability. In conclusion, application of CAR at the level of 3.6% or 6.0% is recommended for Napier grass silage making. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of exogenous epiphytic microbiota inoculation on the fermentation quality and microbial community of sudan grass silage. Gamma irradiated sudan grass was ensiled with distilled water (STR), epiphytic microbiota of sudan grass (SUDm), forage sorghum (FSm), napier grass (NAPm) and whole crop corn (WCCm). The FSm inoculated silage have significantly lower lactic acid (LA) concentration and higher pH during early ensiling, while LA concentration gradually and significantly increased with the progression of ensiling and have lower pH in relation to other treatments for terminal silage. Inoculation of NAPm resulted in lower LA and higher acetic acid (AA) concentrations, higher pH, ammonia-N and dry matter losses for terminal silage, followed by SUDm silage. Inoculations of WCCm significantly increased LA production and pH decline during early ensiling and have higher LA and pH then NAPm and SUDm silages during final ensiling. The early fermentation of SUDm silage was dominated by genus of Pediococcus. The genera of Lactobacillus were predominant in WCCm and NAPm silages during 3 days of ensiling, while Weissella dominated initial microbial community of FS silage. The terminal silage of NAPm was dominated by Enterobacter and Rosenbergiella, while Enterobacter and Lactobacillus dominated terminal SUDm silage. The final silage of FSm was dominated by Lactobacillus, Weissella and Pediococcus, while Lactobacillus and Acetobacter dominated terminal WCCm silages. The results demonstrated that among the four forages the epiphytic microbiota from forage sorghum positively influenced the microbial community and fermentability of sudan grass silage. [ABSTRACT FROM AUTHOR]

An experiment was conducted to investigate the effects of citric acid residue (CAR) and lactic acid bacteria (LAB) on fermentation quality and aerobic stability of alfalfa silage. Alfalfa was treated as follows: (1) control without additive (CON); (2) LAB (L); (3) 12 g/kg CAR (C); (4) 12 g/kg CAR + LAB (CL) and fermented for 3, 6, 9, 15, 30 and 45 days. The residual silages ensiled for 45 days were evaluated for aerobic stability. The results showed that addition of CAR with or without LAB inoculant decreased pH, acetic acid, ammonia nitrogen , neutral detergent fibre, hemicellulose contents and Enterobacteriaceae counts (p <.05) and increased dry matter and lactic acid contents (p <.05) after 45 days of ensiling. Whereas, the lower lactic acid and higher acetic acid contents were observed in L silages (p <.05) after 45 days of ensiling. During aerobic exposure, L and CL silages remained stable in pH, lactic and acetic acid contents, while the control and C silages showed higher pH, yeast and mould counts and lower lactic and acetic acid contents. Compared with the control, L and CL improved aerobic stability, whereas the poorer aerobic stability was shown in C silages (p <.05). In conclusion, applying a combination of CAR and LAB inoculant improved both fermentation quality and aerobic stability of alfalfa silage. Citric acid residue (CAR) was compared with a lactic acid bacteria (LAB) inoculant in ensiling alfalfa. The CAR improved fermentation quality compared to control and LAB treated silages. Aerobic stability improved when CAR was used in combination with LAB but not when used alone. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study was to evaluate the potential of hexanoic acid (Hex) as a silage additive. Methods and Results: The effect of Hex, Lactobacillus plantarum (Lp) and their combination (Hex + Lp) on the aerobic stability of napier grass silage was investigated. Napier grass was ensiled without additives (C) or with Lp, Hex or Hex + Lp for 60 days followed by 7 days of aerobic exposure. After 60 days of ensiling, the Lp silage had the lowest pH and the highest lactic acid (LA) concentration among all silage, whereas the highest water‐soluble carbohydrates (WSC) content was observed in Hex + Lp silage, followed by Hex silage. After 60 days of ensiling, the population of yeasts in C and Lp silages was > 3·0 log10 CFU per g FW, while that of Hex and Hex + Lp was <2·0 log10 CFU per g FW. During aerobic exposure, the pH in the Lp and C silages increased (P < 0·05) above 7·0 on day 5. The pH of Hex silage was the lowest among all silages on day 3 and 5, followed by a significant (P < 0·05) increase until 7 days of aerobic exposure. There were no significant changes in pH and AA of Hex + Lp silage over the duration of aerobic exposure. The concentrations of LA in C, Lp and Hex silages decreased while that of Hex + Lp silage remained stable after 3 days of aerobic exposure. The Hex delayed the decline of WSC contents and the increase in yeasts over the aerobic exposure period. Conclusion: Addition of Hex (97 h) and Hex + Lp (>168 h) improved aerobic stability (P < 0·05) as compared to the control (83 h). Significance and Impact of the Study: Hex or in combination with L. plantarum inhibited the proliferation of yeasts during aerobic exposure of napier grass. Thus, Hex is an alternative antifungal additive to improve aerobic stability. [ABSTRACT FROM AUTHOR]

