Silage Fermentation Research Articles

Genotypic and Phenotypic Characterization of Lactic Acid Bacteria Associated with Silage Fermentation of Pineapple Residue

The natural populations of lactic acid bacteria (LAB) and silage quality of pineapple residue silage were investigated in this study. A total of 34 LAB strains originally isolated from pineapple residue silage were characterized and identified by phenotypic and genotypic methods. These LAB strains were Gram-positive and catalase-negative bacteria, which were divided into four groups: Lactiplantibacillusplantarum (52.9%), Levilactobacillus brevis (14.7%), Lacticaseibacillus paracasei (17.6%) and Leuconostoc citreum (14.7%). Lactiplantibacillus plantarum was the dominant species. Homofermentative strains accounted for 70.5%. After 30 days of ensiling, the pineapple residue silage could be well preserved with low pH value (3.65) and high content of lactic acid (75.57 g/kg of DM). In this study, LAB populations of pineapple residue silage fermentation were investigated, which indicated that pineapple residue silage was a potential good animal feed source. In addition, this result will be valuable for screening-appropriate inoculants aimed at improving the quality.

Effect of rice bran and microorganism as additives in pearl millet silage

ABSTRACT This study aimed to evaluate rice bran (RB) and microbial inoculation effects on pearl millet silage fermentative losses, fermentation profile, nutrients recovery, chemical composition, in vitro degradation and aerobic stability. Seventy-two experimental silos (PVC buckets with 28 cm diameter and 25 cm height) were used to evaluate nine treatments, from a 3 × 3 factorial arrangement: (I) levels of RB: 0, 100 and 200 g/kg as-fed; and (II) microbial inoculation: (1) Control (CON): no inoculation; (2) LPPP: inclusion 1.04 × 105 colony forming units (CFU) of Lactobacillus plantarum and 1.04 × 105 CFU of Pediococcus pentosaceus per g; and (3) LB: inclusion 1.6 × 105 CFU of Lactobacillus buchneri per g. The silage microbial inoculant inclusion had no effect on silage, regardless of RB addition. Rice bran increased silage pH and decreased ammonia-N, propionic, butyric and branched-chain fatty acids content. Rice bran decreased gas losses and recovery of DM, OM, CP and ADF, whereas increased digestible DM recovery. The addition of RB reduced OM, NDF, ADF and ADL silage content, and increased silage DM, CP and EE, and NDF degradation. Therefore, RB increases digestible DM recovery, and improves silage fermentation and nutritional value.

Interspecies and seasonal variations in macroalgae from the Nordic region: Chemical composition and impacts on rumen fermentation and microbiome assembly

Marine macroalgae may serve as sustainable feed resources for ruminant production due to their nutritional attributes, and enteric methane (CH 4 ) mitigating potential. We aimed to characterize the anti-methanogenic properties of 12 Nordic macroalgae species (eight brown, three red, and one green). Differences in the chemical composition across two harvesting seasons and impacts of addition of macroalgae (20% dry matter basis) on in vitro rumen fermentability of maize silage (MS) and associated changes in the rumen microbiome composition were also evaluated. Green and red macroalgae contained twice as much crude protein (CP) as compared to brown macroalgae. The latter had higher mineral and total polyphenol content (TPC: 10 to 20 times). In some brown species, ash and CP contents were up to twice as high in spring than in autumn, but TPC was highest in autumn. The TPC content was inversely correlated with in vitro rumen fermentation characteristics: organic matter (OM) degradability (r = −0.85; P < 0.001), production of total gas (r = −0.79; P < 0.001), total volatile fatty acids (r = −0.78; P < 0.001) and CH 4 (r = −0.53; P < 0.03) per gram of OM. The polyphenol-rich brown species, Fucus vesiculosus and Ascophyllum nodosum , caused a significant reduction in feed degradability (∼25%) due to the suppression of cellulolytic bacteria ( Ruminococcus spp., Lacnospiraceae spp., Rikenellaceae RC9 gut group) in the rumen fluid after fermentation. Interestingly, autumn-harvested samples of those two macroalgae decreased the CH 4 production by 62.6% and 48.2%, respectively, and reduced rumen methanogenic archaea (e.g., Methanobrevibacter spp.), although the reduction was not directly correlated with TPC. Thus, Nordic macroalgae, depending upon their species-specific unique properties, could be utilized as anti-methanogenic feed additives or feeding resources for ruminants. In vivo studies are needed to establish the implications of feeding with these macroalgae on overall animal performance. • Macroalgae generally had greater protein and mineral contents in the spring. • Including 20% macroalgae with a low polyphenol content did not reduce in vitro feed degradability. • Polyphenol-rich brown algae reduced feed degradation by inhibiting cellulolytic microbes. • Brown alga, Fucus vesiculosus mitigated 62.6% of in vitro CH 4 production at 20% inclusion in feed.

