Efficacy of powdered alfalfa leaves to ameliorate the toxic effects of aflatoxin B1 in turkey poults.

This experiment was conducted to determine the effect of an adsorbent material based on powdered alfalfa leaves added in the aflatoxin B1 (AFB1)-contaminated diet of turkey poults on production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology. For this purpose, three hundred and fifty female Nicholas-700 poults were randomly assigned into five treatments: (1) Control, AFB1-free diet; (2) AF, diet contaminated with 250 ng AFB1/g; (3) Alfalfa, AFB1-free diet + 0.5% (w/w) adsorbent; (4) AF+alfalfa, diet contaminated with 250 ng AFB1/g + 0.5% (w/w) adsorbent, and (5) AF+ yeast cell wall (YCW), diet contaminated with 250 ng AFB1/g + 0.5% (w/w) of yeast cell wall (a commercial mycotoxin binder used as reference material). The in vivo efficacy of powdered alfalfa leaves was assessed during a 28-day period. In general, the addition of powdered alfalfa leaves in the AFB1-free diet gave the best performance results (body weight, body weight gain, and feed intake) and improved the values of total protein, glucose, calcium, creatinine, and blood urea nitrogen. Moreover, the addition of powdered alfalfa leaves in the AFB1-contaminated diet enhanced body weight and body weight gain and significantly reduced the feed intake, compared to the AF and AF+YCW groups. Additionally, significant alterations in serum parameters were observed in poults intoxicated with the AFB1, compared to the Control group. Furthermore, typical histopathological lesions were observed in the liver of the AF group, which were significantly ameliorated with the addition of powdered alfalfa leaves. Conclusively, these results pointed out that low inclusion of powdered alfalfa leaves in the contaminated feed counteracted the adverse effects of AFB1 in turkey poults.

The composition and nutritional quality of biorefined lucerne protein depend on precipitation method.

BACKGROUND: Lucerne protein extract is a novel high-quality protein source with excellent amino acid (AA) composition of interest for human consumption. In this study, protein from screw-pressed lucerne juice was extracted by different precipitation methods to evaluate the effect on the chemical composition and nutritional quality of the extracted protein. Methods based on heat, acidification or fermentation were used for protein precipitation, and the nutritional value of protein was evaluated in a rat digestibility trial. RESULTS: Heat precipitation at 85 °C produced a protein product with a crude protein (CP) content of 589 g kg-1 dry matter (DM), a balanced AA composition and a high standardized nitrogen (N) digestibility (82.8%). Precipitation by acidification, at a lower temperature (60 °C) or by fermentation, resulted in lower CP content (425-488 g kg-1 DM). Nitrogen digestibility for the pH-adjusted precipitate was equal to the 85 °C heat-precipitated protein, while the fermented and 60 °C precipitated proteins showed lower N digestibility (76.5% and 78.6%, respectively). By applying a two-step heat precipitation method (60 °C followed by 80 °C), a protein content of 712 g kg-1 DM and an N digestibility of 93.6% was reached, which are comparable to high-quality animal-based protein sources such as milk, whey, casein, and eggs, covering the AA requirements for children >6 months. CONCLUSION: High-quality protein can be extracted from lucerne, but the future focus should be on increased yield as the current low yields of the refined product will challenge the environmental and economic sustainability of production. © 2023 Society of Chemical Industry.

The potential role of alfalfa polysaccharides and their sulphated derivatives in the alleviation of obesity.

