The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
J V Odoherty - One of the best experts on this subject based on the ideXlab platform.
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the interaction between dietary crude protein and fermentable carbohydrate source on piglet post weaning performance diet digestibility and selected faecal microbial populations and Volatile Fatty Acid concentration
2009Co-Authors: Bridget Lynch, J J Callan, J V OdohertyAbstract:Abstract A 2 × 2 × 2 factorial arrangement was used to investigate a 21 day study on the interaction between dietary crude protein (CP) (160 versus 200 g/kg), lactose level (50 versus 230 g/kg), and inulin supplementation (0 versus 15 g/kg) on piglet performance, diet digestibility, faecal Volatile Fatty Acid (VFAs) concentration and selected microbial populations post weaning. Two hundred and fifty six weaned piglets (24 days old, 7.4 kg live weight, S.D. = 1.5 kg) were blocked on the basis of live weight and were assigned to one of 8 dietary treatments (n = 8) for 21 days. There was an interaction between CP and lactose concentration on average daily gain (ADG) during the overall experimental period. Pigs offered high CP diets containing 230 g/kg lactose increased ADG compared to those pigs offered high CP diets containing 50 g/kg lactose. However, there was no effect of lactose concentration in the low CP diets. There was a significant interaction (P
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the effects of seaweed extract inclusion on gut morphology selected intestinal microbiota nutrient digestibility Volatile Fatty Acid concentrations and the immune status of the weaned pig
2008Co-Authors: P Reilly, J J Callan, J V Odoherty, K M Pierce, John T Osullivan, T SweeneyAbstract:An experiment (complete randomised design) was conducted to investigate the effects of Laminaria hyperborea and Laminaria digitata seaweed extract inclusion on gut morphology, selected intestinal microbiota populations, Volatile Fatty Acid concentrations and the immune status of the weaned pig. Twenty-eight piglets (24 days of age, 6.5 ± 1.4 kg live weight) were assigned to one of four dietary treatments for 7 days and then sacrificed: (T1) basal diet (control); (T2) basal diet and 1.5 g/kg L. hyperborea seaweed extract; (T3) basal diet and 1.5 g/kg L. digitata seaweed extract; and (T4) basal diet and 1.5 g/kg of a combination of L. hyperborea and L. digitata seaweed extract. The seaweed extract contained both laminarin and fucoidan. Digesta samples were taken from the caecum and colon to measure the enterobacteria, bifidobacteria and lactobacilli populations and for Volatile Fatty Acid analysis. Tissue samples were taken from the duodenum, jejunum and ileum for morphological examination. Blood samples were taken to determine the cytokine gene expression profile and to measure the phagocytotic capacity of the blood. Pigs offered diets containing L. hyperborea seaweed extract had less bifidobacteria in the colon (P < 0.05) and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). The inclusion of L. digitata seaweed extract resulted in lower populations of enterobacteria in the caecum and colon (P < 0.01), bifidobacteria in the caecum (P < 0.05), and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). Pigs offered the combination of L. hyperborea and L. digitata seaweed extracts had less enterobacteria (P < 0.05) and lactobacilli (P < 0.01) in the caecum and colon. Pigs offered the L. digitata-supplemented diet had a reduced villous height in the duodenum and jejunum (P < 0.05). The inclusion of the L. digitata seaweed extract increased the molar proportion of butyric Acid in the colon (P < 0.05). There was a significant reduction in the ammonia concentration in the colon with the inclusion of L. hyperborea (P < 0.01) and L. digitata (P < 0.05) seaweed extracts. An increase in the expression of the Interleukin-8 mRNA was observed on day 6 with the supplementation of the combination of L. hyperborea and L. digitata seaweed extract (P < 0.05). The inclusion of L. hyperborea seaweed extract resulted in an increase in total monocyte number (P < 0.05). In conclusion, the supplementation of L. hyperborea and L. digitata seaweed extract alone and in combination reduced the enterobacteria, bifidobacteria and lactobacilli populations in the caecum and colon, while only marginal effects on the immune response was observed.
