DRY MATTER LOSS AND VOLATILE FATTY ACID PRODUCTION IN THE ARTIFICIAL RUMEN AS INDICES OF FORAGE QUALITY

1958 ◽  
Vol 38 (2) ◽  
pp. 171-180 ◽  
Author(s):  
J. M. Asplund ◽  
R. T. Berg ◽  
L. W. McElroy ◽  
W. J. Pigden
Keyword(s):  
Fatty Acid ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Dry Matter ◽  
Nutritive Value ◽  
Rumen Fluid ◽  
Fatty Acid Production ◽  
Dry Matter Loss ◽  
Dry Matter Digestibility ◽  
Alfalfa Hay

Procedures are described for determining dry matter losses and for measuring volatile fatty acid production by direct chromatographic separation of acids produced during incubation of finely ground forages in miniature artificial rumen units. The results of preliminary assays done on three samples of unknown digestibility—excellent alfalfa hay, good mixed grass-alfalfa hay, and oat straw—showed that significantly different percentages of dry matter were lost and significantly different amounts of fatty acids were produced when feeds of such diverse quality were fermented. Analysis of the data for two groups of 11 and 6 samples of hay, for which dry matter digestibility coefficients as determined with sheep were available, indicated the existence of a high degree of correlation between dry matter digestibility in vivo and both dry matter loss and fatty acid production in vitro. Differences in assay results were observed when filtered rumen fluid or washed cells from the rumen fluid of sheep fed hay or from sheep fed straw were employed as sources of inocula. Examples of unsolved problems which are pertinent to the appraisal of the efficacy of artificial rumen assays for the estimation of the nutritive value of forages are discussed.

The use of the in vitro fermentation technique to estimate the digestible energy content of some Egyptian forages: III. The effect of periodical renewal of medium on volatile fatty acid production and cellulose digestion in vitro as criteria of energy content

1969 ◽  
Vol 73 (3) ◽  
pp. 431-436
Author(s):  
K. El-Shazly ◽  
M. A. Naga ◽  
M. A. Abaza ◽  
A. R. Abou Akkada
Keyword(s):  
Fatty Acid ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Dry Matter ◽  
Energy Content ◽  
Correlation Coefficients ◽  
Fatty Acid Production ◽  
Cellulose Digestion ◽  
Digestible Energy

SUMMARYEleven forages of known digestible energy/kg dry matter (Naga & el-Shazly, 1963) were used in in vitro fermentation experiments. Direct determinations of digestible energy (D.E./kg D.M.) using the bomb calorimeter were also included, and the values were corrected for gas losses.In vitro fermentations were interrupted every 12, 8 and 6 h, the medium was renewed and volatile fatty acid (VFA) production and cellulose digestion were estimated. Volatile fatty acid production from legumes was high early in the fermentation periods and became lower in later periods. Non-legumes behaved in an opposite manner.Significant negative correlation coefficients between VFA production and D.E./kg D.M. were found for legumes at later intervals of fermentation, while correlation coefficients for non-legumes lost their significance at later periods of fermentation.Digestible energy/kg dry matter could best be predicted for legumes from the volatile fatty acids produced in the second 12 h fermentation period or from the sum of the VFA produced in second, third and fourth 6 h periods of fermentation.

scholarly journals In Vitro Rumen Simulations Show a Reduced Disappearance of Deoxynivalenol, Nivalenol and Enniatin B at Conditions of Rumen Acidosis and Lower Microbial Activity

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 101 ◽  
Author(s):  
Sandra Debevere ◽  
An Cools ◽  
Siegrid De Baere ◽  
Geert Haesaert ◽  
Michael Rychlik ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Rumen Fluid ◽  
Fatty Acid Production ◽  
Lactating Cows ◽  
Rumen Ph ◽  
Rumen Acidosis ◽  
Better Than

