Concentrations Of Individual Fatty Acids Research Articles

Quantitative evaluation of ruminal methane and carbon dioxide formation from formate through C-13 stable isotope analysis in a batch culture system

Methane produced from formate is one of the important methanogensis pathways in the rumen. However, quantitative information of CH4 production from formate has been rarely reported. The aim of this study was to characterize the conversion rate (CR) of formic acid into CH4 and CO2 by rumen microorganisms. Ground lucerne hay was incubated with buffered ruminal fluid for 6, 12, 24 and 48 h. Before the incubation, 13C-labeled H13COOH was also supplied into the incubation bottle at a dose of 0, 1.5, 2.2 or 2.9 mg/g of DM substrate. There were no interactions (P>0.05) between dose and incubation time for all variables evaluated. When expressed as an absolute amount (ml in gas sample) or a relative CR (%), both 13CH4 and 13CO2 production quadratically increased (P<0.01) with the addition of H13COOH. The total 13C (13CH4 and 13CO2) CR was also quadratically increased (P<0.01) when H13COOH was added. Moreover, formate addition linearly decreased (P<0.031) the concentrations of NH3-N, total and individual volatile fatty acids (acetate, propionate and butyrate), and quadratically decreased (P<0.014) the populations of protozoa, total methanogens, Methanosphaera stadtmanae, Methanobrevibacter ruminantium M1, Methanobrevibacter smithii and Methanosarcina barkeri. In summary, formate affects ruminal fermentation and methanogenesis, as well as the rumen microbiome, in particular microorganisms which are directly or indirectly involved in ruminal methanogenesis. This study provides quantitative verification for the rapid dissimilation of formate into CH4 and CO2 by rumen microorganisms.

Dietary fish oil supplementation during early pregnancy in rats on a cafeteria-diet prevents fatty liver in adult male offspring

We studied in rats the effects of cafeteria diet (CD) supplemented (or not) with fish oil (FO) during just the first 12 days of pregnancy, or during the whole of pregnancy and lactation in 14-month old offspring. Female rats were given standard diet (STD) or CD and after mating some animals remained on STD or CD; for some CD rats the diet was supplemented with 8.78% FO. After 12 days, half of the CD-FO group returned to CD (CD-FO12) and the others remained on CD-FO. From weaning all offspring were given STD. The adiposity index of male offspring of CD dams increased but was normal in CD-FO males. Plasma triacylglycerols (TAG) and individual fatty acid concentrations were similar among the groups. Liver total lipids, TAG, fatty acid concentrations, Δ9-desaturase indices and the mRNA expression of fatty acid synthase were higher in male offspring of CD than in those of STD; most of these differences disappeared in male offspring of CD-FO12 and CD-FO dams. Female offspring showed smaller changes. Thus, a moderate supplement with FO during just the first half of gestation or during pregnancy and lactation in rats on CD decreases the liver steatosis in male adult offspring.

Embryogenic callus induction and fatty acid composition analysis of oil palm (Elaeis guineensis cv. Tenera)

Embryogenic callus (EC) induction and plantlet regeneration of oil palm (Elaeis guineensis) are essential platforms for the propagation of uniform hybrid cultivars in large-scale cultivation. In this paper, an embryogenic callus was successfully induced from leaf tissue from the ‘Tenera’ varieties of oil palm and regenerated into plantlets via secondary embryogenesis. The total lipid and separated triacylglycerol (TAG) contents of the EC were determined using GC–MS. The results showed that the EC had a total lipid content of approximately 9.46%, while TAG accounted for 32% of the total lipid content. Considering that the TAG content was more than 95% of the total fatty acids (FAs) in the mesocarp of ripe oil palm fruit, the FA profile of the TAG content in the EC was compared with the total lipid content in the mesocarp of oil palm. The results indicated that the FA profile of the TAG content in the EC was similar to that in the mesocarp, even though there were still significant differences in the content of individual FAs. The similar FA composition in the EC and mesocarp of oil palm will be a valuable marker for predicting FA profiles in the mesocarp of the mature transgenic oil palm fruit obtained from transformation and embryogenesis.