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effects of increasing the intake of dietary β glucans by exchanging wheat for barley on nutrient digestibility nitrogen excretion intestinal microflora Volatile Fatty Acid concentration and manure ammonia emissions in finishing pigs
2007Co-Authors: M B Lynch, J J Callan, T Sweeney, J V OdohertyAbstract:An experiment (complete randomised design) was conducted to investigate the linear and quadratic effects of barley β-glucan inclusion level on total tract nutrient apparent digestibility, nitrogen excretion, intestinal microflora, Volatile Fatty Acid (VFA) profile and manure ammonia emissions in pigs. Twenty-four boars (66 kg) were assigned to one of four treatments: (T1) 0 g/kg barley (control diet) (5.6 g/kg β-glucan), (T2) 222 g/kg barley (12.1 g/kg β-glucan), (T3) 444 g/kg barley (18.9 g/kg β-glucan) and (T4) 666 g/kg barley (25 g/kg β-glucan). Barley was substituted for wheat in the diet. The diets were formulated to contain similar concentrations of digestible energy and digestible lysine. There was a linear decrease (P < 0.001) in the total tract apparent digestibility of dry matter, organic matter, gross energy and neutral-detergent fibre with increasing β-glucan concentration. Faecal nitrogen excretion was affected by dietary β-glucan concentration (quadratic P < 0.05). There was a linear decrease in Enterobacteria concentrations (P < 0.05) with increasing dietary β-glucan concentration. Increasing dietary barley levels caused a linear decrease in colonic (P < 0.01) and caecal pH (P < 0.001). Total caecal VFA and propionic Acid were affected by dietary β-glucan concentration (quadratic, P < 0.05). There was a linear decrease in the proportion of acetic Acid (P < 0.001), isobutyric Acid (P < 0.01) and isovaleric Acid (P < 0.05) with increasing levels of dietary barley in both the caecum and colon. There was a linear increase in the proportion of propionic Acid (P < 0.001) and butyric Acid (P < 0.05) with increasing barley in the colon. In conclusion, high level of dietary β-glucan (25 g/kg) is required to reduce offensive odour forming branched-chain VFAs; however, diet digestibility is compromised at such levels.
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the interaction between lactose level and crude protein concentration on piglet post weaning performance nitrogen metabolism selected faecal microbial populations and faecal Volatile Fatty Acid concentrations
2007Co-Authors: K M Pierce, J J Callan, P Mccarthy, J V OdohertyAbstract:Abstract A performance study and a nitrogen balance study (2×3 factorial) were conducted to investigate the interaction between lactose level (215 and 125 g/kg) (lactofeed 70; 860 g whey permeate/kg, 140 g soya bean meal/kg, Volac International, UK) and crude protein (CP) concentration (160, 185 and 210 g/kg) on post-weaning piglet performance, nitrogen metabolism, faecal microbiology and faecal Volatile Fatty Acid concentrations. In the performance trial, 252 piglets (7.6 kg; 33 days of age) were assigned to one of six dietary treatments following a 12-day period on a commercial creep diet (17 MJ/kg DE, 16 g lysine/kg). The experimental diets were fed for 28 days (days 12–40) and were formulated to have identical digestible energy (15 MJ/kg) and total lysine (14.5 g/kg) contents. In the N balance experiment, 24 boars (20 kg live weight) were offered the same diets as in the performance trial. Faecal samples were collected for selected microbial populations. There was an interaction (P E. coli population and a linear decrease in faecal Lactobacilli population with increasing CP. However at high lactose levels CP concentration had no effect on either E. coli or Lactobacilli populations. Pigs offered 215 g lactose/kg had a significantly higher Bifidobacteria population compared to pigs offered 125 g lactose/kg. There was a linear decrease in Bifidobacteria population as CP increased. In conclusion, at the high lactose level there was a linear increase in ADG and ADFI with increasing CP concentrations. There was no increase in these parameters above 185 g CP/kg at the low lactose level.
