Silage Fermentation Research Articles

Improving the storage of cover crops by co-ensiling with different waste types: Effect on fermentation and effluent production

Cover crops harvested at a low maturity stage generally have a high moisture content, which may generate energy losses during silage storage via effluent production and undesirable fermentations. This paper investigates the use of different waste types as absorbent co-substrates to be added before ensiling. The relation between the absorbent water holding capacity and silage effluent volume was first studied to find an effective parameter to prevent effluent production. Effluent retention was found to be proportional to the absorbent loading and water holding capacity (r2 = 0.98) and up to 90 % of effluent production was avoided when compared to control (295 l.t−1). The impact of different co-substrates (including bio-waste and manures) on overall ensiling performances was then investigated at an optimized absorbent loading. All co-substrates allowed a total effluent retention while a 76 l.t−1 effluent volume was reported for the control. The silage fermentation was modified or mostly unchanged depending on the co-substrate chemical and microbial properties and different metabolic pathways were observed (e.g. homolactic or butyric fermentation). In most conditions, the methane potential of the crop was efficiently preserved over a storage of 60 days. Co-ensiling was shown to be a relevant silage preparation method for biogas production.

The effects of epiphytic microbiota and chemical composition of Italian ryegrass harvested at different growth stages on silage fermentation.

The influence of epiphytic microbiota and chemical composition on fermentation quality and microbial community of Italian ryegrass silage was evaluated. Italian ryegrass harvested at the filling stage (FS) and the dough stage (DS) was sterilized by gamma-ray irradiation and inoculated as follows: (I) FS epiphytic microbiota + irradiated FS (FF); (II) FS epiphytic microbiota + irradiated DS (FD); (III) DS epiphytic microbiota + irradiated DS (DD); (IV) DS epiphytic microbiota + irradiated FS (DF). After 60 days of ensiling, silage made from irradiated FS had a lower pH and ammonia nitrogen (NH3 -N) content and a higher lactic acid (LA) content than that made from irradiated DS. Similarly, silage inoculated with the epiphytic microbiota of DS had a lower pH and NH3 -N content and a higher LA content than that inoculated with the epiphytic microbiota of FS. However, LA-type fermentation (lactic acid:acetic acid > 2:1) was presented at DF and DD. The principal coordinates analysis showed that the distance between FF and DF and FD and DD was closer than other treatments, suggesting that the microbial community of silages made from irradiated FS (or DS) was more similar. The epiphytic microbiota played a more important role in the fermentation type, whereas the chemical composition had a great influence on the contents of fermentation end-products. However, chemical composition had a stronger effect on the microbial community of silage than the epiphytic microbiota. © 2022 Society of Chemical Industry.

Microbiome of rehydrated corn and sorghum grain silages treated with microbial inoculants in different fermentation periods

Due to the co-evolved intricate relationships and mutual influence between changes in the microbiome and silage fermentation quality, we explored the effects of Lactobacillus plantarum and Propionibacterium acidipropionici (Inoc1) or Lactobacillus buchneri (Inoc2) inoculants on the diversity and bacterial and fungal community succession of rehydrated corn (CG) and sorghum (SG) grains and their silages using Illumina Miseq sequencing after 0, 3, 7, 21, 90, and 360 days of fermentation. The effects of inoculants on bacterial and fungal succession differed among the grains. Lactobacillus and Weissella species were the main bacteria involved in the fermentation of rehydrated corn and sorghum grain silage. Aspergillus spp. mold was predominant in rehydrated CG fermentation, while the yeast Wickerhamomyces anomalus was the major fungus in rehydrated SG silages. The Inoc1 was more efficient than CTRL and Inoc2 in promoting the sharp growth of Lactobacillus spp. and maintaining the stability of the bacterial community during long periods of storage in both grain silages. However, the bacterial and fungal communities of rehydrated corn and sorghum grain silages did not remain stable after 360 days of storage.

Nutritive value, silage fermentation characteristics, and aerobic stability of grass-legume round-baled silages at differing moisture concentrations with and without manure fertilization and microbial inoculation.