Effect of Individual Components of Lignocellulosic Biomass on Methane Production and Methanogen Community Structure

One of the major factors that influences the economic feasibility of biogas production is the availability of digestible feedstocks. There is little research on the influence of the chemical composition of biomass on biogas synthesis, especially with regard to the content of lignocellulosic materials. Therefore, the aim of this study was to estimate how differences in the content of cellulose and lignin in lignocellulosic biomass influence the concentrations of individual volatile fatty acids (VFAs) and biogas production. Additionally, the structure of the methanogenic community was examined. The removal of fibrous and non-fibrous materials, the concentrations of individual VFAs, methane production and methanogen community structure were examined during digestion of Zea mays L. and Miscanthus sacchariflorus silages. Organics were removed with higher efficiency during the digestion of Z. mays silage than during digestion of M. sacchariflorus. This was due to the higher non-fibrous carbohydrates content in Z. mays than in M. sacchariflorus. In both digesters, propionate predominated throughout experiment. The methanogenic community in the digester fed with Z. mays was more diverse than that in the digester with M. sacchariflorus. Analysis of 16S rRNA sequences showed that six acetoclastic and four hydrogenotrophic methanogens were present in the digester fed with Z. mays L., while five acetoclastic and three hydrogenotrophic methanogens were in the digester fed with M. sacchariflorus. The abundance of Methanosarcina correlated significantly with the concentration of all analyzed VFAs.

Intermittent feeding of citrus essential oils as a potential strategy to decrease methane production by reducing microbial adaptation

The objective of the present study was to assess the effects of citrus essential oils (CEO) on growth and rumen fermentation of Hu sheep as well as to evaluate the effects of intermittent feeding of CEO to decrease methane production by reducing microbial adaptation in an in vitro batch culture system. Growth and rumen fermentation without CEO supplementation (W0_NE) and with supplementation with 0.8 mL CEO/L rumen volume from week 1 to week 3 (W1_EO, W2_EO, and W3_EO), as well as 2 additional weeks without CEO (W5_NE), were examined in 5 rumen-fistulated Hu sheep. Rumen fermentation and gas production of three substrates, corn meal (CM), Chinese wild rye hay (WH), and mixed feed (MF) of WH + concentrate (2:1, dry matter basis), and three doses of CEO (0, 0.8 and 1.6 mL/L) were tested in rumen fluid collected from W0_NE, W1_EO, W3_EO, and W5_NE in vitro. The results showed the CEO had no significant effects (P > 0.05) on body weight, average daily gain, dry matter intake and total-tract apparent digestibility. The CEO altered nitrogen metabolism and was characterized by reductions (P < 0.01) of the concentrations of blood urea nitrogen and rumen ammonia nitrogen. CEO decreased the concentrations of total and individual volatile fatty acids as well as the acetate to propionate ratio in vivo (P < 0.01). Anti-methanogenic effects of CEO were observed in W1_EO (P < 0.05) without additional CEO supplementation, but they were only observed in W3_EO and W5_NE with additional CEO supplementation. These results suggest that CEO introduce selective pressure on rumen microbes and induce methanogenesis adaptation in microbial communities. Intermittent feeding of CEO might be a potential strategy to decrease methane production by reducing the ability of microbes to adapt.

