Water-soluble Carbohydrate Content Research Articles

Effects of Cellulase and Xylanase on Fermentation Characteristics, Chemical Composition and Bacterial Community of the Mixed Silage of King Grass and Rice Straw.

This study was to investigate the effects of cellulase and xylanase on fermentation characteristics, nutrient composition and the bacterial community of the mixed silage of king grass and rice straw. Lab-scale bag silage was produced and seven groups were studied: blank control (CK); added 1%, 2% cellulase (CE1, CE2); added 1%, 2% xylanase (XY1, XY2); and added 0.5% cellulase +0.5% xylanase, 1% cellulase +1% xylanase (CX1, CX2). The results showed that the application of additives in six treated groups exerted a positive effect on lactic acid (LA) content and their pH values decreased significantly (p < 0.05). The addition of cellulase and xylanase decreased (p < 0.05) the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) significantly and increased (p < 0.01) the crude protein (CP) and water-soluble carbohydrate (WSC) content. Filter paper enzyme activity (FPA) declined and xylanase activity (XA) intensified (p < 0.05) as ensiling was prolonged, where most of the enzymatic treatments (especially XY2, CX2) resulted in increased enzyme activities. Moreover, the addition of cellulase and xylanase reduced the abundance of harmful bacteria such as Acinetobacter and Klebsiella and increased the abundance of lactic acid bacteria such as Lacticaseseibacillus, Lactiplantibacillus. In conclusion, the addition of cellulase and xylanase would improve fermentation quality and nutrient preservation via altering the bacterial community, with 1% cellulase or complex enzyme best.

Effects of cutting height and storage length on fermentation characteristics, microbial community, co-occurrence networks, potential functionality and pathogenic risk of fermented sweet sorghum stem

Postharvest management strategies like cutting height and anaerobic fermentation may affect the microbial risk of vegetables. This study evaluated the effects of cutting height and storage length on the fermentation characteristics, microbial diversity, co-occurrence networks, potential functionality and pathogenic risk of sweet sorghum stem (SSS). Fresh SSS harvested at two cutting heights (15 cm, F15; 45 cm, F45) was spontaneously fermented (S15 and S45) for 2, 4, 8, 16, 32 and 64 days. Decreasing the cutting height of SSS increased the dry matter, water-soluble carbohydrate content as well as Acinetobacter (23.0% vs. 44.9%) and Klebsiella (1.84% vs. 6.58%) proportion but decreased the crude protein content (P < 0.05). After fermentation, both cutting heights presented desirable fermentation. Anaerobic fermentation promoted the Glycolysis pathway (0.009 vs. 0.018) and related enzymes (l-lactate dehydrogenase, etc.) associated with lactate synthesis, but suppressed the degradation pathways of valine, leucine, isoleucine (0.011 vs. 0.003) and lysine (0.008 vs. 0.002). In microbial phenotype analysis, although F15 had higher proportions of ‘Potentially Pathogenic’ than F45, this undesirable phenotype declined to negligible levels via fermentation. These results concluded that, for SSS, concerns about the risk of microbial contamination and pathogens from low cutting height can be dispelled by well fermentation.

Effects of a genetically modified corn hybrid with α-amylase and storage length on fermentation profile and starch disappearance of whole-plant corn silage and earlage

Two experiments were conducted to evaluate the effects of a genetically modified corn hybrid with α-amylase expressed in the kernel (AMY) on fermentation profile, aerobic stability, nutrient composition, and starch disappearance of whole-plant corn silage (WPCS) and earlage. Both hybrids, AMY and an isogenic corn hybrid (ISO), were grown in 10 replicated plots (5 for WPCS and 5 for earlage). Samples of each plot were collected at harvest, homogenized, and divided into 5 subsamples which were randomly assigned to 5 storage lengths (0, 30, 60, 90, and 120 d). Both datasets (WPCS and earlage), were analyzed separately as a completely randomized block design in a factorial arrangement of treatments, with a model including the fixed effects of hybrid, storage length, and their interaction, and the random effect of block. Minor differences on fermentation profile were observed between AMY and ISO for WPCS and earlage. An interaction between hybrid and storage length was observed for DM losses in WPCS, where losses were similar at 30, 60 and 90 d, but lower for AMY compared with ISO at 120 d. No effect of hybrid was observed on yeast and mold counts for WPCS or earlage. The aerobic stability of WPCS was greater for AMY than ISO. For earlage, AMY had greater DM losses and aerobic stability than ISO. An interaction between hybrid and storage length was observed for ammonia-N in both WPCS and earlage, where ammonia-N was similar at 0 d but greater for AMY than ISO throughout later storage lengths. A similar interaction was observed for water-soluble carbohydrates (WSC) concentrations in WPCS, where ISO had greater WSC than AMY at 0 d but was similar throughout later storage lengths. However, AMY earlage had a greater WSC concentration throughout storage length, but a lesser magnitude after ensiling. Starch concentration was greater for AMY than ISO in WPCS and earlage. Greater starch disappearances at 0 h and 6 h were observed for ISO in WPCS and earlage. Minor effects on fermentation profile, microbial counts, aerobic stability and nutrient composition suggests that AMY can be ensiled for prolonged periods with no concerns for undesirable fermentation or nutrient losses. However, in situ starch disappearance was lower for AMY compared with ISO.