For baled silages, production of clostridial fermentation products can be exacerbated by exceeding normal moisture targets (45% to 55%), and/or by the application of dairy slurry before harvest. Our objectives were to test a microbial inoculant as a mitigant of clostridial products in high-moisture, grass-legume (52% ± 13.8% cool-season grasses, 44.0% ± 14.0% legumes [predominately alfalfa]) baled silages in swards that were fertilized with dairy slurry. A secondary objective was to examine the effects of bale moisture and inoculation on the aerobic stability of these fermented silages following exposure to air. After the first-cutting was removed, three manure treatments were applied as a whole-plot factor: 1) control (no manure); 2) slurry applied immediately to stubble (63,250 L/ha); or 3) slurry applied after a 1-wk delay (57,484 L/ha). An interactive arrangement of bale moisture (64.1% or 48.4%) and inoculation (yes or no) served as a subplot term in the experiment. The inoculant contained both homolactic (Lactococcus lactis 0224) and heterolactic (Lactobacillus buchneri LB1819) bacteria. The experimental design was analyzed as a randomized complete block with four replications, and the study included 48 experimental units (1.2 × 1.2-m round bales). Total fermentation acids were affected (P ≤ 0.021) by slurry application strategies, but this was likely related to inconsistent bale moisture across slurry-application treatments. Concentrations of butyric acid were low, and there were no detectable contrasts comparing manure treatments (mean = 0.05%; P ≥ 0.645). Bale moisture affected all measures of fermentation, with bales made at 64.1% moisture exhibiting a more acidic final pH (4.39 vs. 4.63; P < 0.001), less residual water-soluble carbohydrates (2.1% vs. 5.1%; P < 0.001), as well as greater lactic acid (4.64% vs. 2.46%; P < 0.001), acetic acid (2.26% vs. 1.32%; P < 0.001), and total fermentation acids (7.37% vs. 3.97%; P < 0.001). Inoculation also reduced pH (4.47 vs. 4.56; P = 0.029), and increased acetic acid (1.97% vs. 1.61%; P < 0.001) and 1,2-propanediol (1.09% vs. 0.72%; P < 0.001) compared to controls. During a 34-d aerobic exposure period, maximum surface bale temperatures were not affected (P ≥ 0.186) by any aspect of treatment, likely due to the prevailing cool ambient temperatures; however, yeast counts were numerically lower in response to greater (P < 0.001) production of acetic acid that was stimulated by both high bale moisture and inoculation.

Research on pH Value Detection Method during Maize Silage Secondary Fermentation Based on Computer Vision

pH value is a crucial indicator for evaluating silage quality. In this study, taking maize silage as the research object, a quantitative prediction model of pH value change during the secondary fermentation of maize silage was constructed based on computer vision. Firstly, maize silage samples were collected for image acquisition and pH value determination during intermittent and always-aerobic exposure. Secondly, after preprocessing the acquired image with the region of interest (ROI) interception, smoothing, and sharpening, the color and texture features were extracted. In addition, Pearson correlation analysis and RF importance ranking were used to choose useful feature variables. Finally, based on all feature variables and useful feature variables, four regression models were constructed and compared using random forest regression (RFR) and support vector regression (SVR): RFR model 1, RFR model 2, SVR model 1, and SVR model 2. The results showed that—compared with texture features—the correlation between color features and pH value was higher, which could better reflect the dynamic changes in pH value. All four models were highly predictive. The RFR model represented the quantitative analysis relationship between image information and pH value better than the SVR model. RFR model 2 was efficient and accurate, and was the best model for pH prediction, with Rc2, Rp2, RMSEC, RMSEP, and RPD of 0.9891, 0.9425, 0.1758, 0.3651, and 4.2367, respectively. Overall, this study proved the feasibility of using computer vision technology to quantitatively predict pH value during the secondary fermentation of maize silage and provided new insights for monitoring the quality of maize silage.

Effects of laccase and lactic acid bacteria on the fermentation quality, nutrient composition, enzymatic hydrolysis, and bacterial community of alfalfa silage.