Sulfated alfalfa polysaccharides (SAPs) as derivatives of alfalfa polysaccharides (APs) showed better in vitro antioxidant activity and potential obesity inhibition. The purpose of this study was to investigate the effect and mechanisms of APs and SAPs on obesity alleviation. Different concentrations of APs and SAPs were tested for effects on body conditions, gut flora, antioxidant capacity, and immunological factors. The results showed that APs and SAPs improved the physical conditions of obese mice, including organ weight, body weight, intraperitoneal fat ratio, and lipid levels. APs and SAPs increased the antioxidant capacity of the obese mice, enhanced the activity of SOD and CAT, and decreased the activity of MDA in the serum, liver, and colon. APs and SAPs upregulated the mRNA expression of IL-4 and IL-10 and downregulated the mRNA expression of NF-κB, IFN-γ, TNF-α, and IL-6 in the liver and colon. Meanwhile, APs and SAPs improved lipid absorption in the jejunum, upregulated LXR and GLP-2, and down-regulated the mRNA expression of NPC1L1. APs and SAPs also contributed to restoring short-chain fatty acid levels in the colon. APs and SAPs improved the structure of the intestinal flora, promoted the proliferation of bacteria associated with short-chain fatty acid metabolism, and inhibited the proliferation of pathogenic bacteria. At the same concentration, the effect of SAPs on the antioxidant capacity was stronger than that of APs. In the AP group, high concentrations of APs showed the best anti-inflammatory effect, while in the SAP group, medium concentrations of SAPs showed the best inhibition of inflammation. Our results suggest that APs and SAPs alleviate obesity symptoms by relieving inflammation, improving the antioxidant capacity, and regulating intestinal flora and therefore could be used as potential probiotic products to alleviate obesity.

Antibacterial and Antibiofilm Effects of Allelopathic Compounds Identified in Medicago sativa L. Seedling Exudate against Escherichia coli.

In this study, the allelopathic properties of Medicago sativa L. (alfalfa) seedling exudates on the germination of seeds of various species were investigated. The compounds responsible for the allelopathic effects of alfalfa were identified and characterized by employing liquid chromatography ion mobility high-resolution mass spectrometry. Crude exudates inhibited the germination of seeds of all various plant species tested. Overall, nine compounds in alfalfa were identified and quantified. The most predominant compounds were a hyperoside representing a flavonoid glucoside, the non-proteinogenic amino acid canavanine, and two dipeptides, identified as H-Glu-Tyr-OH and H-Phe-Glu-OH. The latter corresponds to the first finding that dipeptides are exuded from alfalfa seedlings. In addition, the antibacterial and antibiofilm activities of alfalfa exudate and its identified compounds were elucidated. Both hyperoside and canavanine revealed the best antibacterial activity with minimum inhibitory concentration (MIC) values that ranged from 8 to 32 and 32 to 256 µg/mL, respectively. Regarding the antibiofilm action, hyperoside and canavanine caused a decline in the percentage of E. coli isolates that possessed a strong and moderate biofilm-forming potential from 68.42% to 21.05% and 31.58%, respectively. Studies on their inhibiting effects exhibit that these major substances are predominantly responsible for the allelopathic and antimicrobial effects of the crude exudates.

Study on the Quality of Mixed Silage of Rapeseed with Alfalfa or Myriophyllum.

The objective of this study was to improve the comprehensive rate of utilization of rapeseed (Brassica napus subsp. napus L.), Myriophyllum (Myriophyllum spicatum L.) spicatum and alfalfa (Medicago sativa L.), reduce resource waste and environmental pollution. In this experiment, the effects of different proportions of the mixed silage of rapeseed and alfalfa or M. spicatum on the fermentation and nutritional quality were analyzed and further improved the quality of mixed silage using molasses and urea. Rapeseed was separately silaged with alfalfa and M. spicatum based on the ratios of 3:7, 5:5 and 7:3. After 60 days of mixed silage, the fermentation index and nutrient contents were measured to explore the appropriate ratio of mixed silage. The mixing ratio of rapeseed and alfalfa was better at 3:7: The contents of NH3-N/TN (4.61%), lactic acid (96.46 g·kg-1 dry matter [DM]) were significantly higher (p < 0.05). The crude protein content (118.20 g·kg-1 DM) was the highest (p < 0.05), while the pH (4.56) was the lowest when the mixing ratio of rapeseed and M. spicatum was 7:3. Considering the fermentation and nutrition quality, it is suggested that rapeseed and alfalfa should be mixed as silage at a ratio of 3:7 with 3% molasses and 0.3% urea, and rapeseed and M. spicatum should be mixed as silage at a ratio of 7:3 with 3% molasses.

