Water-soluble Carbohydrate Content Research Articles

Effects of Cellulase and Xylanase Addition on Fermentation Quality, Aerobic Stability, and Bacteria Composition of Low Water-Soluble Carbohydrates Oat Silage

Most oat forage has low water-soluble carbohydrates (WSC), which may be the main limited factor for silage fermentation safely, but oat is rich in cellulose and hemicellulose; therefore, we assume that xylanase and cellulase as additives can reduce the content of cellulose and xylan in oat silage, increase the microbial fermentable sugar content, and improve the fermentation quality of the silage. After wilting, oats were treated as follows: (i) distributed water (CK); (ii) silages inoculated with xylanase (X); (iii) silages inoculated with cellulase (C), ensiling for 3 days (early stage of silage) and 60 days (late stage of silage), respectively, after ensiling 60 days for a 5-day aerobic exposure study. The pH, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were significantly reduced by xylanase and cellulase treatment during the late stage of silage, and the concentration of lactic acid, acetic acid, and ammonia nitrogen increased remarkably. The WSC content reached its peak with xylanase treatment during the late stage of silage. The content of crude protein (CP) was not affected by additives but by the silage period; CP and ether extract (EE) significantly increased during the late stage of silage compared to the early stage. After ensiling, the bacterial community showed that xylanase and cellulase treatment increased the relative abundance of lactic acid bacteria. Lactobacillus has a higher relative abundance with cellulase treatment after 60 days of ensiling; this can effectively reduce the pH of silage and ensure long-term, stable storage of silage. Cellulase and xylanase increased bacterial diversity during aerobic exposure and improved the aerobic stability of silage significantly. This study indicated that different additives and silage periods had significant effects on chemical compositions, fermentation quality, and bacterial community; meanwhile, both additives improved the aerobic stability of silage. In summary, when the WSC of oat is low, cellulase and xylanase have good effects as silage additives, and the comprehensive effect of cellulase is more prominent.

Effect of isolated lactic acid bacteria on the quality and bacterial diversity of native grass silage.

The objective of this study was to isolate lactic acid bacteria (LAB) from native grasses and naturally fermented silages, determine their identity, and assess their effects on silage quality and bacterial communities of the native grasses of three steppe types fermented for 60 days. Among the 58 isolated LAB strains, Limosilactobacillus fermentum (BL1) and Latilactobacillus graminis (BL5) were identified using 16S rRNA sequences. Both strains showed normal growth at 15- 45°C temperature, 3-6.5% NaCl concentration, and pH 4-9. Two isolated LAB strains (labeled L1 and L5) and two commercial additives (Lactiplantibacillus plantarum and Lentilactobacillus buchneri; designated as LP and LB, respectively) were added individually to native grasses of three steppe types (meadow steppe, MS; typical steppe, TS; desert steppe, DS), and measured after 60 d of fermentation. The fresh material (FM) of different steppe types was treated with LAB (1 × 105 colony forming units/g fresh weight) or distilled water (control treatment [CK]). Compared with CK, the LAB treatment showed favorable effects on all three steppe types, i.e., reduced pH and increased water-soluble carbohydrate content, by modulating the microbiota. The lowest pH was found in the L5 treatment of three steppe types, at the same time, the markedly (p < 0.05) elevated acetic acid (AA) concentration was detected in the L1 and LB treatment. The composition of bacterial community in native grass silage shifted from Pantoea agglomerans and Rosenbergiella nectarea to Lentilactobacillus buchneri at the species level. The abundance of Lentilactobacillus buchneri and Lactiplantibacillus plantarum increased significantly in L1, L5, LP, and LB treatments, respectively, compared with CK (p < 0.05). In summary, the addition of LAB led to the shifted of microbiota and modified the quality of silage, and L. fermentum and L. graminis improved the performance of native grass silage.

Ensiling hybrid Pennisetum with lactic acid bacteria or organic acids improved the fermentation quality and bacterial community.