Ensiling has long been as a mainstream technology of preserving forage for ruminant production. This study investigated the effects of bioaugmented ensiling with laccase and Pediococcus pentosaceus on the fermentation quality, nutritive value, enzymatic hydrolysis, and bacterial community of alfalfa. The application of laccase and Pediococcus pentosaceus combination was more potent in modulating the fermentation quality of silage than laccase and Pediococcus pentosaceus alone, as indicated by higher lactic acid contents and lactic acid to acetic acid ratios, and lower pH, dry matter losses, and ammonia nitrogen contents. Moreover, treatments with additive enhanced protein preservation and structural carbohydrate degradation, while increasing true protein and water-soluble carbohydrate contents. By promoting lignin degradation, treatments containing laccase further facilitated the release of sugars from cellulose compared with treatment with Pediococcus pentosaceus alone. The additive treatments reduced the bacterial diversity and optimized the bacterial community composition of silage, with an increase in the relative abundance of desirable Lactobacillus and a decrease in the relative abundance of undesirable Enterobacter and Klebsiella. PICRUSt functional prediction based on Kyoto Encyclopedia of Genes and Genomes (KEGG) databases revealed that PL and LPL treatments increased the metabolism of membrane transport, carbohydrate, and terpenoids and polyketides related to fermentation activities. It can be concluded that bioaugmented ensiling with laccase and Pediococcus pentosaceus combination can be an effective and practical strategy to improve silage fermentation and nutrient preservation of alfalfa silage.

Ensiling vine tea (Ampelopsis grossedentata) residue with Lactobacillus plantarum inoculant as an animal unconventional fodder

The study aimed to evaluate the application of silage fermentation in storing vine tea residue. Dynamic of fermentation-related product, chemical component and bacterial community of silage with or without Lactobacillus plantarum F1 inoculant were analyzed. The results showed that F1 treatment had a significant (P<0.05) impact on the lactic acid and ammoniacal nitrogen concentrations and pH value. Total phenols were well preserved in both treatments. After 30 days of ensiling, L. plantarum occupied the majority of Lactobacillus genus (more than 95%) in all silage samples. Spearman revealed a positive (P<0.01) correlation between lactic acid content and Lactobacillus. Overall, ensiling vine tea residue with L. plantarum can effectively preserve the nutritional attributes and total phenols, which offers a new insight into utilizing vine tea residue.

Dynamic Changes in Fermentation Quality and Structure and Function of the Microbiome during Mixed Silage of Sesbania cannabina and Sweet Sorghum Grown on Saline-Alkaline Land.

ABSTRACTProtein-rich Sesbania cannabina and sugar-rich sweet sorghum [Sorghum dochna (Forssk.) Snowden] are characterized by their higher tolerance to saline-alkaline stresses and simultaneous harvests. They could be utilized for coensiling because of their nutritional advantages, which are crucial to compensate protein-rich forage in saline-alkaline regions. The current study investigated the fermentation quality, microbial community succession, and predicted microbial functions of Sesbania cannabina and sweet sorghum in mixed silage during the fermentation process. Before ensiling, the mixtures were treated with compound lactic acid bacteria (LAB) inoculants followed by 3, 7, 14, 30, and 60 days of fermentation. The results revealed that the inoculated homofermentative species Lactobacillus plantarum and Lactobacillus farciminis dominated the early phase of fermentation, and these shifted to the heterofermentative species Lactobacillus buchneri and Lactobacillus hilgardii in the later phase of fermentation. As a result, the pH of the mixed silages decreased significantly, accompanied by the growth of acid-producing microorganisms, especially L. buchneri and L. hilgardii, which actively influenced the bacterial community structure and metabolic pathways. Moreover, the contents of lactic acid, acetic acid, 1,2-propanediol, and water-soluble carbohydrates increased, while the contents of ammonia-N and fiber were decreased, with increasing ratios of sweet sorghum in the mixed silage. Overall, coensiling Sesbania cannabina with >30% sweet sorghum is feasible to attain high-quality silage, and the relay action between homofermentative and heterofermentative LAB species could enhance fermentation quality and conserve the nutrients of the mixed silage.IMPORTANCE The coensiling of Sesbania cannabina and sweet sorghum is of great practical importance in order to alleviate the protein-rich forage deficiency in saline-alkaline regions. Furthermore, understanding the microbial community’s dynamic changes, interactions, and metabolic pathways during ensiling will provide the theoretical basis to effectively regulate silage fermentation. Here, we established that coensiling Sesbania cannabina with >30% sweet sorghum was effective at ensuring better fermentation quality and preservation of nutrients. Moreover, the different fermentation types of LAB strains played a relay role during the fermentation process. The homofermentative species L. plantarum and L. farciminis dominated in the early phase of fermentation, while the heterofermentative species L. buchneri and L. hilgardii dominated in the later phase of fermentation. Their relay action in Sesbania cannabina-sweet sorghum mixed silage may help to improve fermentation quality and nutrient preservation.

