Higher Water-soluble Carbohydrate Research Articles

Effect of contrasting water-soluble carbohydrate to crude protein ratio’s in perennial ryegrass on nitrogen metabolism in lambs

ABSTRACT The effect of high and low water-soluble carbohydrate (WSC) to crude protein (CP) ratios on nitrogen balance in lambs was evaluated. Ryegrasses containing either 35.4% WSC and 12% CP (High WSC) or 14.8% WSC and 23.8% CP (High N) were harvested, frozen and fed to lambs in metabolism crates. These contrasts in WSC and CP delivered diets with markedly different WSC:CP ratios (3.17:1 and 0.70:1). These ratios were higher than those reported in ryegrass previously. There was no difference in urinary nitrogen concentration (0.46 vs 0.48 g/l) but as the total urinary volume was higher on the High N diet (4.2 vs 1.5 l/d, P < 0.001), the end result was that more N was excreted in the urine on the high N diet (18.8 vs 7.3 g/d, P < 0.001). However, the proportion of nitrogen intake that was excreted in urine and faeces was higher on the High WSC diet so there was no evidence that a high WSC forage diet improved nitrogen utilisation.

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.

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.

Integrated microbiology and metabolomic analysis reveal the improvement of rice straw silage quality by inoculation of Lactobacillus brevis.

Ensiling technology holds promise for preserving and providing high-quality forage. However, the preservation of rice straw poses challenges due to its high lignocellulosic content and low water-soluble carbohydrate levels. Developing highly effective lactic acid bacteria (LAB) for rice straw silage remains a priority. This study evaluated the impact of three LAB strains, Lactobacillus brevis R33 (Lac33), L. buchneri R17 (Lac17), and Leuconostoc pseudomesenteroides (Leu), on the fermentation quality of rice straw silage. Rice straw silage inoculated with Lac33 alone or in combination with other strains exhibited significantly lower neutral detergent fiber (NDF) (66.5% vs. 72.3%) and acid detergent fiber (ADF) (42.1% vs. 47%) contents, along with higher lactic acid (19.4g/kg vs. not detected) and propionic acid (2.09g/kg vs. 1.54g/kg) contents compared to control silage. Bacterial community analysis revealed Lactobacillus dominance (> 80%) and suppression of unwanted Enterobacter and Clostridium. Metabolomic analysis highlighted increased carbohydrates and essential amino acids, indicating improved nutrient values in Lac33-inoculated rice straw silage and a potential explanation for Lac33 dominance. This research identified a highly efficient LAB candidate for rice straw silage, advancing our comprehension of fermentation from integrated microbiology and metabolomic perspectives.

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

Deciphering the morpho-physiological and biochemical responses in Lablab purpureus (L.), Sweet, seedlings to water stress

Drought is a major crop productivity-limiting factor, which adversely affects growth and yield worldwide. Lablab (Lablab pupureus [L.] Sweet), is better adapted to withstand drought stress, however, characterization of lablab in Kenya has not been undertaken and there is limited knowledge on plant response to drought stress. Ten lablab genotypes were evaluated under greenhouse to determine the morpho-physiological and biochemical response at the seedling stage. The study revealed significant differential responses among lablab genotypes to water stress. The interaction between the water stress and the genotypes significantly affected the evaluated traits. Genotypes D1 and D6 showed significantly increased and superior morphological adaptation, respectively, indicating enhanced adaptation for tolerance to water stress. Significant variations of ascorbate peroxidase, guaiacol peroxidase and catalase activities were detected during the experimental period. The plants exhibited varying non-enzymatic antioxidants and osmolytes with an increase in proline, total phenol and water-soluble carbohydrates and a decline in free amino acids and water-soluble proteins under severe water stress. Genotype D10 recorded high antioxidant enzymatic activity and water-soluble carbohydrates, whereas D1 accumulated more proline and proteins, indicating better adaptation in scavenging reactive oxygen species to prevent membrane damage. The higher photosynthetic efficiency of seedlings of genotype D1 and superior morphological adaptation of D6 indicated better agronomic adaptation to severe water stress and could be utilized in plant breeding programmes for tolerance to drought.