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the effect of lactose and inulin on intestinal morphology selected microbial populations and Volatile Fatty Acid concentrations in the gastro intestinal tract of the weanling pig
2006Co-Authors: K M Pierce, J J Callan, T Sweeney, P Mccarthy, P Brophy, E Fitzpatrick, J V OdohertyAbstract:Twenty piglets (21 days, 7·8 kg live weight (LW)) were used in a 2×2 factorial to investigate interactions between lactose and inulin on intestinal morphology, microbiology and Volatile Fatty Acid (VFA) production of the weanling pig. The piglets were offered the following diets for 6 days and then sacrificed: (T1) 150 g/kg lactose, (T2) 150 g/kg lactose +15 g/kg inulin, ( T3) 330 g/kg lactose, and ( T4) 330 g/kg lactose +15 g/kg inulin. Tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the ileum, caecum and colon. There was an interaction ( P<0·05) between lactose and inulin in villous height in the jejunum. The inclusion of inulin at 150 g/kg lactose increased villous height compared with 150 g/kg lactose without inulin. However, inulin had no effect on villous height at 330 g/kg lactose inclusion. There was a linear relationship between food intake and villous height in the duodenum ( P<0·001, R2 =0·45) and the jejunum ( P< 0·01, R2 =0·25). The inclusion of 330 g/kg lactose increased ( P<0·05) total VFA compared with 150 g/kg lactose in the caecum and the population of lactobacilli in the caecum and colon ( P<0·1). There was an interaction ( P<0·05) between lactose and inulin for total VFA concentration in the colon. The pigs receiving 330 g/kg lactose had a higher total VFA concentration compared with pigs on 150 g/kg lactose. However, there was no difference between 150 g/kg and 330 g/kg lactose when the diets were supplemented with inulin. In conclusion, the inclusion of high dietary concentrations of lactose resulted in increased lactobacilli and short-chain Fatty Acid concentrations. The inclusion of inulin with low dietary concentrations of lactose resulted in improved intestinal health through a reduction of intestinal pH and increases in villous height.
Chun Zhao Liu - One of the best experts on this subject based on the ideXlab platform.
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Enhanced hydrogen and Volatile Fatty Acid production from sweet sorghum stalks by two-steps dark fermentation with dilute Acid treatment in between
2018Co-Authors: Md Saiful Islam, Chen Guo, Chun Zhao LiuAbstract:This study investigated the potential of hydrogen and Volatile Fatty Acid coproduction from two steps dark fermentation with dilute Acid treatments of the residual slurry after 1st step fermentation. Sweet sorghum stalks (SS) was used as substrate along with Clostridium thermosaccharolyticum as production microbe. Residual lignocelluloses after 1st step fermentation were treated for 1 h by sulfuric Acid concentration of 0.25, 0.5, 1.0, 1.5, 2.0 and 2.5% (w/v) with different reaction temperature of 120, 90 and 60 °C were studied. The optimum severity conditions for the highest yield of products found from the treatment Acid concentration of 1.5% (w/v) at 120 °C for 10 g/L of substrate concentration. Experimental data showed that two-step fermentation increased 76% hydrogen, 84% acetic Acid and 113% of butyric Acid production from single step. Maximum yields of hydrogen, acetic Acid and butyric Acid were 5.77 mmol/g-substrate, 2.17 g/L and 2.07 g/L respectively. This two-step fermentation for hydrogen and VFA production using the whole slurry would be a promising approach to SS biorefinery.
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coproduction of hydrogen and Volatile Fatty Acid via thermophilic fermentation of sweet sorghum stalk from co culture of clostridium thermocellum and clostridium thermosaccharolyticum
2017Co-Authors: Md Saiful Islam, Chun Zhao Liu, Chen Guo, Chen Zhang, Kunyan SuiAbstract:Abstract This study was focused on investigating the potential of hydrogen and Volatile Fatty Acid (VFA) coproduction. Sweet sorghum stalks (SS) were used as substrate along with Clostridium thermocellum and Clostridium thermosaccharolyticum as production microbes. Inoculation ratio of C. thermosaccharolyticum to C. thermocellum (0:1–1.5:1 and 1:0 v/v), substrate concentrations (2.5–15.0 g/L) and inoculation time intervals of C. thermosaccharolyticum followed by C. thermocellum (0–48 h) were investigated. Experimental data showed that higher yields of hydrogen and VFA were obtained in the co-culture than their individual cultures. The optimum conditions for the highest yield of products found as 1:1 inoculation ratio of both strains, 24 h of time gap between C. thermosaccharolyticum followed by C. thermocellum after the first inoculation and 5 g/L of substrate concentration. The maximum yield of products was observed as hydrogen (5.1 mmol/g-substrate), acetic Acid (1.27 g/L) and butyric Acid (1.05 g/L) at optimum conditions. The results suggest that SS can be used for simultaneous production of hydrogen and VFA employing co-culture of C. thermocellum and C. thermosaccharolyticum strains. This approach can contribute to the sustainability of biorefinery.