Changes in the fermentation products, taxonomic and functional profiles of microbiota during high-moisture sweet sorghum silage fermentation

The purpose of this study was to evaluate the fermentation quality, microbial community, and functional shifts of sweet sorghum during ensiling. The high-moisture sweet sorghum (SS) was naturally ensiled for 1, 3, 7, 15, 30, and 60 days. After 60 days of ensiling, sweet sorghum silage (SSS) showed homolactic fermentation with absent butyric acid, low pH value, acceptable concentrations of propionic acid, ethanol, and ammonia nitrogen and high lactic acid concentration. Acinetobacter, Sphingomonas, and Pseudomonas were the advantage genera in SS. While, Lactococcus, Weissella, and Pediococcus were dominant in 3-day SSS and subsequently replaced by Lactobacillus in 60-day SSS. Spearman’s correlation heatmap showed that Pediococcus and Leuconostoc were negatively related to the pH value of SSS. There were great differences in the Kyoto Encyclopedia of Genes and Genomes (KEGG) functional profiles of SS and SSS. Ensiling process downregulated the metabolism of amino acid, energy, cofactors, and vitamins, but upregulated the metabolism of nucleotides and carbohydrates. Overall, next-generation sequencing in conjunction with KEGG functional prediction revealed the distinct differences in the initial and late phases of ensiling in terms of both community succession and functional shifts. The knowledge regarding bacterial community dynamics and functional shifts of SS during ensiling is important for understanding the fermentation mechanism and may contribute to the production of high-quality sweet sorghum silage.

Bacterial and fungal microbiota of total mixed ration silage stored at various temperatures.

To obtain insights into how bacterial and fungal microbiota and fermentation products composition are affected by storage temperature for TMR silage, which can be manufactured year-round. TMR silage was stored at 10°C, 25°C, ambient temperature (AT; 20-35°C) and 40°C. Lactic acid production was delayed when stored at 10°C, and acid production stagnated after 2 weeks when stored at 40°C. The patterns of acetic acid and ethanol production were inversely related, with ethanol production promoted at 10°C and 25°C and acetic acid production promoted at AT and 40°C. The bacterial diversity was reduced in TMR silage with high lactic acid and acetic acid content, and the fungal diversity was reduced in TMR silage with high ethanol content. The intensity of lactic acid production was accounted for by the high abundance of Lactobacillus, and its stagnated production at a substantially high storage temperature was related to an increased abundance of Bacillus. The enhanced production of acetic acid or ethanol can be explained by differences in the fungal microbiota. The integrated analysis of bacterial and fungal microbiota can provide in-depth insights into the impact of storage temperature on TMR silage fermentation.

Epicuticular wax of sweet sorghum influenced the microbial community and fermentation quality of silage.