Genetic effects of fatty acid composition in muscle of Atlantic salmon

BackgroundThe replacement of fish oil (FO) and fishmeal with plant ingredients in the diet of farmed Atlantic salmon has resulted in reduced levels of the health-promoting long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA) eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) in their filets. Previous studies showed the potential of selective breeding to increase n-3 LC-PUFA levels in salmon tissues, but knowledge on the genetic parameters for individual muscle fatty acids (FA) and their relationships with other traits is still lacking. Thus, we estimated genetic parameters for muscle content of individual FA, and their relationships with lipid deposition traits, muscle pigmentation, sea lice and pancreas disease in slaughter-sized Atlantic salmon. Our aim was to evaluate the selection potential for increased n-3 LC-PUFA content and provide insight into FA metabolism in Atlantic salmon muscle.ResultsAmong the n-3 PUFA, proportional contents of alpha-linolenic acid (ALA; 18:3n-3) and DHA had the highest heritability (0.26) and EPA the lowest (0.09). Genetic correlations of EPA and DHA proportions with muscle fat differed considerably, 0.60 and 0.01, respectively. The genetic correlation of DHA proportion with visceral fat was positive and high (0.61), whereas that of EPA proportion with lice density was negative. FA that are in close proximity along the bioconversion pathway showed positive correlations with each other, whereas the start (ALA) and end-point (DHA) of the pathway were negatively correlated (− 0.28), indicating active bioconversion of ALA to DHA in the muscle of fish fed high FO-diet.ConclusionsSince contents of individual FA in salmon muscle show additive genetic variation, changing FA composition by selective breeding is possible. Taken together, our results show that the heritabilities of individual n-3 LC-PUFA and their genetic correlations with other traits vary, which indicates that they play different roles in muscle lipid metabolism, and that proportional muscle contents of EPA and DHA are linked to body fat deposition. Thus, different selection strategies can be applied in order to increase the content of healthy omega-3 FAin the salmon muscle. We recommend selection for the proportion of EPA + DHA in the muscle because they are both essential FA and because such selection has no clear detrimental effects on other traits.

Accuracy and application of milk fatty acid estimation with diffuse reflectance near-infrared spectroscopy.

Near infrared spectroscopy (NIRS) has the potential to estimate contents of fatty acids (FA) in milk frequently at-farm or during daily milking routine. In this study, a total of 738 raw milk spectra collected from 33 Holstein cows over a period of 30 weeks were recorded. Reference data on FA composition in milk and in milk fat were analysed in laboratory. Calibration models were calculated for single FA and groups of FA in milk and in milk fat. Validation resulted in sufficient Ratio of Prediction to Deviation (RPD) values for some single FA and in higher RPD values for groups of FA when concentrations of FA in milk were predicted. Since the concentrations of most FA in milk are highly correlated with milk fat content, the prediction of FA contents in milk fat is more meaningful when independent predictions are intended. The accuracy of predicting single FA concentrations in milk fat is rather poor for most FA but still comparable to alternative analysing methods such as MIR analysis. The estimation of different groups of FA in milk fat resulted in an improved accuracy based on higher RPD values, which was sufficient to mirror the development in the different lactation phases. The course of cow individual long chain fatty acid (LCFA) concentration in the early lactation stage can be an indicator for body fat mobilisation. The accurate estimation of the extent and duration of body fat mobilisation in cow individuals was rather difficult with NIR predicted LCFA concentrations and would require a higher measuring frequency than applied in this study.

Dose-dependent effect of statins on the change in the content of individual fatty acids of blood serum and their complexes of men and women with secondary prevention of chronic coronary heart disease