Treatment of corn with lactic acid delayed in vitro ruminal degradation without compromising fermentation: a biological and morphological monitoring study.

Grain processed by lactic acid (LA) is known to improve ruminant growth and health. However, the exact mechanism regarding rumen hydrolysis of LA-treated grain is still ambiguous. This experiment was designed to compare the effects of 5% LA treatment on the trophic and morphological variations in corn and to discover the alternations in ruminal hydrolysis between LA-treated and untreated corn macroscopically and microscopically using in vitro fermentation method. The results showed that, compared with untreated corn (CN), corn treated with 5% LA for 48 h (CNLA) experienced a decrease in the dry matter, albumin fraction, aNDFom, and water-soluble carbohydrate content but an increase in the resistant starch content. The in vitro fermentation showed that the pH of CNLA was higher, but dry matter disappearance was lower than that of CN. Most of the fermentation indices were unaffected, except for decreased iso-butyrate and iso-valerate. The abundances of total bacteria, Prevotella spp., Streptococcus bovis, and Selenomonas ruminantium were higher, but those of Ruminococcus flavefaciens and Ruminococcus albus were lower in CNLA than in CN. There were differences in the scanning electron micrographs between CNLA and CN after 3 h of fermentation. This study suggests that treating corn with LA for 48 h can induce changes in its nutrient composition and alter the bacterial flora during subsequent in vitro fermentation. These changes appeared to be crucial contributors to the beneficial effects observed in rumen fermentation.

Comparison of the Chemical and Microbial Composition and Aerobic Stability of High-Moisture Barley Grain Ensiled with Either Chemical or Viable Lactic Acid Bacteria Application

This experiment was aimed at comparing how a chemical additive or an inoculant would affect the dry matter (DM) losses, fermentation pattern, yeast and mold counts, and aerobic stability (AS) of the ensiled high-moisture barley grain (675 g kg−1 DM). Crimped barley grain was ensiled with or without chemical additive AIV Ässä Na and an inoculant SiloSolve FC, totaling three treatments (1 × 3 factorial scheme) for the fermentation periods lasting 7, 14, 28, 60, and 90 days. The application of a chemical additive showed higher pH levels, retained water-soluble carbohydrates (WSCs) better, lowered DM loss, and reduced concentrations of fermentation products. Barley grain treated with chemicals initially showed a marked reduction in yeast and fungal growth and a higher AS up to day 60 of storage but became less effective in later stages of storage, leading to decreased AS. Barley grain inoculated with homo- and heterofermentative strains had decreased silage pH; its WSC content was similar to control and had higher content of weak acids and 1,2 propanediol, reducing mold and yeast counts. With fermentation duration from 28 days and beyond (i.e., 90 days), the inoculant treatment achieved the longest AS and the lowest increase in pH and weight loss during the period of air exposure.

Lactic Acid Bacteria and Formic Acid Improve Fermentation Quality and Beneficial Predicted Functional Characteristics in Mixed Silage Consisting of Alfalfa and Perennial Ryegrass

