The potential of biogas production and effects of alfalfa silage under the synergistic influence of Lactobacillus acidophilus and Rosa roxburghii pomace waste on the fermentation quality and bacterial community

The process of ensiling serves as a dual-purpose technique, functioning as a means of preserving biomass for biogas production while serving as a biological pretreatment method with the potential for little fermentation loss. In this study, we investigate the potential of Rosa roxburghii pomace (RP) and Lactobacillus acidophilus to improve the biomass preservation of biogas produced from alfalfa during anaerobic storage. Coinoculation of RP and Lactobacillus acidophilus resulted in better preservation of nutrients (biomass), with a significant increase of 47.38% within the lactic acid content and a notable decline of 40.34% in the ammonia nitrogen content relative to those in the control treatment. Moreover, coinoculation of RP and Lactobacillus acidophilus resulted in an elevated proportion of Lactobacillus, and the species Lactiplantibacillus plantarum dominated anaerobic fermentation. The synergistic effect of RP and Lactobacillus acidophilus continuously stimulated anaerobic fermentation, leading to 33.33% and 23.17% increases in methane production and acetate content, respectively, after 72 h of coinoculation with RP and Lactobacillus acidophilus compared to the control treatment. Overall, coinoculation of RP and Lactobacillus acidophilus offers an attractive opportunity to increase methane production from fruit waste while reducing costs and synergistically integrating with other pretreatment techniques to optimize the methane generation potential.

IMPORTANCE

Considering the increasing global energy demand and urgent environmental issues, exploring prospective resources for bioenergy production is imperative. However, the biomass of legume perennials may serve as an inexpensive and stable source of clean energy for modern society due to its wide availability and broad range of sources. In addition, the combination of RP and Lactobacillus acidophilus application increased the abundance of Lactobacillus, inhibited the growth of Kosakonia, and promoted anaerobic fermentation, which had beneficial synergistic effects on biomass retention and biogas production in alfalfa samples. Coinoculation improvements with RP and Lactobacillus acidophilus observed here are expected to reduce costs associated with CH4 conversion bioprocesses and increase CH4 production.

Effects of cellulase or Lactobacillus plantarum on ensiling performance and bacterial community of sorghum straw

This study aimed to evaluate the effects of cellulase or Lactobacillus plantarum (L. plantarum) on the fermentation characteristics and microbial community structure of the sorghum straw silage. Sorghum straw was treated with the following four experimental conditions: distilled water (control, CK), cellulase (CEL), Lactobacillus plantarum (LP), and a combined treatment of Lactobacillus plantarum with cellulase (LPCEL). These results indicated that the LP treatment could markedly (p < 0.05) preserve the crude protein content compared to that in other treatments, whereas the CEL significantly (p < 0.05) reduced the acid detergent fiber content, while the LPCEL had the highest lactic acid content and lowest pH value. Proteobacteria and Pantoea were identified as the dominant phylum and genus in fresh materials, respectively. This phylum level dominance transitioned to Firmicutes post-treatment, while at the genus level, the community shifted from Pantoea to co-dominance of Lactobacillus and Prevotella, with Lactobacillus being the most abundant in both the CEL and LPCEL treatments. In conclusion, adding L. plantarum and cellulase to sorghum straw can significantly improve the fermentation quality of sorghum straw silage, and improve the nutritional value of silage by affecting the microbial community structure and metabolic pathways.

Effects of inoculants on the quality of alfalfa silage

To explore the effects of different silage inoculants on the silage quality of alfalfa (Medicago sativa L.), the experiment used Alfalfa with a moisture content of 60.00% after harvesting as the raw material. The treatments included a control group containing only distilled water (CK), Xinlaiwang I-straw silage agent (A), Xinlaiwang I-alfalfa silage agent (B), Zhuanglemei silage fermentation agent (C), Baoshiqing (D), and Kangfuqing S lactic acid bacteria inoculant (E), totaling six treatments. After 60 days of normal temperature sealing treatment, the silage fermentation and nutritional indicators of Alfalfa were measured, and the silage fermentation effect was analyzed by the membership function method. The experiment showed that when the moisture content of alfalfa was 60.00%, the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the silage agent treatment groups were significantly lower than those of the CK group (p < 0.05). The lactic acid (LA) content was significantly higher in the treatment group than in the CK group (p < 0.05). The addition of Xinlaiwang I-alfalfa silage agent in group B significantly increased the crude protein (CP) and LA levels in the Alfalfa silage (p < 0.05). It also reduced the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents. Additionally, the pH and Ammonia Nitrogen/Total Nitrogen (AN/TN) ratio were lowered. Propionic acid (PA) and butyric acid (BA) were not detected. After the membership function calculation, the average membership value of Xinlaiwang I-alfalfa silage agent (B) group was the highest with a score of 0.90, ranking first, and the silage quality was the best. In summary, through quality analysis and membership function calculation, Xinlaiwang I-alfalfa silage agent can effectively improve the silage quality of WL298HQ alfalfa.

Effect of biological lignin depolymerization on rice straw enzymatic hydrolysis, anerobic fermentation characteristics and in vitro ruminal digestibility

This study investigated the effects of lignin depolymerization using laccase on rice straw silage fermentation characteristics, lignocellulose biodegradation and in vitro digestibility. Rice straw was ensiled for 120 days, either without additives (control), or pretreated with Lactobacillus plantarum and cellulases (LPC), cellulases and laccase (CL), and L. plantarum, cellulases and laccase (LPCL). The results revealed that LPC and LPCL treated silages exhibited significantly lower (P < 0.05) pH values, higher (P < 0.05) lactic acid content (24.76 and 27.02 g/kg dry matter (DM)) and significantly higher water-soluble carbohydrate content (20.12 and 22.46 g/kg DM) compared to control and CL treated silages. Laccase-containing treatments (CL, LPCL) significantly reduced lignin, cellulose and hemicellulose contents in the ensiled rice straw compared to the control and LPC treated silages. Structural alterations in the straw, induced by pretreatments, were confirmed by Fourier Transform Infrared spectroscopy, Scanning Electron Microscope and X-ray diffraction analysis. The CL treated silage exhibited the lowest (P < 0.05) in vitro digestibility, while the LPCL treated silage had the highest in vitro total gas production (25.50 mL). In conclusion, laccase effectively degraded lignin during ensiling, and the combined application of laccase with L. plantarum and cellulases enhanced both the enzymatic hydrolysis and ensiling quality of rice straw. These findings demonstrate the potential of biological lignin depolymerization during ensiling as an innovative strategy to significantly enhance the nutritional value of straw bioresources, paving the way for sustainable livestock production and waste reutilization.

In-depth proteomic analysis of alfalfa silage inoculated with Lactiplantibacillus plantarum reveals protein transformation mechanisms and optimizes dietary nitrogen utilization

Alfalfa is a vital feedstock for ruminants due to its high protein content. However, concerns regarding nitrogen (N) loss in alfalfa silage from protein transformation have arisen, but the underlying molecular mechanisms remain undefined. This study investigated the patterns of protein transformation in alfalfa during fermentation through multi-omics analysis. Lactiplantibacillus plantarum treatment effectively preserved the true protein PB1 and peptide-N, by mitigating N degradation. Proteomic profiling revealed a decrease in the abundance of higher molecular weight proteins (45-70 kDa), coupled with an increase in lower molecular weight proteins (15-45 kDa), mainly located in the membrane, cytoplasm and ribosome. Meanwhile, levels of protein hydrolysates, including peptides and essential amino acids, were elevated. Among these, Ile-Pro, Pro-Val, flavorful L-Glu and the proteogenic Arg were identified as the predominant constituents. Tripeptidyl-peptidase, carboxypeptidase, and serine protease were identified as the primary plant proteases mediating protein transformation. These findings highlight the synergistic effects of plant proteases and microbial activity, mainly from L. plantarum, in transforming large proteins into peptides and amino acids during fermentation. Our findings provide insights for the targeted regulation of alfalfa protein transformation during fermentation, potentially enhancing protein utilization in ruminants.

An In Vitro Nutritional Evaluation of Mixed Silages of Drought-Impaired Grass and Sugar Beet Pulp With or Without Silage Inoculants

Increasing droughts adversely affect grasslands, diminishing the availability and quality of forages for ruminants. We have recently shown that mixed ensiling of drought-impaired grass (DIG) with sugar beet pulp (SBP) improved the conservation and feed value of silage. The application of silage additives may further improve the ruminal degradability, which may thereby shape the fermentation and microbiome in the rumen when those silages are tested as part of dairy diets. Therefore, we performed a long-term in vitro nutritional evaluation of diets containing 50% (DM basis) of mixed silages from DIG and SBP, ensiled either with no additive (T_CON) or with anaerobic fungi culture supernatant (25% in DM; T_AF), mixed ruminal fluid (10% in DM; T_RF) or lactic acid bacteria (1% in FM; T_LAB). The data showed a high degradability of all diets (e.g., > 70% for organic matter), though without differences in nutrient degradabilities among treatments (p > 0.05). Fermentation characteristics, such as ruminal pH, short-chain fatty acid profile, and gas production were only marginally affected by the treatments. Isobutyric acid proportion was higher in T_CON than in T_AF (p = 0.01), whereas isovaleric acid proportion was lower in T_LAB than in T_RF (p = 0.01). The analysis of the bacterial community revealed similar diversity and structure across all treatments in both the liquid and solid fraction. Noteworthy, Lactobacillus was among the predominant genera in the liquid fraction, which may have derived from the mixed silages. In conclusion, mixed silages from DIG and SBP as part of a 50% concentrate diet showed high ruminal degradability, but no beneficial impact by the tested silage additives was observed. Hence, under these conditions, their application appears not justified. Our results warrant further in vivo verification, whereby it would be of interest to determine the impact of the applied silage additives in forage-based diets (e.g., > 50% silage in diet DM) in future research.