Objective. To study the dose-dependent effect of simvastatin on the change of content of individual fatty acids (FA) profile of blood serum and their complexes with secondary prevention of chronic coronary heart disease (CHD) in groups of men and women. Materials and methods. Gas-liquid chromatography-mass spectrometry was used to establish the absolute and relative levels of FA in serum of 155 CHD patients before and after treatment by simvastatin in doses of 40 mg (89 people) and 80 mg (36 people). Results. The statin lowered the content of the FA proportionally by reducing the unsaturated (UFA), mainly polyunsaturated (PUFA) FA, and saturated (SFA) FA. The level of monounsaturated fatty acids (MUFA) decreased in women at a dose of 40 mg. The statin increased endogenous formation of ω6 PUFA, ω9 MUFA, and SFA even (except 80 mg), in group of women (40 mg) – ω3 PUFA, and in men (80 mg) – ω7 MUFA. In women after receiving simvastatin 80 mg, the ratio ω3/ω6 PUFA has been shifted to ω6 PUFA, but in men after receiving simvastatin 40 mg in the direction of ω3 PUFA. Only the dose of 80 mg shifted the ratio of C20:5/C20:4 in the direction of ω3 PUFA. In group of women after receiving simvastatin 40 mg was observed a shift to β-oxidation of C18:1(9), and in men at the dose of 80 mg in the direction of its synthesis. In all cases, increased antioxidant protection of PUFA, but less strong it was at the dose of 40 mg. At the same time the formation of MUFA prevailed over the synthesis of SFA. Absolute content of FA - substrates of energy decreased. In all cases, was noticed the decrease of content of FA this very long chain (C22-26), stronger in women. Conclusion. Simvastatin controlling the quantitative composition of the pool of circulating lipoproteins, FA and cholesterol, is ambiguous, depending on dose, affect the metabolism of fatty acids, changing their quantitative and qualitative composition and performing biological functions.

Kinetic parameters of volatile fatty acids uptake in the ADM1 as key factors for modeling co-digestion of silages with pig manure, thin stillage and glycerine phase

Abstract The present study extended the Anaerobic Digestion Model No. 1 (ADM1) to simulate co-digestion of silages with pig manure and thin stillage, pig manure and glycerine phase, or thin stillage and glycerine phase under mesophilic conditions. New state variables were added, including glycerol, lactate, valerate and iso-valerate. Furthermore, the model was extended to include both the rapidly and slowly degradable fractions of carbohydrates and proteins. It was found that the model is more sensitive to changes in the constant for slowly degraded carbohydrates than to changes in the constant for rapidly degraded carbohydrates. After parameter calibration with the mixture of silages with pig manure and thin stillage, the ADM1 showed good agreement with measurements of daily biogas and methane production, and of concentrations of individual volatile fatty acids (VFAs) in the effluent. Although, initially, the prediction of biogas production with the silages mixture with thin stillage and glycerine phase was not satisfactory because the calibrated KI_h2_pro value (2.86E-08 kg COD/m3) was too low, adjusting this constant to a value of 9.70E-08 kg COD/m3 enabled this to be predicted with high accuracy.

Implications of Lipids in Neonatal Body Weight and Fat Mass in Gestational Diabetic Mothers and Non-Diabetic Controls.

Maternal lipid metabolism greatly changes during pregnancy and we review in this article how they influence fetal adiposity and growth under non-diabetic and gestational diabetic conditions. In pregnant women without diabetes (control), maternal glycemia correlates with neonatal glycemia, neonatal body weight and fat mass. In pregnant women with gestational diabetes mellitus (GDM), maternal glucose correlates with neither neonatal glycemia, neonatal birth weight nor fat mass, but maternal triacylglycerols (TAG), non-esterified fatty acids (NEFA) and glycerol do correlate with birth weight and neonatal adiposity. The proportions of maternal plasma arachidonic (AA) and docosahexaenoic (DHA) acids decrease from the first to the third trimester of pregnancy, and at term these long-chain polyunsaturated fatty acids are higher in cord blood plasma than in mothers, indicating efficient placental transfer. In control or pregnant women with GDM at term, the maternal concentration of individual fatty acids does not correlate with neonatal body weight or fat mass, but cord blood fatty acid levels correlate with birth weight and neonatal adiposity-positively in controls, but negatively in GDM. The proportion of AA and DHA in umbilical artery plasma in GDM is lower than in controls but not in umbilical vein plasma. Therefore, an increased utilization of those two fatty acids by fetal tissues, rather than impaired placental transfer, is responsible for their smaller proportion in plasma of GDM newborns. In control pregnant women, maternal glycemia controls neonatal body weight and fat mass, whereas in mothers with GDM-even with good glycemic control-maternal lipids and their greater utilization by the fetus play a critical role in neonatal body weight and fat mass. We propose that altered lipid metabolism rather than hyperglycemia constitutes a risk for macrosomia in GDM.

Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida).

High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna living in these environments, benthic foraminifera are often the most tolerant to low oxygen levels. Indeed, some species are able to survive complete anoxia for weeks to months. One known mechanism for this, observed in several species, is denitrification. For other species, a state of highly reduced metabolism, essentially a state of dormancy, has been proposed but never demonstrated. Here, we combined a 4 weeks feeding experiment, using 13C-enriched diatom biofilm, with correlated TEM and NanoSIMS imaging, plus bulk analysis of concentration and stable carbon isotopic composition of total organic matter and individual fatty acids, to study metabolic differences in the intertidal species Ammonia tepida exposed to oxic and anoxic conditions. Strongly contrasting cellular-level dynamics of ingestion and transfer of the ingested biofilm components were observed between the two conditions. Under oxic conditions, within a few days, intact diatoms were ingested, degraded, and their components assimilated, in part for biosynthesis of different cellular components: 13C-labeled lipid droplets formed after a few days and were subsequently lost (partially) through respiration. In contrast, in anoxia, fewer diatoms were initially ingested and these were not assimilated or metabolized further, but remained visible within the foraminiferal cytoplasm even after 4 weeks. Under oxic conditions, compound specific 13C analyses showed substantial de novo synthesis by the foraminifera of specific polyunsaturated fatty acids (PUFAs), such as 20:4(n-6). Very limited PUFA synthesis was observed under anoxia. Together, our results show that anoxia induced a greatly reduced rate of heterotrophic metabolism in Ammonia tepida on a time scale of less than 24 hours, these observations are consistent with a state of dormancy.

Lactational Stage of Pasteurized Human Donor Milk Contributes to Nutrient Limitations for Infants.

Background. Mother’s own milk is the first choice for feeding preterm infants, but when not available, pasteurized human donor milk (PDM) is often used. Infants fed PDM have difficulties maintaining appropriate growth velocities. To assess the most basic elements of nutrition, we tested the hypotheses that fatty acid and amino acid composition of PDM is highly variable and standard pooling practices attenuate variability; however, total nutrients may be limiting without supplementation due to late lactational stage of the milk. Methods. A prospective cross-sectional sampling of milk was obtained from five donor milk banks located in Ohio, Michigan, Colorado, Texas-Ft Worth, and California. Milk samples were collected after Institutional Review Board (#07-0035) approval and informed consent. Fatty acid and amino acid contents were measured in milk from individual donors and donor pools (pooled per Human Milk Banking Association of North America guidelines). Statistical comparisons were performed using Kruskal–Wallis, Spearman’s, or Multivariate Regression analyses with center as the fixed factor and lactational stage as co-variate. Results. Ten of the fourteen fatty acids and seventeen of the nineteen amino acids analyzed differed across Banks in the individual milk samples. Pooling minimized these differences in amino acid and fatty acid contents. Concentrations of lysine and docosahexaenoic acid (DHA) were not different across Banks, but concentrations were low compared to recommended levels. Conclusions. Individual donor milk fatty acid and amino acid contents are highly variable. Standardized pooling practice reduces this variability. Lysine and DHA concentrations were consistently low across geographic regions in North America due to lactational stage of the milk, and thus not adequately addressed by pooling. Targeted supplementation is needed to optimize PDM, especially for the preterm or volume restricted infant.

Performance of lactating Friesian cows fed a diet supplemented with coriander oil: Feed intake, nutrient digestibility, ruminal fermentation, blood chemistry, and milk production