The aim of this study was to compare the effect of different additives on nutritional quality, fermentation variables and microbial diversity of hybrid Pennisetum silages. A control (CK - no additives) and seven treatments were tested, namely, Lactiplantibacillus plantarum (LP), Lentilactobacillus buchneri (LB), propionic acid (PA), calcium propionate (CAP), LP + LB; LP + PA and LP + CAP. In comparison with CK, all treatments increased the contents of crude protein and lactic acid, decreased the content of butyric acid, and altered the bacterial communities of the silage. Except for the CAP and LP + CAP treatments, the additives decreased pH and the ammonia nitrogen:total nitrogen (NH3-N:TN) ratio. The results of principal component analysis revealed that the PA, LP + PA and LP + LB treatments ranked as the top three silages. The PA and LP + PA treatments exhibited higher water-soluble carbohydrate content, but lower pH, and NH3-N:TN ratio than the other treatments. With the PA and LP + PA treatments, the relative abundances of Lactobacillus and Enterobacter decreased, and of Proteobacteria and Delftia increased, while the carbohydrate metabolism of the microorganisms improved. The LP and LB treatments reduced the Shannon and Simpson diversities. In the beta diversity, PA and LP + PA separated from the other treatments, indicating that there were differences in the composition of bacterial species. The relative abundance of Lactobacillus increased in the LP and LB treatments and of Leucanostoc and Weissella increased in the CAP and LP + CAP treatments. In summary, the addition of L. plantarum, L. buchneri, propionic acid, calcium propionate, and their combinations improved fermentation quality, inhibited harmful bacteria and conserved the nutrients of hybrid Pennisetum.

Effects of lactic acid bacteria and molasses on the fermentation quality, in vitro dry matter digestibility, and microbial community of Korshinsk peashrub (Caragana korshinskii Kom.) silages harvested at two growth stages

AbstractThis study investigated the effects of additives on fermentation quality, in vitro digestibility and microbial communities of Korshinsk peashrub (Caragana korshinskii Kom.) silages at different maturity stages. Korshinsk peashrub was harvested at budding (S1) and blooming (S2) stages, and ensiled without additives (CON), or with 5% molasses (M0), or a combination of 5% molasses and either L. plantarum CLP (M1) or L. plantarum L694 (M2). Each treatment was triplicated and ensiled for 60 days. Delayed harvest increased water soluble carbohydrates (WSC), neutral detergent fibre (aNDF) and acid detergent fibre (ADF) in silages at S2 stage, whereas crude protein (CP) was lower in silages at S1 stage. Compared with the CON group, the additives treated silages had lower pH, greater lactic acid (LA), acetic acid (AA), and WSC concentrations (p &lt; .05). Application of molasses alone or in combination with CLP had a noticeable effect on bacterial communities, with an increase in Lactobacillus in silages at both stages, whereas M2 silages presented more unfavourable microorganisms. Spearman's rank correlation analysis showed that LA concentration in silage was positively correlated with Lactobacillus relative abundance at both stages, while ammonia nitrogen (NH3‐N) concentration was positively correlated with the relative abundances of unclassified‐f‐Enterobacteriaceae and Enterobacter. In conclusion, delayed harvest could result in greater WSC and aNDF but lower CP in Korshinsk peashrub silage. Low WSC is the primary limiting factor affecting silage quality, and ensiling with molasses accelerated lactic acid fermentation in Korshinsk peashrub silage, providing a high‐quality forage resource for livestock production.

A comparison of the nutritive value of perennial ryegrass, perennial ryegrass and white clover and multispecies‐based farmlet systems

AbstractBackgroundLimited information is available regarding the nutritive value and structural characteristics of multispecies swards when rotationally grazed.MethodsThree farmlet types were investigated in terms of their nutritive value: Lolium perenne (LP); L. perenne+Trifolium repens (LP+TR); and a multispecies sward containing grasses, legumes and herbs (MSS). Farmlets were stocked with beef steers (2.5 livestock units ha−1), grazed on a 1 ha scale to 6 cm (MSS) and 4 cm (LP and LP+TR) residuals.ResultsA greater ash concentration was found in MSS than LP (84 vs. 75 g kg−1 DM). Both LP+TR and MSS had higher crude protein and lower neutral detergent fibre concentrations than LP. The relative ranking of water soluble carbohydrate and dry matter (DM) concentration was LP &gt; LP+TR &gt; MSS. Despite the leaf component of the LP farmlet contributing more to herbage DM, the organic matter digestibilities of the swards were similar.ConclusionsThe MSS and LP+TR farmlets achieved similar forage quality under intensive grazing to LP. However, it is worth noting that MSS had a higher concentration of acid detergent lignin, which can negatively impact digestibility. Further investigation is needed to determine optimal grazing management practices that can minimise the effects of higher lignin concentration on digestibility in multispecies swards.