Exploiting the anaerobic fermentation of alfalfa as a renewable source of squalene.

BACKGROUND: The use of alfalfa is a promising response to the increasing demand for squalene. Ensiling could enhance the squalene content of fresh alfalfa and silage. To investigate and exploit the anaerobic fermentation of forage as a new squalene source, alfalfa was ensiled without (CON) or with molasses (ML) and sunflower seed oil (SSL) for 10, 40, and 70 days. RESULTS: Naturally ensiled alfalfa was of poor quality but had up to 1.93 times higher squalene content (P < 0.001) than fresh alfalfa. The squalene-producing bacteria were found to be cocci lactic acid bacteria (LAB). Adding ML and SSL decreased squalene content (P = 0.002 and P < 0.001) by 6.89% and 11.6%, respectively. Multiple linear regression models and correlation analysis indicated that squalene synthase was the key enzyme for squalene synthesis. The addition of ML and SSL altered the structure of LAB communities, mainly decreasing the relative abundance of cocci LAB, which was responsible for squalene synthesis, and changing the fermentation products (lactic acid, propionic acid, and ammonia-N) influencing the squalene-related enzymes, thereby decreasing squalene production. Compared with squalene production from the reference bacteria (Pediococcus acidilactici Ch-2, Rhodopseudomonas palustris, Bacillus subtilis, engineered Escherichia coli), alfalfa silage had the potential to be a new squalene source. CONCLUSION: Natural ensiled alfalfa was a promising source for squalene, and ensiling was a potential pathway to obtain novel high-yield squalene bacteria. © 2022 Society of Chemical Industry.

Photosensitisation and green egg yolks in laying hens caused by the feeding of ensiled alfalfa leaves.

1. The present study was carried out to determine the effects of feeding ensiled alfalfa leaves (ALS) as an alternative protein source to laying hens under the terms of an organic diet. Due to the occurrence of unexpected negative health effects and undesirable egg yolk pigmentation in the test groups the trial was prematurely stopped and further analysis was conducted to evaluate the responsible substances.2. Body weights of the test groups decreased significantly already in week 2 of the trial. Performance variables dropped. Olive green pigmented egg yolks were found in groups fed diets containing ALS. Severe comb necrosis occurred in the experimental group receiving the highest level of ALS (20%) combined with the option of free-range access and therefore natural light exposure.3. The noxious agent found in ALS, blood serum and egg yolk was the photosensitising chlorophyll derivate pheophorbid a (PPBa), deriving from a strong depletion of chlorophyll contained in the alfalfa leaves. PPBa caused the olive-green pigmentation found in yolks and led to photosensitivity in groups with the highest level of ALS in the diet in combination with light exposure.4. By aiming for high protein and amino acid levels, harvesting and processing have, unintentionally and initially unnoticed, led to a strong accumulation of phototoxic PPBa. From these results it is strongly advised not to include ensiled alfalfa leaves as a protein source in organic laying hen diets.

Effects of Pyroligneous Acid on Diversity and Dynamics of Antibiotic Resistance Genes in Alfalfa Silage.