Thirty multiparous lactating Friesian cows (523±8.9kg BW) were used to study the effect of feeding coriander oil, a natural feed additive, versus salinomycin; an ionophore. Early lactation Friesian cows were used for 63days in a completely randomized experimental design with repeated measures. Cows were randomly assigned to three treatments and fed a basal diet of concentrates, berseem clover (Trifolium alexandrinum) and rice straw in a ratio of 40:40:20 DM basis. The treatments were: (1) the basal diet with no additive (Control treatment); (2) the basal diet supplemented with 4g/cow daily of salinomycin (Salinomycin treatment); and (3) the basal diet supplemented with 14mL coriander oil/cow daily (Coriander treatment). Cows in the salinomycin and coriander groups had greater feed intake (P<0.001) and nutrient digestibility (P<0.01) than control cows. Ruminal ammonia-N concentration was lowered (P<0.001) with coriander versus the other two treatments. Concentrations of total and individual short-chain fatty acids were not affected (P>0.05) by the salinomycin and coriander treatments. Greater serum glucose concentration (P=0.013), without affecting other blood measurements, was noted with coriander and salinomycin treatments. Similarly, coriander and salinomycin resulted in greater (P<0.05) daily outputs of milk, energy corrected milk, fat, and milk energy, and both salinomycin and coriander improved milk efficiency (P<0.05) compared with control. It is concluded that coriander oil at 14mL/cow daily can replace ionophore salinomycin in the diet of early lactating Friesian cows. Enhanced feed utilization and lactational performance were observed with coriander oil supplementation without any negative effect on animal health.

Effect of fat and salt reduction on the changes in the concentrations of free amino acids and free fatty acids in Cheddar-style cheeses during maturation

The study investigated the effects of reducing fat content from 33 (full-fat, FF) to 22 (reduced-fat, RF) or 16 (half-fat, HF) % on the concentrations of total and individual free amino acids (FAA) and free fatty acids (FFA) in Cheddar-style cheeses with 1.9 (full-salt, FS), 1.2 (reduced-salt, RS) or 0.9 (half-salt, HS) % NaCl over a 270d maturation period at 8°C. Both FAA and FFA increased continuously during ripening, from ∼1200 and 230mg/kg at 30d to 5500 and 1593mg/kg, respectively, in FFFS at 270d. Reducing fat content resulted in higher concentrations of FAA (e.g., from 5500mg/kg in FFFS to 6400mg/kg in HFFS at 270d) and lower levels of FFA (e.g., from 1593mg/kg in FFFS to 1140mg/kg in the HFFS cheese at 270d). Reducing salt content from 1.9 to 1.2 or 0.9 % resulted in a significant decrease in FAA in the FF cheese, from 5500mg/kg in FFFS to 4000mg/kg in FFHS at 270d. Salt content did not significantly affect the concentration of FAA in RF or HF cheeses, or the concentration of total or individual FFA in the FF, RF or HF cheeses.

The perspective fluoroplastic porous carrier for conservation and transfer of samples of blood plasma: application of "dry drop" technique with the purpose of detection of individual fatty acids.

It is proposed for preserving samples of biological fluids (blood plasma first of all) and mailing them to analytical laboratory to significantly modify a well-known technique of "dried blood spot" (DBS) at the expense of application of home-made fluoroplastic filtering material type MFFK-G as a porous carrier of fluid biological sample. The synthetic material contains no chemically active molecular fragments and it has four times greater water capacity than filter and chromatographic paper. Thus, fluoroplastic porous disc of mass of 15 mg is suitable to carrying of 70-100 mkl (instead of 15-20 mkl) of fluid. The preliminary impregnation of such a disc with solution of antioxidant - 0.5% - 0.9% 2,6-di-tret-butyl-4-methyl phenol in chloroform - permits to strongly increase stability of higher poly-saturated fatty acids in applied of dry plasma sample or erythrocytic mass on the disc. In that case, time of storage of ready-made disc with dry sample under room temperature increases up to 35-40 days and time of storage in freezer - from 50-60 days to half a year and longer. The storage of dry samples in airtight bottles of vials air-blown with technical propanebutane, also increases time of storage of samples approximately on a degree. This method permits to qualitatively determine content of individual fatty acids in the fraction of etherized and non-etherized fatty acids and also total and free cholesterol in samples of biological fluids.