Effects of rehydrated corn silage inoculated with Rhodotorula mucilaginosa + Trichoderma longibrachiatum on finisher lambs fed a tropical hay-based diet

It is well established in the scientific literature that tropical forages are characterized by low soluble carbohydrates and a high proportion of cell walls containing lignin, negatively impacting animal productivity. Using live microorganisms in diets, such as fungi and yeasts, can benefit animal nutrition and health. This study assessed the effects of using rehydrated ground corn silage as a vehicle for providing an inoculant composed of fungus and yeast (Rhodotorula mucilaginosa + Trichoderma longibrachiatum) isolated from the gastrointestinal contents of sheep on the productive performance of confined lambs. Twenty-two entire male lambs of the Dorper × Santa Inês breed (14.20 ± 1.74 kg body weight) were randomly assigned to two treatments: 1) control diet containing rehydrated corn silage without inoculant (CTL); 2) diet containing rehydrated ground corn silage with inoculant of indigenous microorganisms (INO). Rhodotorula mucilaginosa and Trichoderma longibrachiatum were observed only in samples of rehydrated corn with inoculant (P<0.0001). The inoculated silage had lower neutral detergent fiber (NDF) content (89.9g/kg dry matter - DM) than the control silage (134.8g/kg DM). CTL treatment showed higher other mycelial fungi count than treatment INO (P=0.04). However, the total count of mycelial fungi did not differ between treatments. Treatments did not affect silage pH; however, pH was reduced in samples taken 56 days after ensiling (P<0.001). No differences were observed between treatments for DM digestibility and nutrient and nitrogen balance (P<0.05). Although the combination of microorganisms reduced dry matter intake (DMI) (P<0.05), no treatment effect was observed on growth performance over the 63-day experimental period. These results indicate that Rhodotorula mucilaginosa and Trichoderma longibrachiatum inoculated in rehydrated corn silage can improve feed quality by lowering fiber content without compromising animal growth. In conclusion, feeding lamb with rehydrated corn silage inoculated with Rhodotorula mucilaginosa and Trichoderma longibrachiatum reduces dry matter intake of tropical hay-based diets without affecting body weight gain.

Detoxification of coumarins by rumen anaerobic fungi: insights into microbial degradation pathways and agricultural applications

BACKGROUND

Coumarins are toxic phytochemicals found in a variety of plants and are known to limit microbial degradation and interfere with nutrient cycling. While the degradation of coumarins by fungi has been studied in an environmental context, little is known about their degradation in the gastrointestinal system of herbivores after ingestion.

RESULTS

In this study, we investigated in vitro fermentation by microbial enrichment, transcriptome sequencing, and high-resolution mass spectrometry to evaluate the ability of rumen anaerobic fungi to degrade coumarins. The results showed that despite the low abundance of anaerobic fungi in the rumen microbiota, they were able to effectively degrade coumarins. Specifically, Pecoramyces ruminantium F1 could tolerate coumarin concentrations up to 3 mmol/L and degrade it efficiently via metabolic pathways involving alpha/beta hydrolases and NAD(P)H oxidoreductases within the late growth phase. The fungus metabolized coumarin to less toxic compounds, including o-coumaric acid and melilotic acid, highlighting the detoxification potential of anaerobic fungi.

CONCLUSIONS

This study is the first to demonstrate the ability of rumen anaerobic fungi to degrade coumarin, providing new insights into the use of anaerobic fungi in sustainable agricultural practices and environmental detoxification strategies.

Effects of Lactic Acid Bacteria on Fermentation and Nutritional Value of BRS Capiaçu Elephant Grass Silage at Two Regrowth Ages

The objective of this study was to evaluate the effects of lactic acid bacteria inoculation on the fermentation profile and nutritional value of BRS Capiaçu elephant grass silages harvested at two regrowth ages. The treatments were arranged in a 5 × 2 factorial scheme, with five inoculants (I) and two regrowth ages (A, 90 and 105 days), in a completely randomized design, with three replicates. There were I × A interactions (p < 0.05) on pH, acetic acid, and water-soluble carbohydrates. The silage treated with Kera-Sil showed a lower pH compared with the control silage. The highest ammonia nitrogen content was recorded in the silage treated with Yakult®. There were I × A interactions (p < 0.05) on the dry matter (DM) content, neutral detergent fiber (NDF), and in vitro digestibility of DM (IVDMD) and NDF (IVNDFD). Silages treated with Kera-Sil and Silo-Max at 90 days of regrowth showed a higher DM and higher IVDMD (p < 0.05). A higher NDF content and lower IVDMD and IVNDFD were recorded in silages produced with grass harvested at 105 days of regrowth (p < 0.05). The use of commercial microbial inoculants improved the fermentative and nutritional parameters of the silages.

Assessing the Impact of Silage Inoculants on the Quality of Adina Alfalfa Silage

In order to explore the effects of different silage inoculants on the silage quality of alfalfa (Medicago sativa L.), this study utilized six groups of experimental treatments and five kinds of additive treatments: Xinlaiwang I straw silage (group A), Xinlaiwang I alfalfa silage (group B), Zhuanglemei silage starter culture (group C), Baoshiqing (group D), Kangfuqing S lactic acid bacteria silage (group E), and another blank control group (CK group, distilled water). The effect of silage on fermentation characteristics and nutritional value of Adina alfalfa silage was studied by membership function analysis. The main study variable was inoculant strains. Alfalfa silage was packed into polyethylene plastic vacuum bags in the laboratory and sealed for 60 days. The silage was divided into six treatment groups with three replicates per group. The fermentation performance and nutrient composition of the silage were determined. The results showed that compared with the control group, adding Xinlaiwang I alfalfa silage (group B) could significantly increase the contents of crude protein (CP) and lactic acid (LA) in alfalfa silage (p < 0.05), decrease the contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF), and decrease the pH and ammoniacal nitrogen/total nitrogen (AN/TN). The results showed that different inoculants could improve the silage quality of alfalfa to different extent, and Xinlaiwang I alfalfa silage had the best effect.

Anthocyanins promote the abundance of endophytic lactic acid bacteria by reducing ROS in Medicago truncatula

The microbial community residing on the phyllosphere is influenced by many factors, including the host plant's genotype as well as its secondary metabolites. Anthocyanins are a group of flavonoids renowned for their antioxidative properties and are widely distributed across plant tissues. However, the potential impact of anthocyanins on plant-associated microbial communities remains unknown. In the model legume Medicago truncatula, we isolated a mutant named purple leaves (pl) that produces purple leaves at a young stage due to over-accumulated anthocyanins. Through sequencing 16S rRNA amplicons of phyllosphere microbes in the pl mutant, we show that anthocyanins significantly enhance the abundance of endophytic lactic acid bacteria within plant leaves. Further in vitro study revealed that anthocyanins derived from pl can significantly promote the growth of lactic acid bacteria under anaerobic conditions. The accumulated anthocyanins in pl leaves reduced reactive oxygen species (ROS), thereby creating a favorable environment for the growth of facultative anaerobic lactic acid bacteria and resultantly increasing the abundance of phyllosphere lactic acid bacteria. Our findings elucidate the role of anthocyanins in modulating the community structure of phyllosphere microbiota in M. truncatula and provide new insights into the relationship between plant secondary metabolites and phyllosphere microbiota.

Isolation of lactic acid bacteria and quantification of Lentilactobacillus buchneri using qPCR in sorghum silage inoculated with native strains in tropical conditions

The objective of this study was to isolate lactic bacteria, quantify the population of Lentilactobacillus buchneri by qPCR, and evaluate the effects of the inoculation of native strains of L. buchneri in sorghum silage. The treatments were arranged in a 4 × 5 factorial scheme, with four inoculants (I) and five fermentation periods (P) (7, 14, 28, 45, and 90), in a completely randomized design, with three replicates. Forty-seven LAB strains were isolated from control silage, and L. buchneri was the predominant species at 45 and 90 days of fermentation. The qPCR data showed that L. buchneri predominated during all fermentation periods in the inoculated silages. There was an effect (P<0.05) of I × P interaction on all studied variables of the fermentative profile and microbial population. There was an effect (P<0.05) of I × P interaction on the dry matter (DM), neutral detergent fiber (NDF), in vitro DM digestibility, and in vitro NDF digestibility. Inoculation with L. buchneri resulted in silages with better fermentative quality and digestibility and a lower yeast population. The native LB.1 and LB.4 strains have potential to be used as inoculants in sorghum silage production, with effects on fermentation quality at 45 days of storage.

Effects of different concentrations of Lactiplantibacillus plantarum and Bacillus licheniformis on silage fermentation parameter, chemical composition and microbial community of Pennisetum sinese

The purpose of the experiment was to study the effects of different concentrations of Lactiplantibacillus plantarum (LP) and Bacillus licheniformis (BL) on the quality of Pennisetum sinese (PS) silage. The experiment consisted of seven treatment groups. The control group did not use additives, and the experimental groups were added with LP or BL of 1 × 105 CFU/g fresh weight (FW), 1 × 106 CFU/g FW and 1 × 107 CFU/g FW, respectively. The nutritional value of Pennisetum sinese silage was comprehensively evaluated using CNCPS 6.5 system and 16sDNA sequencing technology. The results showed that the ammonia nitrogen content and pH of each experimental group were significantly lower than those of the control group (p < 0.05). The starch content gradually decreased and the water-soluble carbohydrate (WSC) content increased in both LP and BL groups with the increase of addition concentration. The LP7 group could significantly increase the true protein content in protein (p < 0.05), and CP in BL groups decreased gradually with the increase of concentration. Compared with the control group, the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) was significantly lower in LP7 group (p < 0.05) and the ADF content was significantly lower in BL5 group (p < 0.05). In addition, LP and BL were able to change the proportion of each component in CNCPS system for Pennisetum sinese silage. The use of LP and BL can reduce the relative abundance of harmful microorganisms in silage such as Sediminibacterium and Nitrospira, and significantly change the microbial community structure in silage (p < 0.05). In conclusion, LP and BL have significant effects on silage quality and nutritional value. The nutritional value of Pennisetum sinese in LP groups showed a dose-dependent effect, and adding 1 × 107 CFU/g LP have the best effect in silage. The best effect was achieved by adding 1 × 105 CFU/g BL in BL groups, and the effect of LP7 group was better than that of BL5 group.

