Niubie is derived from a fresh filtrate of semi-digested rumen contents from herb-fed cattle and serves as the distinctive hotpot base in Southwest China. The interplay of ingested herbs and ruminal microbiota shapes its distinctive flavor and functional compound profile. Nonetheless, its quality deteriorates during cold storage, and the underlying molecular mechanisms remain unclear. This study presents an integrated metagenomic and metabolomic framework for dissecting covert spoilage in refrigerated Niubie. Results showed that key physicochemical parameters remained stable during storage. Metagenomic analysis revealed a staged microbial succession. Specifically, genera with lipolytic and putrefactive potential (e.g., Anaerovibrio, Clostridium) increased from day 3 onward. This shift was accompanied by a corresponding rise in the abundance of virulence factor and antibiotic resistance genes. Subsequently, classic spoilage bacteria Pseudomonas and opportunistic pathogens Streptococcus became markedly enriched by day 7. Metabolomic profiling further showed that most beneficial functional metabolites declined, whereas lipid degradation pathways were upregulated, resulting in the accumulation of lipid oxidation markers and biogenic amines. Spearman correlation analysis linked methanogenic archaea, lipolytic bacteria, and amino acid degraders to spoilage metabolites, revealing convergent deterioration networks. These findings demonstrate that, despite stable conventional quality indices, critical microbial and metabolic deterioration commenced as early as day 3 of cold storage, offering molecular-level insights for the early detection and targeted preservation of Niubie.

Mulberry (Morus alba L.), a high-protein woody forage, is promising for alleviating animal husbandry’s protein feed shortage but suffers significant protein degradation during anaerobic fermentation and ruminal digestion. This study evaluated tannic acid (HT) and Acacia mangium tannin (CT) at 1–5 g/kg DM for effects on mulberry fermentation quality, bacterial community, and protein utilisation. Results showed HT dose-dependently reduced fermentation crude protein loss (max 2.72% vs. CK), promoted Lactiplantibacillus dominance, inhibited harmful microbes, and improved protein profiles (increased PB2、PB3, decreased NPN, enhanced methionine). CT exacerbated fermentation protein degradation and suppressed Lactiplantibacillus. Both tannins reduced ruminal protein degradation (by up to 17.94%) and mitigated methane production. Adding tannic acid is an effective strategy to enhance the nutritional value of ensiled mulberry.

Mulberry (Morus alba L.), a high-protein woody forage, has considerable potential to alleviate protein feed shortages in animal husbandry. However, its utilization is constrained by substantial protein degradation during anaerobic fermentation and ruminal digestion. This study investigated the effects of tannic acid (HT) and Acacia mangium tannin (CT) at five graded inclusion levels (1, 2, 3, 4 and 5 g/kg dry matter, DM), together with a control treatment (CK), on the fermentation quality, bacterial community composition and protein utilization of mulberry silage after 60 days of ensiling, with four independent biological replicates per treatment. The results showed that HT dose-dependently reduced crude protein loss during fermentation, with a maximum reduction of 2.72% compared with the control. HT also promoted the dominance of Lactiplantibacillus, suppressed undesirable microorganisms, and optimized silage protein profiles by elevating PB2 and PB3 fractions and reducing non-protein nitrogen (NPN), which is poorly available to ruminants and leads to protein resource waste, increased urinary nitrogen excretion and associated environmental pollution risks. In contrast, CT promoted protein degradation during fermentation and suppressed the abundance of Lactiplantibacillus. Both tannin sources decreased ruminal protein degradation, with reductions of up to 17.94% (add 5 g/kg tannic acid). These findings reveal the regulatory mechanisms of tannins on microbiota and protein degradation in mulberry silage. Amid surging ruminant feed demand and severe environmental pressures from conventional grain feeds, this study lays a theoretical basis for promoting mulberry as sustainable ruminant forage with higher nutrient utilization. It also delivers a viable technique to mitigate silage nitrogen loss and lower nitrogen pollution from ruminant production.