Effects of a mixture of Lentilactobacillus hilgardii, Lentilactobacillus buchneri, Pediococcus pentosaceus and fibrolytic enzymes on silage fermentation, aerobic stability, and performance of growing beef cattle.

This study evaluated the effects of novel silage inoculants containing lactic acid bacteria (LAB) and fibrolytic enzymes on ensiling, aerobic stability (AS), and the performance of growing beef cattle. Whole-plant corn forage was either uninoculated (CON) or inoculated with a mixture of LAB containing (cfu g-1 fresh forage) 1.5 × 105 L. hilgardii (CNCM I-4785), 1.5 × 105 L. buchneri (NCIMB 40788) and 1.0 × 105 P. pentosaceus (NCIMB 12455) for a total of 4.0 × 105 cfu g-1 fresh forage LAB (IB), or a combination of IB plus fibrolytic enzymes (xylanase + β-glucanase) (IC). All treatments were ensiled in mini-silos, whereas CON and IC were also ensiled in silo bags for the growth performance study. Total bacteria (TB) counts were lower (P = 0.02) for IC than CON after 14 d of ensiling, whereas TB counts of IC and IB were greater (P ≤ 0.01) than CON after 60 d of ensiling in mini-silos. The LAB in IC and IB ensiled in mini-silos were greater than CON on d 60 (P ≤ 0.01) and 90 (P ≤ 0.001) of ensiling and after 3 d (P ≤ 0.01) of aerobic exposure (AE). Silage pH of IC ensiled in silo bags was lower than CON on d 3 (P < 0.01), 7 (P < 0.001), and 14 (P = 0.02) of AE. Yeast counts were lower for IC than CON in terminal silage (P < 0.001), and after 3 (P < 0.001) and 7 d (P < 0.01) of AE. Acetate (AC) concentrations were higher (P ≤ 0.02) for IC than CON throughout AE, whereas lactate (LA) concentrations of IC were greater than CON on d 3 (P < 0.001), 7 (P < 0.01), and 14 (P < 0.001) of AE. Greater AC concentration and lower yeast counts resulted in greater (P < 0.001) stability for IC ensiled in silo bags than CON after 14 d of AE. Growth performance of steers was similar (P > 0.05) as the nutrient composition of silage was similar across diets. Improved AS of IC could potentially have a greater impact on DMI, production efficiency, and growth performance in large-scale commercial feedlot operations where silage at the silo face may be exposed to air for longer periods of time.

Changes to the microbiome of alfalfa during the growing season and after ensiling with Lentilactobacillus buchneri and Lentilactobacillus hilgardii inoculant.

This study evaluated changes in epiphytic microbial population of alfalfa (Medicago sativa) during the growing season. First cut forage was harvested to study the effects of an inoculant combining two obligate heterofermentative lactic acid bacteria strains on the bacterial and fungal communities and the fermentation of alfalfa silage. The epiphytic microbiome of alfalfa was evaluated 10-times during the growing season. Alfalfa wilted to 395.0g/kg was treated with water (Control) or with a combination of L. buchneri NCIMB 40788 and L. hilgardii CNCM-I-4785 (LBLH). Mini-silos were opened after 1, 4, 8, 16, 32, and 64 days of ensiling. The relative abundance (RA) of the epiphytic bacterial and fungal families varied during the growing season. After 1day, Weissella was the most abundant genus and present at similar RA in the two treatments (average 80.4%). Compared with Control, LBLH had a higher RA of Lactobacillus at day 1, 16, 32, and 64, and a lower RA of Weissella from day 8 to 64. Control contained more bacteria belonging to the Enterobacteriales than LBLH up to day 16. Inoculated silage had more acetate than Control at day 32 and 64. The fungal population were similar between treatments. The enhanced development and dominance of Lactobacillus in inoculated silage led to greater accumulation of acetate and propionate, which reduced the numbers of culturable yeasts but did not markedly affect the fungal community structure. The bacterial community composition of alfalfa stands in the filed changed over time and was affected by cutting. For the ensiling trial, inoculation modified the composition of the bacterial community of alfalfa, increasing the RA of Lactobacillus while reducing the RA of Weissella and of Enterobacteriaceae. Inoculation increased the RA of Lactobacillus, hampering the dominance of Weissella in the early stages of ensiling, improving antifungal compounds production and reducing the numbers of culturable yeasts.