The purpose of the present study was to investigate the effect of additives on the fermentation properties of ensiled mixed alfalfa and perennial ryegrass silage in the karst terrain of Southwest China. A mixture of alfalfa and perennial ryegrass was ensiled at a ratio of 3:7 using three experimental treatments: (1) CK (without additives) and distilled water (5 mL kg−1 fresh weight (FW)); (2) FA and formic acid (88%) (5 mL kg−1 FW); and (3) LAB combined with the application of Lactiplantibacillus plantarum and Lentilactobacillus buchneri (2 × 107 cfu/g FW). All samples were packed manually into polyethylene bags, and three polyethylene bags from each treatment were sampled on days 7, 15, and 45. The findings demonstrated that the pH values of all the mixed silages gradually decreased during ensiling. The lactic acid (LA) and acetic acid (AA) contents increased gradually with ensiling time and peaked after 45 days of ensiling. After 45 days of ensiling, the FA and LAB groups effectively preserved the nutrient content of the mixed silage, which presented a reduced neutral detergent fiber and acid detergent fiber content (p &lt; 0.05) and higher water-soluble carbohydrate content (p &lt; 0.05) than the CK group. The fermentation quality of the mixed silages in the FA and LAB groups improved, as indicated by higher (p &lt; 0.05) LA contents and lower (p &lt; 0.05) pH and ammoniacal nitrogen contents after 45 days of ensiling compared to those in the CK group. As fermentation progressed, the abundance of harmful microorganisms (Hafnia obesumbacterium, Enterobacteriaceae, and Sphingomonas) and beneficial microorganisms (Lactiplantibacillus and Lentilactobacillus) decreased and increased, respectively. In addition, compared to those in the CK group, the FA group had higher abundances of “lipid metabolism” and “biosynthesis of antibiotics” and lower abundances of “membrane transport”. Briefly, the results of this study suggest that the incorporation of FA and LAB additives could improve the quality of fermented mixed silage, and that FA is better than LAB. This information is useful for combining forage resources to satisfy the requirements for high-protein feed and for manufacturing ruminant feed annually.

Changes in chemical composition and fermentation profile in silages from rehydrated grains of maize hybrids during prolonged air exposure

Most studies investigated the effects of air exposure during the ensiling of whole maize silage and high-moisture maize grains on the chemical composition and fermentation profile, but not of rehydrated grain. The aim of the present study was to investigate the effect of the hybrid and the duration of air exposure on the pH and the content of moisture, main nutrients, fermentation products and nitrogen fractions in silages from three commercial maize hybrids. The grains were rehydrated to 32 % of moisture and ensiled for 63 days with the addition of an inoculant (BIO-SIL®, Dr Pieper Technologie und Produktentwicklung GmbH). After opening, the silages were stored at room temperature for 10 days and samples were taken after 0, 1, 3, 5 and 10 days of air exposure. With increasing duration of air exposure, the content of moisture, lactic and acetic acid and ethanol decreased, while the pH value and the content of water-soluble carbohydrates and ammonia increased. The hybrid affected all the determined properties of the silages except the pH and the ethanol content. There were distinct differences in the contents of moisture, total sugars, water-soluble carbohydrates, lactic, acetic, propionic and isobutyric acids, methanol and ammonia, suggesting that some hybrids may be more susceptible to aerobic spoilage. The majority of the properties remained similar until the fifth day of air exposure, suggesting that the silages of all three hybrids were stable during this period. The only property that increased immediately after air exposure was the content of nitrogen fractions suggesting that proteolysis was occurring, even though pH and lactic acid content remained unchanged. Overall, the results of the study indicate that the behaviour of rehydrated maize silage after exposure to air should be taken into account when selecting maize hybrids.

Stem traits promote wheat climate-resilience.

Wheat grain filling processes under post-anthesis stress scenarios depend mainly on stem traits and remobilization of stem water-soluble carbohydrates (WSC). A diverse panel of advanced semi-dwarf spring wheat lines, representing a natural variation in stem traits (WSC content, stem diameter, peduncle length, and stem wall width), was used to identify specific traits that reliably reflect the relationship between WSC and grain yield. The panel was phenotyped under various environmental conditions: well-watered, water-limited, and heat stress in Mexico, and terminal-drought in Israel. Environmental stresses reduced grain yield (from 626 g m-2 under well-watered to 213 g m-2 under heat), lower internode diameter, and peduncle length. However, stem-WSC generally peaked 3-4 weeks after heading under all environmental conditions except heat (where it peaked earlier) and expressed the highest values under water-limited and terminal-drought environments. Increased investment in internode diameter and peduncle length was associated with a higher accumulation of stem WSC, which showed a positive association with yield and kernel weight. Across all environments, there were no apparent trade-offs between increased crop investment in internode diameter, peduncle length, and grain yield. Our results showed that selecting for genotypes with higher resource investment in stem structural biomass, WSC accumulation, and remobilization could be a valuable strategy to ameliorate grain size reduction under stress without compromising grain yield potential. Furthermore, easy-to-measure proxies for WSC (stem diameter at specific internodes and length of the last internode, i.e., the peduncle) could significantly increase throughput, potentially at the breeding scale.

Effect of Lactiplantibacillus and sea buckthorn pomace on the fermentation quality and microbial community of paper mulberry silage.