Epicuticular wax, as secondary metabolites (hydrophobic compounds) covering plant surface, plays important roles in protecting plants from abiotic and biotic stresses. However, whether these compounds will influence fermentation process of silage is still not clear. In this study, two sweet sorghum cultivars with varying epicuticular wax on sheath (bloom), Yajin 2 (YJ, less bloom), and Jintian (JT, dense bloom), were harvested at flowering and maturing stages, and ensiled with or without bloom, aiming to evaluate the effects of bloom on fermentation quality, feed nutrition and microbial community. The bloom was collected manually with de-waxed cotton and extracted with chloroform. The results showed that the bloom reduced the concentrations of water-soluble carbohydrate and crude protein of the two cultivars at both stages, reduced lactic acid (LA) for YJ at both stages and for JT at flowering stage, and increased LA for JT at mature stage. The α-diversity of bacterial communities of the silage fermentation with bloom was significantly lower than that without bloom. Bloom increased the abundance of Lactobacillus, reduced that of Bacillus and Weissella, and significant correlations were observed between fermentative qualities and bacterial abundances. However, decreased diversity of bacterial community and the contents of LA implied that shifts in bacterial community might exert negative effects on silage fermentation. Our results suggest that bloom wax could alter the microbial community composition of ensiled sweet sorghums, which thus influence the fermentation qualities.

Silajdan Elde Edilen Lactobacillus sp. ve Lb. rhamnosus,’ un bazı Enzim Aktivitelerinin İncelenmesi

Probiotic lactic acid bacteria are vital microbial group for fermentation of silage, which is crucial importance particularly for dairy animal nutrition. These microorganisms are able to degrade amino acids, carbohydrates and fatty acids, our knowledge, however, about their other enzymatic activities is still limited. To investigate the inulinase and invertase activities of silage originated Lactobacillus sp and Lactobacillus rhamnosus, the isolates were incubated for 24h, 36h and 48h in LB broth and MRS broth. Supernatant and cell associated enzyme activities were determined at pH: 6.0 using inulin and sucrose as substrates, and their specific and total enzyme activities were analysed comparatively. Lactobacillus sp showed the highest invertase activity as 22.1 mg/ml (cell associated) for 24h incubation, whilst the utmost invertase activity was observed as 20 mg/ml at the end of 36h incubation period for supernatants. Same enzyme activities were determined as 20,1 mg/ml and 19,9 mg/ml for 24h incubation, for cell associated and supernatant samples of Lb rhamnosus respectively. The highest cell associated inulinase activity of Lactobacillus sp was recorded as 20,1 mg/ml for 36h incubation time while the maximal activity for supernatant was recorded at 24h incubation. Maximum cell associated and supernatant activities of the isolate was observed as 24,6 mg/ml and 26, mg/ml respectively. Both isolates showed noteworthy amount of invertase and inulinase activities which makes them potential silage inoculants.

Effects of Konjac Flour and Lactiplantibacillus plantarum on Fermentation Quality, Aerobic Stability, and Microbial Community of High-Moisture Forage Rape Silages

To obtain high-quality silage and better understand the mechanism underlying silage fermentation, a study was conducted to investigate the effects of konjac flour (KF), Lactiplantibacillus plantarum (LP) and their combination on fermentation quality, aerobic stability, and microbial community of high-moisture forage rape after 60 days of ensiling. Results showed that the KF and LP treatments increased the lactic acid content, decreased the pH value, and inhibited the production of butyric acid in ensiled forage rape (p &lt; 0.05). The additives also altered the bacterial community of forage rape silages, showing reduced Shannon and Simpson indexes (p &lt; 0.05), while the abundance of desirable Lactobacillus was increased, and the abundance of undesirable bacteria, such as enterobacteria and clostridia, was decreased (p &lt; 0.05). In addition, their combination significantly improved the aerobic stability (96 h vs. 28 h, p &lt; 0.05) and exhibited notable influence on the bacterial community, with the highest abundance of Lactobacillus. These results indicated that KF and LP improved the silage quality of high-moisture forage rape, and their combination displayed a beneficial synergistic effect.