Integrated laccase delignification with improved lignocellulose recalcitrance for enhancing enzymatic saccharification of ensiled rice straw

The recalcitrant of straw biomass due to its severe lignification hinders its efficient use as a biofuel of feedstock. Therefore, this study was aimed to develop an integrated approach for treatment of rice straw to improve enzymatic saccharification and increase bioethanol production. We evaluated the effect of Lactobacillus plantarum (LP) and cellulases (CL), along with the ligninolytic enzyme laccase (Lac), on the quality of silage, enzymatic hydrolysis, and ethanol production from rice straw ensiled for 60 days. The rice straw was either ensiled without additive (control) or treated with five combinations of the additives, i.e., LP, CL, LP+CL, LP+Lac, or LP+CL+Lac (LPCL+Lac). The results indicated that adding laccase improved the fermentation and silage preservation quality of rice straw biomass by increasing lactic acid production and decreasing pH (<4) (P < 0.05). It also maintained high water-soluble carbohydrate and mono- and disaccharides. The LPCL+Lac treatment managed to reduce the lignin content of rice straw up to 3.82%. Fourier transform infrared spectroscopic analysis and scanning electron microscopic images confirmed that laccase degraded lignin and altered the physico-chemical structure of rice straw. The delignification and reducing the recalcitrance of lignocellulose of rice straw biomass with integrated laccase pretreatment (LPCL+Lac) resulted in release of high content of reducing sugar (52.42 mg/mL), and produced the highest quantity of ethanol (24.45 mg/mL). These results demonstrate that laccase effectively degraded lignin content of rice straw, and its integrated use with LP and CL provides a feasible approach for improving the preservation and bioconversion efficiency of highly lignified and recalcitrant straw biomass.

Enhancement of Biomass Conservation and Bioethanol Production of Sweet Sorghum Silage by Constructing Synergistic Microbial Consortia.

The efficient storage of materials before bioethanol production could be key to improving pretreatment protocol and facilitating biodegradation, in turn improving the cost-effectiveness of biomass utilization. Biological inoculants were investigated for their effects on ensiling performance, biodegradability of silage materials, and final bioethanol yield from sweet sorghum. Two cellulolytic microbial consortia (CF and PY) were used to inoculate silages of sweet sorghum, with and without combined lactic acid bacteria (Xa), for up to 60 days of ensiling. We found that the consortia notably decreased pH and ammonia nitrogen content while increasing lactic acid/acetic acid ratios. The microbes also functioned in synergy with Xa, significantly reducing lignocellulose content and improving biomass preservation. First-order exponential decay models captured the kinetics of nonstructural carbohydrates and suggested high water-soluble carbohydrate (grams per kilogram dry matter [DM]) preservation potential in PY-Xa (33.48), followed by CF-Xa (30.51). Combined addition efficiently improved enzymatic hydrolysis and enhanced bioethanol yield, and sweet sorghum treated with PY-Xa had the highest ethanol yield (28.42 g L-1). Thus, combined bioaugmentation of synergistic microbes provides an effective method of improving biomass preservation and bioethanol production from sweet sorghum silages. IMPORTANCE Ensiling is an effective storage approach to ensure stable year-round supply for downstream biofuel production; it offers combined facilities of storage and pretreatment. There are challenges in ensiling sweet sorghum due to its coarse structure and high fiber content. This study provides a meaningful evaluation of the effects of adding microbial consortia, with and without lactic acid bacteria, on changes in key properties of sweet sorghum. This study highlighted the bioaugmented ensiling using cellulolytic synergistic microbes to outline a cost-effective strategy to store and pretreat sweet sorghum for bioethanol production.

Outlier analyses and genome-wide association study identify glgC and ERD6-like 4 as candidate genes for foliar water-soluble carbohydrate accumulation in Trifolium repens.

Increasing water-soluble carbohydrate (WSC) content in white clover is important for improving nutritional quality and reducing environmental impacts from pastoral agriculture. Elucidation of genes responsible for foliar WSC variation would enhance genetic improvement by enabling molecular breeding approaches. The aim of the present study was to identify single nucleotide polymorphisms (SNPs) associated with variation in foliar WSC in white clover. A set of 935 white clover individuals, randomly sampled from five breeding pools selectively bred for divergent (low or high) WSC content, were assessed with 14,743 genotyping-by-sequencing SNPs, using three outlier detection methods: PCAdapt, BayeScan and KGD-FST. These analyses identified 33 SNPs as discriminating between high and low WSC populations and putatively under selection. One SNP was located in the intron of ERD6-like 4, a gene coding for a sugar transporter located on the vacuole membrane. A genome-wide association study using a subset of 605 white clover individuals and 5,757 SNPs, identified a further 12 SNPs, one of which was associated with a starch biosynthesis gene, glucose-1-phosphate adenylyltransferase, glgC. Our results provide insight into genomic regions underlying WSC accumulation in white clover, identify candidate genomic regions for further functional validation studies, and reveal valuable information for marker-assisted or genomic selection in white clover.

