Water-soluble Carbohydrate Content Research Articles

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.

Effects and function of citric acid on fermentation quality and microbial community in sugarcane tops silage with high and low water-soluble carbohydrate content

Sugarcane tops silage (STS), as a source of roughage for ruminants, is rich in water-soluble carbohydrate (WSC) content, which significantly affects silage quality. Citric acid (CA) is a low-cost natural antimicrobial agent that can inhibit undesirable microbes and improve silage quality. The objectives of this study were to investigate the effects of CA on the chemical composition, fermentation quality, microbial communities, and metabolic pathways of STS with high and low WSC contents before or after aerobic exposure. Fresh sugarcane tops with low-WSC [143.05 g/kg dry matter (DM)] and high-WSC (249.99 g/kg DM) contents were treated with and without CA and then ensiled for 125 days, followed by aerobic exposure for 4, 8, and 16 days. The results showed that high-WSC STS had lower crude protein (CP) content and higher DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) contents, whether treated with CA or not. CA-inoculated silage exhibited decreased DM loss and enterobacteria (EB) counts compared to the control. High-WSC STS treated with CA had higher WSC content and lower yeast count than those without CA inoculation. During the 0–16 days of aerobic exposure, the propionic acid and butyric acid contents in CA-inoculated silage were almost unchanged and ranged from 0 to 1 g/kg DM. Meanwhile, the ethanol content was almost unchanged and ranged from 0 to 1 g/kg DM only in low-WSC STS, irrespective of CA addition. Before aerobic exposure, CA inoculation decreased the abundances of undesirable microbes (e.g., Clostridium_sensu_stricto_12 and Paecilomyces) and animal pathogens, while amino acid metabolism was lower in high-WSC STS regardless of CA treatment. After aerobic exposure, CA inoculation increased the abundance of bacteria with antibacterial effects, including Paenibacillus and Bacillus. Moreover, the metabolism of energy and nucleotides was lower in high-WSC STS treated with CA, and the animal pathogens was lower in low-WSC STS treated with CA. In conclusion, CA inoculation could be effective in decreasing nutrients loss, improving fermentation quality, inhibiting harmful microorganisms, and modulating the metabolic pathways of microorganisms in STS with high and low WSC contents prior to and after aerobic exposure.

Effect of Experimental Warming on Forage Nutritive Value and Storage in Alpine Meadows at Three Different Altitudes of Nianqing Tanggula Mountain, Northern Tibet: A Long-Term Experience

Effects of climate warming on nutrition quality and storage of alpine grasslands are still controversial, which is not conducive to the management and utilization of alpine grasslands. A long-term warming experiment (with open-top chambers used to elevate temperature) was conducted at three elevations (relatively low, mid-, and high elevations with 4313, 4513, and 4693 m) of Northern Tibet in 2010 to compare the differences in forage nutritional quality and storage response to warming among three elevations and to explore the relationships between forage nutritional quality and production. In 2019, community surveys, observations of forage biomass and nutrition quality, and soil physicochemical properties were carried out. Forage nutrition quality included crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), ether extract (EE), crude ash (Ash), and water-soluble carbohydrate (WSC) content. Warming did not affect community aboveground biomass (AGB) at the three elevations. Warming improved community nutrition quality by increasing community CP content by 25.80% and decreasing community NDF content by 15.51% at the low elevation. In contrast, warming reduced community nutrition quality by increasing community CP, ADF, and NDF contents by 13.45%, 23.68%, and 17.43%, respectively, and decreasing Ash content by 39.50% at the high elevation. Warming did not affect community CP, ADF, NDF, EE, Ash, or WSC contents at the mid-elevation. Warming increased community nutrition storage by increasing community CP, ADF, and NDF storges by 74.69%, 88.18%, and 79.71%, respectively, at the high elevation. Warming did not affect community nutrition storages at the low or mid-elevations. Overall, forbs had higher CP, EE, Ash, and WSC contents and lower ADF and NDF contents compared with graminoids. Community EE content increased with community AGB, but community CP, ADF, NDF, EE, Ash, and WSC contents were not related to community AGB. Therefore, from the low to high elevation, the effects of warming on forage nutrition quality gradually changed from improving to inhibiting. Warming altered rangeland quality by affecting forage nutrition quality rather than forage production. There were no trade-offs between forage nutrition quality and forage production.