Effects of Forestry Waste Neolamarckia cadamba Leaf Meal as an Additive on Fermentation Quality, Antioxidant Activity, and Bacterial Community of High-Moisture Stylo Silage

N. cadamba leaves, a byproduct of wood production, are always discarded in the field. N. cadamba leaves have strong antibacterial property, which might be recycled to inhibit undesirable bacteria and enhance the fermentation quality of silage. Ensiling, a traditional conservation method for animal feed, is commonly used all over the world. It is known that high-moisture forages, especially legumes, are difficult to ensile directly as much ammonia-N and butyric acid produced by undesirable bacteria will reduce the feeding value. To investigate the effects of N. cadamba leaf meal on the fermentation quality of stylo silage, 5% and 10% N. cadamba leaf meal were mixed with stylo for 30 days of ensiling in two independent experiments. Results showed that the silage pH and butyric acid content of stylo silage were decreased (p &amp;lt; 0.01) by 10% N. cadamba leaf meal. In experiment 2, contents of nonprotein-N and ammonia-N were significantly decreased (p &amp;lt; 0.05), while the true protein content was significantly increased (p &amp;lt; 0.05). The same results on the changing tendency were also obtained in experiment 1. In addition, N. cadamba leaf meal addition also decreased the bacterial diversity. The relative abundance of Clostridium and Lelliottia decreased, whereas that of Lactobacillus increased when N. cadamba leaf meal was added. It is worth noting that the addition of N. cadamba leaf meal also improved the antioxidant activity of stylo silage. The aforementioned results suggested that mixing N. cadamba leaf meal to high moisture forages could be an effective strategy to enhance silage fermentation quality, and it is also a feasible way to recycle N. cadamba leaves.

Time of Day for Harvest Affects the Fermentation Parameters, Bacterial Community, and Metabolic Characteristics of Sorghum-Sudangrass Hybrid Silage.

ABSTRACTTo characterize the effects of time of day for harvest on the fermentation parameters, bacterial community, and metabolic characteristics of sorghum-sudangrass hybrid (SSG) silage, SSG (vegetative stage) harvested at 7:00 (AM), 12:00 (M), and 17:00 (PM) on three sunny days were ensiled for 1, 3, 7, 14, 30, and 60 days. Compared to AM silage, M and PM silages were characterized by delayed fermentation, unnormal lower final pH, and lower acetic acid production. In addition, PM silage contained higher residual water-soluble carbohydrates than other silages. After 60 days of ensiling, AM silage was dominated by Lactobacillus, whereas the bacterial communities of M and PM silages were complex and mainly composed of bacteria such as Delftia, Methylobacterium-Methylorubrum, Enhydrobacter, Acinetobacter, and Bacillus. The harvest time affected a wide range of metabolic pathways including “Metabolism” and “Cellular Processes” and “Organismal Systems” in SSG silage. Particularly, at the late stage of ensiling M silage exhibited highest relative abundances of amino acid metabolisms including “glycine, serine, and threonine metabolism,” “phenylalanine metabolism,” and lowest relative abundances of “lysine biosynthesis.” These results suggest that the time of day for harvest could affect the fermentation parameters, bacterial community, and metabolic characteristics of SSG silage. Better SSG silage characteristics could be achieved through morning harvest.IMPORTANCE Ensiling is a common way for preserving green forages worldwide. Silage fermentation quality can vary greatly depending on the chemical and microbial characteristics of forage crop being ensiled. It is well documented that forages exhibit considerable variations in chemical composition and epiphytic microbiota during daylight. However, the effects of the time of day for harvest on silage fermentation is less investigated. Our results demonstrate that the time of day for harvest could affect the fermentation parameters, bacterial community, and metabolic characteristics of SSG hybrid silage. Harvesting SSG late in the day delayed fermentation process, lowered acetic acid production and final pH, and increased the residual water-soluble carbohydrates content in silage. Moreover, the delayed harvest time increased the relative abundances of bacteria such as Delftia, Methylobacterium-Methylorubrum, Acinetobacter, Enhydrobacter, and Bacillus, and amino acid metabolisms at the late stage of SSG ensiling. This study highlights the importance of diurnal changes in forage to fermentation characteristics, providing a strategy to improve silage quality through optimizing the harvest time.