Paper mulberry is a promising alternative fodder source due to its high protein and the abundance of active components. However, paper mulberry often faces susceptibility to contamination during silage fermentation, and there is a need to improve the quality of silage fermentation of paper mulberry through exotic additives. Sea buckthorn pomace (BP) is a feed additive containing antimicrobial and antioxidant substances that help to enhance silage fermentation. Therefore, the objective of this study was to evaluate the effects of BP and Lactiplantibacillus as additives on silage fermentation and bacterial community of paper mulberry. The results showed that BP and Lactiplantibacillus significantly reduced the pH and ammonium nitrogen content of paper mulberry silage (P < 0.05) and significantly increased the content of lactic acid and acetic acid (P < 0.05), resulting in more residual water-soluble carbohydrate and crude protein contents and less fiber content relative to the control. The key microorganisms in paper mulberry silage fermentation are Lactiplantibacillus pentosus and Weissella cibaria. Among these, Lactiplantibacillus favored a rapid increase in Lactiplantibacillus pentosus abundance during the pre-silage fermentation period, whereas BP favored the promotion of Lactiplantibacillus pentosus growth, resulting in higher contents of lactic and acetic acid than those of the control. Simultaneously adding Lactiplantibacillus and BP can effectively improve the quality of paper mulberry silage and increase the abundance of beneficial microorganisms in paper mulberry silage.

Study on Dynamic Fermentation of Oat Silage Assisted by Exogenous Fibrolytic Enzymes.

Based on the low content of water-soluble carbohydrate (WSC) and lactic acid bacteria (LAB) attachment in oat raw materials, we assumed that the neutral detergent fiber (NDF) content of oat can be reduced by adding cellulase or xylanase. The concentration of metabolizable sugars will be increased, which will assist the oat's bacterial community in fermentation and obtain a better quality of oat silage. After wilting the oat, it was treated as follows: (1) distributed water (CK); (2) silages inoculated with xylanase (X); and (3) silages inoculated with cellulase (C), ensiling for 3, 7, 14, 30, and 60 days. Cellulase and xylanase treatments both alter the fermentation and nutritional quality of ensiled oat, resulting in lower NDF, acid detergent fiber (ADF), cellulose, and hemicellulose contents, increased lactic acid and acetic acid contents, and a significant decrease in ensiling environment pH. The bacterial community undergoes significant changes with cellulase and xylanase treatments, with a significant increase in Lactobacillus abundance in the C_14, X_30, C_30, X_60, and C_60 treatment groups, while Weissella abundance gradually decreases with longer ensiling times. Two exogenous fibrolytic enzymes also alter the bacterial diversity of ensiled oat, with different bacterial species and abundances observed in different treatment groups. Ensiled oat treated with cellulase and xylanase experiences significant changes in its own bacterial community, particularly in the abundance of Lactobacillus. These changes result in improved fermentation and nutritional quality of oat, but the higher metabolism levels observed after 60 days of ensiling with cellulase treatment may lead to energy loss.

Effect of sodium diacetate on fermentation, aerobic stability, and microbial diversity of alfalfa silage.

Alfalfa (Medicago sativa L.) is a vital source of forage protein for ruminants, yet its ensiling poses challenges due to high buffering capacity and low water-soluble carbohydrates (WSC). This study investigated the impact of sodium diacetate (SDA) on alfalfa silage quality and aerobic stability. SDA was applied at four different rates to wilted alfalfa on a fresh basis: 0g/kg, 3g/kg, 5g/kg, and 7g/kg, and silages were ensiled in laboratory-scale silos for 45days, followed by 7days of aerobic exposure. A 16S rRNA gene sequencing assay using GenomeLab™ GeXP was performed to determine the relationship between dominant isolated lactic acid bacteria species and fermentation characteristics and aerobic stability on silage. The results showed that Lentilolactobacillus brevis, Pediococcus pentosaceus and Enterococcus faecium were the most prevalent bacteria when silos were opened, whereas Weissella paramesenteroides, Bacillus cereus, B. megaterium and Bacillus spp. were most prevalent bacteria after 7days of aerobic exposure. Dry matter, pH, and WSC content were not affected by SDA, but doses above 5g/kg induced a homofermentative process, which increased lactic acid concentration and lactic acid to acetic acid ratio, decreased yeast count during aerobic exposure, and improved aerobic stability. These findings offer useful information for optimizing SDA usage in silage, assuring improved quality and longer storage, and thereby improving animal husbandry and sustainable feed practices.