Effect of Storage Period on the Fermentation Profile and Bacterial Community of Silage Prepared with Alfalfa, Whole-Plant Corn and Their Mixture

This study aimed to investigate the impact of storage time on the bacterial community and fermentation profile of silage prepared with alfalfa, whole-plant corn, and their mixture. Fresh alfalfa and whole-plant corn were chopped and combined in fresh weight ratios of 1:0 (alfalfa, control), 0.8:0.2 (M1), 0.6:0.4 (M2), and 0:1 (corn). Three silos of each treatment were analyzed after 30, 60, and 90 d of storage. With storage time, pH, acetic acid, propionic acid, butyric acid, and ammonia nitrogen levels increased in alfalfa silage (p &lt; 0.01), whereas lactic acid level decreased (p &lt; 0.01). Compared to alfalfa silage, M1, M2, and corn silages were better fermented and more stable during storage. The dominant bacteria in M1, M2, and corn silages shifted significantly from L. plantarum, L. buchneri, and L. brevis to L. acetotolerans and L. buchneri during 30 to 60–90 d of storage, and storage time decreased the bacterial diversity of these silages. In conclusion, storage time significantly decreased the fermentation quality of alfalfa silage and remarkably optimized the bacterial community structure of well-fermented M1, M2, and corn silages. Alfalfa should be ensiled with at least 20% whole-plant corn to improve silage fermentation quality and storage stability.

Effects of pyroligneous acid as silage additive on fermentation quality and bacterial community structure of waste sugarcane tops

This article intends to improve the recycling of waste sugarcane (Saccharum officinarum) tops and the value-added utilization of pyroligneous acid. Fresh sugarcane tops can be used by ruminants, but they are prone to dehydration and mildew during storage, reducing their feeding value. Pyroligneous acid, a by-product in the process of making biochar, has good antibacterial effects. Adding pyroligneous acid to sugarcane tops for silage fermentation may be an effective way to promote the recycling of sugarcane tops. Thus, the fermentation quality and bacterial community of sugarcane tops ensiled with or without 1–2% pyroligneous acid for 5, 10, 20, or 100 days were investigated. Results showed that pyroligneous acid increased the acetic acid content and reduced ammonia-N concentration, and numbers of coliform bacteria and molds in sugarcane tops silages. On the other hand, the addition of pyroligneous acid decreased the diversity of bacteria in sugarcane-top silage. Pyroligneous acid decreased Firmicutes and Leuconostoc relative abundances while increasing Lactobacillus relative abundances. Fermentation was also limited by the addition of pyroligneous acid, which reduced metabolic activities during ensiling.Graphical abstract

Efectos del suero ácido sobre la calidad química fermentativa y la estabilidad aeróbica del ensilado de grano de maíz rehidratado

The objective was to evaluate the fermentative, chemical characteristics and aerobic stability of corn grain silages rehydrated with whey fluid (WF) or whey powder (WP) and water, with or without the addition of inoculant (I). The corn grain was ground and hydrated adding water without chlorine and/or whey to reach 35 % humidity and stored in silos of 4.36 kg. After 45 d of fermentation, samples of the silages were submitted to chemical-fermentative analyses in opening of silos and 240 h of exposure to air. The aerobic stability of the silages was evaluating during 240 h has considered to the loss when the temperature of the ensiled mass exceeded the ambient temperature by 2 °C. A reduction in the acid detergent fiber (ADF) and lignin content of the silages was observed with the use of WF and WP. The levels of ammoniacal nitrogen (NH3-N) were the lowest for WF and WP (0.7 and 0.9 g/kg TN) and pH was 4.31 for WF after 240 h of aerobic exposure. The use of inoculants provided higher levels of Ash, ether extract (EE), and low buffering capacity (BC), in addition to reductions in ADF levels. The inoculated silages showed higher levels of NH3-N and pH after 240 h. The silage of corn grains rehydrated with WF provided ideal pH values, low NH3-N content, reduced levels of ADF and lignin, and improved aerobic stability. In addition to being a sustainable alternative, the use of fluid whey to rehydrate corn grains adds nutritional value and improves silage fermentation.