Green tea residue (GTR) is an abundant by-product rich in polyphenols. This study aimed to investigate the effects of GTR on growth performance, rumen microbiota, and systemic metabolism in finishing beef cattle. Forty-five 18‑month‑old finishing Angus steers with an average initial body weight of 474.44 ± 14.03 kg (mean ± SD) were individually housed and randomly assigned to three dietary treatments (n = 15 per group) using stratified randomization by initial body weight: control group (CG group, 150 g rice straw), low-dose GTR group (LG group, 75 g rice straw +75 g GTR), and high-dose GTR group (HG group, 150 g GTR). The feeding trial lasted 70 d with a 10-day adaptation period. To elucidate the regulatory mechanisms of GTR on beef cattle growth, we thoroughly assessed growth performance, nutrient digestibility, ruminal fermentation parameters, conducted bacterial 16S rRNA sequencing, analysed plasma biochemical and antioxidant markers, and executed an untargeted plasma metabolomic analysis. The LG group tended to increase average daily gain (ADG). Meanwhile, the LG group exhibited elevated plasma concentrations of β-hydroxybutyrate and glucose, increased activities of superoxide dismutase and glutathione S-transferase, an increased glutathione (GSH)/glutathione disulfide (GSSG) ratio, and reduced GSSG content. GTR treatment decreased reactive oxygen species and oxidative stress index. Furthermore, dietary GTR significantly modified the rumen microbial community structure, enriching Xylanibacter and Prevotellaceae_UCG-003, while reducing the abundance of Rikenellaceae_RC9_gut_group. Plasma metabolomics revealed that GTR treatment enriched GSH Metabolism and the Pentose Phosphate Pathway. Notably, gamma-glutamylcysteine was identified as a key mediator of the association between Xylanibacter and ADG in fattening beef cattle supplemented with GTR. Dietary supplementation with 75 g/steer/d GTR improved growth performance and systemic antioxidant capacity in finishing beef cattle by modulating the rumen microbiota and activating the glutathione system. GTR represents a promising functional feed additive that simultaneously valorizes tea by‑products and enhances livestock productivity.

Mulberry (Morus alba L.) serves as a high-value woody protein feed resource to address the shortage of protein feed supplies, but inherent limitations, including excessive moisture, insufficient indigenous lactic acid bacteria, and intense protein degradation, constrain its silage preparation. To address these problems, this study developed pre-fermented juices using alternative raw materials, including grape pomace and red clover, which are rich in natural antioxidants, such as polyphenols and isoflavonoids. Four groups were set in the experiment: red clover pre-fermented juice (treatment R), grape pomace pre-fermented juice (treatment G), mulberry pre-fermented juice (treatment M), and blank control (CK). Combined with bacterial community and metabolomic analyses, the present research further investigated their effects on the fermentation quality of mulberry silage during a 60-day ensiling period. The results indicated that treatment R exhibited the optimal comprehensive effect, enriching Enterococcus, upregulating the accumulation of isoflavonoids (formononetin, glycitein, and biochanin A), reducing silage pH to 3.99, elevating lactic acid concentration, and restraining protein degradation by inhibiting protease activity. Treatment M facilitated the proliferation of Lactobacillus and the accumulation of beneficial metabolites such as 3,4-dihydroxybenzaldehyde, while treatment G exerted only a mild regulatory effect. Overall, all pre-fermented juice additions effectively improved fermentation performance and nutrient preservation of mulberry silage. This finding elucidates the mechanism of microbial-metabolite interactions during mulberry ensiling, offers a low-cost, environmentally friendly technical strategy for high-quality silage production, and facilitates the sustainable application of mulberry resources in ruminant feeding systems.

