Effects of molasses on the fermentation characteristics of mixed silage prepared with rice straw, local vegetable by-products and alfalfa in Southeast China

This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.Mixture（202 g kg^-1 dry matter（DM））consisting of rice straw,broccoli residue and alfalfa at the ratio of 5：4：1 was ensiled with three experimental treatments：（1）no additives（control）;（2）molasses at 2.5%（M1）;（3）molasses at 5%（M2）on a fresh matter basis of mixture,respectively.All treatments were packed into laboratory-scale silos,and three silos per treatment were sampled on days 1,3,5,14 and 30.The result showed that the p H value of all mixed silages decreased gradually with the time of ensiling except for the control silage,in which a significant increase（P〈0.05）on day 30 occurred.The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14,and a marked decrease（P〈0.05）was found in the control silage on day 30.The changes of acetic acid content showed similar pattern with lactic acid content.A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period.Comparing to the control,M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher（P〈0.05）lactic acid contents and lower（P〈0.05）p H and ammonia-N contents.The Flieg points also showed that M1 and M2 silages were well preserved,whereas the control silage had a bad quality.Overall,the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage,and M1 was more suitable for practical application.

Fermentation characteristics and probiotic activity of a purified fraction of polysaccharides from Fuzhuan brick tea

Polysaccharides from Fuzhuan brick tea(FBTPS),one of most important bioactive components in tea,showed various health-promoting functions.Our previous work demonstrated that the crude FBTPS(CFBTPS)could modulate the gut microbiota.However,which purified fraction in CFBTPS contributing to the modulation of gut microbiota remains unclear.Thus,the fermentation characteristics and probiotic activity of a purified fraction(FBTPS-2-1)of CFBTPS were evaluated in this work.The results showed that gut microbiota could utilize FBTPS-2-1 to produce short-chain fatty acids including acetic,propionic,n-butyric and n-valeric acids.FBTPS-2-1 could modulate the structure and metabolic pathways of gut microbiota.FBTPS-2-1 could increase the health-promoting gut microbiota such as Prevotellaceae and Bifidobacteriaceae,and decreased the harmful bacteria such as Enterobacteriaceae and Fusobacteriaceae.The results of metagenomics showed that Prevotella copri and Megamonas funiformis were the dominant bacteria after fermentation of FBTPS-2-1.Furthermore,FBTPS-2-1 could regulate the biosynthesis and metabolism pathways of gut microbiota.Thus,the enrichment of food with FBTPS-2-1 is expected as a potential strategy for promoting human health due to modulation of gut microbiota.

Effect of fermented Rosa roxburghii Tratt fruit juice on gut microbiota in a dextran sulfate sodium-induced colitis mouse model

This study mainly investigated the regulatory effect of Rosa roxburghii Tratt fruit juice fermented by Lacticaseibacillus paracasei SR10-1(LAB-RRTJ)on modulating gut microbiota in dextran sulfate sodium(DSS)-induced ulcerative colitis in mice.Compared to control group,DSS induction decreased body weight of mice,indexes of Shannon,Simpson,Chao1 and Faith_pd,and increased disease activity index(DAI)and levels of interleukin 1β(IL-1β),IL-6,tumor necrosis factorα(TNF-α)and interferon-γ(IFN-γ);And this induction also led to an increase in Proteobacteria,Verrucomicrobia and Actinobacteria at phylum level,harmful bacterial species richness at genus level,and relative richness of S.sciuri,Desulfovibrio C21_c20,R.gnavus and Akkermansia muciniphila at species level,and a decrease in Firmicutes at phylum level and relative richness of B.acidifaciens in mice.LAB-RRTJ increased body weight of mice with DSS induced ulcerative colitis(UC)and indexes of Shannon,Simpson,Chao1 and Faith_pd,reduced DAI and the content of four infl ammatory factors and improved gut microbiota imbalance in DSS induced UC mice.Besides,the number of operational taxonomic units(OTUs)increased,α-diversity andβ-diversity were restored and similar to those in mice in the control group after LAB-RRTJ treatment.Compared with the positive drug treatment group,LAB-RRTJ has a better effect on regulating gut microbiota diversity in colitis mice.Correlation analysis showed that infl ammatory factors were positively correlated with harmful bacteria and negatively correlated with beneficial bacteria which commonly found in some colitis mice.Taken together,our study demonstrated that LAB-RRTJ could alleviate DSS-induced colitis in mice through the modulation of infl ammatory cytokines and gut microbiota composition.