The Impact of Genotype on Chemical Composition, Feeding Value and In Vitro Rumen Degradability of Fresh and Ensiled Forage of Native Maize (Zea mays L.) from Mexico

The objective of this study was to evaluate the impact of the genotype on the chemical composition, feeding value and in vitro rumen degradability of fresh and ensiled forage of four native maize varieties (Amarillo, Olotillo, Tampiqueño and Tuxpeño) from Tamaulipas, Mexico, and a commercial hybrid, as well as the stability and aerobic deterioration of the silage. In all genotypes, fresh forage consisted of whole plants of maize that were harvested when the grain reached a milky-mass state, and silage was fresh forage chopped and ensiled in plastic bags, where it fermented for 120 days. The hybrid presented the highest content (p &lt; 0.05) of dry matter (DM), organic matter (OM), ether extract, non-fibrous carbohydrates (NFCs) and starch, as well as the lowest content (p &lt; 0.05) of fibers (NDF and ADF), acid detergent lignin and water-soluble carbohydrates (WSCs). Furthermore, the hybrid and Amarillo genotypes obtained the lowest pH and ammoniacal nitrogen content (p &lt; 0.05), intermediate values (p &lt; 0.05) of lactic and butyric acid, and the lowest and highest acetic acid content (p &lt; 0.05), respectively. Although OM did not differ (p &gt; 0.05) between states of the forage, the fresh forage presented a higher (p &lt; 0.05) content of DM, crude protein, NDF, ADF, WSCs, pH and butyric acid in all genotypes, while the rest of the parameters were higher (p &lt; 0.05) in the silage. However, Amarillo obtained the highest feeding value (p &lt; 0.05) in terms of DM intake, relative forage value, digestible energy, metabolizable energy and rumen degradability (DM, NDF and ADF), and between states of the forage, ensiled obtained the highest feeding value (p &lt; 0.05). During the aerobic exposure, the Amarillo and hybrid silage showed greater (p &lt; 0.05) stability (&gt;38 h), and less (p &lt; 0.05) deterioration, pH increase and loss of DM and OM, while Tuxpeño obtained less stability and greater deterioration. In conclusion, the genotype did influence the chemical composition of fresh and ensiled forage, which affected the feeding value and in vitro rumen degradability, and the Amarillo and hybrid genotypes presented the best values in the evaluated parameters.

Effect of lactic acid bacteria and wheat bran on the fermentation quality and bacterial community of Broussonetia papyrifera silage

BackgroundPaper mulberry has been considered as a high-quality protein feedstuff to cope with the shortage of feed and the development of livestock. In addition, the features of high moisture and low water-soluble carbohydrate concentration in fresh paper mulberry make it difficult to ensile. Therefore, it is important to find an optimal way to improve the paper mulberry silage quality. In this study, we aimed to investigate the application of Lactobacillus plantarum (LP) and wheat bran (WB) on the fermentation characteristics, chemical composition and microbial community of paper mulberry silage.ResultsThe objective of this study was to evaluate the effects of Lactobacillus plantarum and wheat bran alone or combination (LP + WB) addition on the fermentation quality and bacterial community of paper mulberry silage. After 60 days of ensiling, the employed three treatments had higher crude protein contents compared with control (P < 0.05). More importantly, WB and LP + WB treatments significantly reduced the pH value and NH3-N concentration, and increased lactic acid content (P < 0.05). Microbial analysis indicated that the bacterial community in WB and LP + WB treatments showed distinct difference with LP and control. Lactobacillus was the dominant genera in all treatments. However, at the species level, Lactobacillus farciminis became the most dominant bacteria in control and LP treatments while the dominant bacteria in WB and LP + WB were Lactobacillus brevis and Lactobacillus farciminis. In addition, Lactobacillus brevis was positively correlated to crude protein and lactic acid and negatively correlated to pH and NH3-N. Overall, this study revealed that ensiling paper mulberry with WB or combination LP could improve silage quality through altering microbial community, which provided a practical approach for enhancing paper mulberry silage quality.ConclusionWheat bran and combinations of Lactobacillus plantarum and wheat bran additions could reduce pH, NH3-N and increase LA content. The application of WB and LP + WB shifted the dominant bacteria species to Lactobacillus brevis. In summary, the addition of wheat bran and combinations of lactic acid bacteria and wheat bran were effective ways to enhance paper mulberry silage fermentation.Graphical

Pengaruh Waktu Fermentasi Terhadap Kualitas Fisi k Silase Kulit Kentang (Solanum tuberosum)