The Effect of Lactobacillus planturum YQM48 Inoculation on the Quality and Microbial Community Structure of Alfalfa Silage Cultured in Saline-Alkali Soil

Alfalfa cultivated in salt–alkali soil was used for fermentation, to which an inoculum of Lactobacillus plantarum YQM48 was added, to assess its effect on the feed quality and the microbial community structure of the fermented silage. A control was included without inoculum. The nutritional components, fermentation quality, pH, and microbial community of the silage were measured after 30 and 60 days of anaerobic fermentation. The results showed that after 30 and 60 days of fermentation in the presence of the inoculum, the content of water-soluble carbohydrates, crude protein content, and dry matter were all significantly higher than those of the control silage, the pH and butyric acid content were lower, and the content of lactic acid and acetic acid were higher (p &lt; 0.05 for all). There was no significant difference in pH and butyric acid content between 30 and 60 days of fermentation in the presence of the inoculum (p &gt; 0.05), while the lactic acid and acetic acid contents were significantly lower in the 60-day silage compared to the 30-day silage (p &lt; 0.05). Fermentation reduced the abundance of Cyanobacteria and Proteobacteria (the abundant phyla in the fresh alfalfa), while the abundance of Firmicutes increased, reaching 92.3% after 60 days of fermentation with inoculum. The dominant genus in that sample was Lactobacillus (70.0%), followed by Enterococcus (12.9%), while fermentation of 60 days without inoculum resulted in only 29.2% Lactobacillus, together with 27.8% Cyanobacteria, and 12.2% Enterococcus. In summary, the addition of L. plantarum YQM48 can improve the nutritional components and fermentation quality of alfalfa silage cultivated on a salt-alkali soil.

Effects of cellulase and xylanase on fermentative profile, bacterial diversity, and in vitro degradation of mixed silage of agro-residue and alfalfa

The objective was to determine effects of cellulase, xylanase, and commercial fibrolytic enzymes on fermentation quality, aerobic stability, bacterial community, and in vitro degradation of mixed silages. Mixtures of alfalfa, wheat bran, and rice straw [80:15:5 on a fresh matter (FM) basis] were ensiled for 1, 3, 5, 7, 15, 30, and 45 d after treatment with: distilled water (control, C); cellulase (E); xylanase (X); or commercial fibrolytic enzymes (EX), with all enzyme preparations applied at 100 U/g FM. The 45-day silages were subjected to an in vitro degradation test. Each of the three enzyme-treated groups enriched relative abundance (RA) of Lactobacillus, Weissella, and Stenotrophomonas maltophilia, increased water soluble carbohydrate (WSC) concentrations, and extended aerobic stability over 384 h, but concurrently inhibited growth of undesirable microbes (i.e., Acinetobacter sp, Lelliottia amnigena, and Sphingomonas sp), reducing pH and concentrations of ammonia nitrogen (AN), butyric acid (BA) and propionic acid (PA). Compared to C, adding X or EX increased the RA of L. paralimentarius and L. parabrevis, enhanced accumulation of acetic acid (AA) and crude protein (CP), and reduced hemicellulose content. Furthermore, E group silage had the highest abundance of W. cibaria. In addition, EX enriched RA of Bacillus velezensis, reduced AN concentration, increased DM degradability, total VFA production, and gas production during in vitro incubation. In conclusion, addition of X or EX enhanced ensiling by enhancing concentrations of AA; however, EX was the most promising enzyme, based on reducing AN concentration and increasing DM content and DM degradability.Graphical

Long transportation duration affects nutrient composition, mycotoxins and microbial community in whole-plant corn silage.