Composição química de plantas de milho: colheita da tarde diminui recuperação de matéria seca e aumenta teor de amido na silagem e degradação in vitro

ABSTRACT: Plants’ physiology changes through the day because photoassimilates can increase water-soluble carbohydrate concentration in the afternoon compared to the morning. This study evaluated the harvest time effect on whole-plant corn silage morphological composition, particle size, fermentation profile, chemical composition, in vitro degradation, and estimated milk yield. A two-year agronomic assay was performed in a completely random design, and one experimental silo was produced by each parcel (n = 16). The afternoon harvest increased (P &lt; 0.01) dry matter content compared to the morning harvest. Harvest time did not affect (P ≥ 0.32) corn grain, stalk, leaf proportion, and silage particle size. However, the morning harvest increased dry matter recovery (P = 0.01) and had no effect (P ≥ 0.10) on silage pH and concentrations of lactic and acetic acid compared to the afternoon harvest. In addition, afternoon harvest instead of morning harvest increased (P ≤ 0.05) silage starch, water-soluble carbohydrates, acid detergent lignin, and ether extract content and dry matter in vitro degradation. Controversially, treatments showed no effect (P ≥ 0.14) on silage energy concentration, estimated energy content, and milk yield. Thus, the morning harvest produces more silage dry matter, but the afternoon harvest improves corn silage’s nutritional value with no impact on estimated milk yield.

Effects of Biological Additives on the Fermentation Quality and Microbial Community of High-Moisture Oat Silage

The primary objective of this study was to explore the effects of biological additives, including Streptococcus bovis (SB), Bacillus subtilis (BS), xylanase (XT), and their combined treatments, including SB + BS (SBBS), SB + XT (SBXT), and BS + XT (BSXT), on the chemical composition, fermentation characteristics, and microbial community of high-moisture oat silage. Compared with the CK group (control group without additives), SB and SBBS treatments increased the lactic acid content (p &lt; 0.05) and reduced the contents of acetic acid, propionic acid, butyric acid, and ammonia nitrogen in silage (p &lt; 0.05). XT, SBXT, and BSXT treatments decreased the neutral detergent fiber and acid detergent fiber contents (p &lt; 0.05), increasing the water-soluble carbohydrate content (p &lt; 0.05). The SB, SBBS, and SBXT treatments increased the abundance of Lactiplantibacillus (p &lt; 0.05) and significantly decreased microbial richness with diversity (p &lt; 0.05), improving the microbial community structure in silage. The addition of XT increased the relative abundance of Clostridium and Enterobacteriaceae, but its combination with SB and BS increased the abundance of Lactiplantibacillus and inhibited the development of undesirable bacteria. Moreover, different additives changed the metabolism of carbohydrates, amino acids, energy, cofactors and vitamins of bacterial communities during ensiling. In summary, the addition of SB and SBBS was more conducive to improving the fermentation characteristics of oat, while XT, SBXT, and BSXT performed better in degrading lignocellulose in plants.

Effect of Roughage-to-Concentrate Ratio and Lactic Acid Bacteria Additive on Quality, Aerobic Stability, and In Vitro Digestibility of Fermented Total Mixed Ration