Ruminants are generally considered to be less susceptible to the effects of mycotoxins than monogastric animals as the rumen microbiota are capable of detoxifying some of these toxins. Despite this potential degradation, mycotoxin-associated subclinical health problems are seen in dairy cows. In this research, the disappearance of several mycotoxins was determined in an in vitro rumen model and the effect of realistic concentrations of those mycotoxins on fermentation was assessed by volatile fatty acid production. In addition, two hypotheses were tested: (1) a lower rumen pH leads to a decreased degradation of mycotoxins and (2) rumen fluid of lactating cows degrade mycotoxins better than rumen fluid of non-lactating cows. Maize silage was spiked with a mixture of deoxynivalenol (DON), nivalenol (NIV), enniatin B (ENN B), mycophenolic acid (MPA), roquefortine C (ROQ-C) and zearalenone (ZEN). Fresh rumen fluid of two lactating cows (L) and two non-lactating cows (N) was added to a buffer of normal pH (6.8) and low pH (5.8), leading to four combinations (L6.8, L5.8, N6.8, N5.8), which were added to the spiked maize substrate. In this study, mycotoxins had no effect on volatile fatty acid production. However, not all mycotoxins fully disappeared during incubation. ENN B and ROQ-C disappeared only partially, whereas MPA showed almost no disappearance. The disappearance of DON, NIV, and ENN B was hampered when pH was low, especially when the inoculum of non-lactating cows was used. For ZEN, a limited transformation of ZEN to α-ZEL and β-ZEL was observed, but only at pH 6.8. In conclusion, based on the type of mycotoxin and the ruminal conditions, mycotoxins can stay intact in the rumen.

Corrigenda

1979 ◽  
Vol 41 (2) ◽  
pp. 407-407
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Fatty Acid ◽  
Bacterial Growth ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Dry Matter ◽  
Fatty Acid Production ◽  
Digestible Organic Matter ◽  
The Relationship

The relationship between rumen bacterial growth intake of dry matter, digestible organic matter and volatile fatty acid production in buffalo (Bos bubalis) calves By Singh U. B. Verma D. N. Verma A. and Ranjhan S. K. Vol. 38 (1977), no. 3 Page 337A model for the estimation of volatile fatty acid production in the rumen in non-steady-state conditions By Morant S. V. Ridley J. L. and Sutton J. D. Vol. 39 (1978), no. 3 Page 452

scholarly journals Nutritive value for ruminants of winter oats–legume intercrops in organic cultivation

2014 ◽  
Vol 54 (10) ◽  
pp. 1791 ◽  
Author(s):  
Alexey Díaz ◽  
María Dolores Carro ◽  
Carlos Palacios ◽  
Iván Mateos ◽  
Cristina Saro ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Nutritive Value ◽  
Gas Production ◽  
Forage Yield ◽  
Total Volatile ◽  
Fatty Acid Production ◽  
Total Volatile Fatty Acid

Winter oats were grown according to European organic farming regulations in monoculture (oats) and in intercropping with bard vetch (BAV), bitter vetch (BIV) or both legumes (MIX) to evaluate the effects of intercropping on forage yield and nutritive value for ruminants. The experiment was carried out as a randomised complete block design with four replications, and whole forage samples were obtained at two harvest dates (June and July). For both harvest times, all intercrops increased (P < 0.05) forage yield compared with oats, but forage crude protein content was only increased (P < 0.05) for BAV and MIX. Compared with oats, intercropping with BAV increased (P < 0.05) in vitro rate of gas production and total volatile fatty acid production, indicating a higher rate and extent of rumen degradation of BAV forage. In contrast, BIV forage harvested in June had lower (P < 0.05) rate of gas production and total volatile fatty acid production than June oats, but in general no differences in the in vitro rumen fermentation were detected between oats and BIV samples harvested in July. The results indicate that forage yield and quality can be enhanced by intercropping oats with BAV; however, intercropping with BIV increased yield but decreased nutritive value of the forage.

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