Antibiotic resistance genes (ARGs) are recognized as contaminants due to their potential risk for human and environment. The aim of the present study is to investigate the effects of pyroligneous acid (PA), a waste of biochar production, on fermentation characteristics, diversity, and dynamics of ARGs during ensiling of alfalfa using metagenomic analysis. The results indicated that PA decreased (P < 0.05) dry matter loss, pH value, gas production, coliform bacteria count, protease activity, and nonprotein-N, ammonia-N, and butyric acid contents and increased (P < 0.05) lactic acid content during ensiling. During fermentation, Bacteria, Firmicutes, and Lactobacillus were the most abundant at kingdom, phylum, and genus levels, respectively. Pyroligneous acid reduced the relative abundance of Bacteria and Firmicutes and increased that of Lactobacillus. The detected ARGs belonged to 36 drug classes, including mainly macrolides, tetracycline, lincosamides, and phenicol. These types of ARGs decreased during fermentation and were further reduced by PA. These types of ARGs were positively correlated (P < 0.05) with fermentation parameters like pH value and ammonia-N content and with bacterial communities. At the genus level, the top several drug classes, including macrolide, tetracycline, lincosamide, phenicol, oxazolidinone, streptogramin, pleuromutilin, and glycopeptide, were positively correlated with Staphylococcus, Streptococcus, Listeria, Bacillus, Klebsiella, Clostridium, and Enterobacter, the potential hosts of ARGs. Overall, ARGs in alfalfa silage were abundant and were influenced by the fermentation parameters and microbial community composition. Ensiling could be a feasible way to mitigate ARGs in forages. The addition of PA could not only improve fermentation quality but also reduce ARG pollution of alfalfa silage. IMPORTANCE Antibiotic resistance genes (ARGs) are considered environmental pollutants posing a potential human health risk. Silage is an important and traditional feed, mainly for ruminants. ARGs in silages might influence the diversity and distribution of ARGs in animal intestinal and feces and then the manure and the manured soil. However, the diversity and dynamics of ARGs in silage during fermentation are still unknown. We ensiled alfalfa, one of the most widely used forages, with or without pyroligneous acid (PA), which was proved to have the ability to reduce ARGs in soils. The results showed that ARGs in alfalfa silage were abundant and were influenced by the fermentation parameters and microbial community. The majority of ARGs in alfalfa silage reduced during fermentation. The addition of PA could improve silage quality and reduce ARG pollution in alfalfa silage. This study can provide useful information for understanding and controlling ARG pollution in animal production.

Nutritional values of forage-legume-based silages and protein concentrates for growing pigs.

In organic pig production systems, one of the main challenges is to meet the demand for resources rich in protein. Among the resources available, temperate green plants, such as forage legumes, are potential sources of energy and protein. The aim of the study was to determine the nutritional value of silages (S) from the whole plant of lucerne (L) and red clover (R) and protein pastes (PPs) obtained from L and R leaves. In a first trial, 30 pigs were used in a factorial design to determine the total tract digestibility (TTD) of dietary nutrients and energy in five dietary treatments. The control group was fed a control diet (C1). The lucerne silage (LS) and red clover silage (RS) groups were fed a 78%:22% mixture (on a DM basis) of the C1 diet and LS or RS. The lucerne protein paste (LPP) and the red clover protein paste (RPP) groups were fed an 81%:19% mixture (on a DM basis) of the C1 diet and LPP or RPP. In the second trial, five pigs were used in a 5 × 5 Latin square design to evaluate the standardised ileal digestibility (SID) of amino acids (AAs) in the four legume products. The control diet (C2) was formulated with casein as the sole protein source. The LS and RS groups were fed an 85%:15% mixture (on a DM basis) of the C2 diet and LS or RS. The LPP and RPP groups were fed an 80%:20% mixture (on a DM basis) of the C2 diet and LPP or RPP. Regardless of the plant species, silages obtained from L and R leaves contained less AA and more fibre than protein pastes. While the fresh forages contained the same percentage of protein N in total N (63.6%), lucerne lost more protein N during ensiling than red clover (-75.5 vs -33.8%). The calculated TTD coefficient of energy was higher in silages than in protein pastes and lower in R than in L products (72.8, 71.5, 67.7, and 61.3 for LS, RS, LPP and RPP, respectively). The SID of total essential AA was higher in LPP than in RPP (87.2 vs 79.2%) whereas it was lower in LS than in RS (33.2 vs 56.8%). The lower SID values in silages were explained by the protein degradation during the ensiling process and a high proportion of AA linked to the NDF fraction. The results of the present study show that protein pastes obtained from lucerne and red clover are valuable protein sources for pig. In contrast, legume silages have to be considered as an energy source rather than a protein source.