Staged aeration offers a controllable lever to relax the strict-anaerobic paradigm in lignocellulosic fermentation. We compared single-dose air injection at early, mid, and late windows with a cellulase benchmark and anaerobic control, integrating fiber fractions, fermentation products, FTIR metrics, metagenomic functional profiles (CAZy and nitrogen cycling), microbial succession, and network topology. Mid and late aeration promoted ADL reduction and fiber deconstruction, lowering acid detergent lignin and acid detergent fiber by 23-34% and 13-15% versus the control, reaching cellulase-comparable levels. Late aeration produced the strongest structural unlocking, with attenuation of carbohydrate- and lignin-aromatic FTIR regions and reduced carbonyl-associated bands, consistent with disrupted lignin shielding and improved substrate accessibility. Late aeration increased glycosyltransferases yet showed the lowest glycoside hydrolases and auxiliary activities while achieving the largest net ADL and fiber losses, indicating that accessibility rather than terminal hydrolytic potential governs deconstruction intensity. Network analysis showed reduced mean degree and K-core but higher modularity under late aeration, consistent with a more compartmentalized interaction structure and reallocated carbon use. Overall, aeration timing is a scalable, low-input lever for process design. Future work should test generality across feedstocks and develop accessibility-based monitoring and control.

This study evaluated the effects of ferulic acid esterase (FAE)-producing Lactiplantibacillus plantarum (LP; 1 × 10⁶ cfu·g⁻¹ FM), applied alone or with cellulase and xylanase (LCX; each enzyme 25 U·g⁻¹ FM) or cellulase and laccase (LCL; each enzyme 25 U·g⁻¹ FM), on the ensiling of rain-affected Sudan grass. After wilting to 75% moisture, the forage was vacuum-sealed in polyethylene bags and ensiled for 60 days, followed by 7 days of aerobic exposure. The LCX treatment significantly enhanced fermentation quality, yielding the lowest pH (3.83, P < 0.05), highest lactic acid (LA, 54.03 g·kg-1 DM, P < 0.05), and water-soluble carbohydrate (WSC, 21.45 g·kg-1 DM, P < 0.05) contents, and promoting the degradation of cellulose and hemicellulose after 60 days of ensiling. However, it resulted in the poorest aerobic stability. In contrast, the LCL treatment effectively reduced lignin and butyric acid (BA, 1.34 g·kg-1 DM, after 7 days of aerobic exposure, P < 0.05) contents, decreased fungal diversity, and increased acetic acid (AA, 4.82 g·kg-1 DM, P < 0.05), crude protein contents, and the relative abundance of Lentilactobacillus (P < 0.05), leading to superior aerobic stability exceeding 168 h, with stable nutritional and fermentation characteristics maintained after aerobic exposure. Both control and LP-only silages showed poor fermentation quality, with high pH (>5.16), substantial butyric acid production, nutrient loss, and proliferation of undesirable microbes such as Enterobacter and Clostridium. In conclusion, ensiling rain-soaked Sudan grass requires synergistic additives. While LCX enhances fermentation quality, LCL is recommended for effectively improving both fermentation quality and aerobic stability, offering a practical strategy for rainy regions. IMPORTANCE:Ensiling rain-soaked forages is a major challenge for livestock production in rainy regions, as it often leads to poor fermentation, nutrient loss, and rapid spoilage. This study demonstrates that tailored microbial-enzyme combinations can effectively overcome these issues. While adding specific enzymes with bacteria significantly improves the silage's nutritional value, it can make the silage prone to spoilage upon air exposure. Crucially, we found that incorporating a lignin-degrading enzyme (laccase) instead creates a more robust silage that resists spoilage for a remarkably longer time. This provides a practical and sustainable strategy for farmers to produce high-quality, stable silage from Sudan grass even when harvested under wet conditions, ensuring a reliable feed supply and supporting sustainable livestock farming in rainy climates like Southwest China.