Effects of Feeding Fermented Medicago sativa (Plus Soybean and DDGS) on Growth Performance, Blood Profiles, Gut Health, and Carcass Characteristics of Lande (Meat) Geese

The objective was to investigate the effects of alfalfa (Medicago sativa Linn)-mixed silage fermentation material (AMSFM) on various aspects of growth, function, and carcass characteristics of Lande (meat) geese. Based on a previous study, we used the following AMSFM: 80% Alfalfa +10% soybean meal +10% DDGS ensiled for 45 days. Lande geese, n = 264, 77 days of age, were randomly allocated into four groups with six replicates in each group. Control geese were fed a basal diet, whereas experimental groups were fed a basal diet supplemented with 6, 12, or 24% AMSFM. The experiment lasted 21 days. The AMSFM promoted some aspects of growth, with increase (p < 0.05) in leg muscle rate, lean meat rate, muscle protein content, and total energy content of leg muscle plus concurrent decreases (p < 0.05) in crude fat content and abdominal fat rate in chest muscle. In addition, AMSFM increased (p < 0.05) glutathione content in chest and leg muscles and serum superoxide dismutase activity, and it reduced (p < 0.05) muscle malondialdehyde content and serum concentrations of triglycerides, total cholesterol, urea, and aspartate aminotransferase, consistent with good liver and kidney function. Moreover, AMSFM improved (p < 0.05) ileum morphology. In conclusion, the optimal supplemented rate of AMSFM in the meat geese diet (12%) improved immunity and antioxidant status and enhanced growth performance and carcass characteristics of meat geese.

Effects of Cellulase and Lactiplantibacillus plantarum on the Fermentation Parameters, Nutrients, and Bacterial Community in Cassia alata Silage.

Silage Cassia alata (CA) can alleviate feed shortage in some areas to a certain extent and reduce feed costs. The present research evaluated the effect of cellulase (CE) and Lactiplantibacillus plantarum (LP) on the fermentation parameters, nutrients, and bacterial community of CA silage. Chopped CA was ensiled with three different treatments, namely, no inoculant (CK), CE, and LP, and the indexes were determined on the 2nd, 6th, 14th, and 30th days of silage fermentation. The fermentation parameters indicate that the pH value of the three groups decreased and then increased with the ensilage process, and the lowest value was observed on the 14th day. The CK and LP groups attained the highest value on the 30th day, while the CE group attained the highest value on the 2nd day. Additionally, the pH value and NH3-N content were significantly lower (P < 0.05) in the CE and LP groups than in the CK group. In terms of nutrients, crude protein (CP) contents significantly increased (P < 0.05) in the CE and LP groups on the 30th day. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the CE group were significantly and negatively associated with fermentation time, and the water-soluble carbohydrate (WSC) contents of the three groups were significantly lower during ensiling. In comparison with the CK group, the NDF and ADF contents were significantly reduced (P < 0.05), and the WSC content increased (P < 0.05) in the CE group on day 30. Sequencing analysis of bacterial communities showed that Lactobacillus became the most dominant genus in the ensilage process. Moreover, both CE and LP groups increased the abundance of Lactobacillus and decreased that of Klebsiella, Weissella, and Acetobacter in comparison to the CK group, in which LP had a better effect. CE and LP could further improve the silage quality of CA, and LP had a more significant effect in reconstructing the bacterial community in the silage environment.