Influence of the ecological environment on the structural characteristics and bioactivities of polysaccharides from alfalfa (Medicago sativa L.).

Polysaccharides from alfalfa (Medicago sativa L.) (APS) exhibit a variety of bioactivities; however, little information is available on the effects of the ecological environment on the structural characteristics and bioactivities of APS. This study aimed to investigate the structural characteristics and bioactivities of two APS types isolated from alfalfa; these APSs were obtained from alfalfa cultured in normal soil (APS1) or saline-alkali soil (APS2). Results indicated that the two kinds of APS had the same monomer compositions in different molar proportions, where APS2 had greater content of arabinose and galacturonic acid than APS1. Furthermore, APS1 exhibited a greater molar mass of 1.77 × 105 g mol-1 as compared to 1.01 × 105 g mol-1 for APS2. Likewise, APS1 and APS2 had highly branched molecules with crosslinking nets composed of similar monomer residues but with different glycosidic linkages. Additionally, both APS significantly inhibited both adipogenesis and lipid accumulation in 3T3-L1 cells by downregulating mRNA expression of Ppar-γ, C/ebp-α, and Fas; APS2 had superior antiadipogenic effects as compared to APS1. Altogether, the ecological environment impacts the structural characteristics and biofunctions of APS, making them potential candidates for antiadipogenic use through functional food. These findings provide a novel perspective for the selection of phytogenic polysaccharides with specific bioactivities by considering growth environmental conditions.

Innovative utilization of herbal residues: Exploring the diversity of mechanisms beneficial to regulate anaerobic fermentation of alfalfa.

In order to increase the utilization of herbal residues, realize efficient utilization of resources, the bacterial community and anaerobic fermentation characteristics of alfalfa ensiling treated with 36 kinds of herbal residues were studied. All the herbal residues improved the anaerobic fermentation quality in different degrees, indicated by lower pH, NH3-N and butyric acid concentrations. However, the contents of lactic and acetic acids varied widely in silage with different herbal residues. Pearson's correlation analysis showed that the improved fermentation quality was closely associated with the variation of lactic acid bacteria community. Consequently, the herbal residues could improve anaerobic fermentation quality by stimulating desirable Lactobacillus species and inhibiting undesirable microbes. This study provides new insights for efficient utilization of herbal residues.

Effect of incremental proportions of Desmanthus spp. in isonitrogenous forage diets on growth performance, rumen fermentation and plasma metabolites of pen-fed growing Brahman, Charbray and Droughtmaster crossbred beef steers.

Desmanthus (Desmanthus spp.), a tropically adapted pasture legume, is highly productive and has the potential to reduce methane emissions in beef cattle. However, liveweight gain response to desmanthus supplementation has been inconclusive in ruminants. This study aimed to evaluate weight gain, rumen fermentation and plasma metabolites of Australian tropical beef cattle in response to supplementation with incremental levels of desmanthus forage legume in isonitrogenous diets. Forty-eight Brahman, Charbray and Droughtmaster crossbred beef steers were pen-housed and fed a basal diet of Rhodes grass (Chloris gayana) hay supplemented with 0, 15, 30 or 45% freshly chopped desmanthus forage on dry matter basis, for 140 days. Varying levels of lucerne (Medicago sativa) hay were added in the 0, 15 and 30% diets to ensure that all diets were isonitrogenous with the 45% desmanthus diet. Data were analyzed using the Mixed Model procedures of SAS software. Results showed that the proportion of desmanthus in the diet had no significant effect on steer liveweight, rumen volatile fatty acids molar proportions and plasma metabolites (P ≥ 0.067). Total bilirubin ranged between 3.0 and 3.6 µmol/L for all the diet treatments (P = 0.67). All plasma metabolites measured were within the expected normal range reported for beef cattle. Rumen ammonia nitrogen content was above the 10 mg/dl threshold required to maintain effective rumen microbial activity and maximize voluntary feed intake in cattle fed low-quality tropical forages. The average daily weight gains averaged 0.5 to 0.6 kg/day (P = 0.13) and were within the range required to meet the target slaughter weight for prime beef markets within 2.5 years of age. These results indicate that desmanthus alone or mixed with other high-quality legume forages can be used to supplement grass-based diets to improve tropical beef cattle production in northern Australia with no adverse effect on cattle health.