Impact of Potentially Antioxidant Probiotic Strains on Fermentation Quality and Antioxidant Status in Alfalfa Silage

The study aimed to characterize the antioxidant properties of isolated lactic acid bacteria (LAB) and assess their impacts on fermentation quality and antioxidant status in alfalfa silage. Two LAB strains of Lactiplantibacillus plantarum XY15 and Lactiplantibacillus plantarum XY20 and a reference strain of Pediococcus acidilactici J17 were subjected to antioxidant property evaluation. This was followed by inoculation into alfalfa silage. The DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl (OH) radical scavenging activities and the glutathione peroxidase (GSH-Px) activity of the cell-free supernatants of L. plantarum YX15 and L. plantarum YX20 were significantly (p < 0.05) higher than those of P. acidilactici J17. In all three strains, the superoxide dismutase (SOD) activity was higher in the cell-free supernatants than in the intracellular lysates. Among all three strains, P. acidilactici J17 showed the highest total antioxidant capacity (T-AOC) in the cell-free supernatant. Inoculating L. plantarum YX20 and P. acidilactici J17 increased lactic acid (LA) concentration and LAB counts, decreased dry matter (DM) loss, ammonia-N concentration, and pH, compared with control (CON) and L. plantarum XY15 inoculated alfalfa silages. After 1 d of ensiling, alfalfa silage inoculated with L. plantarum XY20 exhibited higher SOD activity than other silages. Inoculating L. plantarum XY20 and P. acidilactici J17 increased the DPPH free radical scavenging rates in alfalfa silage, compared with CON and L. plantarum XY15 inoculated 90 d-silages. Both L. plantarum YX15 and L. plantarum YX20 demonstrated a dual function of enhancing the lactic fermentation and improving the antioxidant status in alfalfa silage.

Producing high-quality and safe whole-plant quinoa silage through selecting variety and harvest time

The great potential of whole-plant quinoa (WPQ) as a forage crop has been recognized in recent years. In this study, we investigated the effects of variety and harvest time on the fermentation characteristics, bacterial community, and hygienic quality of WPQ silage. Five varieties (Hongxin, Mengli1, SL577, SL2860, SL923) were grown across five separate experimental fields, with harvest occurring after 90 days (H1), 105 days (H2), or 120 days (H3). The samples were ensiled to evaluate their fermentation characteristics and bacterial composition. Hygienic quality was assessed using the Tax4fun2 and BugBase tools for potential pathogenicity and antimicrobial resistance prediction. The variety significantly influenced (P < 0.05) all fermentation variables (including pH, lactic acid, acetic acid, propionic acid, ethanol, and ammonia nitrogen), while harvest time affected pH and the contents of acetic acid, propionic acid, and NH3-N (P < 0.05). An interaction between variety and harvest time was detected (P < 0.05) for all fermentation variables. Based on the flieg' score index, silage quality increased for Mengli1 (5.20-54.8), SL577 (36.7-71.5), and SL923 (34.9-77.0) with delayed harvest time, while silage quality decreased for Hongxin (52.1-41.4) and SL2860 (78.4-63.6). Compared to other silages, Hongxin silages exhibited greater differences in bacterial community composition between harvest times (indicated by higher PERMANOVA R2-value). Tax4fun2 and BugBase analyses revealed that delaying harvest time significantly increased (P < 0.05) the relative abundances of pathogenic and antibiotic-resistant KEGG pathways ("Infectious disease: bacterial invasion" and "Drug resistance") and harmful microbes associated with potential pathogenicity and antimicrobial resistance in Hongxin silages. This study highlights the importance of variety and harvest time in producing high-quality, safe WPQ silage, which is beneficial for ensuring the safety in our food supply chain.

Inoculation of Lactobacillus parafarraginis enhances silage quality, microbial community structure, and metabolic profiles in hybrid Pennisetum

BACKGROUND

This study investigated the effects of inoculating Lactobacillus parafarraginis alone or in combination with citric acid on the silage quality, microbial community structure, and metabolic characteristics of hybrid Pennisetum. The experiment included three treatments: (1) addition of 10 ml distilled water (CON); (2) addition of 1 × 106 cfu/g L. parafarraginis (LP); (3) addition of 1 × 106 cfu/g L. parafarraginis and 1% citric acid (LCA). The fermentation was maintained at 25 ℃ for 60 days.

RESULTS

The addition of L. parafarraginis increased the dry matter, water-soluble carbohydrates, and crude protein content of the silage and decreased the fiber contents. Moreover, lactic acid content was notably higher, and pH values were lower in the L. parafarraginis group, with higher lactic acid bacteria (LAB) compared with the CON. The microbial community analysis indicated that adding L. parafarraginis promoted the proliferation of beneficial LAB and inhibited spoilage bacteria, such as Clostridium. In the LCA, amino acid metabolism was improved, particularly with an increase in L-tyrosine concentration, along with significant enrichment of pathways related to tryptophan metabolism.

CONCLUSIONS

The addition of L. parafarraginis improved the fermentation quality of the silage, reduced undesirable microorganisms, and increased the content of organic acids, indicating its potential to enhance the flavor of the silage. Compared with individual treatments, the combination of L. parafarraginis and citric acid improved amino acid metabolism and enriched pathways related to tryptophan metabolism, further enhancing the quality of the silage. These findings highlight the potential of L. parafarraginis, especially in combination with citric acid, as an effective additive for producing high-quality, nutritious hybrid Pennisetum silage.

Effects of compound lactic acid bacteria on the quality and microbial diversity of alfalfa silage in saline-alkali soils

With the rapid development of animal husbandry, forage resources are increasingly scarce. Improving the utilization rate of forage products and silage efficiency of planting is an urgent problem to be solved. This experiment used high moisture alfalfa at the budding stage with a water content of 71.4% from saline-alkali and non-saline-alkali soils as raw materials, setting up four experimental groups: non-saline-alkali alfalfa without additives (HNS-CK), non-saline-alkali alfalfa with compound lactic acid bacteria (Lactobacillus plantarum + Lactobacillus buchneri + Pediococcus pentosaceus + Lactobacillus kimchi, HNS-L4), saline-alkali alfalfa without additives (HS-CK), and saline-alkali alfalfa with compound lactic acid bacteria (HS-L4). After 60 days of silage, the quality and microbial diversity of the silage were tested. The results showed that the dry matter (DM) and lactic acid (LA) of the HNS-L4 group were significantly higher than those of the HS-L4 (P < 0.05), while there was no significant difference in crude protein (CP) between the HNS-L4 group and the HS-L4 (P < 0.05). The neutral detergent fiber (NDF), acid detergent fiber (ADF), pH of the HNS-L4 group were all lower than those of the HS-L4. The results of the microbial community showed that compared with the non-additives group, the Shannon index decreased and the Simpson index increased in the compound lactic acid bacteria group, indicating a significant reduction in microbial diversity in the silage environment (P < 0.05). The dominant bacteria in the HNS-CK and HS-CK groups were Enterobacteriaceae, while the dominant bacteria in the HNS-L4 and HS-L4 groups were Lactobacillus. At the phylum level, the dominant bacteria in alfalfa after lactic acid bacteria treatment were Firmicutes, which were significantly higher than the control group (P < 0.05). Therefore, compound lactic acid bacteria can improve the quality of alfalfa silage in both saline alkali and non-saline-alkali soils, with saline-alkali soils being better than non-saline-alkali soils, and both can reduce microbial diversity.

Probiotic-Enzyme Synergy Regulates Fermentation of Distiller's Grains by Modifying Microbiome Structures and Symbiotic Relationships

The high fiber content and low rumen digestibility prevent the efficient use of distiller's grains (DGS) in ruminant feeds. This study investigated the effects of probiotics (Lactiplantibacillus plantarum and Bacillus subtilis) and enzymes (β-glucanase, xylanase, β-mannanase, and cellulase) on DGS nutrient content, ruminal degradability, and microbial communities under anaerobic storage for 30 days. Groups included control (C), probiotics (B), enzymes (E), and their mixture (EB). As compared to groups C, B, and E, neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, and cellulose contents were significantly decreased and the ruminal degradability of NDF and ADF at 48 h was significantly increased in group EB (p < 0.05). Enzyme activities significantly affected bacterial abundance, and the contents of these enzymes were negatively correlated with the content of fibrous components. The abundances of Bacillus and Rummeliibacillus were negatively correlated with fiber content but positively correlated with the activities of these enzymes. The symbiotic relationship between Bacillus and Anaerocolumna in the EB group sustained the synergistic effects of probiotics and enzymes. Co-fermentation of probiotics and enzyme additives enhanced the nutritional value of DGS, which was associated not only with probiotic-enzyme synergy but also variations in dominant microbes and microbiome commensal relationships.

Fermentative profile and bacterial community structure of whole-plant triticale silage (Triticosecale Wittmack) with or without the addition of Streptococcus bovis and Lactiplantibacillus plantarum

This study aimed to investigate the effects of Streptococcus bovis and Lactiplantibacillus plantarum on the chemical composition, fermentation characteristics, bacterial communities, and predicted metabolic pathways of whole-plant triticale silage (Triticosecale Wittmack). Fresh triticale harvested at the milk stage was ensiled in sterile distilled water (CON), Streptococcus bovis (ST), Lactiplantibacillus plantarum (LP), and a combination of S. bovis and L. plantarum (LS) for 3, 7, 15, and 30 days. During ensiling, the pH and water-soluble carbohydrate (WSC) content in the inoculated groups was significantly lower than those in the CON group (P < 0.05), especially in the LS group (P < 0.05). After 7 days of ensiling, the ST and LS groups had lower (P < 0.05) starch content and higher (P < 0.05) concentrations of lactic acid (LA) and acetic acid (AA). Inoculation with S. bovis and L. plantarum, either alone or in combination, increased the abundance of Lactobacillus and Pediococcus while reducing the abundance of Weissella, Rosenbergiella, Pantoea, and Enterobacter. Metabolic prediction analysis indicated that inoculation with S. bovis enhanced starch and sucrose metabolism during the early stages of ensiling. The abundance of Streptococcus positively correlated with LA (P < 0.05) and AA concentration but negatively correlated with starch content, pH, and propionic acid (PA) concentration (P < 0.05). S. bovis inoculation increased starch hydrolysis and carbohydrate metabolism during the early stages. S. bovis and L. plantarum synergistically improved the fermentation characteristics and bacterial communities of triticale silage. Therefore, S. bovis can be used as an additive or for a fast start-up agent to improve silage fermentation quality.IMPORTANCEEnsiling is a widely used method for preserving fresh forage. Silage quality is determined by the chemical and microbial composition. Studies have shown that S. bovis grew faster than commercial species, thereby creating advantages for other lactic acid bacteria during ensiling. Therefore, we believe that S. bovis and L. plantarum can synergistically improve the fermentation characteristics and bacterial community in silage. However, few studies use high-throughput methods to explain the impact of S. bovis on silage fermentation. Results showed that S. bovis significantly affected the fermentation parameters, bacterial community, and metabolic characteristics of triticale silage. S. bovis and L. plantarum synergistically accelerated the fermentation, reducing pH and WSC while increasing lactic acid and acetic acid concentrations in the early stages of ensiling. Additionally, co-inoculation increased the abundance of Lactobacillus and Pediococcus and carbohydrate metabolism. This study emphasizes the synergistic role of S. bovis and L. plantarum in enhancing triticale silage quality, providing scientific support for novel silage additives.