Effects of Maize Varieties on Biomass Yield and Silage Quality of Maize–Soybean Intercropping in the Qinghai–Tibet Plateau

Forage deficiency is the bottleneck that restricts the development of plateau animal husbandry. Maize (Zea mays L.)–soybean (Glycine max L.) intercropping can improve the forage biomass yield and silage quality. This experiment was conducted in Ganzi Tibetan Autonomous Prefecture to explore the effects of four maize varieties (M1, Rongyu Silage No. 1; M2, Yayu 04889; M3, Demeiya No. 1; M4, Zhenghong 505) on biomass yield, nutritional composition, and silage quality in maize–soybean intercropping. The results showed that M1S had the highest total dry matter yield (18.03 t ha−1), M3S had the highest crude protein (CP) content (8.46% DM), and soybeans had the highest water-soluble carbohydrate (WSC) content (8.55% DM). After silage, the CP content (13.44% DM) of mixed silage in M3S was higher, and the contents of neutral detergent fiber (39.42% DM) and acid detergent fiber (25.42% DM) were lower than those in maize silage alone. The WSC content (4.45% DM) of mixed silage in M3S was higher and the pH value (4.46) and ammonia–nitrogen to total nitrogen (3.97%) were lower than those of soybean silage alone. The results of membership function analysis showed that M3S was the best in fresh feeding and silage utilization, followed by M1S. Therefore, M3S (Demeiya No 1. intercropped with soybeans) is recommended in high-altitude areas.

Tannin tolerance lactic acid bacteria screening and their effects on fermentation quality of stylo and soybean silages.

Some excellent legume forages are difficult to ensile naturally due to their high buffering capacity and low water-soluble carbohydrate content. This may cause serious problems like proteolysis. In the present study, strains of lactic acid bacteria with high acid productivity and high tannin tolerance were screened from different silages and combined with tannic acid (TA) as an addition to ensiling. The screened strains were identified as Lactobacillus plantarum (LP), with four of these strains then selected for their high tannin tolerance. Stylosanthes guianensis and whole-plant soybean (WPS) were ensiled with 1 and 2% (fresh matter basis) TA, four LP strains alone (6 log10 colony forming units per gram of fresh matter), or TA combined with LP strains. Fermentation parameters and in vitro rumen fermentation characteristics were analyzed after 30 days of fermentation. The results showed that TA + LP can be used to reduce pH values (P < 0.01), non-protein nitrogen (P < 0.01), and ammonia-nitrogen (P < 0.01). The in vitro crude protein digestibility of WPS silage was also decreased with the addition of TA + LP (P < 0.01). These results indicate that the addition of TA combined with tannin tolerance LP strains may improve the fermentation quality of legume silage, especially for reducing proteolysis.

An innovative strategy to enhance the ensiling quality and methane production of excessively wilted wheat straw: Using acetic acid or hetero-fermentative lactic acid bacterial community as additives

Ensiling is an effective storage strategy for agricultural biomass, especially for energy crops (mainly energy grasses and maize). However, the ensiling of excessively wilted crop straw is limited due to material characteristics, such as a high lignocellulosic content and low water-soluble carbohydrate and moisture contents. In this study, acetic acid or hetero-fermentative lactic acid bacterial community (hetero-fermentative LAB) were employed as silage additives to improve the ensiling process of excessively wilted wheat straw (EWS). The results showed that the additives inhibited the growth of Enterobacteriaceae and Clostridium_sensu_stricto_12, whose abundances decreased from 55.8% to 0.03–0.2%, respectively. The growth of Lactobacillus was accelerated, and the abundances increased from 1.3% to 80.1–98.4% during the ensiling process. Lactic acid fermentation was the dominant metabolic pathway in the no additive treatment. The additives increased acetic acid fermentation and preserved the hemicellulose and cellulose contents, increasing the methane yield by 17.7–23.9%. This study shows that ensiling with acetic acid or hetero-fermentative LAB is an effective preservation and storage strategy for efficient methane production from EWS.

The Potential of Pre-fermented Juice or Lactobacillus Inoculants to Improve the Fermentation Quality of Mixed Silage of Agro-Residue and Lucerne.

