scholarly journals Fitting of pH conditions for the study of concentrate feeds fermentation by the in vitro gas-production technique

2018 ◽  
Vol 58 (9) ◽  
pp. 1751 ◽  
Author(s):  
Z. Amanzougarene ◽  
M. Fondevila

Two experiments were conducted to simulate in vitro the fermentation conditions under high-concentrate feeding. The concentration of bicarbonate ion in the buffer of the incubation solution was assayed in Experiment 1, by adjusting medium pH to 6.50, 6.25, 6.00, 5.75 and 5.50, in two incubation series of 12 h, using barley as the reference substrate. The pH diminished linearly (P < 0001) by lowering the buffer, and remained constant throughout 12 h, except for treatments 5.75 and 5.50, where pH dropped to 5.51 and 5.31 at 12 h. Gas production decreased linearly with a decreasing medium pH (P < 0.001), with the total volume of gas produced after 12 h being highly dependent (P < 0.01) on pH at 12 h (R2 = 0.629), thus demonstrating the importance of the incubation pH for estimation of fermentation of concentrate feeds. In Experiment 2, the effect of pH on direct and indirect proportion of gas was studied by adding 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mmol of acetic acid, either with or without (water added instead) rumen inoculum, to the media. Linear multiple regressions established between the volume of gas produced and the addition of acetic acid, and the bicarbonate ion concentration showed high determination coefficients for water (R2 = 0.929) and rumen inoculum (R2 = 0.851). Without inoculum, indirect gas production ranged from 9.4 to 12.4 mL/mmol of acid for medium pH of 5.50–6.50. With rumen inoculum, indirect gas was 20.8 mL/mmol acid, although this may have been biased by the contribution of inoculum itself to direct fermentation.

2017 ◽  
Vol 57 (2) ◽  
pp. 327 ◽  
Author(s):  
Sungchhang Kang ◽  
Metha Wanapat ◽  
Kampanat Phesatcha ◽  
Thitima Norrapoke ◽  
Suban Foiklang ◽  
...  

An in vitro gas production system was conducted to investigate the effect of krabok (Irvingia malayana) seed oil (KSO) and Flemingia (Flemingia macrophylla) leaf powder (FLM) supplementation on gas production kinetics, volatile fatty acid (VFA) and methane production with different ratios of rice straw to cassava chip (RS : CC). The treatments were arranged according to a 4 × 2 × 2 factorial arrangement in a completely randomised design using four different ratios of RS : CC (100 : 0; 60 : 40; 20 : 80; and 0 : 100), two levels of KSO supplement (0% and 2.5% of total dietary substrate) and two levels of FLM supplement (0% and 2.5% of total dietary substrate). The gas production kinetics were affected by RS : CC, KSO and FLM supplementation (P < 0.05). However, there was no interaction between RS : CC*FLM, FLM*KSO, or RS : CC*FLM*KSO; with the exception of RS : CC*KSO (P < 0.05). Cumulative gas at 96 h post incubation was increased with increasing RS : CC especially at 0 : 100. However, KSO supplementation suppressed gas production whereas FLM could enhance gas production from feed fraction (P < 0.05). Increasing RS : CC ratio resulted in increasing total VFA, propionic acid and butyric acid whereas acetic acid concentration was reduced; therefore, ratio of acetic acid : propionic acid was reduced. However, KSO supplementation depressed VFA production whereas the FLM supplement had no effect. The methane production was reduced with increasing level of RS : CC especially with supplementation of KSO. Based on this study, it is concluded that KSO addition could reduce methane production whereas FLM could enhance the gas production and fermentation end products; hence, the combined use is potentially beneficial. However, further research under in vivo conditions should be conducted.


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1935
Author(s):  
Zahia Amanzougarene ◽  
Manuel Fondevila

In vitro rumen fermentation systems are often adapted to forage feeding conditions, with pH values ranging in a range close to neutrality (between 6.5 and 7.0). Several attempts using different buffers have been made to control incubation pH in order to evaluate microbial fermentation under conditions simulating high concentrate feeding, but results have not been completely successful because of rapid exhaustion of buffering capacity. Recently, a modification of bicarbonate ion concentration in the buffer of incubation solution has been proposed, which, together with using rumen inoculum from donor ruminants given high-concentrate diets, allows for mimicking such conditions in vitro. It is important to consider that the gas volume recorded is in part directly produced from microbial fermentation of substrates, but also indirectly from the buffering capacity of the medium. Thus, the contribution of each (direct and indirect) gas source to the overall production should be estimated. Another major factor affecting fermentation is the rate of passage, but closed batch systems cannot be adapted to its consideration. Therefore, a simple semicontinuous incubation system has been developed, which studies the rate and extent of fermentation by gas production at the time it allows for controlling medium pH and rate of passage by manual replacement of incubation medium by fresh saliva without including rumen inoculum. The application of this system to studies using high concentrate feeding conditions will also be reviewed here.