The study aimed to disclose the microbial community dynamics and their contributions to organic acid production during the ensiling of Napier grass. Napier grass was harvested at the vegetative growth phase and ensiled for 30 days. Three silos were opened after 1, 2, 3, 5, 7, 14, and 30 days of ensiling respectively. The intensive fermentation was observed during the initial stage of ensiling, indicated by lower pH (<4.0) on d 2 of ensiling. Lactic acid (LA) was the primary fermentation product, although acetic acid (AA) concentration rapidly increased and LA/AA concentration gradually decreased after 3 days of ensiling. The ethanol concentration was already 11.8 g/kg DM on d 1 of ensiling and then remained stable until the end of ensiling. Lactococcus was the predominant genus during the initial 2 days of ensiling, and then, it was gradually replaced by Lactobacillus. The increase in ammonia nitrogen and butyric acid concentration after 7 days of ensiling was attributed to the growth of Clostridia, which is favored by the high moisture concentration in the Napier grass. The natural ensiling of Napier grass displayed LA‐type fermentation and was dominated by the fermentation of Lactobacillus and Lactococcus. Lactobacillus is mainly responsible for the LA production during the ensiling of Napier grass. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to characterize the dynamics of nitrogen (N) transformations in alfalfa and red clover and their mixture during ensiling. Alfalfa, red clover and a mixture of them (1:1 on fresh weight) were ensiled for 3, 5, 7, 14 and 30 days. The fermentation qualities and dynamic change of N components of the three silages were determined. Red clover and mixed silages showed better fermentation qualities, indicated by lower (p < 0.05) pH value, higher (p < 0.05) lactic acid concentration compared with alfalfa silage after ensiling. Retarded N transformation was observed in red clover and mixed silages, as evidenced by lower (p < 0.05) free amino acid concentrations at all intervals of ensiling, higher (p < 0.05) peptide N and lower (p < 0.05) ammonia N concentrations after 14 days of ensiling as opposed to alfalfa silage. Mixing red clover apparently delayed the degradation process of alfalfa protein in mixed silage, as demonstrated by no significant difference in non‐protein N (NPN) concentrations in comparison with pure red clover silage at most intervals of ensiling. The results of this study, from the perspective of N transformation, confirmed the lower rate of protein degradation in red clover in contrast to alfalfa during ensiling and potentially provide an effective strategy to reduce protein loss for alfalfa silage production. [ABSTRACT FROM AUTHOR]

In order to enhance the feed's nutritive value and utilisation efficiency of local straws in Tibet, hulless-barley straw was conserved as silage by mixing with tall fescue and adding the tested additives and their combination. In experiment 1, hulless-barley straw was ensiled with four levels of tall fescue (0, 20, 40 or 60 of fresh weight, FW) in laboratory silos (1 L) for 60 days. The results suggested that 40% hulless-barley straw inclusion of 60% tall fescue was proper for further study. In experiment 2, a mixture of hulless-barley straw and tall fescue (40/60) were treated with (1) no additive (control), (2) fibrolytic enzymes (E, 0.1% FW), (3) molasses (M, 4% FW), (4) Lactobacillus plantarum MTD-1 (Lp, 106 cfu g−1 FW), (5) E + Lp and (6) M + Lp, respectively. Silos were opened after 7, 24, 45 and 60 days of ensiling respectively. The fermentation quality and structural carbohydrates were analysed. After 60 days of ensiling, all the additives except fibrolytic enzymes increased the lactic acid contents, and decreased the pH, ammonia nitrogen and butyric acid contents. All the treated silages had lower neutral detergent fibre, acid detergent fibre, hemicellulose and cellulose contents than that of control, especially in E + Lp and M + Lp treated silages. In conclusion, application of L. plantarum together with fibrolytic enzymes or molasses could further improve the fermentation quality and structural carbohydrate compositions in comparison with using each of the three additives alone. Enhancing the utilisation efficiency of local straws by mixed silage. Improving the feed's nutritive value by reducing the crude fibre contents. [ABSTRACT FROM AUTHOR]