Ensiling characteristics, in vitro digestibility and bacterial community structure of mulberry leaf silage with or without the addition of cellulase, protease, and starch

Objective

This study aimed to investigate the effects of cellulase, protease, and starch on the fermentation quality, in vitro digestibility, and microbial community of mulberry leaf silage after 30d of ensiling.

Methods

Mulberry leaves (376 g/kg dry matter (DM)) were ensiled with four experimental treatments: i) CON, no additives; ii) CEL, added cellulase (120 U/g fresh matter [FM]); iii) CPR, added cellulase (120 U/g FM) and protease (50 U/g FM); and iv) CPS, added cellulase (120 U/g FM), protease (50 U/g FM), and starch (2% FM).

Results

All treatments with additives improved fermentation quality, showing higher DM (353 ~ 378 vs. 341 g/kg DM), lactic acid (LA) content (51.6 ~ 64.6 vs. 40.2 g/kg DM), lactic acid bacteria (LAB) counts (7.63 ~ 7.73 vs. 7.49 log10 CFU /g of FM), along with lower pH values (4.29 ~ 4.60 vs. 5.09), and DM losses (124 ~ 130 vs. 134 g/kg DM) compared to the CON group. All the additive treated groups showed higher in vitro digestibility of DM (698 ~ 720 vs. 618 g/kg DM), in vitro digestibility of NDF (395 ~ 412 vs. 336 g/kg DM), and ADF (277 ~ 298 vs. 232 g/kg DM) than CON. Among all the groups, the CPS group exhibited the highest DM content (378 g/kg DM), LA content (64.6 g/kg DM) and LAB counts (7.73 log10 CFU /g of FM), with the lowest pH value (4.29) and DM losses (124 g/kg DM). Additionally, the additive treatments increased abundance of bacteria like Firmicutes and Enteroccocus, while reducing Proteobacteria abundance, and resulted in lower diversity and richness of the microbial community. Specifically, CPR and CPS silages showed increased Pediococcus and decreased Enterobacter compared to CON and CEL, and CPS silage had a relatively high abundance of favorable Bacteroidota. Furthermore, the CPS silage exhibited upregulated genetic functions, energy and lipid metabolism, as well as metabolism of cofactors and vitamins compared to the other groups.

Conclusion

The combined application of cellulase, protease, and starch effectively improved the fermentation quality, in vitro digestibility, and microbial community of mulberry leaf silage over the 30-day ensiling period.

Effects of Moisture Content Gradient on Alfalfa Silage Quality, Odor, and Bacterial Community Revealed by Electronic Nose and GC-MS

Better quality and odor of silage and normal microbial fermentation metabolism are mostly dependent on an appropriate moisture content. The purpose of this study was to determine the effects of different moisture content gradients (50, 60, 70, and 80%) on the bacterial community, odor, and quality of alfalfa silage at 60 days by using gas chromatography-mass spectrometry (GC-MS) and electronic nose, with six replicates per group. The results showed that there were significant differences in odor response intensity among all groups, among which the 80% group had the strongest reaction to terpenoids, sulfides, and nitrogen oxides. Similarly, the different volatile organic compounds (VOCs) were mainly terpenoids, alcohols, and ketones, such as pine, camphor, and menthol (e.g., carlin and levomenthol). The dominant bacterium was Enterococcus with higher fiber, pH, and ammonia nitrogen (NH3-N) content but poorer quality and odor (p < 0.05). The differential VOCs in the 60% group were mainly heterocyclics, esters, and phenols with fruity, floral, and sweet odors such as 2-butylthiophene and acorone. Pediococcus and Lactiplantibacillus were the dominant bacteria, with higher crude protein (CP), water-soluble carbohydrates (WSC), and lactic acid (LA) contents, as well as better quality and odor (p < 0.05). The biosynthesis of terpenoids and steroids, biosynthesis of secondary metabolites, and biosynthesis of phenylpropanoids were the main metabolic pathways of differential VOCs. In conclusion, regulating moisture content can alter bacterial community and metabolites, which will encourage fermentation and enhance alfalfa silage quality and odor.

Compound lactic acid bacteria enhance the aerobic stability of Sesbania cannabina and corn mixed silage

BACKGROUND

The strategic delay of aerobic deterioration in Sesbania cannabina and corn (SC) mixed silage, coupled with effective fermentation, could increase the protein-rich silage utilization by ruminants. Thus, we sought to investigate the role of a compound lactic acid bacteria (LAB) inoculant (Lactobacillus plantarum + Lactobacillus farciminis + Lactobacillus buchneri + Lactobacillus hilgardii; at a level of 106 CFU/g fresh weight) in enhancing the aerobic stability of SC mixed silage. Specifically, we focused on the potential for corn supplementation to improve fermentation quality while concurrently increasing the susceptibility of SC mixed silage to aerobic spoilage.

RESULTS

Results revealed that compound LAB additive diversified the microbial community of SC mixed silage, making Lactobacillus hilgardii and Lactobacillus buchneri dominant bacterial species, while decreasing the abundance of Kazachstania humilis fungal specie. As a result, the LAB-treated mixed silages had higher acetic acid contents and lower yeast populations. Aerobic stability analysis revealed that the SC mixed silages with a high corn proportion deteriorated rapidly when the silages were exposed to air. The high aerobic stability of the LAB-treated mixed silages especially S7C3 contrasted with the low acetic acid concentrations in the CK mixed silages (processed with sterilized water), concomitant with increased Kazachstania humilis abundance.

CONCLUSION

Our study revealed that inoculation with a compound LAB additive altered the consequences of aerobic exposure by increasing acetic acid production after ensiling, promoting diverse bacterial populations, and mitigating the negative effects of fungi on the aerobic stability of SC mixed silage.

Total mixed ration silage based on cactus pear and cottonseed cake in the feeding of feedlot finished lambs

The purpose of this study was to assess the fermentative characteristics of total mixed ration silage (TMR) based on cactus pear and cottonseed cake and its effect on the productive performance and ingestive behaviour of lambs in feedlot. The study was divided into two experimental trials. The first experimental trial evaluated the fermentative quality of the total mixed ration silages, in five replications per treatment, and the second evaluated the productive performance and ingestive behaviour of lambs, in eight replications per treatment, with the treatments being represented by the proportion of cottonseed cake in the TMR (0; 20; 25 and 30% cottonseed cake on dry matter basis). Significant treatment effects (P < 0.05) were observed on yeast population, pH, gas losses, effluent losses, dry matter recovery, ether extract intake, digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber and non-fiber carbohydrates, and on all ingestive behaviour variables except for those of feeding. Thus, cactus pear ensures the fermentative and hygienic quality of total mixed ration silages, regardless of the proportions of cottonseed cake. Therefore, based on the productive performance and ingestive behaviour of feedlot finished Dorper lambs, it is recommended the use total mixed ration silages with 30% cottonseed cake.

Biomass production and silage quality of ensiled BRS Capiaçu elephant grass at different regrowth ages and residue heights

The aim of this study was to determine the optimal combination of regrowth age and residue height of BRS Capiaçu elephant grass that yields the best balance between the dry mass production (DMP) of the harvested forage and silage quality. Four regrowth ages (75, 90, 105, and 120 days) and two residue heights (10 and 50 cm) were evaluated. The experimental design used a randomized complete block design with a 4 × 2 factorial scheme and 3 replicates. The regrowth age led to a linear increase in DMP. As regrowth age advanced, there were linear increases in the dry matter (DM) concentration, cell wall constituents, and fraction C (acid detergent insoluble nitrogen) of crude protein and reductions in the in vitro digestibility of DM and neutral detergent fiber (IVNDFD) in both the plant and its silage. Lower pH values were observed in silage made from plants harvested at 10 cm. No significant effects of the studied factors were found on the concentrations of organic acids in the silage, except for propionic acid. Management using a 105-day regrowth period and a 10-cm residue height resulted in a better balance between the dry mass production, fermentative profile and nutritional value of silage.

Additives improve the fermentation quality, anthocyanin content, and biological activity of purple Napier grass silage

BACKGROUND

Purple Napier grass (PNG), a widely used grass rich in anthocyanin, is commonly employed in the production of silage. However, there is currently limited research on the retention of anthocyanin with or without additives during ensiling. Therefore, this study aimed to investigate the effect of different additives (Lactiplantibacillus plantarum CCZZ1 (LP), glucose, acetic acid, and dried soybean curd residue) on fermentation quality, anthocyanin content, and microbial community structure of PNG silage.

RESULTS

Ensiling PNG without additives led to poor fermentation quality and rapid degradation of anthocyanin, resulting in a decline in antioxidant activity and the persistence of harmful microorganisms with high relative abundance. The use of additives, especially LP, effectively increased the relative abundance of L. plantarum, enhancing fermentation quality, the retention of anthocyanin (up to 166% increase rate) and antioxidant activity, while reducing the relative abundance of harmful microorganisms during ensiling for 30 days. Additionally, prolonged ensiling negatively affected the preservation of anthocyanin. Based on both fermentation quality and bioactivity, PNG should be ensiled for 30 days with LP inoculation.

CONCLUSION

The employment of additives, especially LP, improved the fermentation quality, anthocyanin retention, and microbial community structure in PNG silage. To optimize both fermentation quality and bioactivity, it is recommended that PNG be ensiled for 30 days with LP inoculation. © 2024 Society of Chemical Industry.