J J Callan - One of the best experts on this subject based on the ideXlab platform.
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the interaction between dietary crude protein and fermentable carbohydrate source on piglet post weaning performance diet digestibility and selected faecal microbial populations and Volatile Fatty Acid concentration
2009Co-Authors: Bridget Lynch, J J Callan, J V OdohertyAbstract:Abstract A 2 × 2 × 2 factorial arrangement was used to investigate a 21 day study on the interaction between dietary crude protein (CP) (160 versus 200 g/kg), lactose level (50 versus 230 g/kg), and inulin supplementation (0 versus 15 g/kg) on piglet performance, diet digestibility, faecal Volatile Fatty Acid (VFAs) concentration and selected microbial populations post weaning. Two hundred and fifty six weaned piglets (24 days old, 7.4 kg live weight, S.D. = 1.5 kg) were blocked on the basis of live weight and were assigned to one of 8 dietary treatments (n = 8) for 21 days. There was an interaction between CP and lactose concentration on average daily gain (ADG) during the overall experimental period. Pigs offered high CP diets containing 230 g/kg lactose increased ADG compared to those pigs offered high CP diets containing 50 g/kg lactose. However, there was no effect of lactose concentration in the low CP diets. There was a significant interaction (P
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the effects of seaweed extract inclusion on gut morphology selected intestinal microbiota nutrient digestibility Volatile Fatty Acid concentrations and the immune status of the weaned pig
2008Co-Authors: P Reilly, J J Callan, J V Odoherty, K M Pierce, John T Osullivan, T SweeneyAbstract:An experiment (complete randomised design) was conducted to investigate the effects of Laminaria hyperborea and Laminaria digitata seaweed extract inclusion on gut morphology, selected intestinal microbiota populations, Volatile Fatty Acid concentrations and the immune status of the weaned pig. Twenty-eight piglets (24 days of age, 6.5 ± 1.4 kg live weight) were assigned to one of four dietary treatments for 7 days and then sacrificed: (T1) basal diet (control); (T2) basal diet and 1.5 g/kg L. hyperborea seaweed extract; (T3) basal diet and 1.5 g/kg L. digitata seaweed extract; and (T4) basal diet and 1.5 g/kg of a combination of L. hyperborea and L. digitata seaweed extract. The seaweed extract contained both laminarin and fucoidan. Digesta samples were taken from the caecum and colon to measure the enterobacteria, bifidobacteria and lactobacilli populations and for Volatile Fatty Acid analysis. Tissue samples were taken from the duodenum, jejunum and ileum for morphological examination. Blood samples were taken to determine the cytokine gene expression profile and to measure the phagocytotic capacity of the blood. Pigs offered diets containing L. hyperborea seaweed extract had less bifidobacteria in the colon (P < 0.05) and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). The inclusion of L. digitata seaweed extract resulted in lower populations of enterobacteria in the caecum and colon (P < 0.01), bifidobacteria in the caecum (P < 0.05), and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). Pigs offered the combination of L. hyperborea and L. digitata seaweed extracts had less enterobacteria (P < 0.05) and lactobacilli (P < 0.01) in the caecum and colon. Pigs offered the L. digitata-supplemented diet had a reduced villous height in the duodenum and jejunum (P < 0.05). The inclusion of the L. digitata seaweed extract increased the molar proportion of butyric Acid in the colon (P < 0.05). There was a significant reduction in the ammonia concentration in the colon with the inclusion of L. hyperborea (P < 0.01) and L. digitata (P < 0.05) seaweed extracts. An increase in the expression of the Interleukin-8 mRNA was observed on day 6 with the supplementation of the combination of L. hyperborea and L. digitata seaweed extract (P < 0.05). The inclusion of L. hyperborea seaweed extract resulted in an increase in total monocyte number (P < 0.05). In conclusion, the supplementation of L. hyperborea and L. digitata seaweed extract alone and in combination reduced the enterobacteria, bifidobacteria and lactobacilli populations in the caecum and colon, while only marginal effects on the immune response was observed.