Identification of quantitative trait loci underlying fatty acid content of soybean (Glycine max), including main, epistatic and QTL×environment effects across multiple environments

The uses and nutritional value of soybean (Glycine max (L.) Merrill) oil are largely influenced by the levels and relative proportions in the seed of the five major fatty acids: oleic (OA), palmitic (PA), stearic (SA), linoleic (LLA), linolenic (LNA). The present study was undertaken to identify quantitative trait loci (QTLs) that are associated with fatty acid content (particularly OA) and to determine the effects of epistasis and the environment. The mapping population included 134 recombinant inbred lines (RILs) derived from soybean varieties Suinong10 and L-9. Phenotypic data of the two parents and their RILs were obtained at Harbin in 2013, 2014 and 2015. Nineteen QTLs associated with individual fatty acid content (six for OA, four for LNA, three for PA, two for SA, four for LLA) were identified. Twelve of these QTLs (four for OA, three for LNA, two for PA, one for SA, two for LLA) were detected with an additive main effect and/or additive × environment interaction effect in certain environments. Epistatic QTLs were identified for contents of OA (two QTLs), LNA (one QTL) and LLA (one QTL) in different environments, and which exhibited significant epistatic effects. Our observation of these additive and epistatic QTLs suggested that soybean possesses a complex network for fatty acid accumulation, which is valuable for marker-assisted selection.

Enzymatically Modified Starch Favorably Modulated Intestinal Transit Time and Hindgut Fermentation in Growing Pigs.

Aside from being used as stabilizing agents in many processed foods, chemically modified starches may act as functional dietary ingredients. Therefore, development of chemically modified starches that are less digestible in the upper intestinal segments and promote fermentation in the hindgut receives considerable attention. This study aimed to investigate the impact of an enzymatically modified starch (EMS) on nutrient flow, passage rate, and bacterial activity at ileal and post-ileal level. Eight ileal-cannulated growing pigs were fed 2 diets containing 72% purified starch (EMS or waxy cornstarch as control) in a cross-over design for 10 d, followed by a 4-d collection of feces and 2-d collection of ileal digesta. On d 17, solid and liquid phase markers were added to the diet to determine ileal digesta flow for 8 h after feeding. Reduced small intestinal digestion after the consumption of the EMS diet was indicated by a 10%-increase in ileal flow and fecal excretion of dry matter and energy compared to the control diet (P<0.05). Moreover, EMS feeding reduced ileal transit time of both liquid and solid fractions compared to the control diet (P<0.05). The greater substrate flow to the large intestine with the EMS diet increased the concentrations of total and individual short-chain fatty acids (SCFA) in feces (P<0.05). Total bacterial 16S rRNA gene abundance was not affected by diet, whereas the relative abundance of the Lactobacillus group decreased (P<0.01) by 50% and of Enterobacteriaceae tended (P<0.1) to increase by 20% in ileal digesta with the EMS diet compared to the control diet. In conclusion, EMS appears to resemble a slowly digestible starch by reducing intestinal transit and increasing SCFA in the distal large intestine.

Effect of season and trophic level on fatty acid composition and content of four commercial fish species from Krasnoyarsk Reservoir (Siberia, Russia)

Two groups of factors, phylogenetic and ecological, are presently regarded as controlling fatty acid composition of fish, including essential eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Environmental effects, e.g., trophic position, temperature and/or seasonality, were previously studied using sums of fatty acids or only their level data. We tested the hypothesis that differences in trophic levels of piscivorous (pike and perch) and omnivorous (roach and bream) fish from a mesotrophic reservoir allow discriminating levels and contents of individual fatty acids, especially EPA and DHA. The more established measurements, i.e., stomach contents and carbon and nitrogen stable isotopes in fish muscles, were also carried out to provide linkages between the different ecological tracers, fatty acids versus stable isotopes, and matching the methods for long-term food sources (fatty acids and stable isotopes) and recent foraging (stomach content analysis). We also studied a putative influence of seasonality. Similar to other studies, there were seasonal changes in fatty acid composition and contents of two fish, perch and roach, due to direct and indirect effects of water temperature. Meanwhile, the piscivorous and omnivorous species captured in the same month, were explicitly differentiated on a base of stable isotopes and fatty acids. Significantly higher percentages and contents of DHA in piscivorous fish, perch and pike, relatively to those in roach and bream, likely indicated a higher trophic transfer efficiency for this essential fatty acid. All the fishes have commercial importance for regional fishery and are harvested from the studied reservoir for human nutrition. Regarding content of EPA+DHA (mgg−1 fish) as the indicator of nutritive value for humans, pike had the highest nutritive value, roach and perch had intermediate overlapped values, and bream was of the least benefit.