Potential nutrient losses and mycotoxin accumulation caused by abnormal fermentation during transportation from cropland to dairy farms leads to the diseases incidence and threatens the health of dairy cows, then further causes financial losses. The aim of this study was to investigate the effects of different transportation times on the nutritional composition, mycotoxins, and microbial communities in whole-plant corn silage (WPCS). Three groups were subjected to different transport times: DY, short (<200 min); ZY, medium time (300-500 min); and CY, long transport time (>600 min). WPCS were collected from the same field, and nutrient composition and microbial composition before and after transportation were analyzed. Our results showed that the temperature of WPCS was higher in the ZY and CY groups than in the DY group (P < 0.01). There were no significant differences in dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE) and starch contents after different transportation times (P > 0.05), whereas the starch and water-soluble carbohydrates (WSC) contents in the CY group was significantly decreased after transport (P < 0.05). Similarly, the concentration of vomitoxin in the DY and CY groups declined markedly (P < 0.05) and the zearalenone content in the DY group also significantly decreased after transportation (P < 0.05). Regarding the analysis of microorganisms in WPCS, UniFrac-distance matrices and Shannon indices showed differences in the ZY group (P < 0.05), but fungal diversities were not influenced by the transport time (P > 0.05). In the ZY group, the relative abundance of Lactiplantibacillus decreased significantly after transportation (P > 0.05), but the relative abundances of unidentified_Chloroplast, Pantoea, Gluconobacter, unidentified Acetobacter and Acinetobacter increased markedly (P < 0.05). In addition, the relative abundances of Acetobacter and Gluconobacter in the CY group increased after transport (P < 0.05). Among fungal communities, a total of three, nine, and ten different fungal flora were observed in the DY, ZY, and CY groups, respectively, although no difference was found in fungal diversity. In conclusion, increased temperature, loss of starch, and mycotoxin variation were found with increased transport time. This might be the result of competition between bacteria and fungi, and novel technologies will need to be utilized for further exploration of the mechanism.

50 Water-soluble carbohydrate content in equine pasture: Impact of fertilization, season, and grass species

Horses spend a significant proportion of time grazing to meet their nutritional requirements. However, many domesticated horses now graze on energy-dense pastures designed to support production animals. Excessive consumption of these pastures that often contain significant quantities of water-soluble carbohydrates (WSC) has been linked to the development of pasture-associated laminitis. Although seasonal changes in pasture WSC content are well documented, the impact of fertilization or grass species composition are less defined. To evaluate the effect of season and fertilization on WSC concentrations, grassland plots were established at SRUC Aberdeen, UK. Six distinct cool-season seed mixtures (Table 1) were sown in triplicate plots (3m x 4m) and split in half to evaluate the effect of fertilizer treatment (285kg/ha of 21–8-11, annual application in March). Samples were collected on ice at set 6-to-8-week intervals (May–October) across 2 consecutive years. The Anthrone method was employed to estimate WSC content of lyophilised and milled samples, expressed as glucose and fructose equivalents [g/kg DM]. Independent t-test analysis (significance set at P < 0.05) revealed that fertilization had no overall effect on the WSC fraction for glucose (t(94) = 1.02, P = 0.99, 95% CI [-7.57, 23.51]) or fructose (t(94) = 1.28, P = 0.78, 95% CI [-4.69, 21.85]). Analysis of variance analysis demonstrated a significant effect of seed mixture (F = 2.56, P = 0.033 for glucose, F = 2.39, P = 0.044 for fructose) and season (glucose: F = 21.88, P = < 0.001, fructose:F = 21.09, P = < 0.001). WSC concentration was highest in samples collected in Spring, while the perennial rye grass mix (5) and a diverse herb mix (4) had the highest and lowest WSC contents across all samples, respectively. These preliminary results suggest that season and grass species composition have a greater effect on WSC concentrations in pasture than fertilizer treatment. Further studies are warranted to estimate the impact of fertilizer on other aspects of grass chemical composition that may have implications for managing pasture for grazing animals.