The effect of cultivar and stage of growth on the fermentation, aerobic stability and nutritive value of ensiled Quinoa

Quinoa can be an important source of silage as an alternative forage crop. However, there is limited information on the ensiling of quinoa. This study aimed to investigate the silage fermentation quality, nutritive value and aerobic stability of quinoa cultivars harvested at different plant growing stages. The experiment was carried out in experimental area of the Hatay Mustafa Kemal University, Faculty of Agriculture in 2019 and 2020 growing seasons. The experiment was laid out in a split plot in randomized block design with three replications, three main plots were harvesting times (flowering, milky and dough stages) and five sub-plots were cultivars (Mint Vanilla, Cherry Vanilla, French Vanilla, Red Head and Titicaca). Traits such as pH, ammonia nitrogen, lactic acid bacteria, lactic acid, acetic acid, butyric acid, propionic acid, ethanol, dry matter, neutral detergent fiber, acid detergent fiber, acid detergent lignin, crude protein, ash, ether extract, water soluble carbohydrate and relative feed value were investigated to determine silage fermentation quality and nutritive value. In addition, all silages were evaluated in terms of aerobic stability. Among the evaluated quinoa cultivars in terms of fermentation quality, cv. Titicaca and cv. French Vanilla provided superior results compared to other cultivars. It was also determined that it would be more appropriate to harvest these superior quinoa cultivars during the dough stage for quality silage. Among the silages, the cv. Titicaca had the best aerobic stability. As a result of this study, it was concluded that cv. French Vanilla and cv. Titicaca should be harvested during the dough stage to obtain better silage quality. According to the results of this study, it was deduced that the quinoa plant could be an alternative ensiling crop.

Efficacy of adding chemical and microbial additives to silage on beef cattle performance: Systematic review and meta‐analysis

AbstractThe effects of different additives on farm‐scale silage quality and beef cattle performance are inconsistent. This study aimed to carry out a systematic review and meta‐analysis to evaluate the efficacy of chemical and microbial additives to silage on beef cattle performance. Systematic searches were performed using databases and scientific journals, and 42 articles were selected. Data for all variables were grouped into subgroups according to the additive type. For dry matter intake and average daily gain, the data were also grouped by forage type due to greater comparison numbers. The treatment mean differences and 95% confidence intervals (p &lt; 0.05) were analysed using a random‐effects model. The use of homo‐ and heterofermentative microbial inoculant mixtures and chemical additives (Ch) increased the average daily gain of beef cattle fed maize/sorghum silage. Homofermentative microbial inoculant (Ho), Ch, and a mixture of microbial inoculant and chemical additives also increased the average daily gain of beef cattle fed temperate grasses. Only Ch increased dry matter intake. Ch increased feed efficiency, and Ch and Ho increased carcass weight. The evaluated additives improved the silage fermentation process mainly via pH and ammonia nitrogen reduction. Overall, this meta‐analysis demonstrated that silage additives improved the ensiling process and beef cattle performance, with better results with Ch use. Due to the aerobic stability and microbiological profile analyses being carried out more in laboratory‐scale silos, more studies are needed to determine these silage parameters after opening the silo at the farm scale.