Two novel screened microbial consortia and their application in combination with Lactobacillus plantarum for improving fermentation quality of high-moisture alfalfa.

AIMS: To enrich lignocellulolytic microbial consortia and evaluate whether a combination of these consortia and Lactobacillus plantarum can facilitate degradation of structural carbohydrates and improve fermentation quality of high-moisture alfalfa silage. METHODS AND RESULTS: Two novel microbial consortia (CL and YL) with high lignocellulolytic potential were enriched, and had higher enzyme activities at slightly acidic conditions (pH 3.5-6.5). Two consortia were inoculated with and without combined L. plantarum (LP) to alfalfa for up to 120 days of ensiling. The two consortia alone or combined with LP significantly (p < 0.05) increased lactic-to-acetic acid ratios and decreased contents of volatile organic acids and NH3 -N as compared to the control. Treatments that combining microbial consortia and LP further resulted in the higher contents of lactic acid (LA), water soluble carbohydrates (WSC) and crude protein, dry matter (DM) recovery, and lower neutral detergent fibre, acid detergent lignin and cellulose contents, with YLP silage showing the lowest pH (4.41) and highest LA content (76.72 g kg-1  DM) and the conversion of WSC into LA (184.03%). CONCLUSIONS: The addition of lignocellulolytic microbial consortia (CL or YL) to alfalfa silages as attractive silage inoculants could improve fermentation quality, and that their combination with L. plantarum appeared more effective on the degradation of structural carbohydrates and conversion of soluble carbohydrates into LA. SIGNIFICANCE AND IMPACT OF THE STUDY: High-moisture alfalfa is difficult to ensile due to its high buffering capacity and low readily fermentable carbohydrate contents. Microbial consortia (CL and YL) can encode a broad selection of multi-functional CAZymes, and their combination with LP could be promising for the degradation of structural carbohydrates simultaneously with improvement fermentation quality, with high performance in LA production.

Effects of malic or citric acid on the fermentation quality, proteolysis and lipolysis of alfalfa silage ensiled at two dry matter contents.

This study evaluated the effects of two organic acids on the fermentation of alfalfa silages at different dry matter (DM) contents. Alfalfa was wilted to DM contents of 30% (moderately low) and 38% (normal) and ensiled without additives (control) or treated with 0.6% fresh matter DL-malic acid (MA) or 0.6% fresh matter citric acid (CA) for 60 days. After ensiling, silages with a normal DM were higher in pH, water-soluble carbohydrates (WSC) and DM loss (p < 0.05) when compared to silages ensiled at a moderately low DM. The higher DM content also limited proteolysis in silages indicated by lower concentrations of ammonia N (NH3 -N). Compared with the control group, MA and CA-treated silages had lower pH, lower concentrations of acetic acid and NH3 -N but higher concentrations of lactic acid. The addition of MA and CA reduced DM losses in silages when compared to the control group except for MA-treated silage at a moderately low DM in which only numerically lower DM loss was observed. Malic acid and CA also resulted in a higher proportion of polyunsaturated fatty acids, especially in silages with a moderately low DM. Including MA and CA could promote silage fermentation, limit proteolysis and lipolysis at the lower and medium-to-high end of DM contents in alfalfa silages.

An Optimized SPME-GC-MS Method for Volatile Metabolite Profiling of Different Alfalfa (Medicago sativa L.) Tissues.