The role of rumen microbiome in the development of methane mitigation strategies for ruminant livestock

Ruminants play an important role in global food security and nutrition. The rumen microbial community provides ruminants with a unique ability to convert human indigestible plant matter, into high quality edible protein. However, enteric CH4 produced in the rumen is both a potent GHG and a metabolizable energy loss for ruminants. As the rumen microbiome constitutes 15-40% of the inter-animal variation in enteric CH4 emissions, understanding the microbiological mechanisms underpinning ruminal methanogenesis and its interaction with the host animal, is crucial for developing CH4 mitigation strategies. Variation in the relative abundance of different microbial species has been observed in cattle with contrasting residual CH4 emission and CH4 yield with up to 20% of the variation in inter-animal CH4 emissions attributable to the presence of a small number of microbial species. The demonstration of ruminotypes associated with high or low CH4 emissions suggests that interactions within complex microbial consortia and with their host are a major source of variation in CH4 emissions. Consequently, microbiome-assisted genomic approaches are being developed to select low CH4 emitting cattle, with breeding values for enteric CH4 being included as part of national breeding programmes. Generating rumen microbiome data for use in selection programs is expensive, therefore, identifying microbial biomarkers in milk or plasma to develop predictive models which include microbial predictors in equations based on animal related data, is required. A better understanding of the rumen microbiome has also aided the development and refinements of anti-methanogenic feed additives. However, these strategies, which increase the amount of reducing equivalents in the rumen ecosystem, do not generally result in an enrichment of propionate or an improvement in animal performance. Current research aims to provide alternative sinks to reducing equivalents and to stimulate activity of commensal microbes or the supplementation of direct fed microbials to capture lost energy. Furthering our knowledge of the rumen microbiome and its interaction with the host, will aid in the development of CH4 mitigation strategies for ruminant livestock.

Effects of Mixing Ratio and Lactic Acid Bacteria Preparation on the Quality of Whole-Plant Quinoa and Whole-Plant Corn or Stevia Powder Mixed Silage

Quinoa is the only single plant that can meet all the nutritional needs of human, and its potential for feed utilization has been continuously explored, becoming a prosperous industry for poverty alleviation. In order to further tap the feeding value of whole quinoa, develop quinoa as a feed substitute for conventional crops such as corn, and improve its comprehensive utilization rate, this experiment analyzed the silage quality and mycotoxin content of mixed silage of whole-plant quinoa (WPQ) with whole-plant corn (WPC) or stevia powder(SP) in different proportions, and further improved the silage quality of mixed silage by using two lactic acid bacteria preparations (Sila-Max and Sila-Mix). The quality, microbial population, and mycotoxin levels of quinoa and corn silage, as well as that of the mixed silage of quinoa and stevia, were evaluated using single-factor analysis of variance. The impact of various lactic acid bacteria preparations on the quality of whole-quinoa and whole-corn mixed silage was investigated through two-factor analysis of variance. WPQ and WPC were mixed at the ratio of 5:5 (QB5), 6:4 (QB6), 7:3 (QB7), 8:2 (QB8), 9:1 (QB9) and 10:0 (QB10). SP was mixed with WPQ at the supplemental levels of 0.2% (QB10S2), 0.4% (QB10S4), 0.6% (QB10S6), 0.8% (QB10S8) and 1.0% (QB10S10). After 60 days of silage, the silage indexes, the number of harmful microorganisms, and the mycotoxin levels were measured, to explore the appropriate ratio of mixed silage. The membership function analysis showed that the quality of mixed silage of WPQ with SP was better, and the optimal addition amount of SP was 0.6%. The results of Max and Mix on the quality improvement test of WPQ with WPC mixed silage showed that the two lactic acid bacteria formulations increased CP and AA content, and reduced NH3-N/TN; pH was significantly lower than the control group (p < 0.01), and LA was significantly higher than the control group (p < 0.01). The microbial count results showed that the addition of lactic acid bacteria preparation significantly reduced the number of molds and aerobic bacteria, and the effect of Mix was better than that of Max. When the mixing ratio was between QB7 and QB10, mold was not detected in the lactic-acid-bacteria preparation groups. Max and Mix significantly reduced the levels of mycotoxins, both of which were far below the range of feed safety testing, and 16S rRNA sequencing revealed that the silage microbiota varied with different mixing ratios and whether lactic acid bacteria preparations were used. Max and Mix increased the relative abundance of Firmicutes, with Mix having a more significant effect, especially in the QB6 (65.05%) and QB7 (63.61%) groups. The relative abundance of Lactobacillus was significantly higher than that of the control group (p < 0.05). The relative abundance of Enterobacteriaceae and Streptococcus were negatively and positively correlated with the addition level of quinoa, respectively. Comprehensive analysis showed that adding 0.6% SP to the WPQ and using Mix in mixed silage of WPQ and WPC with the proportion of WPQ no less than 70% had the best silage effect, and was more beneficial to animal health.

Effects of rumen fluid and molasses on the nutrient composition, fermentation quality, and microflora of Caragana korshinskii Kom. silage

The aim of this experiment was to investigate the effects of rumen fluid and molasses on the nutrient composition, fermentation quality, and microflora of Caragana korshinskii Kom. The trial included four treatments: a control group (CK) without additives and experimental groups supplemented with 7% rumen fluid (R), 4% molasses (M), and 7% rumen fluid + 4% molasses (RM). 15 days and 60 days of ensiling. The results showed that the addition of R, M, and RM reduced the contents of neutral detergent fibre (NDF) and acid detergent fibre (ADF). The addition of M and RM increased the content of water soluble carbohydrates (WSC) but increased the loss of DM. The addition of M and RM promoted rapid pH reduction below 4.2. At 60 days of ensiling, the addition of R alone promoted the production of lactic acid (LA). The addition of R and RM increased microbial diversity. The addition of RM slowed the rate at which Lactobacillus became the dominant genus and improved the ability of Enterobacter to compete for fermentable substrates. M and RM could increase microbial activity and promote metabolism. In general, the addition of M or RM improved the fermentation quality and nutritional value of C. korshinskii silage.

Effect of Lactic Acid Bacteria and Propionic Acid on Fermentation Characteristics, Chemical Composition, and Aerobic Stability of High-Moisture Corn Grain Silage

This investigation aimed to assess the effect of additives on the aerobic stability, fermentation profile, and chemical composition of high-moisture corn grain silage. The corn grain was milled and divided this into four distinct treatment groups: Lentilactobacillus buchneri, propionic acid, Lactiplantibacillus plantarum, and no additive (control). The capacity of the silos was 1 L and density was 1000 kg/m3. Each group had three replicates and was fermented for 45 d. At silo opening, one part of silage was used for fermentation parameters, chemical composition, and in vitro dry matter digestibility analysis; another part was used for aerobic stability determination. Compared with the control, all additives increased lactic acid and dry matter concentrations (p < 0.001) and decreased neutral detergent fiber level (p < 0.001). In comparison with the control, the application of Lentilactobacillus buchneri and propionic acid improved silage aerobic stability, showed by lower pH level and yeast and mold populations after exposure to air. The findings offer theoretical groundwork and technological backing for the use of high-moisture corn grain silage.

Phycocyanin Additives Regulate Bacterial Community Structure and Antioxidant Activity of Alfalfa Silage

Phycocyanin is a water-soluble pigment protein extracted from prokaryotes such as cyanobacteria and has strong antioxidant activity. As a silage additive, it is expected to enhance the antioxidant activity and fermentation quality of alfalfa silage. This study revealed the effects of different proportions of phycocyanin (1%, 3%, 5%) on the quality, bacterial community and antioxidant capacity of alfalfa silage. The results showed that 5% phycocyanin supplementation could maintain dry matter (DM), crude protein (CP) and water-soluble carbohydrate (WSC) content; increase lactic acid (LA) content; decrease pH and butyric acid (BA) and ammonia nitrogen (NH3-N) content; and improve fermentation quality. At the same time, the contents of total antioxidant capacity (TAOC), total phenol content (TP), polysaccharide content (P) and total flavonoid content (F) in the addition group were significantly increased, the antioxidant capacity was enhanced and the abundance of lactic acid bacteria was increased, which was positively correlated with silage quality. Phycocyanin can improve the metabolic function of carbohydrates and amino acids and promote the production of secondary metabolites. The application of phycocyanin broadens the variety of additives for alfalfa silage.

Isolation and screening of high biofilm producing lactic acid bacteria, and exploration of its effects on the microbial hazard in corn straw silage

Silage is a well-established method for preserving feed. However, the preparation process still poses several potential microbial hazards. Lactic acid bacteria exhibiting a biofilm phenotype are considered the most advanced 'fourth-generation probiotics' due to their significant potential in enhancing fermentation quality. In this study, a strain of high-biofilm-producing lactic acid bacteria (HBP-LAB) was successfully isolated from silage samples using the crystal violet method and designated as Lactiplantibacillus plantarum S23Y. This strain was subsequently used as an inoculant in corn straw for experimental purposes. The results indicated that it effectively reduced dry matter loss caused by microorganisms, thereby enhancing the retention of dry matter in silage. Following aerobic exposure, this strain was able to maintain the population of Lactobacillus and the concentration of lactic acid, which significantly decreased the likelihood of yeast-induced aerobic spoilage and improved the aerobic stability of the silage. However, it is important to note that this HBP-LAB did not have a significant impact on antibiotic resistance genes (ARGs) or mobile genetic elements (MGEs) in the silage. In conclusion, using S23Y as a representative strain, we have demonstrated that HBP-LAB can enhance the fermentation quality of silage to a certain extent and mitigate the detrimental effects of microorganisms. The findings of this study provide valuable insights for the application of lactic acid bacteria with a biofilm phenotype in silage fermentation.

Effects of different additives on fermentation quality, mycotoxin concentrations, and microbial communities in high-moisture corn kernels during wet storage

Introduction

The moisture content of corn kernels at harvest in China is relatively high, and wet storage effectively preserves high-moisture corn kernels. However, ensuring effective fermentation during storage is crucial.