Nutritional Quality of Corn Silage on Dairy Farms in the Republic of Croatia

Za potrebe vrjednovanja kvalitete kukuruzne silaže, u ovome je istraživanju analizirano 270 uzoraka na mliječnim farmama u dvanaest (12) županija. Pripremljeni uzorci analizirani su uz pomoć FT-NIR uređaju uz primjenu spektrometra AgriQuant-B1 (Model: QIA 1020), kojim su analizirane vrijednosti devet (9) nutritivnih, dva (2) pokazatelja fermentacije buraga te tri (3) pokazatelja fermentacije silaže kukuruza. Jedan fizički pokazatelj, distribucija veličine čestica silaže, određen je prosijavanjem preko sustava triju sita (Penn State Separator). Prosječne vrijednosti većine praćenih nutritivnih pokazatelja bile su zadovoljavajuće: suha tvar (ST) = 349 g kg-1, sir. protein = 65 g kg-1ST, sir. pepeo = 38 g kg-1ST, sir. vlakna = 180 g kg-1 ST, kisela deterdžentska vlakna (KDV) = 210 g kg-1ST, neutralna deterdžentska vlakna (NDV) = 387 g kg-1ST, kiseli deterdžentski lignin (KDL) = 17 g kg-1ST, škrob = 336 g kg-1ST, neto energija mlijeka = 6,76 MJ g kg-1ST. Značajnija odstupanja u Max. i Min. utvrđena su za vrijednosti ST (156 nesukladnih uzoraka), za sirovi protein utvrđen je čak 231 nesukladan uzorak, za kisela deterdžentska vlakna 90, a za škrob 233 uzorka. Pokazatelji fermentacije buraga kao prosječna probavljiva organska tvar (pOT) iznosila je = 75,6 %, a probavljiva neutralna deterdžentska vlakna (pNDV) = 52,8 %. Prosječna pH vrijednost je bila poželjnih 3,85, uz prosječnu koncentraciju mliječne (54,9 g kg-1ST) i octene (21,1 g kg-1ST) kiseline. Prosječne vrijednosti distribucije veličine čestica silaža, mjerene četirima frakcijama rezultirale su sljedećim vrijednostima: sito 1–5,7 %; sito 2–55,7 %; sito 3–26,1 % i posuda na dnu–12,6 %. Najjača pozitivna korelativna povezanost utvrđena je između sirovih vlakana u odnosu na KDV (r = 0,870), NDV (r = 0,959) i KDL (r = 0,790) te između NDV-a i KDV-a (r = 0,845). Korelativna povezanost negativnoga predznaka bila je najjača između KDL-a i pOT-a (r = -0,844), škroba u odnosu na sir. vlakna (r = -0,835) i NDV (r = -0,809), te pH i mliječne kiseline (r = -0,804). Navedene korelativne veze između pokazatelja bile su i statistički visoko značajne (p &amp;lt; 0,001).

Using PacBio SMRT Sequencing Technology and Metabolomics to Explore the Microbiota-Metabolome Interaction Related to Silage Fermentation of Woody Plant

Silage fermentation is a dynamic process involving the succession of microbial communities and changes in metabolites. Fresh branched and leaves of paper mulberry were used to prepared silage. Crop by-products including corn bran, rice bran, and wheat bran were used as exogenous additives. Pacific Biosciences single-molecule real-time (SMRT) sequencing technology and metabolomics are used to explore the interaction mechanism of microbial structure and metabolites during woody silage fermentation and to verify the principle that exogenous additives can modulate silage fermentation. Under the dual stress of anaerobic and acidic environment of silage fermentation, the microbial community changed from Gram-negative to Gram-positive bacteria, and a large amount of lactic acid and volatile fatty acid were produced, which lowered the pH value and caused the rapid death of aerobic bacteria with thin cell walls. The exogenous additives of corn bran and wheat bran accelerated the dynamic succession of lactic acid bacteria as the dominant microbial community in silage fermentation, increased the metabolic pathways of lactic acid, unsaturated fatty acids, citric acid, L-malic acid and other flavoring agents, and inhibited the growth of Clostridium and Enterobacter, thereby improving the flavor and quality of the silage. However, because rice bran contained butyric acid spore bacteria, it can multiply in an anaerobic environment, led to butyric acid fermentation, and promoted protein degradation and ammonia nitrogen production, thereby reduced the fermentation quality of woody silage. The results showed that during the silage fermentation process, the microbial community and the metabolome can interact, and exogenous additives can affect the fermentation quality of silage. SMRT sequencing technology and untargeted metabolomics revealed the microbiota-metabolome interaction during silage fermentation. Changes in the structure of the microbial community can affect the metabolic pathways, and the final metabolites can inhibit the growth of microorganisms that are not conducive to silage fermentation. Exogenous carbohydrate additives can change the fermentation substrate and affect microbial community structure, thus modulate the silage fermentation.