Yields of summer/autumn tea in China are relatively high, but its utilization and market value remain limited because of the pronounced bitterness and inferior flavor. In southwestern China, fresh summer/autumn tea leaves are traditionally pickled through anaerobic fermentation. In this study, fresh summer/autumn tea leaves were subjected to controlled anaerobic fermentation with Lactiplantibacillus plantarum (LP) inoculation, and the dynamic changes in nutritional quality, fermentation characteristics, active ingredients, and microbial community were evaluated. Compared with the noninoculated treatment (CK), LP treatment significantly reduced levels of water-soluble carbohydrates (WSCs), acetic acid (AA), and propionic acid (PA), while increasing the acid detergent fiber (ADF) and ammonia nitrogen (NH3-N) contents in fermented tea leaves (all p < 0.05). The total free amino acids (FAA) content peaked on Day 30, reaching 8.15% and 7.94% for the CK and LP treatments, respectively. In addition, the contents of the flavor-related FAA, including Glu and Ala, in the LP treatment were increased by 241.74% and 268.26% on Day 15, respectively. LP inoculation markedly elevated the relative abundance of Lactiplantibacillus and reduced the relative abundance of Listeria. Overall, LP inoculation improved the fermentation quality, enhanced the levels of bioactive and nutritional components, enriched specific flavor-related FAA, and altered the microbial community by promoting the LAB abundance. These findings provide a theoretical basis for the efficient utilization and value promotion of summer/autumn tea leaves in southwest China.

Niubie juice is a traditional ingredient unique to the Dong and Miao ethnic groups in Southwest China, and its storage stability significantly impacts product quality. This study investigates the storage stability of Niubie juice through flavoromics and metabolomics analyses. GC-MS identified 76 VOCs, with 3-methylindole identified as a key negative contributor to aroma deterioration of Niubie juice during storage. Non-targeted metabolomics revealed 2161 metabolites, predominantly lipids. During 0-3 days, nutrients and characteristic herbal, floral, and fruity aromas were well preserved. However, from days 3-7, nutrient loss increased and flavors weakened. After 7 days, deterioration accelerated: characteristic aromas faded, 3-methylindole levels surged by day 9, and both sulfur compounds and lipid oxidation increased. Flavor deterioration was linked to the protein degradation, tryptophan pathway, and lipid oxidation. Consequently, it is recommended to store it under low-temperature conditions for no more than 7 days, with the first 3 days providing relatively better quality.

The oxidation-reduction potential (ORP) is a primary factor influencing the growth and metabolism of anaerobic microorganisms and regulates anaerobic fermentation. Our research on ORP-regulated silage fermentation revealed that initial ORP regulation significantly affects fermentation. Nevertheless, how the ORP regulates microbial dynamics, enzyme activity, and metabolic pathways remains underexplored. We investigated the regulatory effects of ORP on Lactobacillus acidophilus growth, fermentation quality, and metabolic activity in Sudan grass silage. Redox agents l-cysteine (Cys, ORP-increasing) and potassium iodate (KIO3, ORP-decreasing) were applied to establish distinct ORP gradients. Results revealed that a decreased initial ORP (0.01C/200-220 mV and 0.05C/120-140 mV) can significantly increase L. acidophilus proliferation and accelerate lactic acid production, yielding superior fermentation quality with lower pH and ammonia nitrogen level (P < 0.05). Moreover, it increased beneficial bacteria abundance (Lactiplantibacillus, Lacticaseibacillus, and Leuconostoc) during early ensiling. Conversely, an increased initial ORP (0.2 K/420-440 mV) inhibited microorganisms proliferation and delayed fermentation. Metabolomics revealed that decreased ORP facilitated efficient substrate utilization, increasing lactic acid bacteria (LAB) dominance to promote silage fermentation, while maintaining core metabolic stability and reducing dulcitol levels. In contrast, increased ORP delayed fermentation by initially inhibiting microbial growth, reallocating metabolic flux, increasing the cis-aconitic acid concentration and decreasing ascorbic acid levels. Enzyme assays further demonstrated that decreased ORP optimized NADH availability and glycolytic flux, whereas oxidative conditions from increased ORP triggered compensatory metabolic responses. These findings highlight the ORP as a critical determinant of silage efficiency and offer practical insights for the efficient utilization of forage.