Methods

To address this, we systematically investigated the variations in fermentation quality, mycotoxin concentrations, and microbial community composition under different additive treatments. The treatments included CK (control, deionized water), LAB homo- and hetero-lactic acid bacteria: Lactiplantibacillus plantarum and Weissella confusa MF01, and EN (cellulase), followed by 60 and 90 days of fermentation.

Results

The results indicated that both LAB and EN treatments significantly reduced the concentrations of deoxynivalenol (DON), aflatoxin B1 (AFB1), and zearalenone (ZEN) compared to CK during the wet storage of high-moisture corn kernels. LAB treatment notably increased lactic and acetic acid levels, decreased pH and NH3-N content, and improved crude protein (CP, 8.24% DM) and starch content (73.01% DM) compared to CK. LAB treatment also reduced water-soluble carbohydrate (WSC) content (5.05% DM). Microbial diversity was reduced in the LAB treatment, as evidenced by decreases in both common and unique operational taxonomic units, while the relative abundance of Weissella increased after 60 days compared to CK. In contrast, despite higher lactic and acetic acid levels in the EN treatment, the pH did not decrease significantly due to higher NH3-N content. Overall, the LAB treatment outperformed other treatments by achieving lower mycotoxin concentrations, better fermentation quality, and superior preservation of nutritional components.

Discussion

This study provides valuable theoretical support and practical guidance for improving the wet storage of high-moisture corn kernels and enhancing their safety and nutritional value during storage.

The Prophylactic Protection of Salmonella Typhimurium Infection by Lentilactobacillus buchneri GX0328-6 in Mice

Salmonellosis is a disease caused by non-typhoid Salmonella, and although some lactic acid bacteria strains have been shown previously to relieve Salmonellosis symptoms, little has been studied about the preventive mechanism of Lentilactobacillus buchneri (L. buchneri) against Salmonella infection in vivo. Therefore, the L. buchneri was fed to C57BL/6 mice for 10 days to build a protective system of mice to study its prevention and possible mechanisms. The results showed that L. buchneri GX0328-6 alleviated symptoms caused by Salmonella typhimurium infection among C57BL/6 mice, including low survival rate, weight loss, increase in immune organ index and hepatosplenomegaly, and modulated serum immunoglobulin levels and intrinsic immunity. Importantly, the L. buchneri GX0328-6 enhanced the mucosal barrier of the mouse jejunum by upregulating the expression of tight junction proteins such as ZO-1, occludins, and claudins-4 and improved absorptive capacity by increasing the length of mouse jejunal villus and the ratio of villus length to crypt depth and decreasing the crypt depth. L. buchneri GX0328-6 reduced the intestinal proliferation and invasion of Salmonella typhimurium by modulating the expression of antimicrobial peptides in the intestinal tract of mice, and reduced intestinal inflammation and systemic spread in mice by downregulating the expression of IL-6 and promoting the expression of IL-10. Furthermore, L. buchneri GX0328-6 increased the relative abundance of beneficial bacteria colonies and decreased the relative abundance of harmful bacteria in the cecum microflora by modulating the microflora in the cecum contents.

Game changer for anaerobic fermentation of paper mulberry: Sucrose-loaded biochar enhancing microbial communities and lactic acid fermentation

This study investigated biochar effects, either alone or combined with sucrose, on fermentation quality, microbial communities, and in vitro rumen digestion of anaerobic fermented paper mulberry. The biochar alkaline functional groups bind to lactic acid, reducing acid inhibition and promoting Lactiplantibacillus proliferation. Owing to the low sugar content of paper mulberry, lactic acid bacteria in the biochar group primarily underwent heterofermentation, resulting in the lowest lactic and highest acetic acid contents. Treated with sucrose-loaded biochar, the increased substrate supported homofermentation, leading to the highest lactic and lowest acetic acid contents, with a 15.0 % increase in lactic acid and a 22.2 % decrease in ammoniacal nitrogen compared with the control after 75 days. In vitro rumen tests showed that the biochar-sucrose group had the highest dry matter degradation rate (45.9 %) and a 24.2 % reduction in methane emissions. Concludingly, sucrose-loaded biochar is recommended as effective for lactic acid production under anaerobic conditions.

Fermentation quality, amino acids profile, and microbial communities of whole-plant soybean silage in response to Lactiplantibacillus plantarum B90 alone or in combination with functional microbes

Promoting the availability of silage with a high protein content on farms can lead to profitable and sustainable ruminant production systems. Whole plant soybean (Glycine max L. Merrill, WPS) is a promising high-protein forage material for silage production. In this study, we investigated the fermentation quality, amino acids profile and microbial communities of WPS silage in response to inoculation of lactic acid bacteria (LAB) alone or in combination with non-LAB agents. Before preparing the treatments, the chopped WPS was homogenized thoroughly with 0.3% molasses (0.3 g molasses per 100 g fresh matter). The treatments included CK (sterilized water), LP (Lactiplantibacillus plantarum B90), LPBS (LP combined with Bacillus subtilis C5B1), and LPSC (LP combined with Saccharomyces cerevisiae LO-1), followed by 60 days of fermentation. The inoculants significantly decreased the bacterial diversity and increased the fungal diversity of WPS silage after ensiling. As a result, the contents of lactic acid and acetic acid increased, while the pH value and propionic acid content decreased in the inoculated silages. The amino acids profile was not influenced by inoculants except phenylalanine amino acid, but LP and LPSC silages had substantial greater (p < 0.05) relative feed values of 177.89 and 172.77, respectively, compared with other silages. Taken together, the inoculation of LP alone or in combination with BS was more effective in preserving the nutrients of WPS silage and improve fermentation quality.

Effects of fermented rice husk powder on growth performance, rumen fermentation, and rumen microbial communities in fattening Hu sheep

Introduction

This study aimed to examine the effects of fermented rice husk powder feed on growth performance, apparent nutrient digestibility, and rumen microbial communities in fattening Hu sheep.

Methods

Twenty-one male Hu sheep with similar body weights (32.68 ± 1.59 kg) were randomly assigned to three groups: a control group (CON) receiving a TMR with soybean straw, a rice husk powder group (RH), and a fermented rice husk powder group (FHR).

Results

The results indicated that the FHR group exhibited a significant increase in ADG and FBW of Hu sheep compared to the other two groups (p < 0.05). The digestibility of CP and EE was significantly higher in the CON and FHR groups than in the RH group (p < 0.01). Furthermore, the digestibility of DM in the CON group was higher than in the FHR and RH groups (p < 0.01). The FHR group showed lower NDF and ADF digestibility compared to the CON group, but higher than the RH group (p < 0.05). Additionally, serum ALB and ALT levels in the CON group were elevated compared to those in the two groups (p < 0.05). The rumen concentrations of TVFA, butyrate, and valerate in the FHR group were significantly elevated compared to the other two groups (p < 0.05). At the genus level, the relative abundances of Rikenellaceae RC9 gut group, Succinimonas, UCG-010_norank, UCG-005, p-251-o5_norank, and Lachnospiraceae AC2044 group were significantly diminished in the FHR group compared to the CON group (p < 0.05). In contrast, the relative abundance of Succinivibrio was significantly higher (p < 0.05), while the abundances of Eubacterium coprostanoligenes group_norank and Quinella were significantly lower (p < 0.05) in the RH group compared to the CON group. Spearman correlation analysis revealed negative correlations between the Rikenellaceae RC9 gut group and propionate, butyrate, and TVFA, as well as between Prevotellaceae UCG-003 and both propionate and TVFA. Conversely, Ruminococcus showed a positive correlation with propionate and TVFA.

Discussion

In conclusion, replacing 15% of soybean straw with fermented rice husk powder feed modified the rumen microbiota and improved the growth performance of fattening Hu sheep.

The Effects of Indigo Waste Silage Prepared with Additives on Feed Availability, Rumen Fermentation Patterns, Blood Metabolites, and Hematological Indices in Beef Cattle

The purpose of this study was to evaluate the impact of different additives in fermented indigo waste on feed availability, rumen fermentation patterns, blood chemistry, and hematology in beef cattle. Four male crossbred beef cattle with a body weight (BW) of 230 ± 14 kg and 25 months of age were used in a 4 × 4 Latin square design. The indigo waste was ensiled without additive (CON) and with calcium hydroxide (CH), molasses (M), or cellulase (C). The indigo waste silage was incorporated into a fermented total mixed ration (FTMR). The neutral detergent fiber (NDF) content was lower in C-treated silage. The feed intake did not alter among treatments (p > 0.05). The ensiled indigo waste with additives had no influence on nutrient digestibility (p > 0.05), whereas the ensiled indigo waste with M increased CP digestibility (p < 0.01). The rumen pH, ammonia-nitrogen (NH3-N), or volatile fatty acid (VFA) proportions did not change by additive (p > 0.05). However, adding M increased the acetate-to-propionate ratio (C2:C3) (p = 0.04). In addition, the total protein in the blood was higher in C-treated silage (p = 0.01). The homological indices did not change by additive (p > 0.05), except for lymphocytes, which decreased when M and C were added (p < 0.01). In conclusion, adding M and C to indigo waste silage could enhance its nutritional value and improve digestibility, blood chemistry, or health status in beef cattle.

Multi-omics analysis reveals the core microbiome and biomarker for nutrition degradation in alfalfa silage fermentation

Alfalfa (Medicago sativa L.) is one of the most extensively cultivated forage crops globally, and its nutritional quality critically influences the productivity of dairy cows. Silage fermentation is recognized as a crucial technique for the preservation of fresh forage, ensuring the retention of its vital nutrients. However, the detailed microbial components and their functions in silage fermentation are not fully understood. This study integrated large-scale microbial culturing with high-throughput sequencing to thoroughly examine the microbial community structure in alfalfa silage and explored the potential pathways of nutritional degradation via metagenomic analysis. The findings revealed an enriched microbial diversity in silage, indicated by the identification of amplicon sequence variants. Significantly, the large-scale culturing approach recovered a considerable number of unique microbes undetectable by high-throughput sequencing. Predominant genera, such as Lactiplantibacillus, Leuconostoc, Lentilactobacillus, Weissella, and Liquorilactobacillus, were identified based on their abundance and prevalence. Additionally, genes associated with Enterobacteriaceae were discovered, which might be involved in pathways leading to the production of ammonia-N and butyric acid. Overall, this study offers a comprehensive insight into the microbial ecology of silage fermentation and provides valuable information for leveraging microbial consortia to enhance fermentation quality.