182 Feed intake and metabolic responses in horses in transition from haylage feeding to pasture grazing

The transition from winter-feeding to pasture involves a considerable diet change that might compromise health of horses, and info on the metabolic responses in horses on pasture are scarce. The objective of the study was to investigate how the transition from haylage feeding to strip grazing affected feed intake (FI) and metabolic responses (blood glucose (GLU)-insulin (INS) and cecal pH). Four cecum-cannulated Norwegian cold-blooded trotter geldings were used in a longitudinal study consisting of 3 periods: 1) haylage only (d 0 to 8) reflecting winter-feeding, 2) transition (d 9 to 20) reflecting a diet where the proportion of forage decreased and grazing increased (0 min to 2 × 3 h per d), and 3) grazing only (d 21 to 28) reflecting horses on pasture (2 × 3 h per d). Strip grazing was used to control and measure daily FI in period 2 and 3. From d 9 to 28 the horses were allowed access to a new strip of grass for a specified time-period. The remaining grass was cut each day after grazing, collected, weighed, and compared with the amount of grass from a strip of ungrazed pasture. It was possible to estimate FI for all horses and calculate an average FI per horse. Haylage and grass samples from every 4th d were analyzed for nutritional composition (neutral detergent fiber excluding residual ash (aNDFom), water soluble carbohydrates (WSC), and crude protein (CP)) and used to estimate dry matter (DM) and nutrientintake. On d 8 and 28, blood and cecal samples were collected before and each h after feeding (2 kg haylage as fed vs. 3 h of grazing) for 8 h. ?Area under the curve (AUC) of GLU and INS were calculated using GraphPad Prism. The effect of d on nutrient content, FI, body weight (BW), AUC and peak GLU and INS, and minimum pH were compared using PROC mixed in SAS and considered different if P < 0.05. Grass yield increased (P < 0.001) over time as the grass matured (0.32 to 0.54 kg DM/m2). Plant maturity of the grass affected the nutrient content (P < 0.001) as aNDFom increased (545 to 636 g/kg DM), and CP decreased (158 to 101 g/kg DM). The WSC content varied (P < 0.001) over time (73 to 128 g/kg DM). Similar BW was measured on d 8 and 28 (568 ± 31 kg). The DM intake was 1.62 kg (0.29% of BW) on d 8 and estimated to be 3.7 kg (0.65% of BW) on d 28. There was no effect of d on AUC and peak GLU and INS, but cecal pH was higher (P < 0.001) when feeding haylage (6.89) on d 8 than pasture (6.57) on d 28. In conclusion, FI was controlled by strip grazing, BW was maintained, and metabolic responses were within the expected ranges. However, a longer grazing time would probably result in increased FI and undesired BW gain.

Isolation and identification of ligninolytic bacterium (Bacillus cereus) from buffalo (Bubalus bubalis) rumen and its effects on the fermentation quality, nutrient composition, and bacterial community of rape silage.

This study aimed to isolate and identify a ligninolytic bacterium from the rumen of buffalo (Bubalus bubalis) and investigate its effects as a silage additive for whole-plant rape. Three lignin-degradation strains were isolated from the buffalo rumen, with AH7-7 being chosen for further experiments. Strain AH7-7, with acid tolerance and a 51.4% survival rate at pH 4, was identified as Bacillus cereus. It exhibited a lignin-degradation rate of 20.5% after being inoculated in a lignin-degrading medium for 8 days. We divided the rape into four groups according to the various additive compositions to examine the fermentation quality, nutritional value, and bacterial community after ensiling: Bc group (inoculated with B. cereus AH7-7 3.0 × 106 CFU g FW-1), Blac group (inoculated with B. cereus AH7-7 1.0 × 106 CFU g FW-1, L. plantarum 1.0 × 106 CFU g FW-1, and L. buchneri 1.0 × 106 CFU g FW-1), Lac group (inoculated with L. plantarum 1.5 × 106 CFU g FW-1 and L. buchneri 1.5 × 106 CFU g FW-1), and Ctrl group (no additives). After 60 days of fermentation, the application of B. cereus AH7-7 was potent in modulating the fermentation quality of silage, especially when combined with L. plantarum and L. buchneri, as indicated by lower dry matter loss and higher contents of crude protein, water-soluble carbohydrate, and lactic acid. Furthermore, treatments with the B. cereus AH7-7 additive decreased the contents of acid detergent lignin, cellulose, and hemicellulose. The B. cereus AH7-7 additive treatments reduced the bacterial diversity and optimized the bacterial community compositions of silage, with an increase in the relative abundance of beneficial Lactobacillus and a decrease in the relative abundance of undesirable Pantoea and Erwinia. Functional prediction revealed that inoculation with B. cereus AH7-7 could increase the cofactors and vitamins metabolism, amino acid metabolism, translation, replication and repair, and nucleotide metabolism, while decreasing the carbohydrate metabolism, membrane transport, and energy metabolism. In brief, B. cereus AH7-7 improved the microbial community, fermentation activity, and ultimately the quality of silage. The ensiling with B. cereus AH7-7, L. plantarum, and L. buchneri combination is an effective and practical strategy to improve the fermentation and nutrition preservation of rape silage.

