New Approach for Determination of Volatile Fatty Acid in Anaerobic Digester Sample

2018 ◽  
Vol 35 (4) ◽  
pp. 333-351 ◽  
Author(s):  
Biswabandhu Chatterjee ◽  
Loganath Radhakrishnan ◽  
Debabrata Mazumder
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Anaerobic Digester ◽  
New Approach

Overview of AD

2020 ◽  
Author(s):  
Jacob Joseph Lamb
Keyword(s):  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Mathematical Models ◽  
Volatile Fatty Acid ◽  
Biological Process ◽  
Gas Production ◽  
Anaerobic Digester ◽  
Chemical Parameters ◽  
Reactor Configuration ◽  
Biogas Output

There are many methodologies for improving the biogas output from anaerobic digestion. These techniques include physical (e.g., gas production and feedstock parameters), reactor configuration and chemical parameters (e.g., pH and volatile fatty acid concentrations) within the digester can help to link particular functions and features of the process. Using this expanse of data, mathematical models can be used to understand and forecast the biological process within an anaerobic digester. Such models can then be further developed on a process and biological level to improve their ability to mimic the function of the reactor. This chapter will provide background into modelling and reactor configuration in order to obtain a digital twin of an anaerobic digester.

scholarly journals The determination of volatile fatty acids in the caecum of the conscious rabbit

1976 ◽  
Vol 35 (3) ◽  
pp. 365-371 ◽  
Author(s):  
D. S. Parker ◽  
R. T. Mcmillan
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Acid Level ◽  
Volatile Fatty Acids ◽  
Fatty Acid Content ◽  
Diurnal Fluctuation ◽  
Fatty Acid Level ◽  
Conscious Rabbit

1. A method of obtaining dialysed samples from the caecum of the conscious rabbit is described.2. Values for total volatile fatty acid content and for molar proportions of individual volatile fatty acids in dialysate samples were in good agreement with those obtained from caecal material.3. The volatile fatty acid level in the caecum throughout the day was determined using two groups of animals, one group fed ad lib. and the other group on a restricted food intake. These results indicated a marked diurnal fluctuation in volatile fatty acid level in the caecum of rabbits fed once/d which was not evident in those fed ad lib.

scholarly journals Determination of volatile fatty acids clearance in intact ruminal digesta

2019 ◽  
Vol 14 (1) ◽  
pp. 8-17
Author(s):  
João Chrysostomo de Resende ◽  
João Luiz Pratti Daniel ◽  
André Rodrigues da Cunha Barreto-Vianna ◽  
Juliano Vogas Peixoto ◽  
Gregório Correia Guimarães ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Fractional Rate ◽  
Edta Solution ◽  
The Difference ◽  
Cr Concentration ◽  
Over Time

Cannulated cows were allocated to a cross-over design to evaluate the technique for determination of volatile fatty acid (VFA) clearance by infusion of marker solution into intact ruminal digesta, and verify the technique sensibility to the variation in the diet. Animals received diet of forage or forage plus concentrate and infusion of valeric acid and Cr-EDTA solution into intact or evacuated ruminal digesta. The total fractional rate of VFA clearance (FRVFAC) was estimated by the exponential decay of valerate over time. The passage FRVFAC to the omasum was assumed as the decay in ruminal Cr concentration and the absorption FRVFAC was estimated by the difference. The total FRVFAC and absorption did not differ between techniques. The passage FRVFAC, however, was lower when the marker solution was added into the evacuated digesta, probably reflecting the destabilization of the rumen environment during the evacuation and the largest volume of fluid observed in animals with evacuated digesta. In conclusion, the infusion of marker solution into intact digesta with homogenization performed by ruminal motility could be usable for the VFA ruminal clearance determination since it seems to cause lesser disturbance in the ruminal environment.

Effects of nutrient variability in corn and xylanase inclusion on broiler performance, nutrient utilisation, and volatile fatty acid profiles

2018 ◽  
Vol 6 ◽  
Author(s):  
M.P. Williams ◽  
H. V. Masey O'Neill ◽  
T. York ◽  
J.T. Lee
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Feed Conversion ◽  
Broiler Performance ◽  
Nutrient Utilisation ◽  
The Us ◽  
Nutrient Profiles ◽  
Nutrient Variability ◽  
The Impact

AbstractThe objective of the trial was to determine the impact of corn source and xylanase on broiler performance, digestibility, and volatile fatty acid (VFA) profiles. Six corn samples were obtained from different regions of the US. Twelve treatments were derived using corn source, with each corn diet being fed with or without xylanase. Three dietary phases were used throughout the trial, starter (d 1–18), grower (d 19–31), and finisher (d 32–41). On d 18 and 41, ileal and excreta contents were collected for the determination of ileal digestible energy (IDE), ileal energy and nitrogen digestibility coefficients (IEDC and INDC), apparent metabolisable energy (AME), and caecal VFA profiles. Day 18 body weight (BW) was affected by corn source and varied between 724 and 764g (P = 0.001). For d 31 BW, there was an interaction of corn source with xylanase (P = 0.001), with the effect of xylanase being inconsistent. The effect of xylanase on feed conversion ratio (FCR) during the grower phase depended on corn source (interactive term, P = 0.021). Xylanase reduced (P = 0.026) FCR during the finisher phase (1.943 vs. 1.992). Variation of corn source influenced digestibility on all evaluated parameters. A range of 152 and 213 kcal/kg for IDE was observed on d 18 and 41, respectively (P = 0.005 and 0.001). The range of AME was 176 kcal/kg on d 18 of age which increased to 194 kcal/kg on d 41. Nitrogen digestibility was influenced by corn source, with an observed range of 4.4 and 6.1% for d 18 and 41, respectively, amongst all corn sources (P = 0.001). Xylanase increased (P = 0.031) the concentration of butyrate in the caecum on d 18. On d 41, an interaction between corn source and xylanase was observed with isovalerate in the caecal contents (P = 0.038). These data demonstrate the impact of varying corn nutrient profiles on nutrient utilisation and growth performance.

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