Planting oat forage in fallow fields during winter and producing total mixed ration (TMR) silage can effectively address issues of land wastage and forage shortages while maintaining forage quality. This study used oats and common vetch grown in winter fields in southern China as base materials, with additives including corn flour, soybean meal, corn lees, cottonseed meal, and premixes to formulate mixed feeds with roughage-to-concentrate ratios of 75:25, 70:30, and 65:35 on a dry matter basis. TMR silage was inoculated with a customized mixed lactic acid bacteria (LAB) additive composed of Lactobacillus plantarum 160 (patent number ZL202210218695.5), Lactobacillus pentosus 260 (patent number ZL202210204293), and Lactobacillus buchneri 225 (patent number ZL202210204293), at a ratio of 2:1:1, with addition rates of 4 × 106, 2 × 106, and 2 × 106 cfu/g, respectively (IN), while sterile distilled water served as the control (CK). After a 60-day fermentation, the cornell net carbohydrate protein system (CNCPS) and in vitro digestion analysis were used to assess the effects of different roughage-to-concentrate ratios on the carbohydrate and protein components and ruminal degradation rate of fermented TMR (FTMR) silage, as well as to evaluate the impact of mixed LAB inoculation on FTMR nutritional quality, fermentation quality, and aerobic stability. The results indicated the following: (1) Regardless of the LAB addition, dry matter (DM), ether extract (EE), crude protein (CP), and Ash contents significantly decreased (p &lt; 0.05) as the concentrate level decreased. In the IN group, as the concentrate level decreased, the water-soluble carbohydrate (WSC) content significantly increased (p &lt; 0.05), the pH significantly decreased (p &lt; 0.05), and the NH3-N/TN significantly decreased (p &lt; 0.05), with LAB counts significantly higher at a 65:35 roughage-to-concentrate ratio than in the other two groups. In the CK group, no significant changes (p &gt; 0.05) were observed in the WSC content, pH, or LAB counts. (2) CNCPS analysis showed that in the IN group, the carbohydrate (CHO) content at a 75:25 roughage-to-concentrate ratio was significantly higher than in the other two groups (p &lt; 0.05), while the non-utilizable carbohydrate (CC) content was significantly lower (p &lt; 0.05). As the concentrate levels decreased, the non-protein nitrogen (PA) and moderately degradable true protein (PB2) content significantly increased (p &lt; 0.05), whereas the rapidly degradable true protein (PB1) and slowly degradable true protein (PB3) content significantly decreased (p &lt; 0.05). In the CK group, the CHO, PA, PB2, and PC content significantly increased (p &lt; 0.05) as concentrate levels decreased, while the PB1 and PB3 content significantly decreased (p &lt; 0.05). (3) In vitro digestibility characteristics indicated that gas production (GP) in the IN group was significantly lower than in the CK group (p &lt; 0.05), with crude protein degradability increasing as concentrate levels decreased, regardless of the LAB addition. (4) At a 65:35 roughage-to-concentrate ratio, aerobic stability in the IN group was significantly higher than in the CK group (p &lt; 0.05). In conclusion, higher concentrate ratios in total mixed rations (TMRs) with varying roughage-to-concentrate proportions improve the nutritional quality and promote the ruminal degradation of the FTMR. LAB inoculant addition could be an effective approach for addressing FTMR feed challenges.

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.

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

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. 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. 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. 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 Effects of Lactobacillus plantarum, Bacillus subtilis, a Lignocellulolytic Enzyme System, and Their Combination on the Fermentation Profiles, Chemical Composition, Bacterial Community, and In Situ Rumen Digestion of Fresh Waxy Corn Stalk Silage.