Characterization of Lactic Acid Bacteria Isolated from Banana and Its Application in Silage Fermentation of Defective Banana.

To effectively utilize banana by-products, we prepared silage with defective bananas using screened lactic acid bacteria (LAB), sucrose, and tannase as additives. Eleven strains of LAB were isolated from the fruits and flowers of defective bananas, all of which were Gram-positive and catalase-negative bacteria that produced lactic acid from glucose. Among these LAB, homofermentative strain CG1 was selected as the most suitable silage additive due to its high lactic acid production and good growth in a low pH environment. Based on its physiological and biochemical properties and 16S rRNA gene sequence analysis, strain CG1 was identified as Lactiplantibacillus plantarum. Defective bananas contain 74.8–76.3% moisture, 7.2–8.2% crude protein, 5.9–6.5% ether extract, and 25.3–27.8% neutral detergent fibre on a dry matter basis. After 45 d of fermentation, the silage of deficient bananas treated with LAB or sucrose alone improved fermentation quality, with significantly (p < 0.05) lower pH and higher lactic acid contents than the control. The combination of LAB and sucrose had a synergistic effect on the fermentation quality of silage. The tannase-treated silage significantly (p < 0.05) decreased the tannin content, while the combination of tannase and LAB in silage not only decreased (p < 0.05) the tannin content, but also improved the fermentation quality. The study confirmed that defective bananas are rich in nutrients, can prepare good quality silage, and have good potential as a feed source for livestock.

Separating the chemical and microbial factors of oat harvested at two growth stages to determine the main factor on silage fermentation.

This work evaluated the effects of epiphytic microbiota and chemical components on fermentation quality and microbial community of ensiled oat. 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. The chemical component rather than the epiphytic microbiota at harvest exerted more effects on oat silages. 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.

Altitudinal Distribution Patterns of Phyllosphere Microbial Communities and Their Contribution to Silage Fermentation of Kobresia pygmaea Along the Elevation Gradient on the Tibetan Plateau.

The study aimed to reveal altitudinal distribution patterns of phyllosphere microbial communities and silage fermentation of Kobresia pygmaea along the elevation gradient on the Tibetan Plateau. The K. pygmaea was individually collected from 2,500, 3,000, 4,000, 4,500, and 5,000 m above sea level (a.s.l.) on the Tibetan Plateau and ensiled for 60 days, respectively. The phyllosphere bacterial diversity increased while fungal diversity decreased along the elevation gradient, and bacterial and fungal richness showed a unimodal distribution with peak abundance at 4,000 and 3,000 m a.s.l., respectively. After 60 days of ensiling, the bacterial and fungal community composition changed but did not exhibit clear altitudinal distribution patterns. All K. pygmaea underwent a weak fermentation indicated by pH above 5.0 and low ratio of lactic/acetic acid (LA/AA). The S5000 and S3000 showed the highest and lowest pH, respectively. Although Lactobacillus dominated S4000 after 60 days of ensiling, S4000 still exhibited poor fermentation quality as well as silages from the other four regions. The higher ammonia N concentrations in S3000 and S4000 than the other silages were consistent with the detectable butyric acid in S3000 and S4000. The silage fermentation of K. pygmaea collected from five regions exhibited poor fermentation quality, thereby inoculating lactic acid bacteria to K. pygmaea before ensiling is highly recommended to improve fermentation quality on the Tibetan Plateau.