Italian ryegrass is a high-quality forage grass, and a full understanding of the changes in its microbiome and metabolome during aerobic exposure can prolong its aerobic stability and improve its utilization value. Italian ryegrass silage was prepared with deionized water (CK), Lactobacillus rhamnosus BDy3-10 (LR), Lactobacillus buchneri TSy1-3 (LB), and a mixture of these two lactic acid bacteria (M). The silage was maintained at ambient temperature for 60 days followed by aerobic exposure. The results show that the Italian ryegrass silage in the LB and M groups exhibited aerobic stability for up to 19 days. A total of 1881 chemicals were identified in Italian ryegrass silage. These metabolites are associated with bacterial communities, especially Lactobacillus. The addition of lactic acid bacteria resulted in a common differential metabolic pathway compared to CK: “phenylpropanoid biosynthesis”. “Flavone and flavonol biosynthesis” was the significant differential metabolic pathway between LB and LR. Inoculation with LB significantly increased the concentrations of lactic acid, acetic acid, vitexin, and luteolin. In conclusion, lactic acid bacteria (LAB) additives affect the microbial community and metabolites of silage. The application of LB inoculants is a feasible way to obtain well-fermented Italian ryegrass silage and improve aerobic stability, even at higher moisture content levels.

Mulberry (Morus alba L.) is a new bioresource for alleviating the feed supply crisis. This study evaluated pre-fermented mulberry juice (M), pre-fermented red clover juice (R), and pre-fermented grape pomace juice (G) to achieve clean and efficient production of mulberry silage.R treatment enriched Enterococcus (LDA > 5) and up-regulated L-aspartic acid and fumaric acid; M treatment enriched Lactobacillus (LDA > 5) and up-regulated colchicine and 3,4-dihydroxybenzaldehyde; and G treatment enriched Kosakonia (LDA > 4) and Lactiplantibacillus (LDA > 5) and up-regulated p-coumaric acid and chlorogenic acid. Pre-fermented juices modulated the microbiota community and metabolites of mulberry silage, thus regulating silage quality, especially in dry matter, crude protein, total nitrogen, nonprotein nitrogen, ammonia nitrogen, pH, lactic acid, and acetic acid. Furthermore, pre-fermented juices improved the in vitro rumen fermentation. R and M treatments increased in vitro gas production while reducing CO2 emissions without increasing CH4 production, illustrating that R and M treatments alleviated greenhouse gas production.Pre-fermented juices promoted in vitro rumen fermentation and enhanced the nutrition and fermentation quality of mulberry silages. This study revealed that pre-fermented juices achieved clean and efficient production of mulberry silage, which may promote sustainable development of the livestock industry.

Ferulic acid possesses certain antioxidant and antibacterial properties. Additionally, ferulic acid esterase (FAE) and cellulolytic enzymes have been associated with synergistic degradation of ferulic acid ester bonds, thereby facilitating greater release of ferulic acid from lignocellulose, which could have important effects on silage quality and aerobic stability. This study examined the effects of ensiling Broussonetia papyrifera with FAE-producing Lactiplantibacillus plantarum (LP), cellulase (CE) and xylanase (XY) under aerobic exposure conditions. The following treatments were used: distilled water (CK), LP, LP + CE, LP + XY and LP + XY + CE. After 60 days of silage treatment, the samples were unsealed for aerobic exposure for 1, 3, 5, or 7 days. Compared with the CK treatment, the addition of FAE-producing L. plantarum significantly (P < 0.05) led to lower pH, reduced dry matter loss of the silage and increased lactic acid (LA) concentration after 60 d of ensiling (especially for the LP + CE and LP + CE + XY groups). During the aerobic exposure stage, the combined treatment with LP and enzymes effectively inhibited the increase in pH, significantly reduced the rate of dry matter loss and increased the LA concentration and aerobic stability of the silage (P < 0.05). Moreover, the LP + CE and LP + CE + XY treatment groups exhibited higher ferulic acid levels than the other groups did, corresponding with greater aerobic stability, especially for the LP + CE group, which remained stable. In this group, the pH values showed minimal change, increasing by only 0.31 (4.24–4.55) after 7 days of aerobic exposure. In addition, the LP and enzyme co-treatment was linked to shifts in the microbial community of the silage during aerobic exposure, with increased relative abundance of Lactiplantibacillus plantarum, and its abundance positively correlated with lactic acid and ferulic acid concentrations, while negatively correlated with ammonia nitrogen; and inhibited proliferation of spoilage-related bacteria (Enterobacter, Gluconobacter and Cladosporium). The combination of FAE-producing L. plantarum and cellulase can be used as an effective method to increase the preservation efficiency and aerobic stability of B. papyrifera silage.