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effects of increasing the intake of dietary β glucans by exchanging wheat for barley on nutrient digestibility nitrogen excretion intestinal microflora Volatile Fatty Acid concentration and manure ammonia emissions in finishing pigs
2007Co-Authors: M B Lynch, J J Callan, T Sweeney, J V OdohertyAbstract:An experiment (complete randomised design) was conducted to investigate the linear and quadratic effects of barley β-glucan inclusion level on total tract nutrient apparent digestibility, nitrogen excretion, intestinal microflora, Volatile Fatty Acid (VFA) profile and manure ammonia emissions in pigs. Twenty-four boars (66 kg) were assigned to one of four treatments: (T1) 0 g/kg barley (control diet) (5.6 g/kg β-glucan), (T2) 222 g/kg barley (12.1 g/kg β-glucan), (T3) 444 g/kg barley (18.9 g/kg β-glucan) and (T4) 666 g/kg barley (25 g/kg β-glucan). Barley was substituted for wheat in the diet. The diets were formulated to contain similar concentrations of digestible energy and digestible lysine. There was a linear decrease (P < 0.001) in the total tract apparent digestibility of dry matter, organic matter, gross energy and neutral-detergent fibre with increasing β-glucan concentration. Faecal nitrogen excretion was affected by dietary β-glucan concentration (quadratic P < 0.05). There was a linear decrease in Enterobacteria concentrations (P < 0.05) with increasing dietary β-glucan concentration. Increasing dietary barley levels caused a linear decrease in colonic (P < 0.01) and caecal pH (P < 0.001). Total caecal VFA and propionic Acid were affected by dietary β-glucan concentration (quadratic, P < 0.05). There was a linear decrease in the proportion of acetic Acid (P < 0.001), isobutyric Acid (P < 0.01) and isovaleric Acid (P < 0.05) with increasing levels of dietary barley in both the caecum and colon. There was a linear increase in the proportion of propionic Acid (P < 0.001) and butyric Acid (P < 0.05) with increasing barley in the colon. In conclusion, high level of dietary β-glucan (25 g/kg) is required to reduce offensive odour forming branched-chain VFAs; however, diet digestibility is compromised at such levels.
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the interaction between lactose level and crude protein concentration on piglet post weaning performance nitrogen metabolism selected faecal microbial populations and faecal Volatile Fatty Acid concentrations
2007Co-Authors: K M Pierce, J J Callan, P Mccarthy, J V OdohertyAbstract:Abstract A performance study and a nitrogen balance study (2×3 factorial) were conducted to investigate the interaction between lactose level (215 and 125 g/kg) (lactofeed 70; 860 g whey permeate/kg, 140 g soya bean meal/kg, Volac International, UK) and crude protein (CP) concentration (160, 185 and 210 g/kg) on post-weaning piglet performance, nitrogen metabolism, faecal microbiology and faecal Volatile Fatty Acid concentrations. In the performance trial, 252 piglets (7.6 kg; 33 days of age) were assigned to one of six dietary treatments following a 12-day period on a commercial creep diet (17 MJ/kg DE, 16 g lysine/kg). The experimental diets were fed for 28 days (days 12–40) and were formulated to have identical digestible energy (15 MJ/kg) and total lysine (14.5 g/kg) contents. In the N balance experiment, 24 boars (20 kg live weight) were offered the same diets as in the performance trial. Faecal samples were collected for selected microbial populations. There was an interaction (P E. coli population and a linear decrease in faecal Lactobacilli population with increasing CP. However at high lactose levels CP concentration had no effect on either E. coli or Lactobacilli populations. Pigs offered 215 g lactose/kg had a significantly higher Bifidobacteria population compared to pigs offered 125 g lactose/kg. There was a linear decrease in Bifidobacteria population as CP increased. In conclusion, at the high lactose level there was a linear increase in ADG and ADFI with increasing CP concentrations. There was no increase in these parameters above 185 g CP/kg at the low lactose level.