Fermentation Characteristics and Microbiota during the Ensiling of Myriophyllum aquaticum Inoculated with Lactic Acid Bacteria

Myriophyllum aquaticum (M. aquaticum) is a commonly used aquatic macrophyte for water purification and could be utilized as animal food. However, the high water content of M. aquaticum makes it difficult for long-term preservation, which leads to challenges as an ideal animal feed ingredient. The storage of Silage for long periods may be a proper method to solve the problem. In the present paper, we assess the effects of lactic acid bacteria Lactobacillus buchneri (LB), Lactobacillus plantarum (LP), or their combination on fermentation and microbial communities during the ensiling of M. aquaticum silage. The results show that the LP-treated silage displays a higher lactic acid concentration than that in the control silage. Both LB and LP increased the abundance of Lactobacillus, but decreased the abundance of Serratia and Prevotella_9 in M. aquaticum silage after 60 days of ensiling. Both LB and LP increased the diversity and richness of fungi. Therefore, the inoculation of LP improved silage fermentation during ensiling. These results show that the inoculation of lactic acid bacteria improves the fermentation quality of M. aquaticum silage, which makes it possible for the application of M. aquaticum to animal forage in the future.

Silage Fermentation Quality, Anthocyanin Stability, and in vitro Rumen Fermentation Characteristic of Ferrous Sulfate Heptahydrate-Treated Black Cane (Saccharum sinensis R.).

Pretreatment of lignocellulose agricultural biomass with iron prior to ensiling is required to accelerate biomass breakdown during fermentation, which could result in functional microorganisms and chemicals that reduce nutrition loss, harmful substances, and improve animal performance. The objective of this study was to investigate the effects of increasing dilutions of ferrous sulfate heptahydrate (FS) pretreatment at fresh matter concentrations of 0, 0.015, and 0.030% on the fermentation quality of black cane (BC) silage, anthocyanin stability, ruminal biogas, rumen fermentation profile, and microbial community. Pre-ensiled and silage materials were evaluated. High moisture, fiber, anthocyanin, and lignification of biomass, as well as undesirable ensiling microorganisms, were found in BC' pre-ensiled form. Increasing dilutions of FS incorporated into silages were observed to linearly decrease dry matter, anthocyanin, and nutritive value losses. The lignin values decreased linearly as the percentage of FS increased up to 0.030%. Given that the ruminants were fed pre-ensiled materials, BC silage treated with 0.030% FS dilution had comparable results to pre-ensiled BC in terms of increasing in vitro volatile fatty acid concentrations, maintaining total gas production, and reducing methane production, when compared to other FS-treated silages. In addition, BC silage treated with a 0.030% FS dilution inhibited methanogenic bacteria and regulated cellulolytic bacteria in rumen fluid. Overall, the anthocyanin content of BC remained constant throughout the rumen fermentation process after increasing dilutions of FS, indicating that BC is a viable ruminant feedstock and that pretreatment of BC with dilute FS-assisted ensiling at 0.030% could be used to generate ruminant diets.

Effects of Lactobacillus plantarum on Silage Fermentation and Bacterial Community of Three Tropical Forages

The fermentation quality and microbial diversity of king grass (K), cassava foliage (C), and Broussonetia papyrifera (B) ensiled in the absence of an inoculant (K, C, B) or the presence of Lactobacillus plantarum (KL, CL, BL) for 60 days were investigated. The bacterial community was characterized by using the 16S rDNA sequencing technology. The relative abundance of Lactobacillus in K was very high, and it decreased after adding L. plantarum while Acinetobacter increased to some extent. The relative abundance of Lactobacillus in group C was also very high, and the inoculant L. plantarum enriched it in the CL group. As the second dominant genus of group C, the relative abundance of Pseudomonas decreased significantly in CL. Weissella and Enterobacter were the dominant genera in B and BL, and the relative abundance of Lactobacillus decreased in BL. For K, C, and B, the inoculant L. plantarum decreased the pH value and NH3-N content markedly, inhibited the production of butyric acid, increased the content of lactic acid, and significantly improved the fermentation quality. In conclusion, L. plantarum affected the bacterial community of C and improved the silage quality of K, C, and B to a certain extent.