IMPORTANCE

Silage fermentation is a microbial-driven anaerobic process that efficiently converts various substrates into nutrients readily absorbable and metabolizable by ruminant animals. This study, integrating culturomics and metagenomics, has successfully identified core microorganisms involved in silage fermentation, including those at low abundance. This discovery is crucial for the targeted cultivation of specific microorganisms to optimize fermentation processes. Furthermore, our research has uncovered signature microorganisms that play pivotal roles in nutrient metabolism, significantly advancing our understanding of the intricate relationships between microbial communities and nutrient degradation during silage fermentation.

Comparative impact analysis of nitrate reduction by typical components of natural organic compounds in magnetite-bearing riparian zones

As the key interface, the nitrate removal capacity of riparian zones is receiving close attention. Although naturally occurring organic compounds in this environment play a pivotal role in shaping microbial communities and influencing the nitrate removal capacity, the relevant research is inadequate. Given the complexity of riparian environments, in this study, we added representative natural organic matter (fulvic acid, butyric acid, naphthalene, starch, and sodium bicarbonate) as carbon conditions and incorporated magnetite to simulate riparian zone components. The study investigated the nitrate degradation efficiency and microbial responses under different natural carbon conditions in real iron-containing environments. Butyric acid exhibited the most efficient nitrate reduction, followed in descending order by naphthalene, starch, sodium bicarbonate, and humic acid. However, this did not imply that butyric acid efficiently removed nitrogen; instead, the nitrogen would circulate in the environment in the form of ammonium. Denitrification and DNRA were the primary drivers of nitrate reduction in each system, while naphthalene and humic acid systems also exhibited nitrification and mineralization. Nitrogen-fixing bacteria represent a unique microbial community in the butyrate system. Further, the synergistic degradation of naphthalene and nitrate demonstrated significant potential applications. High-throughput sequencing revealed that carbon conditions exerted selective pressure on microorganisms, driving Fe (Ⅱ)/Fe (Ⅲ) transformation by shaping the microbial community structure and influencing the nitrogen cycling process.

Suitable fermentation temperature of forage sorghum silage increases greenhouse gas production: Exploring the relationship between temperature, microbial community, and gas production

Silage is an excellent method of feed preservation; however, carbon dioxide, methane and nitrous oxide produced during fermentation are significant sources of agricultural greenhouse gases. Therefore, determining a specific production method is crucial for reducing global warming. The effects of four temperatures (10 °C, 20 °C, 30 °C, and 40 °C) on silage quality, greenhouse gas yield and microbial community composition of forage sorghum were investigated. At 20 °C and 30 °C, the silage has a lower pH value and a higher lactic acid content, resulting in higher silage quality and higher total gas production. In the first five days of ensiling, there was a significant increase in the production of carbon dioxide, methane, and nitrous oxide. After that, the output remained relatively stable, and their production at 20 °C and 30 °C was significantly higher than that at 10 °C and 40 °C. Firmicutes and Proteobacteria were the predominant silage microorganisms at the phylum level. Under the treatment of 20 °C, 30 °C, and 40 °C, Lactobacillus had already dominated on the second day of silage. However, low temperatures under 10 °C slowed down the microbial community succession, allowing, bad microorganisms such as Chryseobacterium, Pantoea and Pseudomonas dominate the fermentation, in the early stage of ensiling, which also resulted in the highest bacterial network complexity. According to random forest and structural equation model analysis, the production of carbon dioxide, methane and nitrous oxide is mainly affected by microorganisms such as Lactobacillus, Klebsiella and Enterobacter, and temperature influences the activity of these microorganisms to mediate gas production in silage. This study helps reveal the relationship between temperature, microbial community and greenhouse gas production during silage fermentation, providing a reference for clean silage fermentation.

Heterofermentative Lentilactobacillus buchneri and low dry matter reduce high-risk antibiotic resistance genes in corn silage by regulating pathogens and mobile genetic element

The study of antibiotic resistance in the silage microbiome has attracted initial attention. However, the influences of lactic acid bacteria inoculants and dry matter (DM) content on antibiotic resistance genes (ARGs) reduction in whole-plant corn silage remain poorly studied. This study accessed the ARGs' risk and transmission mechanism in whole-plant corn silage with different DM levels and treated with Lactiplantibacillus plantarum or Lentilactobacillus buchneri. The macrolide and tetracycline were the main ARGs in corn silage. The dominant species (Lent. buchneri and Lactobacillus acetotolerans) were the main ARGs carriers in whole-plant corn silage. The application of Lent. buchneri increased total ARGs abundance regardless of corn DM. Whole-plant corn silage with 30 % DM reduced the abundances of integrase and plasmid compared with 40 % DM. The correlation and structural equation model analysis demonstrated that bacterial community succession, resulting from changes in DM content, was the primary driving factor influencing the ARGs distribution in whole-plant corn silage. Interestingly, whole-plant corn silage inoculated with Lent. buchneri reduced abundances of high-risk ARGs (mdtG, mepA, tetM, mecA, vatE and tetW) by regulating pathogens (Escherichia coli), mobile genetic elements (MGEs) genes (IS3 and IS1182), and this effect was more pronounced at 30 % DM level. In summary, although whole-plant corn silage inoculated with Lent. buchneri increased the total ARGs abundance at both DM levels, it decreased the abundance of high-risk ARGs by reducing the abundances of the pathogens and MGEs, and this effect was more noticeable at 30 % DM level.

Impact of corn shredlage and crabtree-negative yeast on silage quality and rumen fermentation characteristics

The physical attributes of corn silage are enhanced by shredlage (SHR), while there is a rising interest in boosting its biological performance. This study aimed to assess and compare the impact of both the chopping method and different yeast strains on ensilage quality including the in vitro evaluation of corn silage. Both types of corn, including chopped and shredded, were harvested on the same day from the same field where the same corn hybrid (Suwan 5) was grown. Subsequently, whole-corn plants were fermented with additives. A 2 × 5 Factorial completely randomized design was employed, where factor A represents corn chopped (CON) and corn shredded (SHR), and factor B represents the additives: no additives, molasses + urea (M + U), M + U + Candida tropicalis KKU20, M + U + Pichia kudriavzevii KKU20, and M + U + saccharomyces cerevisiae. The results demonstrated that SHR fermentation with M + U and yeast significantly increased in vitro dry matter degradability (IVDMD) and organic matter degradability (IVOMD). Specifically, at 4 h post-incubation, the addition of Crabtree-negative yeast led to a 5.8% increase in total volatile fatty acids (TVFA) compared to the Crabtree-positive yeast group (P < 0.01). The C2 (acetic acid) + C4 (normal butyric acid and isobutyric acid): C3 (propionic acid) ratio showed a significant decrease without additives, but P. kudriavzevii KKU20 led to the highest ratio and methane production (P < 0.01). Based on this study, it could be concluded that SHR harvesting led to higher digestion efficiency in the rumen. The use of M + U + yeast also demonstrated uncertain effects on rumen fermentation efficiency, and the inclusion of P. kudriazevii KKU20 may potentially reduce rumen fermentation efficiency when used with corn silage.

The effect of replacing conventional alfalfa hay with lower-lignin alfalfa hay on feed intake, nutrient digestibility, and energy utilization in lactating Jersey cows

Lower-lignin (LoL) varieties of alfalfa (Medicago sativa L.) have been developed in recent years and have the potential to positively affect animal performance. The objective of this study was to evaluate the effects of increasing the proportion of LoL alfalfa hay in diets fed to lactating dairy cows. Research plots were planted with a conventional variety of alfalfa (CON; Dairyland Hybriforce 3400) and 2 LoL varieties (genetically engineered lower-lignin alfalfa [LLG], 54HVX42, and breeding-derived lower-lignin alfalfa [LLB], Aflorex HiGest 460). After harvest, the LoL varieties were blended in equal proportions for feeding. A total of 12 multiparous Jersey cows (100 ± 4 DIM) were used in a 3 × 3 Latin square with 3 periods of 28 d. Cows were assigned to 3 diets containing 0% (control diet; CNTRL), 16.1% (low diet; MdLL), and 32.2% (high diet; HiLL) of the diet DM as LoL alfalfa hay, which replaced CON. The CON alfalfa had average CP, NDF, and lignin contents (DM basis) of 20.5 ± 1.15%, 42.1 ± 1.37%, and 6.81 ± 0.57%, respectively, whereas the LoL alfalfa averaged 19.8 ± 0.75%, 39.9 ± 1.56%, and 6.07 ± 0.28%, respectively. No difference was observed in DMI (20.4 ± 0.61 kg/d). No difference in milk yield was observed, averaging 31.0 ± 1.02 kg/d across treatments. Similarly, no difference was observed in ECM yield (averaging 36.2 ± 1.43 kg/d). Feed conversion (ECM/DMI) tended to increase linearly with LoL alfalfa inclusion (1.74 to 1.80 ± 0.03). No difference was observed for milk fat yield and content (1.39 ± 0.075 kg/d and 4.51 ± 0.219%) or milk protein yield and content (1.06 ± 0.041 kg/d and 3.43 ± 0.096%). Total methane production quadratically decreased from CNTRL to MdLL then increased to HiLL (441, 389, 412 ± 18.2 L/d, respectively). No differences were observed on total-tract digestibility of DM (averaging 67.2 ± 0.55%) and NDF (averaging 50.9 ± 1.56%). No difference was observed in the concentration of digestible energy, metabolizable energy, or NEL was observed averaging 2.82 ± 0.021, 2.51 ± 0.027, and 1.72 ± 0.030 Mcal/kg, respectively. Our results suggest that replacing CON alfalfa with LoL alfalfa has no effects on milk production, milk composition, or nutrient digestibility, but may improve feed efficiency.