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the effect of lactose and inulin on intestinal morphology selected microbial populations and Volatile Fatty Acid concentrations in the gastro intestinal tract of the weanling pig
2006Co-Authors: K M Pierce, J J Callan, T Sweeney, P Mccarthy, P Brophy, E Fitzpatrick, J V OdohertyAbstract:Twenty piglets (21 days, 7·8 kg live weight (LW)) were used in a 2×2 factorial to investigate interactions between lactose and inulin on intestinal morphology, microbiology and Volatile Fatty Acid (VFA) production of the weanling pig. The piglets were offered the following diets for 6 days and then sacrificed: (T1) 150 g/kg lactose, (T2) 150 g/kg lactose +15 g/kg inulin, ( T3) 330 g/kg lactose, and ( T4) 330 g/kg lactose +15 g/kg inulin. Tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the ileum, caecum and colon. There was an interaction ( P<0·05) between lactose and inulin in villous height in the jejunum. The inclusion of inulin at 150 g/kg lactose increased villous height compared with 150 g/kg lactose without inulin. However, inulin had no effect on villous height at 330 g/kg lactose inclusion. There was a linear relationship between food intake and villous height in the duodenum ( P<0·001, R2 =0·45) and the jejunum ( P< 0·01, R2 =0·25). The inclusion of 330 g/kg lactose increased ( P<0·05) total VFA compared with 150 g/kg lactose in the caecum and the population of lactobacilli in the caecum and colon ( P<0·1). There was an interaction ( P<0·05) between lactose and inulin for total VFA concentration in the colon. The pigs receiving 330 g/kg lactose had a higher total VFA concentration compared with pigs on 150 g/kg lactose. However, there was no difference between 150 g/kg and 330 g/kg lactose when the diets were supplemented with inulin. In conclusion, the inclusion of high dietary concentrations of lactose resulted in increased lactobacilli and short-chain Fatty Acid concentrations. The inclusion of inulin with low dietary concentrations of lactose resulted in improved intestinal health through a reduction of intestinal pH and increases in villous height.
Zeynep Cetecioglu - One of the best experts on this subject based on the ideXlab platform.
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bio based Volatile Fatty Acid production and recovery from waste streams current status and future challenges
2018Co-Authors: Merve Atasoy, Isaac Owusuagyeman, Elzbieta Plaza, Zeynep CeteciogluAbstract:Bio-based Volatile Fatty Acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally fri ...
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bio based Volatile Fatty Acid production and recovery from waste streams current status and future challenges
2018Co-Authors: Merve Atasoy, Isaac Owusuagyeman, Elzbieta Plaza, Zeynep CeteciogluAbstract:Abstract Bio-based Volatile Fatty Acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally friendly approach. The aim of this paper is to give a comprehensive review of bio-based VFA production and recovery methods and to give an opinion on future research outlook. Effects of operation conditions including pH, temperature, retention time, type of substrate and mixed microbial cultures on VFA production and composition were reviewed. The recovery methods in terms of gas stripping with absorption, adsorption, solvent extraction, electrodialysis, reverse osmosis, nanofiltration, and membrane contractor of VFA were evaluated. Furthermore, strategies to enhance bio-based VFA production and recovery from waste streams, specifically, in-line VFA recovery and bioaugmentation, which are currently not used in common practice, are seen as some of the approaches to enhance bio-based VFA production.
N B Kristensen - One of the best experts on this subject based on the ideXlab platform.