The objective of this study was to assess the impact of Lactobacillus plantarum, Bacillus subtilis, and a lignocellulolytic enzyme system on the nutritional value, fermentation profiles, rumen digestion, and bacterial community of fresh waxy corn stalk silage. Fresh waxy corn stalks harvested after 90 days of growth were treated with no additives (CON), compound multiple lactobacilli (ML, comprising Lactobacillus plantarum at 1.0 × 105 cfu/g fresh weight and Bacillus subtilis at 1.0 × 105 cfu/g fresh weight), a lignocellulolytic enzyme system (LE, at 500 g/t), and a combination of the lignocellulolytic enzyme system and multiple lactobacilli (MLLE). Throughout the fermentation process, the contents of dry matter (DM) and water-soluble carbohydrates (WSC), as well as the counts of lactic acid bacteria, yeast, and mold, continuously decreased with the extension of the fermentation time. In contrast, the concentrations of acetic acid, propionic acid, and ammonia N progressively increased over time. Notably, the pH initially decreased and then increased as fermentation progressed, while the lactic acid concentration first increased and then decreased with the extension of the fermentation time. After 45 days of fermentation, the DM contents of LE and MLLE were significantly lower than that of CON, while the WSC content of MLLE was significantly higher than that of CON. LE most effectively increased the ED of DM and neutral detergent fiber (NDF). Compared to ML and LE, MLLE showed a greater increase in the "a" value of DM and NDF. The DM content in LE and MLLE was lower than in CON, with a higher WSC content. Both ML and MLLE produced more lactic acid than CON and LE, resulting in a lower pH in these groups. Additionally, the acetic acid content and ammonia N content were lower in ML and MLLE compared to CON and LE. The counts of lactic acid bacteria, yeast, and mold declined over the fermentation period, dropping below detectable levels on the seventh and fifth days, respectively. Relative to CON, the three additives reduced the relative abundance of Weissella and Klebsiella and increased that of Lactobacillus. In conclusion, LE improved the nutritional value and rumen digestion of the silage, ML enhanced its fermentation profiles and bacterial community, and MLLE significantly improved the nutritional value, rumen digestion characteristics, fermentation profiles, and bacterial community of the fresh waxy corn stalk silage.

Effects of Wilting and Exogenous Lactic Acid Bacteria on the Fermentation Quality and Microbial Community of Plantago lanceolata Silage

This study aimed to evaluate the effects of wilting and exogenous lactic acid bacteria treatments on the chemical composition, fermentation quality, and microbial community composition of Plantago lanceolata silage (PS). This experiment was carried out in the Guizhou Extension Station of Grassland Technology (25°38′48″ N, 106°13′6″ E). The PS samples were divided into four treatment groups, namely control PS (C-PS), wilting-treated PS (W-PS), Lactobacillus brucei-treated PS (LB-PS), and wilting + L. brucei-treated PS (WLB-PS) groups, and analyzed after 60 d of treatment. The W-PS and WLB-PS groups showed significantly lower ether extract, ash, and Neutral detergent fiber contents but significantly higher water-soluble carbohydrate content compared to the C-PS and LB-PS groups (p &lt; 0.05). Additionally, the W-PS group had significantly lower propionic acid content but significantly higher butyric acid content compared to the other groups (p &lt; 0.05). Meanwhile, the WLB-PS group had the highest lactic acid content, the lowest pH, and no butyric acid content (p &lt; 0.05). Additionally, the WLB-PS group showed a high proliferation of beneficial bacterial species (Lactobacillus buchneri and Lactobacillus plantarum) and decreased proliferation of undesirable bacterial species (Clostridium lutlcellarli and Clostridium tyrobutyricum). In conclusion, the combination treatment with wilting and L. brucei increased beneficial microorganisms and inhibited undesirable microorganisms during ensiling, thereby improving the fermentation quality of PS. Therefore, the combination treatment with wilting and L. brucei may be an effective Plantago lanceolata silage modulation technique.

Effects of Different Additives and Ratios on Broom Sorghum Straw Silage Characteristics and Bacterial Communities