The objective of this study was to evaluate the synergistic and differential effects of inoculation with lignocellulolytic enzymes and ferulic acid esterase (FAE)-producing Lactobacillus plantarum on the fermentation characteristics, bacterial community and in vitro degradability of Sudan grass and mulberry and their mixed silage. Sudan grass and mulberry were mixed at mass ratios of 10:0 (S), 7:3 (S–7), 5:5 (S–5), 3:7 (S–3) and 0:10 (M). With the following treatments were applied: no treatment (CK); L. plantarum alone (LP); L. plantarum, cellulase and xylanase combined (LCX); or L. plantarum, xylanase and laccase combined (LXL). Compared with the control, all the additives (especially the bacterium–enzyme combinations) increased the lactic acid (LA) concentration, water-soluble carbohydrate (WSC) content and relative abundance of Lactobacillus; decreased the pH, ammonia–nitrogen (AN) concentration, coliform count and relative abundance of undesirable bacteria such as Enterobacter; and facilitated lignocellulosic degradation. LCX was more effective in degrading neutral detergent fiber (aNDF) and acid detergent fiber (ADF), decreased the pH, increased the WSC content and simplified the structure of the bacterial network, whereas LXL was better in degrading lignin and enhanced in vitro fermentation efficiency. In addition, LXL improved the silage quality by increasing the acetic acid (AA) concentration and relative abundance of Lactobacillus buchneri. Compared with ensiling alone, mixed ensiling balanced the nutrient composition, reduced the butyric acid (BA) concentration and relative abundance of Enterobacter, increased the relative abundance of Lactobacillus, increased the bacterial network positive correlation ratio and promoted in vitro dry matter (DM) digestibility. Overall, mixed ensiling and bacterium–enzyme inoculation improved fermentation quality.

This study was designed to evaluate the effects of dietary selenium yeast (SY) supplementation (0.3–0.9 mg/kg Se) on key production performance parameters, egg quality traits, antioxidant capacity, and plasma immune indices in laying hens, with concurrent verification of the safety profile of the upper test dose. A total of 108 healthy Hy-Line Brown laying hens (162 days old, weighing 1.61 ± 0.05 kg) were randomly allocated to four treatment groups, each comprising three replicates of nine birds. Following a 10-day acclimatisation period, a 60-day feeding trial was conducted. Dietary SY had no significant impact on core production metrics (all P > 0.05) but improved egg quality in a time and dose-dependent manner under the present experimental conditions: eggshell thickness, albumen height, and Haugh units were elevated in linear/quadratic patterns (P < 0.05), with the most pronounced effects observed in the 0.9SY treatment. SY supplementation increased the selenium content in eggs (0.32–0.977 mg/kg) and plasma (0.15–0.42 mg/L) of laying hens in a dose-dependent manner (linear trends, P < 0.05), with all SY groups meeting the Chinese standard for selenium-enriched eggs (GH/T1135-2017; ≥0.15 mg/kg). Antioxidant capacity was enhanced in a tissue-specific manner: hepatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), alongside plasma total antioxidant capacity (T-AOC), were elevated linearly and/or quadratically (P < 0.05), while yolk malondialdehyde (MDA) concentrations were reduced by Day 60 (linear/quadratic P < 0.05). SY exerted selective immunomodulatory effects: plasma concentrations of interleukin-6 (IL-6) and immunoglobulin M (IgM) decreased in linear and/or quadratic trends (P < 0.05), immunoglobulin G (IgG) tended to increase linearly (0.05 < P < 0.10), and immunoglobulin A (IgA) remained unaltered (P > 0.05). Critically, the 0.9 mg/kg Se dose—exhibiting the most favourable outcomes across all measured endpoints—remained within the dietary Se safety threshold (≤ 1.0 mg/kg) established by the National Research Council (NRC, 1994), in the absence of overt toxicological manifestations. In conclusion, under the parameters of this 60-day trial, dietary SY supplementation safely enhances egg quality, antioxidant defence, and immune homeostasis in laying hens, with 0.9 mg/kg Se emerging as the optimal dose. These findings support the potential utility of SY as a functional feed additive for selenium-enriched egg production in analogous commercial production systems.