1962 ◽  
Vol 40 (6) ◽  
pp. 991-1011 ◽  
Author(s):  
R. P. Harpur

The anaerobic carbon dioxide production of minced ascaris muscle decreases markedly when worms are kept in vitro for 3 days. Using this gas production as an index, and a factorial design, the effects of nitrogen, oxygen, carbon dioxide, antibiotics, vitamins, amino acids, glucose, potassium, and ammonium ions were investigated. For this study the worms were kept in media which were changed every 3 hours and the gaseous phases were maintained by bubbling gas continuously through the media. Under these conditions 20% oxygen was extremely toxic but carbon dioxide (5%) provided some relief from this effect. Even 5% oxygen caused more decrease in the index than did nitrogen alone, but this was not true when a mixture of amino acids and glucose was present. Ammonium ions had a beneficial effect in nitrogen but a detrimental effect in the presence of 20% oxygen. A high potassium ion concentration (24 mM) was detrimental in the absence of carbon dioxide but appeared to enhance the beneficial effects of carbon dioxide.


2020 ◽  
Vol 23 (2) ◽  
pp. 265-272
Author(s):  
Fatma Hadhoud ◽  
M. Shaaban ◽  
A. Abd El Tawab ◽  
M. Khattab ◽  
H. Ebeid ◽  
...  

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Yichong Wang ◽  
Sijiong Yu ◽  
Yang Li ◽  
Shuang Zhang ◽  
Xiaolong Qi ◽  
...  

Nutritional strategies can be employed to mitigate greenhouse emissions from ruminants. This article investigates the effects of polyphenols extracted from the involucres of Castanea mollissima Blume (PICB) on in vitro rumen fermentation. Three healthy Angus bulls (350 ± 50 kg), with permanent rumen fistula, were used as the donors of rumen fluids. A basic diet was supplemented with five doses of PICB (0%–0.5% dry matter (DM)), replicated thrice for each dose. Volatile fatty acids (VFAs), ammonia nitrogen concentration (NH3-N), and methane (CH4) yield were measured after 24 h of in vitro fermentation, and gas production was monitored for 96 h. The trial was carried out over three runs. The results showed that the addition of PICB significantly reduced NH3-N (p < 0.05) compared to control. The 0.1%–0.4% PICB significantly decreased acetic acid content (p < 0.05). Addition of 0.2% and 0.3% PICB significantly increased the propionic acid content (p < 0.05) and reduced the acetic acid/propionic acid ratio, CH4 content, and yield (p < 0.05). A highly significant quadratic response was shown, with increasing PICB levels for all the parameters abovementioned (p < 0.01). The increases in PICB concentration resulted in a highly significant linear and quadratic response by 96-h dynamic fermentation parameters (p < 0.01). Our results indicate that 0.2% PICB had the best effect on in-vitro rumen fermentation efficiency and reduced greenhouse gas production.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2212
Author(s):  
Mónica Gandarillas ◽  
Juan Pablo Keim ◽  
Elisa María Gapp

Background: Horses are hindgut fermenters, and it is therefore important to determine the postgastric nutritive value of their feedstuffs and diets. Moreover, it has been demonstrated in other animal species that the fermentation of diets results in different values than those expected from pure ingredients. Therefore, the general objective of this work is to evaluate the gas production (GP) and volatile fatty acid (VFA) concentration, as well as the associative effects, of mixtures of different forages and concentrated foods, which are representative of the traditional diets of high-performance horses. Methods: An in vitro gas production experiment was conducted to assess the fermentation of two forages and three concentrates that are typical in horse diets. The combination of 70% of forage and 30% concentrates was also assessed to determine potential associative effects. Results: Concentrates and grains produced higher GP and VFA than forages when evaluated alone. When experimental diets were incubated, GP parameters and VFA concentrations of forage–concentrate mixtures had unexpected differences from the values expected from the fermentation of pure ingredients, suggesting the occurrence of associative effects. Conclusions: Our results indicate that there is a need to evaluate the fermentation of diets, rather than predicting from the values of pure ingredients.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1957
Author(s):  
Margarita Novoa-Garrido ◽  
Carlos Navarro Marcos ◽  
María Dolores Carro Travieso ◽  
Eduarda Molina Alcaide ◽  
Mogens Larsen ◽  
...  

The study analyzed the characteristics, chemical composition, and in vitro gas production kinetics of Porphyra umbilicalis and Saccharina latissima silages. Each seaweed was ensiled in vacuum bags (three bags/silage) following a 2 × 3 factorial design, with two pre-treatments (unwilted or pre-wilted) and three silage types: unwashed seaweed ensiled without additive; seaweed washed and ensiled without additive; and seaweed washed and ensiled with 4 g of formic acid (FAC) per kg seaweed. Silages were kept for 3 months in darkness at 20 °C. Pre-wilting prevented (p < 0.001) effluent formation and reduced (p ≤ 0.038) the production of NH3-N and volatile fatty acids for both seaweeds. Both pre-wilting and washing increased (p < 0.05) the ruminal degradability of P. umbilicalis silages but not of S. latissima silages. The pH of the FAC-treated silages was below 4.0, but ranged from 4.54 to 6.23 in non FAC-treated silages. DL-lactate concentrations were low (≤23.0 g/kg dry matter) and acetate was the predominant fermentation product, indicating a non-lactic fermentation. The estimated ruminal degradability of the P. umbilicalis and S. latissima silages was as average, 59.9 and 86.1% of that for high-quality rye-grass silages, respectively, indicating a medium-low nutritional value of these seaweed silages for ruminants.


2005 ◽  
Vol 123-124 ◽  
pp. 107-118 ◽  
Author(s):  
Gonzalo Hervás ◽  
Pilar Frutos ◽  
F. Javier Giráldez ◽  
Manuel J. Mora ◽  
Begoña Fernández ◽  
...  

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