As a large agricultural country, China produces a large number of agricultural and sideline products while harvesting agricultural products every year. Crop straw is one of them. Broom sorghum is a traditional crop in China, which produces a large amount of straw resources every year. These straw resources are placed in the field and cannot be used efficiently. The purpose of this study was to solve the problem of straw utilization of Broom sorghum, one of the main food crops in arid and semi-arid areas of northern China. Broom sorghum is not only a nutritious food crop, its straw is also rich in crude fiber and mineral elements, which has high utilization value. However, due to the high content of lignocellulose in straw, the texture is hard, which limits its digestion and utilization efficiency as feed. In this study, the broom sorghum straw was used as the research object, and the straw raw materials were treated with Lactobacillus plantarum, cellulase and xylanase, respectively. After silage fermentation for 30 d and 60 d, the bags were opened to determine the nutritional quality, fermentation quality, microbial community structure and other indicators. The best fermentation time and additives for broom sorghum straw silage were comprehensively screened to improve the nutritional value of straw and animal production performance. The results showed that the nutritional quality of silage straw increased with the extension of fermentation time. Compared with silage straw after 30 days of fermentation, the nutritional quality and fermentation quality of straw were significantly improved after 60 days of fermentation. Lactobacillus plantarum, cellulase and xylanase could improve the silage performance of broom sorghum straw by improving the microbial community structure in straw, and the effect of cellulase was the best. When cellulase was used in straw at the standard of 20 U/g FM, the content of water-soluble carbohydrates could be significantly increased to 31.35 g/kg FM, and the concentration of lactic acid was also significantly increased to 23.79 g/kg FM. Therefore, in actual production, it is recommended to use cellulase at a dose of 20 U/g FM in broom sorghum silage and open the bag after 60 days of silage fermentation. The results of this study provided a scientific basis for the efficient utilization of broom sorghum straw as feed.

Distribution of Non-Structural Carbohydrates and Root Structure of Plantago lanceolata L. under Different Defoliation Frequencies and Intensities.

Plantago lanceolata L. (plantain) increases herbage dry matter (DM) production and quality during warm and dry conditions due to its deep roots and drought tolerance and reduces nitrogen losses in grazing systems compared to traditional pastures. However, plantain density usually declines after the third growing season, mainly due to defoliation management. The effects of defoliation frequency and intensity on water-soluble carbohydrate (WSC) reserves and below-ground plant responses need further research to optimize grazing strategies for improved productivity and sustainability of grazing systems. Our study investigated the effects of defoliation frequencies (15, 25, and 35 cm of extended leaf length, ELL) and intensities (5 and 8 cm of residual heights) on morphological traits and WSC concentrations in plantain biomass under controlled environmental conditions. Defoliation frequency significantly influenced morphological and chemical characteristics and biomass distribution more than residual height. Less frequent defoliations promoted above-ground herbage DM production, reproductive stems, and root biomass. Root architecture showed adaptations in response to defoliation frequency, optimizing resource acquisition efficiency. Frequent defoliation reduced high molecular weight WSC concentrations in leaves, affecting regrowth capacity and DM mass. A defoliation frequency of 25 cm ELL (~15 days) balances herbage production and root development, promoting long-term pasture sustainability.

The effects of applying cellulase and laccase on fermentation quality and microbial community in mixed silage containing corn stover and wet brewer's grains.

The purpose of this experiment was to explore the effect of adding cellulase and laccase on fermentation quality and microbial community in mixed silage of corn stover and wet brewer's grains. Try to a new approach for the proper preservation and utilization of the agro-industrial by-products (corn stover and wet brewer's grains). The experiment was divided into four groups: CK (control), C (cellulase, 120 U/g fresh matter [FM]), L (laccase, 50 U/g FM), CL (cellulase 120 U/g FW and laccase 50 U/g FM), and the chemical composition, fermentation quality, microbial population and microbial community in mixed silage of corn stover and wet brewer's grains after 30 day's fermentation were determined. Compared to control, the addition of cellulase significantly increased crude protein (CP), water-soluble carbohydrate (WSC), lactic acid bacteria (LAB) counts, while significantly decreased the neutral detergent fiber (NDF), acid detergent fiber (ADF) content (P < 0.05). Adding laccase significantly decreased the acid detergent lignin (ADL) content (P < 0.05). Combined application of cellulase and laccase significantly increased the CP, WSC content and LAB counts, while significantly decreased pH value, NDF, ADF and ADL content (P < 0.05), thereby improving fermentation quality. In addition, the application of cellulase and laccase increased the abundance of Firmicutes and LAB genera, and decreased microbial diversity level of the sample. The combined application of cellulase and laccase further improved fermentation quality and microbial community in mixed silage of corn stover and wet brewer's grains.