Microbial Dynamics and Pathogen Control During Fermentation of Distiller Grains: Effects of Fermentation Time on Feed Safety

Determining the effects of fermentation duration on the microbial ecosystem, potential pathogenic risks, and metabolite generation during the fermentation of distilled grains is essential for safeguarding the safety and enhancing the nutritional profile of animal feed. This study investigates the effect of varying fermentation times (9, 30, and 60 days) on microbial diversity, pathogenic risk, and metabolite profiles in distiller grains using 16S rDNA sequencing and LC-MS-based metabolomics. The results showed that early fermentation (9-30 days) enhanced the abundance of beneficial bacteria, such as Lactobacillus reuteri and Lactobacillus pontis (p < 0.05), while pathogenic bacteria, like Serratia marcescens and Citrobacter freundii, were significantly reduced (p < 0.05). Metabolomic analysis revealed an increase in unsaturated fatty acids and the degradation of biogenic amines during early fermentation. However, prolonged fermentation (60 days) led to a resurgence of pathogenic bacteria and reduced the synthesis of essential metabolites. These findings suggest that fermentation duration must be optimized to balance microbial safety and nutrient quality, with 30 days being the optimal period to reduce pathogenic risks and enhance feed quality.

Translating 2D-Chromatographic Fingerprinting to Quantitative Volatilomics: Unrevealing Compositional Changes in Maize Silage Volatilome for Robust Marker Discovery

This study examines the complex volatilome of maize silage, both with and without commercial heterolactic strain inoculation, conserved for 100 days, using quantitative volatilomics. Chemical classes linked to microbial metabolism were analyzed across a concentration range from 10 μg g-1 to 1 ng g-1. A reference method using comprehensive two-dimensional gas chromatography (GC × GC) and time-of-flight mass spectrometry (TOF MS) with loop-type thermal modulation (TM) was translated to a differential-flow modulation (FM) platform with parallel MS and flame ionization detector (FID) detection. With translation, the original method's analyte elution order and resolution are preserved. The new method allowed for accurate quantification using multiple headspace solid-phase microextraction (MHS-SPME) and FID-predicted relative response factors (RRFs). Both methods showed comparable discriminatory power with FM GC × GC-MS/FID achieving satisfactory quantification accuracy without external calibration. Analysis of 98 volatiles provided insights into silage fermentation, supporting marker discovery and correlations with silage quality and stability.

Innovative Lactic Acid Production Techniques Driving Advances in Silage Fermentation

Lactic acid (LA) plays a crucial role in the silage process, which occurs through LA fermentation. Consequently, there is a strong correlation between lactic acid production and the efficiency of the silage. However, traditional methods face challenges like long fermentation times, low acid production, and unstable quality, limiting agricultural preservation. This paper aims to explore innovations in lactic acid production technologies and show how these technologies have driven the development of silage fermentation for agricultural conservation. First, the important role of LA in agricultural preservation and the limitations of traditional silage techniques are presented. Next, advancements in LA production methods are thoroughly examined, covering the selection of microbial strains and the substitution of fermentation substrates. Following this, new technologies for silage fermentation are explored, drawing from innovations in LA production. These include the selection of LA strains, optimization of fermentation conditions, and improvements in fermentation techniques. These innovations have proven effective in increasing LA production, improving feed quality, extending shelf life, and providing new solutions to enhance agricultural production and sustainability.

Influence of Ensiling Timing and Inoculation on Whole Plant Maize Silage Fermentation and Aerobic Stability (Preliminary Research)

Despite efforts to prevent atypical ensiling conditions, such as delayed ensiling or sealing, these issues frequently occur in practice. This study aimed to investigate the effects of delayed ensiling (forage held for 24 h) and sealing, along with inoculation using a blend of Lentilactobacillus buchneri and Lactococcus lactis, on the characteristics of the resulting silages. Whole-plant maize (Zea mays L.) was treated with or without a commercial inoculant and ensiled (36% dry matter) for 60 days in 3.0 L glass containers. The forage was either ensiled immediately or subjected to a 24 h delay before ensiling. During the delay, the forage was either covered or left uncovered. Each treatment was replicated five times. All data were analyzed using the MIXED procedure of SAS statistical software (version 9.4; SAS Institute Inc., Cary, NC, USA). Delaying the ensiling process by 24 h worsens fermentation parameters, significantly increases dry matter (DM) losses (p < 0.01), and significantly reduces aerobic stability and the hygienic quality of the silage (p < 0.01), as evidenced by higher concentrations of undesirable fermentation products and elevated yeast and mold counts. The inoculation has a significant impact on both forage before ensiling and the characteristics of the resulting silage. Maize forage treated with inoculant showed a lower temperature increase by 8.2-8.1 °C (p < 0.01) when delayed for 24 h before ensiling. In silages, it also resulted in a reduced pH (p < 0.01); increased concentrations of lactic acid; acetic acid; and 1,2-propanediol (p < 0.01); and decreased levels of negative fermentation indicators such as ammonia-N, alcohols, and butyric acid (p < 0.01) During both the fermentation and aerobic exposure periods, inoculated silages exhibited up to 36% and 2.6 times lower (p < 0.01) dry matter loss, while suppressing the growth of yeasts and molds by up to 2.6 and 3.1 times (p < 0.01), respectively, compared to non-inoculated silages. The results of this study support the recommendation to minimize the duration of aerobic exposure of fresh forage during silo filling and to use LAB-based inoculants.

Impact of Additives and Packing Density on Fermentation Weight Loss, Microbial Diversity, and Fermentation Quality of Rape Straw Silage

To investigate the effects of the combined addition of Lactiplantibacillus plantarum and sucrose on the fermentation weight loss (FWL), fermentation quality, and microbial community structure of ensiled rape straw under varying packing density conditions. After harvesting, the rapeseed straw was collected, cut into 1-2 cm pieces, and sprayed with sterile water to adjust the moisture content to 60%. The straw was then divided into two groups: one treated with additives (1 × 105 CFU/g fresh material of Lactiplantibacillus plantarum and 10 kg/t fresh material of sucrose), and the other sprayed with an equivalent amount of sterile water as the control (CK). The treated materials were thoroughly mixed and packed into silos at densities of 450, 500, and 550 kg/m3. FWL was recorded on days 1, 3, 6, 15, 20, and 45 of fermentation. On day 45, the samples were analyzed for fermentation quality, microbial counts, and microbial diversity. FWL increased significantly (p < 0.05) in both the treated (LS) and control groups during fermentation. The LS group showed higher lactic acid (LA) levels (p < 0.05) and lower ammonia nitrogen levels (p < 0.05) compared to CK. The CK group had significantly higher (p < 0.05) counts of Coliforms and lower bacterial counts (p < 0.05) than LS. The dominant genera in the silage were Xanthomonas, Lactiplantibacillus plantarum, and Lentilactobacillus. In the LS group, the relative abundances of Lactiplantibacillus plantarum and Lentilactobacillus ranged from 16.93% to 20.43% and 15.63% to 27.46%, respectively, with their combined abundance being higher than in CK. At a packing density of 500 kg/m3, the relative abundances of Lactiplantibacillus plantarum and Lentilactobacillus in the LS group were significantly higher (p < 0.05) than in CK. Increasing packing density and applying additives to rape straw silage effectively reduced FWL, improved fermentation quality, boosted the relative abundance of beneficial lactic acid bacteria, and decreased the presence of undesirable bacteria such as Enterobacter and Bacillus.

Animal Food Products to Support Human Nutrition and to Boost Human Health: The Potential of Feedstuffs Resources and Their Metabolites as Health-Promoters

Recent attention has been given to animal feeding and its impact on human nutrition. Animal feeding is essential for meeting human dietary needs, making it a subject of significant interest and investigation. This review seeks to outline the current understanding of this disciplinary area, with a focus on key research areas and their potential implications. The initial part of the paper discusses the importance of animal feed resources and recognizes their crucial role in guaranteeing sufficient nutrition for both humans and animals. Furthermore, we analyzed the categorization of animal feeds based on the guidelines established by the National Research Council. This approach offers a valuable structure for comprehending and classifying diverse types of animal feed. Through an examination of this classification, we gain an understanding of the composition and nutritional content of various feedstuffs. We discuss the major categories of metabolites found in animal feed and their impact on animal nutrition, as well as their potential health advantages for humans. Flavonoids, polyphenols, tannins, terpenoids, vitamins, antioxidants, alkaloids, and essential oils are the primary focus of the examination. Moreover, we analyzed their possible transference into animal products, and later we observed their occurrence in foods from animal sources. Finally, we discuss their potential to promote human health. This review offers an understanding of the connections among the major metabolites found in feedstuffs, their occurrence in animal products, and their possible impact on the health of both animals and humans.

Effect of sodium formate and lactic acid bacteria treated rye silage on methane yield and energy balance in Hanwoo steers

This study was performed to evaluate the effects of rye silage treated with sodium formate (Na-Fa) and lactic acid bacteria (LAB) inoculants on the ruminal fermentation characteristics, methane yield and energy balance in Hanwoo steers. Forage rye was harvested in May 2019 and ensiled without additives (control) or with either a LAB inoculant or Na-Fa. The LAB (Lactobacillus plantarum) were inoculated at 1.5 × 1010 CFU/g fresh matter, and the inoculant was sprayed onto the forage rye during wrapping at a rate of 4 L/ton of fresh rye forage. Sixteen percent of the Na-Fa solution was sprayed at a rate of approximately 6.6 L/ton. Hanwoo steers (body weight 275 ± 8.4 kg (n = 3, group 1); average body weight 360 ± 32.1 kg (n = 3, group 2)) were allocated into two pens equipped with individual feeding gates and used in duplicated 3 × 3 Latin square design. The experimental diet was fed twice daily (09:00 and 18:00) during the experimental period. Each period comprised 10 days for adaptation to the pen and 9 days for measurements in a direct respiratory chamber. The body weights of the steers were measured at the beginning and at the end of the experiment. Feces and urine were collected for 5 days after 1 day of adaptation to the chamber, methane production was measured for 2 days, and ruminal fluid was collected on the final day. In the LAB group, the ratio of acetic acid in the rumen fluid was significantly lower (p = 0.044) and the ratio of propionic acid in the rumen fluid was significantly higher (p = 0.017). Methane production per DDMI of the Na-FA treatment group was lower than that of the other groups (p = 0.052), and methane production per DNDFI of the LAB treatment group was higher than that of the other groups (p = 0.056). The use of an acid-based additive in silage production has a positive effect on net energy and has the potential to reduce enteric methane emissions in ruminants.