Abstract: To enlarge the feed resources and enhance the utilization efficiency of straws as ruminant feed in Tibet, four kinds of local crop straws with tall fescue (Festuca arundinacea Schreb.) based on the ratio of 40/60 (fresh weight) were ensiled with four levels (0, 10%, 20% and 30% of fresh weight) of alfalfa (Medicago sativa L.), respectively. The laboratory silos (1L) were opened after 45 days of ensiling, and the fermentation characteristics, nutritive value and in vitro digestibility of the mixed silages were analysed. The silages including alfalfa had significantly (p < 0.05) or numerically (p > 0.05) higher lactic acid and crude protein contents, lactic acid bacteria counts, in vitro digestibility of dry matter, neutral detergent fibre (NDF) and acid detergent fibre (ADF), and lower NDF and ADF contents than controls. The results suggest that inclusion of alfalfa to mixtures of straws and tall fescue had favourable effects on fermentation quality and obviously improved the nutritive value and in vitro digestibility of mixed silages. This effect was most evident when the inclusion proportion of alfalfa was 30% in oat straw mixed silage. [ABSTRACT FROM AUTHOR]

Two bacteria strains with cellulolytic potential isolated from Tibetan yak ( Bos grunniens ) rumen were identified as Enterococcus faecalis (JF85) and Enterococcus faecium ( Y83). Isolates grow well within a range of temperature 15 to 55 °C and pH 3.0–7.0, respectively. Two strains were inoculated with or without Lactobacillus plantarum (Lp) to Pennisetum sinese silage for 90 days. All inoculants increased lactic acid content, decreased pH and lignocellulose contents compared with silage without additives (control). The lowest pH, highest lactic acid and largest reduction in lignocellulose contents were observed in JF85+Lp and Y83+Lp silages. Isolates alone or in combination with Lp significantly increased WSC, mono- and disaccharides contents as compared to the control. Combined addition efficiently improved enzymatic hydrolysis of Pennisetum sinese silage, indicated by higher glucose yield and cellulose convertibility. Pennisetum sinese ensiled with combined additives is a suitable storage and pretreatment method prior to sugars production from energy crop. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two microbial consortia with cellulolytic activities were enriched from yak rumen. • Application of two consortia improved fermentation quality of rice straw silages. • The microbial consortia accelerated the degradation of structural carbohydrates. • Rice straw ensiled with the microbial consortia enhanced ethanol production. The present study extracts and enriches cellulolytic microbial consortia from yak (Bos grunniens) and evaluates their effects on the fermentation profile and bioethanol yield in rice straw silage. Two microbial consortia (CF and PY) with high cellulolytic activity were isolated and observed to be prone to utilize natural carbon sources. Two consortia were introduced with and without combined lactic acid bacteria (CLAB) to rice straw for up to 60 days of ensiling, and their application notably decreased the levels of structural carbohydrates and pH values of rice straw silages. Treatments that combining microbial consortia and CLAB resulted in the highest levels of lactic acid, water soluble carbohydrates, mono- and disaccharides, and lignocellulose degradation, with PY + CLAB group yielding the highest bioethanol production. The microbial consortia identified herein exhibit great potential for degrading fibrous substrates, and their combination with CLAB provides a feasible way to efficiently use rice straw for bioethanol production. [ABSTRACT FROM AUTHOR]

The fermentation characteristics, structural carbohydrate degradation and enzymatic hydrolysis of rice straw ensiled with hemicellulase and Lactobacillus plantarum were examined. Fresh rice straw was ensiled in 1-L laboratory silos with no additive control (CK), L. plantarum (L), hemicellulase (HC) and hemicellulase +  L. plantarum (HCL) for 6, 15, 30 and 60 days. All additives increased lactic acid concentration, and reduced pH and lignocellulosic content of the resulting silage relative to the control. The highest organic acid and residual sugar contents and lignocellulose degradation were observed in HCL silage. Hemicellulase alone or combined with L. plantarum improved the enzymatic hydrolysis with higher glucose yield and cellulose convertibility. Fresh rice straw ensiled with the combined additives increased feedstock preservation and cellulose conversion, and is thus recommended as a biological pretreatment for subsequent biofuel production. [ABSTRACT FROM AUTHOR]