Annual and seasonal dry matter production, botanical species composition, and nutritive value of multispecies, permanent pasture, and perennial ryegrass swards managed under grazing

AbstractReduced reliance on inputs such as fertilizer is fundamental to sustainable grazing systems. This two‐year study compared four sward types, including multispecies swards (MSS), for herbage dry matter (DM) production, species contribution to DM, and herbage nutritive value under grazing. The systems were: (1) Lolium perenne L. monoculture (PRG; 170 kg N ha−1 year−1); (2) permanent pasture (PP; 135 kg N ha−1 year−1), (3) six species sward consisting of two grasses, two legumes and two herbs (6S; 70 kg N ha−1 year−1), (4) twelve species sward consisting of three grasses, four legumes and five herbs (12S; 70 kg N ha−1 year−1). Herbage samples were collected for DM yield, botanical composition, and nutritive value. Mean annual DM production for PRG, PP, 6S, and 12S was 11,374, 8526, 13,783, and 13,338 kg DM ha−1 respectively. Herb proportions decreased in 6S and 12S from 2020 to 2021 while grass proportions increased. Mean crude protein levels were similar across all systems (p &gt; 0.05), with higher ash content in 6S and 12S compared to PRG (p &lt; 0.001). Organic matter digestibility was lowest in PP compared to PRG (p &lt; 0.001) while neutral detergent fibre content of PP and PRG were greater than 6S and 12S (p &lt; 0.001). Water soluble carbohydrate content was highest in PRG (p &lt; 0.0001). Over 2 years, MSS delivered increased herbage DM yield and nutritive quality relative to PRG and PP swards, from reduced N inputs. However, maintenance of the herb component of MSS is a challenge.

Effect of feeding time and time of harvest of fresh pasture on urinary and faecal nitrogen excretion patterns in sheep

ABSTRACT Under New Zealand grazing systems, a high proportion of the nitrogen consumed by ruminants is excreted. This experiment examined the effect of feeding morning and afternoon harvested annual ryegrass, fed shortly after harvest, on the timing of nitrogen excretion in one-year-old sheep during winter. Dry matter and water-soluble carbohydrate (WSC) content increased in the afternoon-harvested ryegrass. This resulted in increased protein and WSC intakes and a decrease in nitrogen loss in the sheep fed in the afternoon with afternoon-harvested grass. The pattern of urinary nitrogen excretion was related to feeding time with peak urinary urea excretion in the period 4–8 hours after feeding, with over 60% of the daily urinary urea excreted in the 12 hours after the feed was offered. This study suggests that shifting stock onto new pasture breaks in the afternoon could reduce nitrous oxide production by increasing the efficiency of nitrogen utilisation in animals and reducing the total amount of nitrogen excreted. It may be possible to utilise the potential diurnal differences in pasture composition to reduce nitrogen losses. This practise could also improve animal performance as well as change the timing of nitrogen excretion.

Effects of Additives and Planting Density on Silage Performance and Bacterial Community of Novel Sorghum bicolor × S. propinquum Hybrids

In the enhancement of Novel Sorghum bicolor × S. propinquum Hybrid utilization, optimal planting densities and silage methods remain elusive. This study assesses the effects of planting densities, cellulase (CE), Lactobacillus buchneri (LAB), and their combination (LC) on fermentation quality and bacterial diversity of the hybrid silage. The experiment was carried out in a completely random block design with four additives and five planting densities (M1, M2, M3, M4, M5) as follows (4 additives × 5 planting densities): a control group without additives (CK), a group treated with Lactobacillus buchneri (LAB), a group with cellulase (CE), and a group treated with a combination of LAB and CE (LC), maintaining triplicates per treatment. In this study, the additive treatment improved the fermentation quality of silage compared with the control. In the M2-LC group, the contents of crude protein (CP; 7.88%), ether extract (EE; 1.91%), and ash (7.76%) were the highest, while the pH (3.30) was the lowest. The water-soluble carbohydrate (WSC; 11.28%) content was the highest in the M3-CE group, the lactic acid (LA; 6.79%) content was the highest in the M4-CE group, and the acetic acid (AA; 7.71%) content was the highest in the M2-LAB group. Meanwhile, the neutral washing fiber (NDF; 53.17%) content was the lowest in the M5-CE group, the acid detergent fiber (ADF; 41.01%) content was the lowest in the M2-CE group, and the propionic acid (PA; 0.26%) content was the lowest in the M1-LAB group. Adding LC notably reduced bacterial diversity, boosted Lentilactobacillus, and curbed Proteobacteria. LAB and LC markedly improved amino acid metabolism over CE and CK. Conversely, beta-lactam resistance, flagellar assembly, and ascorbate/aldarate metabolism pathways were suppressed. In the future, we will explore a variety of additives and adjust the cutting height to improve its comprehensive quality, create an innovative path for silage production, promote the efficient use of agricultural resources, and provide high-quality feed for animal husbandry.