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ergot alkaloids from endophyte infected tall fescue decrease reticuloruminal epithelial blood flow and Volatile Fatty Acid absorption from the washed reticulorumen
2013Co-Authors: A P Foote, N B Kristensen, J L Klotz, D H Kim, A F Koontz, K R Mcleod, Lowell P Bush, F N Schrick, D L HarmonAbstract:An experiment was conducted to deter- mine if ergot alkaloids affect blood flow to the absorptive surface of the rumen. Steers (n = 8) were pair-fed alfalfa cubes and received ground endophyte-infected (Neoty- phodium coenophialum) tall fescue (Lolium arundina- ceum; E+) seed (0.015 mg ergovaline·kg BW -1 ·d -1 ) or endophyte-free tall fescue (E-) seed via the rumen can- nula 2x daily for 7 d at thermoneutral (TN; 22°C) and heat stress (HS; 32°C) conditions. On d 8, the rumen was emptied and rinsed. A buffer containing VFA was incubated in the following sequence: control (CON), 15 μg ergovaline·kg BW -1 (1×EXT) from a tall fescue seed extract, and 45 μg ergovaline·kg BW -1 (3×EXT). For each buffer treatment there were two 30-min incuba- tions: a 30-min incubation of a treatment buffer with no sampling followed by an incubation of an identical sam- pling buffer with the addition of Cr-EDTA and deuteri- um oxide (D 2 O). Epithelial blood flow was calculated as ruminal clearance of D 2 O corrected for influx of physi- ological water and liquid outflow. Feed intake decreased with dosing E+ seed at HS but not at thermoneutral con- ditions (TN; P 0.05). Inclusion of the extract in the buffer caused at least a 50% reduction in epithelial blood flow at TN (P = 0.004), but there was no difference between 1×EXT and 3×EXT. There was a seed × buffer treatment interaction at HS (P = 0.005), indicating that the reduction of blood flow induced by incubating the extract was larger for steers receiving E- seed than E+ seed. Volatile Fatty Acid flux was reduced during the 1×EXT and 3×EXT treat- ments (P 0.80), indicating that observed differences are due to the presence of ergot alkaloids in the rumen. A decrease in VFA absorption could contribute to the signs of fescue toxicosis includ- ing depressed growth and performance.
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effects of ruminal ammonia and butyrate concentrations on reticuloruminal epithelial blood flow and Volatile Fatty Acid absorption kinetics under washed reticulorumen conditions in lactating dairy cows
2011Co-Authors: A C Storm, M D Hanigan, N B KristensenAbstract:Abstract The effect of reticuloruminal epithelial blood flow on the absorption of propionate as a Volatile Fatty Acid (VFA) marker in 8 lactating Holstein cows was studied under washed rumen conditions. The cows were surgically prepared with ruminal cannulas and permanent catheters in an artery and mesenteric, right ruminal, and hepatic portal veins. The experiment was designed with 2 groups of cows: 4 cows adapted to high crude protein (CP) and 4 to low CP. All cows were subjected to 3 buffers: butyric, ammonia, and control in a randomized replicated 3 × 3 incomplete Latin square design. The buffers (30 kg) were maintained in a temporarily emptied and washed rumen for 40 min. The initial concentration of VFA was 84.2 mmol/L. Butyrate was increased from 4 to 36 mmol/L in butyric buffer by replacement of acetate, and ammonia (NH3) was increased from 2.5 to 22.5 mmol/L in ammonia buffer by replacement of NaCl. Increasing amounts of deuterium oxide (D2O) were added to the buffers as the order of buffer sequence increased (6, 12, and 18 g of D2O). Ruminal clearance of D2O was used to estimate epithelial blood flow. To increase accuracy of the epithelial blood flow estimates, data of ruminal liquid marker (Cr-EDTA), and initial and final buffer volumes were fitted to a dynamic simulation model. The model was used to estimate ruminal liquid passages, residual liquid, and water influx (saliva and epithelia water) for each combination of cow and buffer (n = 24). Epithelial blood flow increased 49 ± 11% for butyric buffer compared with control. The ruminal disappearance of propionate (marker VFA) was affected by buffer and followed the same pattern as for epithelial blood flow. The correlation between ruminal disappearance of propionate and epithelial blood flow (r = 0.56) indicates that the removal of propionate can be limited by epithelial blood flow. The ruminal disappearance of propionate increased 30 ± 12% for the butyric compared with ammonia buffer and 12.5 ± 8% when compared with control. The net portal flux of propionate increased 32 ± 6% in butyric compared with control. In conclusion, rumen epithelial blood flow is positively correlated with ruminal disappearance of propionate and affects the kinetics of ruminal VFA absorption.