The objective of this study was to determine the effect of pre-fermented juice, Lactobacillus plantarum, and L. buchneri on chemical composition, fermentation, aerobic stability, dynamics of microbial community, and metabolic pathway of a mixture of lucerne, wheat bran (WB), and rice straw (RS). All mixtures were ensiled for 1, 3, 5, 7, 15, 30, and 45 days after treatment with uninoculated (control, C); L. plantarum [LP, 1 × 106 cfu/g of fresh weight (FW)]; L. buchneri (LB, 1 × 106 cfu/g of FW); LP + LB (LPB, 1 × 106 cfu/g of FW of each inoculant); and pre-fermented juice (J; 2 × 106 cfu/g of FW). Four lactic acid bacteria (LAB) species from three genera were cultured from the pre-fermented juice, with W. cibaria being dominant. The inoculants increased lactic acid (LA), decreased pH and ammonia nitrogen (AN) compared to C silage at earlier stages of ensiling, and high dry matter (DM) and water-soluble carbohydrate (WSC) content in inoculated silages. Adding LPB increased the abundance of L. plantarum, L. paralimentarius, and L. nodensis, resulting in the lowest pH. Pre-fermented juice enriched W. cibaria, L. sakei, L. parabrevis, Pseudomonas putida, and Stenotrophomonas maltophilia, mainly enhanced accumulation of acetic acid (AA) and LA, and decreased pH, crude protein losses, AN, and hemicellulose contents. L. buchneri and L. brevis had a high abundance in LB-treated and J silages, respectively, inhibited undesirable bacteria, and improved aerobic stability with more than 16 days. In addition, the metabolic pathways changed with time and L. buchneri inoculants promoted global metabolism. In conclusion, inoculations altered bacterial succession and metabolic pathways in silage; LB and pre-fermented juice enhanced ensiling by promoting pH reductions, enhancing concentrations of LA and AA, and extending aerobic stability more than 16 days.

Effects of Lactic Acid Bacteria and Molasses Additives on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage.

Ensiling native grass is an effective method to protect the nutritional quality of forage and alleviate feed shortages in the cold winter of the Inner Mongolian Plateau. To improve the usability of native grass resources as feed in China, the effects of lactic acid bacteria and molasses additions on the microbial population, fermentation quality, and nutritional quality of native grass during silage were investigated. Treatments were a control treatment with no additive (CK), lactic acid bacteria (L), molasses (M), and lactic acid bacteria in combination with molasses (L+M), all of which were stored at ambient temperature (17–28°C) for 7, 14, 30, and 60 days. The results showed that all additives improved nutritional value and fermentation quality with low pH and ammonia nitrogen (NH3–N) and high crude protein (CP) and water soluble carbohydrate (WSC) than control silage over the ensiling period. Compared with L or M silage, the L+M silage combination improved fermentability, as evidenced by higher LA content and a faster pH drop during the first 7 days of ensiling. With prolonged ensiling time, the combined addition of L and M could increase the count of desirable Lactobacillus, decrease microbial diversity, and inhibit the growth of undesirable microorganism, such as Clostridia, Escherichia, and Enterobacter abundance compared with silage treated with CK, L. or M. Application of L together with M could further improve the silage quality of native grass by altering bacterial community structure. In summary, the addition of lactic acid bacteria and molasses increased the relative abundance of Lactobacillus of native grass silage and improved fermentation quality.

Effect of Bacillus amyloliquefaciens and Bacillus subtilis on fermentation, dynamics of bacterial community and their functional shifts of whole-plant corn silage

BackgroundBacillus amyloliquefaciens (BA) and Bacillus subtilis (BS) are usually used as feed supplements directly or bacterial inoculants in biological feeds for animals. However, few research have reported the effects of BA and BS on fermentation characteristics and bacterial community successions of whole-plant corn silage during ensiling. If the BA and BS inoculants have positive effects on silages, then they could not only improve fermentation characteristics, but also deliver BA or BS viable cells to ruminants, which would play its probiotic effect. Therefore, the objectives of this study were to investigate the effects of BA and BS on the fermentation, chemical characteristics, bacterial community and their metabolic pathway of whole-plant corn silage.ResultsFreshly chopped whole-plant corn was inoculated without or with BA and BS, respectively, and ensiled for 1, 3, 7, 14 and 60 d. Results showed that BA and BS inoculations increased lactic acid concentrations of whole-plant corn silages compared with control, and BA inoculation decreased acetic acid concentrations, whereas BS inoculation decreased fiber contents and increased crude protein (CP) content. Higher water-soluble carbohydrate contents and lower starch contents were observed in BA- and BS-inoculated silages compared with that in control. The decreased CP content and increased non-protein nitrogen content were observed in BA-inoculated silage, which was consistent with the higher amino acid metabolism abundances observed in BA-inoculated silage. In addition, it was noteworthy that BA and BS inoculations increased the metabolism of cofactors and vitamins, and decreased the relative abundances of drug resistance: antimicrobial pathways. We also found that the bacterial metabolism pathways were clearly separated into three clusters based on the ensiling times of whole-plant corn silage in the present study. There were no significant differences in bacterial community compositions among the three groups during ensiling. However, BA and BS inoculations decreased the relative abundances of undesirable bacteria such as Acetobacter and Acinetobacter.ConclusionOur findings suggested that the BS strain was more suitable as silage inoculants than the BA strain in whole-plant corn silage in this study.