The purpose of this study was to determine the effect of fermentation time on the physical quality of potato skin silage (Solanum tuberosum) which included testing of pH, color, aroma, and texture. The research was carried out in Pakunden Village, Sukorejo District, Blitar City, East Java for one month in June. The materials used are potato skins which can be obtained from the potato crusher in the Pakunden area, EM4, molasses, pollard. The method used in this study was an experiment based on a completely randomized design consisting of five treatments and four replications and continued with Duncan's Multiple test. The results of this study showed the average pH of P0 (4,22 ± 0,12), P1 (4,05 ± 0,05 P2 (4,00 ± 0,08), P3 (4,02 ± 0,28), P4 (4,10 ± 0,08), then from the variable presence of fungi there was no presence of fungi in each treatment. From the results of the organoleptic test, the color P0 (3,14 ± 0,16), P1 (2,96 ± 0,13), P2 (2,95 ± 0,06), P3 (2,95 ± 0,15), P4 (2,89 ± 0,08), of the odor variable P0 (3,11 ± 0,06), P1 (3,12 ± 0,03), P2 (3,03 ± 0,03), P3 (3,05 ± 0,05), P4 (3,10 ± 0,05), of the texture P0 (4,00 ± 0), P1 (3,92 ± 0,03), P2 (3,87 ± 0,08), P3 (3,85 ± 0,08), P4 (3,88 ± 0,10). From the research data, it can be concluded that the duration of fermentation has no effect on color, odor, texture, pH, and fungus (P&gt; 0.05). This is due to the low content of WSC (water soluble carbohydrates) and LAB (Lactic Acid Bacteria) so that the ensilase process runs slowly. The pH of silage at a shelf life of 28 days showed the number 4.1 which indicated that the silage process was running well.&#x0D;

Microbiomics and volatile metabolomics-based investigation of changes in quality and flavor of oat (Avena sativa L.) silage at different stages.

This study aimed to analyze the fermentation quality, microbial community, and volatile metabolites of oat silage harvested at two different stages, while examining the correlation between microorganisms and volatile metabolites. Oats were harvested at two growth stages (pre-heading [PRH] and post-heading [POH] stages), followed by 90 days of natural fermentation, with 6 replicates per treatment. Pre- and post-silage samples were randomly selected for nutrient composition, fermentation parameters, microbial population, and high-throughput sequencing analysis. Volatile metabolomics analysis was also performed on samples after 90 days of fermentation to detect differences in flavor quality after silage. The effect of growth stage on the nutrient content of oats was significant, with pre-heading oats having higher crude protein and post-heading oats having higher water soluble carbohydrates content (p < 0.05). Following a 90-day fermentation period, the pH and ammonia nitrogen/total nitrogen levels in the PRH-90 (silage from pre-heading oats after 90 days of fermentation) group demonstrated a significant decrease (p < 0.05), whereas the lactic acid content was notably higher compared to the POH-90 (silage from post-heading oats after 90 days of fermentation) group (p <0.05). Lactiplantibacillus dominated in the PRH-90 group and Enterococcus dominated in the POH-90 group, with abundances of (> 86%) and (> 87%), respectively. The differential volatile metabolites of the two treatment groups were dominated by esters and terpenoids, and the differences in flavor were mainly concentrated in sweet, green, and fruity odors. The results of Kyoto encyclopedia of genes and genomes pathway enrichment analysis demonstrated three major metabolic pathways: phenylpropanoid biosynthesis, phenylalanine metabolism, and biosynthesis of secondary metabolites. Specific microorganisms were significantly correlated with flavor indicators and flavor metabolites. Lactiplantibacillus was significantly positively correlated with flavor substances indicating sweet and fruity flavors, contributing to good flavor, while Enterococcus was significantly and positively correlated with flavor substances indicating bad flavors. In summary, growth stage had significant effects on nutritional components, fermentation parameters and flavor quality of oats, with the fermentation process dominated by Lactiplantibacillus leading to good flavor, while the fermentation process dominated by Enterococcus led to the development of poor flavor.