Solid-phase microextraction (SPME) was coupled to gas chromatography mass spectrometry (GC-MS) and a method optimized to quantitatively and qualitatively measure a large array of volatile metabolites in alfalfa glandular trichomes isolated from stems, trichome-free stems, and leaves as part of a non-targeted metabolomics approach. Major SPME extraction parameters optimized included SPME fiber composition, extraction temperature, and extraction time. The optimized SPME method provided the most chemically diverse coverage of alfalfa volatile and semi-volatile metabolites using a DVB/CAR/PDMS fiber, extraction temperature of 60 °C, and an extraction time of 20 min. Alfalfa SPME-GC-MS profiles were processed using automated peak deconvolution and identification (AMDIS) and quantitative data extraction software (MET-IDEA). A total of 87 trichome, 59 stem, and 99 leaf volatile metabolites were detected after background subtraction which removed contaminants present in ambient air and associated with the fibers and NaOH/EDTA buffer solution containing CaCl2. Thirty-seven volatile metabolites were detected in all samples, while 15 volatile metabolites were uniquely detected only in glandular trichomes, 9 only in stems, and 33 specifically in leaves as tissue specific volatile metabolites. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) of glandular trichomes, stems, and leaves showed that the volatile metabolic profiles obtained from the optimized SPME-GC-MS method clearly differentiated the three tissues (glandular trichomes, stems, and leaves), and the biochemical basis for this differentiation is discussed. Although optimized using plant tissues, the method can be applied to other types of samples including fruits and other foods.

Effects of mulberry leaf silage on antioxidant and immunomodulatory activity and rumen bacterial community of lambs.

BACKGROUND: Rumen is a natural fermentation system and the microorganisms inside can effectively utilize plant bioresource and interact with host metabolism. Here, analysis of rumen microbiome, together with animal performance and serum metabolism in a lamb model were performed to identify the potential use of mulberry leaf silage (MS) to replace alfalfa silage (AS) as a new functional feed resource and to mining the novel specific mulberry leaf associated rumen bacteria interact with host metabolism. RESULTS: The lambs fed with MS diet showed improved antioxidant capacity and immune function compared to those fed AS diet. The MS diet significantly altered rumen microbiota α- and ß-diversity and taxonomic composition. Microbial analysis revealed that Bifidobacterium, Lactobacillus and Schwartzia were enhanced, and Ruminococcaceae UCG-010 and Lachnospiraceae_XPB1014_group were down-regulated in the rumen of MS group. A strong association was also found between these rumen microbial taxa and host antioxidant and immunomodulatory capacity. CONCLUSION: These findings indicated that mulberry leaf silage can be a high-quality feed source or bioactive pharmaceutical that is responsible for ruminant's health benefits. The modified rumen microbial community by mulberry leaf silage were associated with the enhanced antioxidant capacity and immunomodulatory of lambs.

Tissue specific changes in elements and organic compounds of alfalfa (Medicago sativa L.) cultivars differing in salt tolerance under salt stress.

Soil salinity is a global concern and often the primary factor contributing to land degradation, limiting crop growth and production. Alfalfa (Medicago sativa L.) is a low input high value forage legume with a wide adaptation. Examining the tissue-specific responses to salt stress will be important to understanding physiological changes of alfalfa. The responses of two alfalfa cultivars (salt tolerant 'Halo', salt intolerant 'Vernal') were studied for 12 weeks in five gradients of salt stress in a sand based hydroponic system in the greenhouse. The accumulation and localization of elements and organic compounds in different tissues of alfalfa under salt stress were evaluated using synchrotron beamlines. The pattern of chlorine accumulation for 'Halo' was: root > stem ~ leaf at 8 dSm-1, and root ~ leaf > stem at 12 dSm-1, potentially preventing toxic ion accumulation in leaf tissues. In contrast, for 'Vernal', it was leaf > stem ~ root at 8 dSm-1 and leaf > root ~ stem at 12 dSm-1. The distribution of chlorine in 'Halo' was relatively uniform in the leaf surface and vascular bundles of the stem. Amide concentration in the leaf and stem tissues was greater for 'Halo' than 'Vernal' at all salt gradients. This study determined that low ion accumulation in the shoot was a common strategy in salt tolerant alfalfa up to 8 dSm-1 of salt stress, which was then replaced by shoot tissue tolerance at 12 dSm-1.