The study evaluated the effects of growth stage and ensiling time on silage fermentation characteristics, bacterial communities and their predicted functional potential in Italian ryegrass (Lolium multiflorum Lam.) silage. Italian ryegrass (IR) was harvested at heading (Earing rate >50 %, IR1) and blooming stages (>50% bloom, IR2), respectively. The harvested IR was ensiled in 15-L plastic silos. The experiment had a completely randomized design. Triplicate silos were sampled after 1, 3, 7, 15, 30 and 60 days of fermentation, respectively. The fermentation products were analyzed on each sampling day. The bacterial communities and their functional potential and phenotype on day 3 and 60 were analyzed by high-throughput sequencing technique and PICRUSt2 (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) method. With the advancing maturity of IR, the neutral detergent fiber and dry matter (DM) contents, lactic acid bacteria, yeast, Enterobacteriaceae and aerobic bacteria populations increased, while water soluble carbohydrate contents and buffering capacity decreased. Larger lactic acid contents were accumulated in IR1 than IR2 at the early stage of fermentation. Higher contents of ethanol and ammonia nitrogen (NH 3 -N) were found in IR1 compared to IR2 at the late stage of ensiling. After 60 days, IR1 and IR2 both had good fermentation quality with low pH values (∼4.08), and acceptable levels of NH 3 -N (∼67.6 g/kg total nitrogen) and butyric acid (∼1.08 g/kg DM). The IR2 had lower abundance of Lactobacillus on day 3, and higher abundances of Kosakonia and Pantoea on day 60 compared to IR1. The bacterial community in IR2 had higher activity in metabolic pathway. Overall, high throughput sequencing technique combined with PICRUSt2 method can improve our understanding of the silage microbiology to further regulate the fermentation products. • Italian ryegrass harvested at heading and blooming stages are both preserved well. • High lactic acid contents are found in young Italian ryegrass silage initially. • Low ammonia nitrogen contents are found in matured Italian ryegrass silage. • Large ratios of Kosakonia and Pantoea are found in matured Italian ryegrass silage. • The metabolic activity of bacterial community in matured Italian ryegrass is high. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate the effects of natamycin, hexanoic acid, and Lactobacillus plantarum on fermentation characteristics, aerobic stability, mycotoxins concentrations, and bacterial community in high moisture whole-crop corn silage. Whole-crop corn was harvested at 1/2 milk lines stage and ensiled without additive (CON), with L. plantarum (LP, 1 ×106 cfu/g FW), natamycin (NAT, 0.2 mg/kg FW), or hexanoic acid (HEX, 0.4 mg/kg FW). The addition of NAT and LP enhanced (P < 0.05) lactic acid (LA) production as compared to CON and HEX silage. HEX depressed LA accumulation leading to higher (P < 0.05) pH and water-soluble carbohydrates (WSC). The HEX and NAT silages had lower (P < 0.05) yeast count and ethanol concentration than CON and LP silages. NAT and LP decreased the concentration of ammonia N as compared to CON silage with the lowest value in LP silage. After 60 d of ensiling, LP silage spoiled within 22 h, NAT silage was stable for 41 h, which was slightly (P > 0.05) longer than CON silage (34 h). The HEX silage showed the longest aerobic stability (>144 h) among all silages. Ensiling decreased zearalenone (ZEN) and deoxynivalenol (DON) concentrations (P < 0.05). The LP and NAT silages had significantly (P < 0.05) lower aflatoxin B 1 (AFB 1), ZEN, and DON concentrations than fresh corn, CON, and HEX silages. All additives depressed the growth of Lactococcus , but increased the relative abundance (RA) of Lactobacillus compared to CON. LP reduced the RA of Leuconostocs , while HEX showed stronger antibacterial abilities to Klebsiella than LP and NAT. In conclusion, HEX improved the aerobic stability, whereas NAT and LP improved fermentation quality by enhancing the proliferation of Lactobacillus during ensiling of high moisture whole-crop corn. • Ensiling decreased Zearalenone and Deoxynivalenol concentrations. • Adding hexanoic acid depressed lactic acid production in corn silage. • L. plantarum and natamycin enhanced the proliferation of Lactobacillus. • Hexanoic acid improved aerobic stability of high moisture whole crop corn silage. [ABSTRACT FROM AUTHOR]