Alteration of Carbohydrate Metabolism in Fusarium Infected Wheat Kernels Treated with Fungicides and Its Relation to Baking Technological Parameters and Deoxynivalenol Contamination

Changes of water-soluble carbohydrate (WSC) content such as fructose, glucose, sucrose, maltose, nystose, raffinose, stachyose and fructan were analyzed in wheat kernels in Fusarium epidemic and non-epidemic seasons. In both season types, eight commercial fungicides were applied and three wheat varieties with differing Fusarium resistance were tested. In the epidemic year, the average total amount of WSC was above 1.6% which was 2 times higher than in the non-epidemic year (0.7%). Sucrose, maltose, raffinose and fructan components determined the increased WSC value, but the most substantial change was observed in maltose content where its average amount was 28 times higher in the epidemic year. Fungicide application also significantly increased all the carbohydrate components except maltose, where significant reduction was observed. WSC components had strong correlation with several farinograph or extensograph parameters, but only the maltose content showed positive strong correlation (r = 0.9) with deoxynivalenol (DON) toxin that was highly affected by the applied fungicide. The changes of WSC indicate altered carbohydrate synthesis along with abnormal degradation processes and thus have impaction on the baking features. It seems that the sugar metabolism interacts with DON synthesis and the results give important additional information to the altered metabolism of the attacked plant.

Alternations of ensiling performance and bacterial community in response to different native grassland in Mongolian Plateau

The aim of this study was to investigate the dynamics of bacterial communities and natural fermentation quality in three steppe types [meadow steppe (MS); typical steppe (TS); and desert steppe (DS)] on the Mongolian Plateau. PacBio single molecule with real-time sequencing technology was applied to provide insights into the dynamics of the physicochemical characteristics and the complex microbiome of native grass after 1, 7, 15, and 30 days of fermentation process. The dry matter, crude protein, and water soluble carbohydrate (WSC) contents of the three groups slowly decreased after 1 day of fermentation process, and the lowest WSC concentration after 30 days of ensiling was detected in the DS group compared to that in the MS and TS groups. There was no significant effect of steppe types on lactic acid and butyric acid content (P>0.05). The pH was higher in the early stages of fermentation. After 30 days of fermentation, the pH of MS and DS dropped to ∼5.60, while TS was as high as 5.94. At different ensiling days, the pH of TS was significantly higher than that of MS (P<0.05). The ammonia nitrogen content of MS was significantly higher than TS and DS (P<0.05). During the whole fermentation process, Leuconostoc mesenteroides and Pseudocitrobacter faecalis were the main species of DS, while Enterobacter roggenkampii and Faecalibacterium prausnitzii dominated the fermentation process in MS and TS, respectively. The fermentation quality of native grass silage of different steppe types was less satisfactory, with the silage quality ranging from DS, MS, and TS in descending order. The epiphytic bacteria dominating the fermentation process differed between steppe types of silage. Leuconostoc mesenteroides as the main strain of DS had a modulating effect on pH and LA content, while the main strains of MS and TS (Enterobacter roggenkampii and Faecalibacterium prausnitzii) dominated the silage without significant effect on improving fermentation characteristics and nutritional quality.

Study on the effect of additives on microbial diversity, predicted functional profiles, and fermentation quality of Broussonetia papyrifera and Pennisetum sinese mixed ensilage in the karst region.

In this research, we evaluated the effect of exogenous lactic acid bacteria and Amomum villosum essential oil (AVEO) on the chemical composition, microbial community composition, microbial functional diversity, and fermentation quality of Broussonetia papyrifera (BP) and Pennisetum sinese (PS) mixed silages. The BP:PS mixing ratios were 100:0, 70:30, 50:50, 30:70, and 0:100. After 3 and 30 days of ensiling at 22°C-25°C, microbial diversity and function, and fermentation quality, were assessed. Increasing PS content resulted in decreased ammoniacal nitrogen and pH, increased water-soluble carbohydrate content, increased relative abundance of Lactococcus and Acinetobacter, and reduced relative abundance of Caproiciproducens and Pseudomonas. A 50:50 BP:PS ratio effectively improved the fermentation quality compared to anaerobic fermentation with BP or PS alone, while AVEO treatment further improved fermentation quality by increasing Lactococcus relative abundance. Moreover, as fermentation proceeded, ensiling enhanced the 'Human diseases', 'Environmental information processing', and 'Cellular processes' functions at the first level, as well as the 'Two-component system' and 'ABC transporters' functions at the third level. Different additives affected the fermentation of BP and PS mixed silage by regulating microbial community succession and metabolic pathways during ensiling.