Effects of atmospheric CO2 concentration on transpiration and leaf elongation responses to drought in Triticum aestivum, Lolium perenne and Festuca arundinacea.

Leaf elongation is vital for productivity of Poaceae species, influenced by atmospheric CO2 concentration ([CO2]) and climate-induced water availability changes. Although [CO2] mitigates the effects of drought on reducing transpiration per unit leaf area, it also increases total leaf area and water use. These complex interactions associated with leaf growth pose challenges in anticipating climate change effects. This study aims to assess [CO2] effects on leaf growth response to drought in perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea) and wheat (Triticum aestivum). Plants were cultivated in growth chambers with [CO2] at 200 or 800 ppm. At leaf six to seven unfolding, half of the plants were subjected to severe drought treatment. Leaf elongation rate (LER) was measured daily, whereas plant transpiration was continuously recorded gravimetrically. Additionally, water-soluble carbohydrate (WSC) content along with water and osmotic potentials in the leaf growing zone were measured at drought onset, mid-drought and leaf growth cessation. Elevated [CO2] mitigated drought impacts on LER and delayed growth cessation across species. A positive correlation between LER and soil relative water content (SRWC) was observed. At the same SRWC, perennial grasses exhibited a higher LER with elevated [CO2], probably due to enhanced stomatal regulation. Despite stomatal closure and WSC accumulation, CO2 did not influence nighttime water potential or osmotic potential. The marked increase in leaf area across species resulted in similar (wheat and tall fescue) or higher (ryegrass) total water use by the end of the experiment, under both watered and unwatered conditions. Elevated [CO2] mitigates the adverse effects of drought on leaf elongation in three Poaceae species, due to its impact on plant transpiration. Overall, these findings provide valuable insights into CO2 and drought interactions that may help anticipate plant responses to climate change.

The microbiota of ensiled forages and of bulk tank milk on dairy cattle farms in northern Sweden

Factors contributing to variations in the quality and microbiota of ensiled forages and in bulk tank microbiota in milk from cows fed different forages were investigated. Nutritional quality, fermentation parameters and hygiene quality of forage samples and corresponding bulk tank milk samples collected in 3 periods from 18 commercial farms located in northern Sweden were compared. Principal coordinates analysis revealed that the microbiota in forage and bulk milk, analyzed using 16S rRNA gene-based amplicon sequencing, were significantly different. The genera Lactobacillus, Weissella, and Leuconostoc dominated in forage samples, whereas Pseudomonas, Staphylococcus, and Streptococcus dominated in bulk milk samples. Forage quality and forage-associated microbiota were affected by ensiling method and by use of silage additive. Forages stored in bunker and tower silos (confounded with use of additive) were associated with higher levels of acetic and lactic acid and Lactobacillus. Forage ensiled as bales (confounded with no use of additive) was associated with higher DM content, water-soluble carbohydrate content, pH, yeast count, and the genera Weissella, Leuconostoc, and Enterococcus. For bulk tank milk samples, milking system was identified as the major factor affecting the microbiota and type of forage preservation had little effect. Analysis of common amplicon sequence variants (ASV) suggested that forage was not the major source of Lactobacillus found in bulk tank milk.