Possibilities of using dried mulberry pulp as an additive in alfalfa silage

This study was conducted to determine the effects of dried mulberry (Morus alba) pulp with high water-soluble carbohydrate (WSC) content on the nutrient substance composition, pH and silage acids of alfalfa silage. The alfalfa used in the study was harvested in the 10% flowering period and ensiled by mixing with dried mulberry pulp at different ratios (0%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15%). The alfalfa that was ensiled for three months was analyzed at the end of this period, and the values measured for the control and treatment groups were compared. As a result, it was determined that the addition of dried mulberry pulp at different ratios into alfalfa silage was effective on some properties of the silage. In the case of adding mulberry pulp at 5-7.5% into the silage, it was observed that the silage pH decreased, and the lactic acid ratio increased. This positive result shows that in alfalfa silage mulberry pulp may be used as an additive. Hence, it may be stated that it would be suitable to add 5-7.5% mulberry pulp to increase the quality in alfalfa silage.

Growth stage and ensiling: impact on chemical composition, conservation quality and in situ ruminal degradability of whole-crop oat.

The effects of growth stage (GS) and ensiling were assessed on whole-crop oat's (Avena sativa L. cv. Cantara) chemical composition, silage fermentation quality and in situ ruminal degradability. Oat was harvested and ensiled at six GS: boot, heading, water ripe, early milk, early dough and grain ripe (144, 151, 178, 234, 362 and 512 g kg-1 of dry matter (DM) of whole-crop forage, respectively). GS influenced chemical composition, silage fermentation quality and ruminal degradability of whole-crop oat. Lower DM and higher water-soluble carbohydrates (WSC) contents lead to adequate forage compaction and fermentation at early GS; however, effluent was produced until the dough stage (L and Q; P ≤ 0.003). Advancing in maturity increased (P < 0.001) crop yield (4.5 to 9.4t DM ha-1 ), DM (144 to 512 g kg-1 ), neutral detergent fibre (NDF; 537 to 571 g kg-1 DM), lignin (44.6 to 71.3g kg-1 DM) and starch contents (26.4 to 201 g kg-1 DM), and reduced (P < 0.001) crude protein (107 to 60 g kg-1 DM) and WSC (115 to 17.5g kg-1 DM). DM and NDF ruminal degradability declined with maturity for fresh and ensiled forages (L and Q; P < 0.05). Density and buffering capacity decreased with GS (L and Q; P < 0.001), whereas pH and soluble protein increased (L and Q; P ≤ 0.004). The growth stage of oat influenced the nutritive value and ruminal degradation to a greater extent than ensiling, and thus it can play a paramount role in whole-crop oat silage quality. © 2021 Society of Chemical Industry.

Effects of fatty acid salts on fermentation characteristics, bacterial diversity and aerobic stability of mixed silage prepared with alfalfa, rice straw and wheat bran.

The objective was to determine effects of potassium diformate (PD), sodium diacetate (SD) and calcium propionate (CAP) on dynamics of microbial community, fermentation characteristics and aerobic stability of silage comprised of a mixture of alfalfa (AF), rice straw (RS) and wheat bran (MF). Treatments included control (C), PD [5.5g kg-1 fresh weight (FW)], SD (7g kg-1 FW), and CAP (10g kg-1 FW), which were ensiled for 1, 3, 5, 7, 15, 30 and 45 days in vacuum-sealed polythene bags. After day 1 of ensiling, the most dominant bacterial species in all silages was Weissella cibaria, whereas Lactobacillus parabrevis, L. nodensis, L. plantarum and L. paralimentarius were dominant species after 5 and 15 days of ensiling, and ultimately Pseudomonas putida and Stenotrophomonas maltophilia became dominant after 45 days. The positive correlation between PD and L. plantarum supported the lowest pH, butyric acid, ammonia nitrogen, neutral and acid detergent fiber, and hemicellulose content, and high water-soluble carbohydrates and crude protein content in PD silage. In addition, SD and CAP enriched the abundance of L. parabrevis and mainly increased lactic acid (LA) and acetic acid (AA). CAP increased abundance of L. acetotolerans after 45 days of ensiling with more LA and AA than other treatments. The succession of the bacterial community of mixed silage was modulated by the three fatty acid salts; furthermore, PD and CAP further improved fermentation quality by accelerating the decrease in pH and the increase in LA. The chemical additives prolonged the aerobic stability more than 16 days. © 2021 Society of Chemical Industry.