Comparative Studies of Selected Criteria Enabling Optimization of the Extraction of Polar Biologically Active Compounds from Alfalfa with Supercritical Carbon Dioxide.

The aim of this research was to provide crucial and useful data about the selection of the optimization criteria of supercritical carbon dioxide extraction of alfalfa at a quarter-technical plant. The correlation between more general output, including total phenolics and flavonoids content, and a more specified composition of polar constituents was extensively studied. In all alfalfa extracts, polar bioactive constituents were analyzed by both spectrometric (general output) and chromatographic (detailed output) analyses. Eight specific phenolic acids and nine flavonoids were determined. The most dominant were salicylic acid (221.41 µg g-1), ferulic acid (119.73 µg g-1), quercetin (2.23 µg g-1), and apigenin (2.60 µg g-1). For all seventeen analyzed compounds, response surface methodology and analysis of variance were used to provide the optimal conditions of supercritical fluid extraction for each individual constituent. The obtained data have shown that eight of those compounds have a similar range of optimal process parameters, being significantly analogous for optimization based on total flavonoid content.

Cryotropic gel-forming capacity of alfalfa (Medicago sativa L.) and fenugreek (Trigonella foenum graecum) seed galactomannans.

Cryotropic gelation is one of the most common approaches to design novel hydrogels with multifaceted technological and biological functionalities. In the present paper, we studied the ability of highly galactosyl-substituted galactomannans, i.e. fenugreek and alfalfa gum, to form physically crosslinked hydrogels via cryogenic processing. Cycling of the galactomannan solutions (0.25 to 4% wt) from 25 to -20 to 25 °C induced the physical crosslinking of the galactomannan chains leading to the formation of different cryogel structures, i.e. filamentous aggregates (c* < c < 1%), cellular-like gel networks (1 ≤ c < 4%) or a homogeneously swollen gel (c ≥ 4%), depending on the total biopolymer content. Alfalfa gum-based cryogels exhibited higher elasticity and stiffness, better uniformity of the structure and a lower macropore size than their fenugreek counterparts. The physical blending of alfalfa or fenugreek gum with locust bean gum (2% total biopolymer) led to the reinforcement of the mechanical properties of the cryogels without significantly altering their microstructural aspects.

Photosynthesis, fluorescence, and nutrition of Zhonglan No. 2, a new alfalfa cultivar.

BACKGROUND: The years after planting play an important role in the above-ground biomass and nutritive value of alfalfa. Zhonglan No. 2 (Medicago sativa L. cv. Zhonglan No. 2) is a new breeding alfalfa cultivar characterized by high drought tolerance and high yield. To determine the optimum time for utilization of Zhonglan No. 2, we examined growth traits, chlorophyll content, photosynthetic and fluorescence parameters, and composition and nutritive values at the late vegetative and early flowering stages of the first stubble in the second, third, fourth, sixth, and eleventh years after planting. RESULTS: In general, the height and leaf area decreased with increasing number of years after planting. At the late vegetative stage, the fourth-year alfalfa exhibited higher stomatal conductance (Gs) and intercellular CO2 concentration (Ci), and better water use efficiency, and at the early flowering stage, the fourth-year alfalfa had the highest (P < 0.05) leaf net photosynthetic rate (Pn) and carboxylation efficiency (CE). Total digestible nutrients did not differ among years, but, in the early flowering stage, crude protein content decreased with years (P < 0.05). Malondialdehyde (MDA) content and total antioxidant capacity did not differ among years after planting, suggesting aging did not impose oxidative stress on this alfalfa cultivar. CONCLUSIONS: Based on height, chlorophyll content, crude protein (CP) content, and photosynthetic and fluorescence parameters, the fourth year after planting, at the early flowering stage, was the best for using Zhonglan No. 2. © 2021 Society of Chemical Industry.