Effect of commercial slow-release urea product on in vitro rumen fermentation and ruminal microbial community using RUSITEC technique

Background:The objectives of this study were to determine the effect of commercial slow-release urea(SRU)on in vitro fermentation characteristics,nutrient digestibility,gas production,microbial protein synthesis and bacterial community using a rumen simulation technique(RUSITEC).The experiment was a completely randomized design with four treatments and four replications of each treatment.Treatments were:control diet(no SRU addition),control diet plus 0.28%SRU(U28),or plus 0.56%SRU(U56),and control diet that was modified substituting a part of soybean meal equivalent to 0.35%SRU(MU35;dry matter[DM]basis).The experiment consisted of 8 d of adaptation and 7 d of data and sample collection.Rumen inoculum was obtained from three ruminally fistulated Angus cows fed the same diet to the substrate incubated.Results:Digestibility of DM,organic matter(OM),crude protein(CP),fibre and starch was not affected,but daily production of gas(P<0.07)and methane(P<0.05)was quadratically increased with increasing SRU supplementation.The increase of SRU addition did not affect fermentation pH and total volatile fatty acid(VFA)production,whereas linearly(P<0.01)decreased proportion of propionate,and linearly(P<0.01)increased acetate to propionate ratio and ammonia nitrogen(N)concentration.The microbial N efficiency was also linearly(P<0.03)improved with increasing supplementation of SRU.In comparison with control diet,the dietary substitution of SRU for part of soybean meal increased(P<0.05)the digestibility of DM,OM and CP and decreased(P<0.02)the total gas production.The total VFA production and acetate to propionate ratio did not differ between control and MU35,whereas the proportion of butyrate was lower(P<0.05)and that of branched-chain VFA was greater(P<0.05)with MU35 than control diet.Total and liquid-associated microbial N production as well as ammonia N concentration were greater(P<0.03)with MU35 than control diet.Observed operational taxonomic units(OTUs),Shannon diversity index,and beta diversity of the microbial community did not differ among treatments.Taxonomic analysis revealed no effect of adding SRU on the relative abundance of bacteria at the phylum level,while at the genus level,the beneficial impact of SRU on relative abundance of Rikenellaceae and Prevotellaceae in feed particleassociated bacteria,and the abundance of Roseburia in liquid associate bacteria was greater(P<0.05)with MU35.Conclusions:Supplementation of a dairy cow diet with SRU showed potential of increase in ammonia N concentration and microbial protein production,and change fermentation pattern to more acetate production.Adding SRU in dairy cow diet also showed beneficial effect on improving digestibility of OM and fibre.The results suggest that SRU can partially substitute soybean meal in dairy cow diet to increase microbial protein production without impairing rumen fermentation.

Composition analysis of acid hydrolysates from Cucurbita moschata Duch.polysaccharides and their effect on oxidative stress resistance of Caenorhabditis elegans