Effect of grassland cutting frequency, species mixture, wilting and fermentation pattern of grass silages on in vitro methane yield

Mitigating enteric methane (CH4) emissions is crucial as ruminants account for 5% of global greenhouse gas emissions. We hypothesised that less frequent harvesting, use of crops with lower WSC concentration, ensiling at low crop dry matter (DM) and extensive lactic acid fermentation would reduce in vitro CH4 production. Timothy (T), timothy + red clover mixture (T + RC) or perennial ryegrass (RG), cut either two or three times per season, was wilted to 22.5% or 37.5% DM and ensiled with or without formic acid-based additive. Silages were analysed for chemical composition and fermentation products. In vitro CH4 production was measured using an automated gas in vitro system. Methane production was, on average, 2.8 mL/g OM lower in the two-cut system than in the three-cut system (P < 0.001), and 1.9 mL/g OM lower in T than in RG (P < 0.001). Silage DM did not affect CH4 production (P = 0.235), but formic acid increased CH4 production by 1.2 mL/g OM compared to the untreated silage (P = 0.003). In conclusion, less frequent harvesting and extensive silage fermentation reduce in vitro CH4 production, while RG in comparison to T resulted in higher production of CH4.

WYBRANE ELEMENTY SKŁADU CHEMICZNEGO MIESZANEK ŁUBINU WĄSKOLISTNEGO (LUPINUS ANGUSTIFOLIUS L.) Z PSZENŻYTEM JARYM (X TRITICOSECALE WITTMACK) UPRAWIANYCH NA ZIELONĄ MASĘ

Field studies were conducted in 2016–2018 at the Agricultural Experimental Station in Zawady, which belongs to the Siedlce University of Natural Sciences and Humanities, located near Siedlce in the Mazowieckie Voivodeship. The aim of the conducted research was to evaluate the content of selected nutrients in mixtures of narrowleaf lupin with spring triticale harvested at two developmental stages of narrowleaf lupin. The highest content of total carbohydrates, water-soluble carbohydrates and crude ash, among the mixtures, was revealed in a mixture with 75% narrowleaf lupin and 25% spring triticale. In contrast, the highest crude fat content was found in mixtures with component shares of narrowleaf lupin and spring triticale of 75% + 25% and 50% + 50%, respectively. A higher carbohydrate and crude ash content was determined in mixtures harvested at the flowering stage of narrowleaf lupin, while higher crude fat contents were determined in mixtures harvested at the flat green pod stage of narrowleaf lupin. Among the mixtures to be grown to achieve fodder with a high content of total carbohydrates, water-soluble carbohydrates, crude fat and crude ash a mixture with 75% + 25% components of narrowleaf lupin and spring triticale, respectively, should be recommended and harvested at the narrowleaf lupin flowering stage.

Effects of additives containing a novel strain on the fermentation characteristics, structural carbohydrates, and α-tocopherol content of rice straw and corn stover silages

A novel α-tocopherol-producing bacteria strain was isolated and identified as Bacillus tequilensis QH1 (QH1). The effects of QH1 strain inoculation alone (QH), combined with cell wall degradation enzyme (QC), or Lactiplantibacillus plantarum subsp. plantarum YM3 and cell wall degradation enzyme (QLC) as the additives on the fermentation characteristics, structural carbohydrates, and α-tocopherol content of rice straw and corn stover silages were investigated, and without additives as the control (CON), in 4 replicates. After silages were kept in a laboratory cabinet (26–34 ℃) and the dark for 42 d, experimental silos (polyethylene plastic bags) were opened for analysis. The results exhibited that the control and additives-treated rice straw and corn stover were ensiled well, indicated by high lactic acid content and little butyric acid content. The QH and QC degraded structural carbohydrates, demonstrated by lower (P < 0.001) neutral detergent fiber (NDF) and acid detergent fiber (ADF) than the control, but did not enhance lactic acid fermentation, evidenced by lower (P < 0.001) lactic acid content in QH-treated silages compared with the control silages. The effect of QLC on degrading structural carbohydrates was influenced by material factors, evidenced by no role in decreasing the contents of NDF and ADF in rice straw silage and a good role in decreasing the contents of NDF and ADF in corn stover silage. However, the water-soluble carbohydrate (WSC) contents in both rice straw and corn stover silages were increased (P < 0.001) by QLC compared with the control. The control and additives-treated silages had much higher (P < 0.001) α-tocopherol content and lower (P < 0.001) chlorophyll content compared with the material before ensiling. Compared with the control, higher α-tocopherol content was found in QH-treated rice straw (P = 0.071) and corn stover silages (P < 0.05), and QLC-treated corn stover silage (P < 0.05). Therefore, the QH1 strain had the potential to be applied in rice straw silage production, and QLC was recommended to be applied in corn stover silage production.Graphical