Effects of kinds of additives on fermentation quality, nutrient content, aerobic stability, and microbial community of the mixed silage of king grass and rice straw.

To investigate the effects of kinds of additives on silage quality, the mixture of king grass and rice straw was ensiled with addition of sucrose, citric acid and malic acid at the levels of 0, 1 and 2%, being blank control (CK), citric acid groups (CA1, CA2), malic acid groups (MA1, MA2), citric acid + malic acid groups (CM1, CM2), sucrose groups (SU1, SU2), mainly focusing on fermentation quality, nutrient content, aerobic stability and microbial community of the silages. The results showed that the addition of sucrose decreased (p < 0.05) pH and increased the content of water soluble carbohydrate (p < 0.05). The sucrose groups and mixed acid groups also had a lower (p < 0.01) neutral detergent fiber content. The addition of citric acid and the mixed acid increased (p < 0.01) the aerobic stability of the silage, reduced the abundance of Acinetobacter, and the addition of citric acid also increased the abundance of Lactiplantibacillus. It is inferred that citric acid and malic acid could influence fermentation quality by inhibiting harmful bacteria and improve aerobic stability, while sucrose influenced fermentation quality by by promoting the generation of lactic acid. It is suggested that the application of citric acid, malic acid and sucrose would achieve an improvement effect on fermentation quality of the mixed silage.

Effects of Sweet and Forge Sorghum Silages Compared to Maize Silage without Additional Grain Supplement on Lactation Performance and Digestibility of Lactating Dairy Cows.

This study investigated the effects of replacing maize silage (MZS) with high-sugar sorghum silage (HSS) or forage sorghum silage (FSS) without additional grain supplement in the diets of dairy cows on nutrient digestibility, milk composition, nitrogen (N) use, and rumen fermentation. Twenty-four Chinese Holstein cows (545 ± 42.8 kg; 21.41 ± 0.62 kg milk yield; 150 ± 5.6 days in milk) were randomly assigned to three dietary treatments (n = 8 cows/treatment). The cows were fed ad libitum total mixed rations containing (dry matter basis) either 40% MZS (MZS-based diet), 40% HSS (HSS-based diet), or 40% FSS (FSS-based diet). The study lasted for 42 days, with 14 days devoted to adaptation, 21 days to daily feed intake and milk production, and 7 days to the sampling of feed, refusals, feces, urine, and rumen fluid. Milk production was measured twice daily, and digestibility was estimated using the method of acid-insoluble ash. The data were analyzed using a one-way ANOVA in SPSS 22.0 according to a completely randomized design. Dietary treatments were used as fixed effects and cows as random effects. The results indicate that MZS and HSS had greater crude protein but less neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and a lower pH than FSS (p ≤ 0.04). High starch contents in MZS and water-soluble carbohydrate (WSC) contents in HSS were observed (p < 0.01). While the highest starch intake was observed for the MZS-based diet, the highest WSC intake was noted for the HSS-based diet, and the highest NDF, ADF, ADL intake was observed for the FSS-based diet (p ≤ 0.05). The diets, including MZS and HSS, had greater digestibility than that of FSS (p ≤ 0.03). Feeding MZS- and HSS-based diets increased the yield, fat, and protein content of the milk, as well as feed conversion efficiency (p ≤ 0.03). However, feeding the MZS- and HSS-based diets decreased the contents of milk urea N, urinary urea N, and urinary N excretion more than the FSS-based diet (p ≤ 0.05). The N use efficiency tended to increase relative to diets containing MZS and HSS compared with FSS (p = 0.06 and p = 0.09). Ruminal ammonia-N and pH were lower, but total volatile fatty acids, acetate, and propionate were higher in cows fed the HSS- and MZS-based diets compared to those fed the FSS-based diet (p ≤ 0.03). It appears as though replacing MZS with HSS in the diet of cows without additional grain supplements has no negative influence on feed intake, milk yield, N utilization, or ruminal fermentation.