Laccase (L), xylanase (X), and ferulic acid esterase (FAE) act on lignin - carbohydrate complexes. Whether these enzymes, alone or combined, can improve mulberry ensiling and aerobic stability is unclear. This study assessed the effects of L, X, and FAE - producing L. plantarum (LP) on whole - plant mulberry silage’s fermentation quality, aerobic stability, and microbial communities during aerobic exposure. After 60 days of ensiling, mulberry silage treated with CK, LP, LX, or M was unsealed for 1, 3, 5, or 7 days for exposure to air. The results indicated that the LP and M treatments decreased mulberry silage pH. The lower aminopeptidase and carboxypeptidase activities in the LP and M treatments might have contributed to the reduced degradation of crude protein (CP) and ammoniacal nitrogen (NH3-N) content (P < 0.05). Compared with the CK treatment, the addition of LX and M increased the acetic acid (AA) content by 1.49-2.68-fold, indicating greater aerobic stability (P < 0.05), which contributed to maintaining the storage quality of the silages during aerobic exposure. The application of additives to mulberry silage reduced the species richness; specifically, the additive treatments led to an increase in the relative abundance of Kondoa and Lentilactobacillus while decreasing that of Enterococcus and Delftia. Notably, Lentilactobacillus exhibited the capacity to inhibit the growth of other harmful microorganisms and emerged as the dominant genus within the LX group. In conclusion, treatment with the combination of laccase, xylanase, and FAE-producing L. plantarum can serve as an effective method to improve the silage quality and aerobic stability of mulberry.

In tropical or subtropical areas, high temperatures and prolonged storage time usually result in poor fermentation quality, poor aerobic stability and dry matter loss of silages. This study explored the effect of heat-resistant Lactobacillus buchneri TSy1-3 (LB), Lactobacillus rhamnosus BDy3-10 (LR), and their combination (M) on the nutritional characteristics, fermentation parameters and microbiota of whole plant maize silage during long-duration ensiling in the subtropical area. The results showed that long-term ensiling naturally led to a decrease in water-soluble carbohydrate, neutral detergent fiber and acid detergent fiber concentrations. In contrast to the control treatment, LB, LR and M reduced the coliform bacteria population and the nutrient loss, while increased lactic acid bacteria population and acetic acid and propionic acid concentrations after 180 d of fermentation. Moreover, they helped to increase Lactobacillus abundance and made it still dominate the bacterial community during long-term storage. The negative/positive ratio was higher in the LR and LB treatments when compared with the control treatment, suggesting that LR and LB increased the stability of the bacterial community networks. The heat-resistant inoculants rapidly produced lactic acid to modulate the bacterial community composition during 60 d of ensiling, while generated more acetic acid and propionic acid to alter the microflora during 180 d of ensiling. This may be caused by predicted functions indicating that metabolism pathways were modulated by different inoculations and storage times. Overall, heat-resistant lactic acid bacteria improved the nutritional and fermentation quality of ensiled forage and regulated the bacterial community during long-term storage in the subtropical region.