Strip grazing: Changes in biomass, nutrient content and digestibility of temperate, midsummer pasture by strip-grazed or ‘free’-grazing ponies, over 4 weeks

The digestibility and nutritive values of pastures that were either freely or strip-grazed for 28 days were compared. Twelve ponies were individually grazed in adjacent, 10 m wide, rectangular paddocks. On day -1, each paddock length was adjusted to contain a 28-day supply of herbage DM at 1.5 % of pony BW/d. Ponies, (4/treatment) either accessed the entire 28-day supply from day 1 (TA), or gradually via strip-grazing treatments, SG1 and SG2. SG1 had a ‘lead’ fence spanning the paddock width that from day 3 was moved forward 1/26th of the paddock length daily, whereas SG2 had an additional ‘back fence’, that was advanced the same distance as the lead fence daily. Pasture nutrient contents and estimated nutrient digestibilities (eD) were determined weekly. From weeks 1-4, mean strip-grazed pasture contents (% DM) of water-soluble carbohydrate (WSC) and crude protein declined from 15.7-10.2 and 9.4-8.7, respectively, whereas neutral- and acid-detergent fibre increased from 53.6-60.5 and 35.2-38.0, respectively. Corresponding values for TA pastures were 17.7-5.2, 8.9-8.7, 54.6-69.2 and 35.7-43.6. Concomitantly, calculated digestible energy (cDE) (MJ/kg DM) of strip-grazed and TA pastures declined from 9.7-8.9 and 9.6-7.8, respectively and eDMD of all treatments declined (P<0.05). By week 4, TA pasture WSC, cDE and eDMD were lower and fibre contents higher (P<0.05) than the strip-grazed pastures. TA animal cDE intakes in weeks 1 and 2 exceeded requirements by 42 % vs. 8 % by strip-grazed animals. Strip-grazing delivered a steadier nutrient supply than TA, potentially conferring health benefits to animals prone to metabolic dysfunction.

Zero-cost decision-making of mowing height selection for promoting cleaner and safer production in the feed industry

Selection of a reasonable herbage mowing height is a crucial but easy-to-overlook problem for promoting cleaner production for a feed company. To evaluate the effects of mowing height at harvest on the fermentation products, microbial community, co-occurrence networks, functionality and pathogenic contamination risk of hybrid Pennisetum (HP) silage, HP harvested at two mowing heights (45 cm, F45; 15 cm, F15) were spontaneously ensiled (S45 and S15) for 2, 4, 8, 16, 32 and 64 days. The decrease of the mowing height significantly (P < 0.05) increased the water soluble carbohydrate content (145–162 g/kg dry matter), and numerically increased Enterobacter cloacae (0.02%–0.47%), Klebsiella oxytoca (0.00%–0.12%) and Serratia marcescens (0.00%–0.05%) levels. After ensilage, S45 and S15 presented lactic fermentation with high lactic acid concentration and Lactiplantibacillus proportion, low pH value and absent butyric acid. Both mowing height and storage length affected the complexity of bacterial co-occurrence networks. The decrease of mowing height significantly (P < 0.05) reduced the bacterial KEGG carbohydrate metabolism before ensilage, but there were no significant (P > 0.05) differences in this crucial functionality between mowing heights after ensilage. Ensilage promoted the key Glycolysis pathway and related enzymes (glucose-6-phosphate isomerase, 1-phosphofructokinase, pyruvate kinase, L-lactate dehydrogenase) associated with lactic acid synthesis, but suppressed undesirable lysine, valine, leucine and isoleucine degradation pathways. In bacterial phenotype analysis, regardless of storage length, low mowing height (F15 or S15) had significantly (P < 0.05) higher proportions of ‘Contains Mobile Elements’ and ‘Potentially Pathogenic’ than high mowing height (F45 or S45). These results concluded that although both mowing heights appeared to present the parameters of desirable fermentation, the risk of microbial contamination and pathogens from low mowing heights was not eliminated by 64-day ensilage. Therefore, a relatively high mowing height, e.g. 45 cm, is recommended to ensure the cleanliness, hygiene and safety of HP silage.

Effects of harvest period and mixed ratio on the characteristic and quality of mixed silage of alfalfa and maize