Pumpkin polysaccharides(PPe)have a variety of bioactive effects and our previous research showed the acid hydrolysate(PPe-S,a mixture)from PPe had an antioxidative capacity both in vitro and in viro.The aim of this study was to purify PPe-S and investigate the antioxidant stress effects of 2 purified components(PPe-S-1 and PPe-S-2)using Caenorhabditis elegans as model organism.The results showed that PPe-S-2 had a notable antioxidant effect,and could significantly enhance the activities of antioxidant enzymes including superoxide dismutase(SOD)(P<0.01),catalase(CAT)(P<0.01)and glutathione reductase(GR)(P<0.05),and increase the level of glutathione(GSH)(P<0.01),and decreased the content of malondialdehyde(MDA)(P<0.05).PPe-S-2 could significantly extend the survival time of C.elegans(P<0.01),which were stress-induced by hydrogen peroxide and methyl viologen.PPe-S-2 was a heteropolys accharide composed of glucose,arabinose,rhamnose and galactose with the molar ratio of 1.00:0.03:0.02:0.14.The molecular weight of PPe-S-2 was 0.73 kDa detected by high performance liquid chromatography.These studies demonstrated that PPe-S-2 obtained by the acid hydrolysis of PPe had a prominent protective effect to the damage induced by the intracellular free radical generating agents.

Effects of Chinese herbal medicine on plasma glucose,protein and energy metabolism in sheep

Background： The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in the past two decades and played an increasingly important role in livestock production. The present study was carried out to assess the feeding effects of a traditional nourishing Chinese herbal medicine mixture on kinetics of plasma glucose, protein and energy metabolism in sheep. Ruminal fermentation characteristics were also determined. Methods： Four sheep were fed on either mixed hay （MH-diet） or MH-diet supplemented with 2% of Chinese herbal medicine （mixture of Astragalus root, Angelica root and Atractylodes rhizome; CHM-diet） over two 3S-day periods using a crossover design. The turnover rate of plasma glucose was measured with an isotope dilution method using [U-^13C]glucose. The rates of plasma leucine turnover and leucine oxidation, whole body protein synthesis （WBPS） and metabolic heat production were measured using the [1-^13C]leucine dilution and open circuit calorimetry. Results： Body weight gain of sheep was higher （P = 0.03） for CHM-diet than for MH-diet. Rumen pH was lower （P = 0.02）, concentration of rumen total volatile fatty acid tended to be higher （P = 0.05） and acetate was higher （P = 0.04） for CHM-diet than for MH-diet. Turnover rates of plasma glucose and leucine did not differ between diets. Oxidation rate of leucine tended to be higher （P = 0.06） for CHM-diet than for MH-diet, but the WBPS did not differ between diets. Metabolic heat production tended to be greater （P = 0.05） for CHM-diet than for MH-diet. Conclusions： The sheep fed on CHM-diet had a higher body weight gain and showed positive impacts on rumen fermentation and energy metabolism without resulting in any adverse response. Therefore, these results suggested that the Chinese herbal medicine mixture should be considered as a potential feed additive for sheep.

An increase in corn resistant starch decreases protein fermentation and modulates gut microbiota during in vitro cultivation of pig large intestinal inocula

High-protein diet could cause an increase in protein fermentation in the large intestine, leading to an increased production of potentially detrimental metabolites. We hypothesized that an increase in corn resistant starch content may attenuate the protein fermentation. The aim of this study was to evaluate the effect of resistant starch on protein fermentation by inocula from large intestine of pigs using in vitro cultivation. Fermentation patterns were analyzed during a 24-h incubation of cecal and colonic digesta with varying corn resistant starch contents, using casein protein as sole nitrogen source. The results showed that the concentration of short-chain fatty acids(SCFA) and cumulative gas production were significantly increased(P < 0.05), while ammonia-nitrogen(NH_3-N) and branched-chain fatty acids(BCFA), which indicated protein fermentation, decreased when the corn resistant starch levels increased(P < 0.05). The copies of total bacteria, Bifidobacterium and Lactobacillus were significantly increased with the increased corn resistant starch levels after incubation(P < 0.05). The copies of the Bifidobacterium and Lactobacillus in cecum were significantly higher than those in colon(P < 0.05). We conclude that the addition of corn resistant starch weakens the protein fermentation by influencing microbial population and reducing protein fermentation in the cecum and colon in vitro.