Background With its high nutritional value and productivity, Italian ryegrass as a biomass feedstock constantly supplies rumen degradable nitrogen and digestible fiber to ruminants. However, biofuel production is easily reduced during ensiling due to the high-moisture content of Italian ryegrass, leading to economic losses. Lactic acid bacteria inoculants could improve lignocellulosic degradation and fermentation quality and decrease dry matter loss during the bioprocessing of silage. Therefore, this study analyzed the effects of Lactobacillus buchneri TSy1-3 (HE), Lactobacillus rhamnosus BDy3-10 (HO), and the combination of HE and HO (M) on fermentation quality, bacterial community and metabolome in high-moisture Italian ryegrass silage during ensiling. Results The results showed that the pH value was significantly lower in the HO groups than in the other treatments at the end of ensiling, and the dry matter and acetic acid contents were significantly higher in the HO group than in the other inoculated groups. All inoculants decreased the diversity of the bacterial community and significantly increased the relative abundance of Lactobacillus . Inoculation with HO significantly improved the concentrations of organic acids, dipeptides, ferulic acid, apigenin, and laricitrin. Compared with Lactobacillus buchneri TSy1-3 (HE), HO significantly upregulated the flavonoid compounds in the flavone and flavonol biosynthesis pathway. Conclusions Overall, these findings suggest that inoculation with HO was beneficial for the development of Italian ryegrass as a biomass feedstock, improving fermentation quality, accelerating changes in bacterial community composition and increasing biofunctional metabolites in high-moisture Italian ryegrass silage.

Silage can be contaminated with mycotoxins and accidental fungi after aerobic exposure. The study assessed the effects of bunker silos (BS), round bales (RB), and silage bags (SB) on the nutritional characteristics, fermentation quality, aerobic stability, mycotoxin levels and microbial communities of whole-plant corn silage (WPCS). After 90 days of fermentation, silages were opened and sampled at 0, 1, 3, 5, 7, and 9 days of exposure. SB group conserved higher lactic acid and dry matter contents and a lower pH value than other groups after 9 days of exposure (p < 0.05). The SB group showed the longest aerobic stability (202 h) among all silages (p < 0.05). The concentrations of aflatoxin B1, trichothecenes and fumonisin B1 were significantly lower in SB after 9 days of exposure (p < 0.05). Acetobacter became the dominant bacteria in BS and RB groups after 5 days of exposure. However, Lactobacillus still dominated the bacterial community in SB group. Acetobacter was positively correlated with pH, acetic acid content, and ammonia-N content (p < 0.05). Lactobacillus was positively correlated with Kazachstania and Candida abundances (p < 0.01) but negatively correlated with Fusarium abundance (p < 0.05). Considering the feed value and food safety of silage in the feeding process, silage bags are recommended for WPCS according to the observed nutritional quality, fermentation index and mycotoxin content.

全株玉米(Zea mays)青贮饲料作为畜牧养殖产业的优质粗饲料,提高其饲用价值具有重要意义.本研究旨在探究喀斯特区域全株玉米青贮饲料在有氧暴露下品质及细菌菌群动态的变化规律,为其合理利用提供参考依据.试验分别以关岭和威宁两地区的全株玉米在同一环境下青贮发酵45d后开封,对有氧暴露3个时段(0、2和5d)的两组全株玉米青贮饲料进行有氧稳定性、营养成分、发酵品质和微生物结构分析.结果表明:关岭组和威宁组的有氧稳定性分别为130.50和61.83 h;随有氧暴露天数的延长,两组的干物质、粗蛋白、可溶性碳水化合物、淀粉、中性洗涤纤维、酸性洗涤纤维、乳酸和乙酸含量均显著减少(P＜0.05),两组的pH、丙酸和氨态氮含量均显著升高或增加(P＜0.05),均未检测到丁酸;两组有氧暴露5d后的OTU数量较0d均显著降低(P＜0.05),关岭组的Chao、ACE、Shannon和Simpson数量在有氧暴露5 d后较0d显著降低(P＜0.05),威宁组的Chao、ACE、Shannon和Simpson数量较0d无显著变化(P＞0.05),但存在降低的趋势;两组有氧暴露5d后的门、属水平优势菌群均分别为变形菌门(Proteobacteria)和醋酸杆菌属(Acetobacter).综上,两组全株玉米青贮饲料在有氧暴露期间的品质、细菌丰度及菌群多样性均呈现降低趋势,建议在温暖湿润环境下表层全株玉米青贮饲料的饲喂时间不超过2d.