In order to improve the silage quality and rationally develop and utilize feed resources, the experiment will explore the effects of harvest periods and the ratios on silage characteristics and quality of silage maize (Zea mays L.) and alfalfa (Medicago sativa L.). Results showed that dry matter (DM) content, neutral detergent fiber (NDF), acid detergent fiber (ADF) of whole silage maize increased significantly (P < 0.05), water soluble carbohydrate (WSC) content of in 3/4 milk line stage was significantly lower than that in other harvesting stages (P < 0.05), and the CP content of 1/4 milk line stage and relative feed value (RFV) of late milk stage were the maximum, respectively; With the delay of the mowing period, the content of DM, NDF and ADF in the third crop of alfalfa increased significantly (P < 0.05), while the CP content decreased significantly (P < 0.05), the harvest period with the highest RFV was at the early flowering period. To sum up, silage corn can be harvested at the end of milk maturity to early wax maturity, and the third crop of alfalfa can be harvested at the early flowering stage, so that silage materials with high nutritional value can be obtained. The corn silage harvested in late september the best harvest period was mixed with alfalfa at the ratio of 10:0, 8:2, 6:4, 5:5, 4:6, 2:8, 0:10, and the mixed silage was fermented for 60 days, then proceeded determination of silage quality, and the principal component analysis (PCA) was used to analyze 10 nutritional quality indicators of 7 different mixed ratios. The results showed that compared with alfalfa silage alone, in the mixed silage of alfalfa and corn silage, with the increase of the proportion of corn silage, the fermentation quality of silage was gradually improved. Sensory evaluation scores and RFV values were higher, WSC and lactic acid (LA) contents were significantly increased (P < 0.05), and pH and ammonia nitrogen (AN) content were significantly decreased (P < 0.05). The in vitro gas productions ( IVGP, at 0, 2, 4, 6, 8, 12, 24, 36, 48 and 72 h) were measured, the results showed that IVGP increased with the increase of silage corn mixed ratio. In summary, the effects of the harvest period of silage corn and alfalfa and different mixing ratios of silage on the quality of silage provide a theoretical basis for improving the quality of silage and rationally developing and utilizing feed resources, so as to be better applied to actual production.

Comparing the predictive ability of Sentinel-2 multispectral imagery and a proximal hyperspectral sensor for the estimation of pasture nutritive characteristics in an intensive rotational grazing system

Using remote sensing to estimate the nutritive characteristics of pasture in livestock systems is a rapidly developing area that has the potential to improve pasture management and utilisation and in turn improve livestock productivity. The Copernicus Sentinel-2 paired satellites have shown promise in predicting pasture nutritive characteristics and have a pixel size small enough to be able to identify intra-paddock nutrient variation in rotational dairy grazing systems where paddock sizes are small. This study sought to develop nutrient prediction models using a dataset of nine Sentinel-2A and -2B satellite images, by linking imagery to perennial ryegrass dairy pasture samples cut within known pixels of the images in the days directly after each cloud-free overpass. Just before destructive pasture sampling, a handheld, proximal, hyperspectral sensor was used to gather spectral signatures (400–2500 nm) from areas to be sampled. Pasture samples (n = 200) were analysed using wet chemistry techniques for seven nutritive characteristics. The dry matter concentration of the samples was also measured, creating eight variates to be modelled in total. The Sentinel-2 data from within the selected pixels was extracted and used to create input features for Random Forest prediction models. Input features included the raw multispectral bands, common vegetation indices, and independent variables ‘season’ and ‘month’. Predictive models were also developed from the hyperspectral sensor data using Partial Least Squares Regression. For both modelling types, variable selection was used to reduce model inputs to only those sensitive to each nutrient. Results comparing the final models in an independent validation test showed similar predictive performance of the Sentinel-2 satellite and the proximal hyperspectral sensor for all variates of interest, shown by mean absolute errors that were not significantly different. In each case, the dry matter concentration was the best predicted variable (Lin’s concordance correlation coefficient (LCCC) > 0.90) with excellent potential to be quantified by Sentinel-2 satellites. Crude protein, metabolisable energy, neutral detergent fibre, non-fibre carbohydrate, and water-soluble carbohydrate concentrations were also predicted with good to moderate accuracy by both sensors (LCCC between 0.50 and 0.80). These models would be sufficiently accurate for making qualitative predictions (e.g., grouping into high to low categories). Ash and acid detergent fibre concentrations were poorly predicted (LCCC < 0.50) and these models would not be recommended for further use. It was concluded that multispectral data from Sentinel-2 has great potential to estimate pasture nutrient concentrations for intensively grazed pastures such as those used in dairy systems in temperate regions.

Determination of water-soluble carbohydrates by near-infrared spectroscopy for canola, maize, and sorghum stem fractions

Near infrared spectroscopy (NIRS) was evaluated as a rapid and non-destructive method for determining the concentration of water-soluble carbohydrates (WSC) in stem fractions for winter canola (Brassica napus L.), maize (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) crops. For each crop at different growth stages, stem WSC concentration was determined using NIRS, and benchmarked against the anthrone reagent method, chemical lab analysis. Partial least squares regression was implemented to associate the WSC predicted via NIRS relative to those obtained by laboratory analysis. Spectral regions between 1100 and 1480 nm were critical for WSC determination. The predictive models resulted in coefficient of determinations of 0.93, 0.94, and 0.95, and a Root Mean Square Error of prediction of 10, 20, and 17 for winter-canola, maize and sorghum crops, respectively. The NIRS spectroscopy is a reliable method for WSC determination in stem tissues on these major field crops.