Effects of Different Additives on the Chemical Composition, Fermentation Profile, In Vitro and In Situ Digestibility of Paper mulberry Silage

Paper mulberry (Broussonetia papyrifera) plants are served as a local roughage in China, and they are mostly processed as silage for ruminants. This study aimed to explore the effects of different silage additives on the chemical composition, fermentation profile, as well as the in vitro and in situ digestibility of paper mulberry (PM) silage. Four groups consisting of PM silage, three with additives and one without any additives as the control group (CON), were established. The three experimental groups with additives were set up as follows: CON with 5 × 106 CFU per gram of fresh PM weight of lactic acid bacteria (Lactobacillus plantarum) (LAB); CON with 3% fresh PM weight of molasses (MOL) added to the PM silage; and CON with both LAB and MOL added (LM). After 45 days of ensiling at 20 °C, all of the PM treatment groups increased their ash content and decreased their water-soluble carbohydrate content (p &lt; 0.05). Meanwhile, the pH and NH3-N content of the PM silage were lower in the additive treatment groups than in the CON group (p &lt; 0.05). Lactic acid in the LM group was the highest (p &lt; 0.05) among the four groups, and trace amounts of butyric acid was detected only in the CON group. In vitro dry matter digestibility was similar among all groups. Results of the in situ experiment found that the effective digestibility of the PM silage dry matter, as well as the acid detergent fiber digestibility was higher in the LM group than in the CON group (p &lt; 0.05). In conclusion, the addition of LAB, MOL, and their combination can improve PM silage fermentation and improve the in situ digestibility of dry matter and acid detergent fiber; however they do not affect in the vitro digestibility of PM silage.

Fermentation quality, nutritive value and in vitro ruminal digestion of Napier grass, sugarcane top and their mixed silages prepared using lactic acid bacteria and formic acid

AbstractThis study aimed to determine the fermentation quality, nutritive value and in vitro ruminal digestion of silages produced with mixtures of Napier grass (NG) and sugarcane top (ST) in five different ratios of fresh matter: 100:0 (N100), 75:25 (N75), 50:50 (N50), 25:75 (N25) and 0:100 (N0) with or without lactic acid bacteria (LAB) and formic acid (FA). The NG contained a higher crude protein (CP) content and buffering capacity, but lower dry matter (DM), organic matter, neutral detergent fiber, acid detergent fiber and water‐soluble carbohydrates contents than ST. The N25 silage fermented well, with a significantly higher lactic acid (LA) content (p &lt; .05) and lower pH and NH3‐N concentration than those of other mixed silages (p &lt; .05). The FA addition resulted in the highest CP content and lowest pH, LA, acetic acid (AA) and NH3‐N contents, while LAB addition resulted in the highest LA content compared with other treatments. Although in vitro DM digestibility (IVDMD) did not significantly differ among the mixed silages (p &gt; .05), mixing with ST and adding LAB or FA increased the IVDMD. Gas production (GP) and AA content of N25 silages were significantly higher than those of other silages (p &lt; .05). The LAB‐ or FA‐treated silages had higher IVDMD, GP, total volatile fatty acid and AA contents (p &lt; .05) but lower pH compared with the control silage (p &lt; .05). These results demonstrated that NG utilization improved upon mixing with ST due to the enhanced fermentation during ensiling, and the optimum mixing ratio for NG and ST was 25:75 on FM basis. Using LAB and FA as additives during ensiling can improve silage fermentation quality and in vitro ruminal digestion.

Comparisons of Ramie and Corn Stover Silages: Effects on Chewing Activity, Rumen Fermentation, Microbiota and Methane Emissions in Goats