Comparison of ruminal fermentation parameters, fatty acid composition and flavour of beef in finishing bulls fed active dry yeast (Saccharomyces cerevisiae) and yeast culture

This study was conducted to compare the effect of active dry yeasts (ADY) and yeast cultures (YC), two typical products of yeast preparations, on ruminal fermentation parameters, and on the fatty acid composition and flavour of beef from finishing bulls fed a high-concentrate diet. Forty-five finishing bulls (mean bodyweight ± s.d.: 505.4 ± 29.1 kg body weight) were allocated to three groups of 15 bulls and assigned randomly to one of three diets, which were CON diet (basal diet), ADY diet (basal diet + Levucell SC) and YC diet (basal diet + Diamond V XP). After 112 days trial, all bulls (mean bodyweight ± s.d.: 591.6 ± 64.2 kg body weight) were slaughtered. The rumen fluid of each animal was collected at slaughter and cross-sectional samples of longissimus lumborum were collected from three treatments at carcass segmentation after a 24-h chill. The result indicated that both ADY and YC supplementation had no significant effect (P &gt; 0.05) on rumen pH, concentration of ammonia-N and total volatile fatty acid compared with CON. ADY had no significant effect (P &gt; 0.05) on percentage of rumen individual fatty acid whereas YC significantly decreased valerate molar percentage (P = 0.008) and increased acetate molar percentage (P = 0.029) and the ratio of acetate to propionate (P = 0.035). In addition, compared with CON, ADY significantly (P = 0.003) increased the concentration of C16:1n7 and significantly (P = 0.012) decreased the concentration of C18:3n6c compared with CON. YC significantly decreased the concentration of C18:3n6c (P = 0.014) compared with CON. However, both ADY and YC had no significant effect (P &gt; 0.05) on other individual fatty acid concentrations, the proportions of saturated fatty acids and monounsaturated fatty acids and nutritionally important values including the ratio of n-6/n-3, polyunsaturated fatty acids/saturated fatty acid and C18:2n6/C:18:3n3. Both ADY and YC significantly improved beef tenderness for cooking method of chaffy dish (P &lt; 0.05) and beef tenderness also tended improve for ADY (P = 0.075) and YC (P = 0.097) when samples were fried. Both ADY and YC did not show improvements in flavour or juiciness compared with CON for either cooking method.

Electrochemical techniques for evaluating short-chain fatty acid utilization by bioanodes.

The utilization of propionic, n-butyric, and isobutyric acids in microbial electrolysis cells (MECs) was examined by monitoring individual short-chain fatty acid concentration and using electrochemical techniques, such as linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). When n-butyric or isobutyric acid was provided as a single substrate, acetic acid was consistently observed in experiments, indicating that acetic acid was produced as a byproduct and utilized by exoelectrogenic bacteria as an additional substrate in MECs. When isobutyric acid was given as a sole substrate, the applied potential governed the electric current (i.e., rate of substrate utilization). In addition, the coulombic efficiency was substantially high (90%), indicating direct utilization of isobutyric acid by exoelectrogenic bacteria. However, the coulombic efficiency was relatively low (30-60%) when n-butyric acid was provided as a sole substrate. In another experiment, the magnitude of electric current was more dependent on the concentration of acetic acid than that of other short-chain fatty acids. In the EIS analysis, the exchange current was found to be a more reliable indicator of substrate favorability than the charge transfer resistance.