Effect of growth stage on Italian ryegrass (Lolium multiflorum Lam.) silage fermentation from microbiological perspective

BackgroundItalian ryegrass is a temperate climate crop, which is widely cultivated in the winter fallow paddy fields of subtropical China. The utilization efficiency of Italian ryegrass depends greatly on its growth stage at harvest. Previous studies have reported the optimum stage for harvesting various forage to balance their quality and quantity. However, when considering the practice condition, such as rainy or unavailability of harvest equipment, the harvest stage of forage cannot always be implemented according to the production schedules. Thus, to characterize the effect of growth stage on the silage fermentation profile, bacterial community construction and metabolisms of carbohydrates and amino acids, Italian ryegrass were naturally ensiled at the filling stage (FSN) and the dough stage (DSN), respectively. After ensiling for 1, 3, 7, 15, 30, and 60 days, triplicate silos were opened for sampling.ResultsThe growth of Italian ryegrass increased the pH, dry matter, neutral, and acid detergent fiber contents, but decreased buffering capacity, crude protein and water-soluble carbohydrates contents, and the epiphytic microbiota of Italian ryegrass harvested at the filling stage was simpler than that harvested at the dough stage. During ensiling, FSN had lower pH and higher organic acid content than DSN. The bacterial succession rate in FSN was also faster than DSN, which showed that Lactobacillus becomes the dominant genus in the early stage of ensiling. The predicted metabolisms revealed that carbohydrate and amino acid metabolisms were the two main metabolisms in silage fermentation. When compared with epiphytic microbiota, ensiling enhanced carbohydrate metabolism and diminished amino acid metabolism. The difference of these two metabolisms between FSN and DSN was obvious at the early stage of ensiling.ConclusionsGrowth stage affected the chemical and microbial composition of Italian ryegrass, so as to the fermentation profile, bacterial community and its metabolisms intensity. Italian ryegrass harvested at the filling stage was prone to ferment. The complexity of epiphytic microbiota made Italian ryegrass harvested at the dough stage more difficult to ferment.Graphical

Influences of growth stage and ensiling time on fermentation profile, bacterial community compositions and their predicted functionality during ensiling of Italian ryegrass

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 (NH3-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 NH3-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.

Influence of Cellulase or Lactiplantibacillus plantarum on the Ensiling Performance and Bacterial Community in Mixed Silage of Alfalfa and Leymus chinensis

The objective of this study was to evaluate the effects of Lactiplantibacillus plantarum or cellulase on the fermentation characteristics and bacterial community of mixed alfalfa (Medicago sativa L., AF) and Leymus chinensis (LC) silage. The harvested alfalfa and Leymus chinensis were cut into 1-2 cm lengths by a crop chopper and they were thoroughly mixed at a ratio of 3/2 (wet weight). The mixtures were treated with no addition (CON), Lactiplantibacillus plantarum (LP, 1 × 106 cfu/g fresh material), cellulase (CE, 7.5 × 102 U/kg fresh material) and their combination (LPCE). The forages were packed into triplicate vacuum-sealed, polyethylene bags per treatment and ensiled for 1, 3, 5, 7 and 30 d at room temperature (17-25 °C). Compared to the CON groups, all the additives increased the lactic acid content and decreased the pH and ammonia nitrogen content over the ensiling period. In comparison to the other groups, higher water-soluble carbohydrate contents were discovered in the CE-inoculated silages. Compared to the CON groups, the treatment with LPCE retained the crude protein content and reduced the acid detergent fiber content. The principal coordinate analysis based on the unweighted UniFrac distance showed that individuals in the AF, LC, CON and LPCE treatment could be significantly separated from each other. At the genus level, the bacterial community in the mixed silage involves a shift from Cyanobacteria_unclassified to Lactobacillus. Lactobacillus dominated in all the treatments until the end of the silage, but when added with Lactiplantibacillus plantarum, it was more effective in inhibiting undesirable microorganisms, such as Enterobacter, while reducing microbial diversity. By changing the bacterial community structure after applying Lactiplantibacillus plantarum and cellulase, the mixed silages quality could be further improved. During ensiling, the metabolism of the nucleotide and carbohydrate were enhanced whereas the metabolism of the amino acid, energy, cofactors and vitamins were hindered. In conclusion, the relative abundance of Lactobacillus in the mixed silage increased with the addition of Lactiplantibacillus plantarum and cellulase, which also improved the fermentation quality.