The study aimed to investigate the nutritional value of ramie (Boehmeria nivea) silage, and its consequences for chewing activity, rumen fermentation, and enteric methane (CH4) emissions in goats, by comparing it with corn stover (CS) silage. An in vitro ruminal experiment was firstly performed to investigate the substrate degradation and fermentation of CS and ramie silage. The ramie silage diet was formulated by replacing 60% of CS silage with ramie silage (dry matter (DM) basis). Eight female Xiangdong Black goats (a local breed in Southern China, 1 to 1.2 years of age) with BW of 21.0 ± 1.05 kg were used for this experiment and were randomly assigned to either one of the two dietary treatments in a cross-over design. The ramie silage had higher crude protein (CP) and ash content and lower hemicellulose content, together with decreased (p &lt; 0.05) nutrient degradation and methane production and increased (p &lt; 0.05) acetate molar percentage and acetate to propionate ratio through in vitro ruminal fermentation. Feeding the ramie silage diet did not alter feed intake (p &gt; 0.05), decreased (p &lt; 0.05) nutrient digestibility, and increased (p &lt; 0.05) chewing activity and rumination activity, with reductions (p &lt; 0.05) in eating activity and idle activity. Although feeding the ramie silage diet caused a greater (p &lt; 0.05) molar percentage of acetate and lower molar percentage of propionate, it decreased the rumen-dissolved CH4 concentration and enteric CH4 emissions (p &lt; 0.05). Feeding the ramie silage diet did not alter (p &gt; 0.05) the population of bacteria, protozoa, and fungi; it increased the 16S rRNA gene copies of Ruminococcus flavefaciens (p &lt; 0.05). Further 16SrRNA gene amplicon analysis indicated a distinct bacterial composition between the two treatments (p &lt; 0.05). Feeding the ramie silage diet led to a lower abundance of genera Lawsonibacter, Sedimentibacter, Saccharofermentans, Sediminibacterium, and Bifidobacterium (p &lt; 0.05). Ramie can be an alternative forage resource to stimulate chewing activity and reduce CH4 emissions in ruminants.

Polygenic Olive by-products to Silage production by Anaerobic Digestion : a new alternative of sustainable agriculture security and socio-economic advantage impact

Olive by-products consisting of 40 % wood pruning and leaves, 40 % Olive pomace and 20 % OMW were ground and combined with preserving them by anaerobic fermentation (wet silage) for 4 months. The pH and total nitrogen/dry matter silage sample were 5.46 and 45 mg/g, respectively; the values comply with standards norms. After the silage process, a decreasing of phenol compound concentration of 67.85% was revealed and among 37 fatty acids compounds were identified with a valuable richness in mineralnutrients. The silage was devoid of total coliforms and fecal coliforms and yeast number doesn't exceed 489.95104 by gram of the silage. Correlation studies were done between the Silage and silage by-products parameters to evaluate the fermentation silage process. They showed different significant trends. A social-economic challenge was studied and discussed. Compared to that of using barley, the cost was 3 times less, with better quality for silage.

Effects of Lactiplantibacillus plantarum inoculation on the quality and bacterial community of whole-crop corn silage at different harvest stages

BackgroundSilage is achieved by anaerobic fermentation of lactic acid bacteria. However, harvest stage and Lactiplantibacillus plantarum (L. plantarum) content affect the changes of microbial community in silage, which play an important role in silage quality and mycotoxin levels. The current study evaluated the effects exerted by the application of L. plantarum on fermentation, mycotoxins and bacterial community of whole-crop corn silage at different harvest stages. The fresh whole plant corn from the same area was harvested during the milk stage and the dough stage, following which from each harvest stage was subjected to four L. plantarum treatments: 0 cfu/g; 1 × 106 cfu/g; 1 × 107 cfu/g; and 1 × 108 cfu/g in a 2 × 4 factorial experimental design. Samples were collected on days 0, 3, 7, 21 and 42. Subsequently, nutrition parameters, fermentation parameters, mycotoxin levels and bacterial community were determined.ResultsProlonging the harvest stage resulted in an increase in the levels of starch and dry matter as well as deoxynivalenol in corn silage. Addition of 1 × 107 cfu/g and 1 × 108 cfu/g of L. plantarum applied after 42 d of ensilage reduced dry matter loss, which significantly lowered deoxynivalenol concentration in corn silage at the dough stage (P < 0.01). The pH of corn silage decreased, whereas the lactic acid concentration increased after ensiling. The effects exerted by the interaction (harvest stage × dose of L. plantarum) on pH on day 21 as well as on fermentation and lactic acid on days 21 and 42 were significant (P < 0.05). Addition of 1 × 107 cfu/g of L. plantarum at the dough stage significantly increased the relative abundance of Firmicutes while decreasing that of Bacteroidetes, compared to when L. plantarum was not added (P < 0.05).ConclusionsAdding L. plantarum improved the fermentation quality and bacterial community of silage, which reduced part of mycotoxin content and relative abundance of harmful bacteria. In addition, adding L. plantarum in dough stage resulted in greater improvements to mycotoxin content and bacterial community.