Effects of Cultivar, Nitrogen Rate and Harvest Time on the Content of Carbohydrates and Protein in the Biomass of Perennial Ryegrass

The aim of this study was to determine the effects of cultivar, nitrogen (N) rate and harvest time on the content of water-soluble carbohydrates (WSC), crude protein (CP) and the WSC:CP ratio in the aboveground biomass of perennial ryegrass (Lolium perenne L.). A small-area field experiment was conducted in the Agricultural Experiment Station in Tomaszkowo (53°42′40.8″ N 20°26′04.7″ E, north-eastern Poland). Data were presented for three years of full utilization (2013–2015). The experimental factors were as follows: (i) perennial ryegrass cultivar: Bajka and Baronka, (ii) N rate (kg ha−1): 0, 120, and 240, and (iii) harvest time: 8.00–10.00 a.m., 12.00–2.00 p.m., and 4.00–6.00 p.m. The tetraploid cultivar Baronka had higher WSC content and lower CP content on a dry matter (DM) basis than the diploid cultivar Bajka (by approx. 3% on average). An increase in N fertilizer rate to 240 kg ha−1 contributed to a decrease in WSC concentrations by 23% in cv. Bajka and by 19% in cv. Baronka, and to an increase in the CP content of aboveground biomass by 32% and 23%, respectively. Both cultivars accumulated significantly higher WSC amounts when biomass was harvested at noon and in the afternoon than in the morning. The CP content of biomass was also affected by harvest time, and it was higher in cv. Bajka when harvesting was carried out at 12.00–2.00 p.m. and 4.00–6.00 p.m., and in cv. Baronka when harvesting was carried out at 4.00–6.00 p.m. The WSC:CP ratio in the biomass of the analyzed cultivars was within the optimal range for ruminants, and it was higher in cv. Baronka (1:1.11). Nitrogen applied at 240 kg ha−1 had a negative influence on the WSC:CP ratio, decreasing its value by around 36% (relative to the rate of 120 kg N ha−1) and around 35% (relative to the unfertilized treatment). In both perennial ryegrass cultivars, biomass harvested in the morning was characterized by the lowest WSC:CP ratio.

Retrospective case review investigating the effect of replacing oaten hay with a non‐cereal hay on equine peripheral caries in 42 cases

Equine peripheral caries can cause significant morbidity and can have considerable welfare implications. Recent research suggests that diets with high water soluble carbohydrate (WSC) content are associated with high risk of peripheral caries. Previous work has indicated that the condition may be treatable if the inciting cause is removed and the damaged tooth allowed to erupt out, being replaced by the unaffected tooth previously under the gingival margin. To see whether the peripheral caries process can be ceased if oaten hay (typically high WSC) is removed from the diet and replaced with a non-cereal hay (typically lower WSC). Retrospective blinded longitudinal study. Forty-two cases with peripheral caries that were on oaten hay were asked if they would change the hay type from oaten hay to a non-cereal hay or straw (meadow, Rhodes hay, lucerne hay or barley straw). Photographs were taken at the time and then again at subsequent visits. The photographs were anonymised, randomised and scored by six equine veterinary dentists using the Jackson et al. 'Peripheral Caries Grading System' grading scale. At follow-up, 69.0% of cases were marked as inactive, compared with 47.6% of cases at baseline (OR: 2.45, 95%CI: 1.12-5.36, P=.02). Significantly lower grades of peripheral caries were observed in the gingival, middle and occlusive third of the molars (triadan 9-11's) at follow-up compared with baseline. However, significant improvements were not observed in the premolars (triadan 6-8's). This is a review of clinical records, not a prospective study. As such, other changes in the diet and management were not recorded, and there was no control group. Recommending clients change their horse's diet from oaten hay (high WSC) to a typically lower WSC hay was associated with significant improvements in equine peripheral caries located in the molars.