This study aimed to separate the effects of chemical composition and epiphytic microflora on the fermentation quality and bacterial community of Napier grass silage. Napier grass was harvested in two vegetative stages (Early, E G ; Late, L G) with 24 or 28% dry matter, cut into theoretical lengths of 2–3 cm, and ensiled in bag-type silos containing 450 g fresh matter for 30 d. A 2 × 2 factorial arrangement of treatments (2 chemical composition × 2 epiphytic microbiota) in a completely randomized design were as follows: E G epiphytic microbiota + gamma-ray irradiated E G (E M E G), L G epiphytic microbiota + gamma-ray irradiated E G (L M E G), E G epiphytic microbiota + gamma-ray irradiated L G (E M L G), and L G epiphytic microbiota + gamma-ray irradiated L G (L M L G). Triplicates per treatment were sampled after 30 d of ensiling for fermentation quality and bacterial community analyses. The maturity of Napier grass had a great impact on its chemical composition and epiphytic microflora at harvest. Silages made from irradiated E G (E M E G and L M E G) had higher lactic acid concentration and lactic:acetic acid ratio, and lower pH value and ammonia nitrogen (NH 3 -N) concentration than the silages made from irradiated L G (E M L G and L M L G). Species differential analyses showed that the chemical composition variation significantly affected the relative abundance of Lactobacillus , Lactococcus , Enterobacter , Serratia , unclassified Lactobacillales , Leuconostoc and Pediococcus in E M E G and E M L G silages. While there was no effect of epiphytic microbial variation on the relative abundance of bacterial genera in E M L G and L M L G silages. These results manifested that, in this study, chemical composition rather than epiphytic microflora affected the succession of bacterial community in Napier grass silages, thereby affecting the final fermentation quality. • γ-ray sterilization and microbiota transplantation were applied in this study. • Vegetative stage affected the chemical and microbial composition of grass. • Chemical factor was the main factor influencing the quality of Napier grass silage. [ABSTRACT FROM AUTHOR]

• Addition of citric acid residue improved fermentation quality of alfalfa silage. • Citric acid residue enhanced lactic acid accumulation and fibre degradation. • Citric acid residue inhibited the production of ammonia nitrogen. This experiment was conducted to investigate the effects of citric acid residue (CAR) on the fermentation quality and aerobic stability of alfalfa silage and to define the optimal application level of CAR in silage making. Alfalfa was ensiled without additives (CON) or with 1.2 % CAR (C1), 3.6 % CAR (C2) and 6.0 % CAR (C3) on a fresh weight (FW) basis for 3, 6, 9, 15, 30 and 45 days. Chemical and microbial compositions were determined after ensiling. The residual silages ensiled for 45 days were evaluated for aerobic stability. The addition of CAR to alfalfa silages increased (P< 0.05) dry matter (DM) and water-soluble carbohydrate (WSC) contents and decreased (P< 0.05) acetic acid, ethanol, ammonia nitrogen (NH 3 -N) and neutral detergent fibre (NDF) contents compared with those of the control. The values of pH and the contents of DM, lactic acid, acetic acid, ethanol, WSC, NH 3 -N, hemicellulose and cellulose showed a linear relationship with the increasing application level of CAR (P< 0.05). The C3 silages showed the optimal fermentation quality. The C1 and C2 silages showed lower aerobic stability than that of the control (P< 0.05). The results indicated that addition of CAR effectively improved the fermentation quality and enhanced fibre degradation, but had no obvious positive effects on aerobic stability. By comprehensive consideration, 6.0 % CAR was recommended for alfalfa silage making. [ABSTRACT FROM AUTHOR]

• First combined the NGS, γ-ray radiation and microbiota transplantation methods. • Different exogenous microbiota promoted various fermentation types. • Exogenous microbiota changed microbial community of oat silage. • The key microorganisms on affecting silage fermentation type were identified. This study was aimed to assess the effects of exogenous microbiota on fermentation quality and bacterial community dynamics in oat (OT) silage. The irradiated OT was treated with the following: (i) sterile water (STOT); (ii) epiphytic microbiota on oat (OTOT); (iii) epiphytic microbiota on maize (OTMZ); (iv) epiphytic microbiota on sorghum (OTSG). γ-Ray irradiation, microbiota transplantation and sequencing methods were firstly used. After 60 days of ensiling, OTMZ group had higher lactic acid (LA) and lower acetic acid (AA) contents than OTOT group. Inversely, lower LA content and higher ratio of LA to AA was observed in OTSG group than OTOT group. Lactobacillus was predominant in OTMZ-60 group, while Lactobacillus and Enterobacteriaceae were both dominant in OTSG-60 group. Overall, the higher amounts of Enterobacteriaceae and heterofermentative Lactobacillus are conductive to acetic acid-type fermentation, and forage microbiota transplantation may be a potential way to identify the role of microbe during ensiling. [ABSTRACT FROM AUTHOR]