scholarly journals Volatile fatty acid production in the rumen of cattle given an all-concentrate diet

1970 ◽  
Vol 24 (1) ◽  
pp. 179-195 ◽  
Author(s):  
F. G. Whitelaw ◽  
J. Hyldgaard-Jensen ◽  
R. S. Reid ◽  
Moird G. Kay

1. Short-term in vitro incubations of whole rumen contents have been used to measure the rate of production of volatile fatty acids (VFA) in two heifers given a diet containing 85% barley and 15% protein-mineral-vitamin supplement. Daily intake of the diet was restricted to 5.1 kg which was given in three equal feeds. In one heifer (no. 794), VFA production was measured over a 24 h feeding cycle; in the other (no. 832), a single 6 h feeding period was examined.2. The feeding schedule outlined above was found in previous work to result in a major alteration in the rumen environment and in the end-products of rumen fermentation relative to findings in animals given the same diet ad lib. Some of these earlier observations have been confirmed and extended in the present work.3. In heifer 794, the rate of VFA production reached a maximum (52–62 m-moles/l. h) 15 minafter each feed and then declined steadily throughout the remainder of the feeding period. Consistent changes with time were observed in rumen pH and in the concentration of VFA and dry matter in rumen contents during each feeding period.4. Simultaneous measurements of rumen fluid volume and outflow allowed estimates to be made of VFA production and absorption in the entire rumen during each feeding period. In heifer 794, total VFA production amounted to 18.2 moles/day of which approximately 85 % was absorbed directly from the reticulo-rumen. On a caloric basis, total daily production accounted for 36. 5% of the digestible energy intake.5. In heifer 832 there were significant differences in the rate of VFA production and in rumen pH and VFA concentration between two sets of observations made some 8 weeks apart. These differences appeared to be related to changes in the rumen microbial population and particular to a marked alteration in the numbers of ciliate protozoa. The possible role of rumen ciliates in modifying both the rate of VFA production and the environment within the rumen is discussed.

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 101 ◽  
Author(s):  
Sandra Debevere ◽  
An Cools ◽  
Siegrid De Baere ◽  
Geert Haesaert ◽  
Michael Rychlik ◽  
...  

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.


2017 ◽  
Vol 57 (1) ◽  
pp. 129 ◽  
Author(s):  
A. K. S. Schulze ◽  
A. C. Storm ◽  
M. R. Weisbjerg ◽  
P. Nørgaard

The major microbial fermentation of forages and production of volatile fatty acids (VFA) takes place in the medial part of the rumen, whereas the absorption of VFA occurs through the rumen epithelium, for example the ventral sac. The objective was to study effects of forage neutral detergent fibre (NDF) content and time after feeding on the medial to ventral VFA and pH gradient as well as rumen motility in the rumen of heifers fed grass/clover silages. Four silages were harvested at different growth stages with NDF contents of 31–45% of DM and in vitro organic matter digestibilities of 75–82% and fed to four rumen-fistulated Jersey heifers at 90% of ad libitum level in a Latin square design, with half the ration fed at 0800 hours and 1530 hours. Rumen fluid was sampled hourly from 0730 hours to 1530 hours in the medial and ventral rumen, and analysed for pH and concentrations of VFA, L-lactic acid, and ammonia to assess ruminal chemical gradient. Reticular contractions were continuously recorded by a pressure transducer. Time relative to feeding affected rumen parameters as pH was generally lower and VFA content greater in medial compared with ventral rumen fluid. Greater NDF content of the silage caused lower VFA concentration and higher pH in the rumen mat, and therefore the gradient diminished at greater NDF content in the silages; an effect probably caused by reduced organic matter digestibility rather than digesta NDF properties. This study therefore suggests that VFA production decreased with greater NDF content of forages, whereas intra-ruminal equilibration increased.


2011 ◽  
Vol 11 (2) ◽  
pp. 29-34 ◽  
Author(s):  
Novita Hindratiningrum ◽  
Muhamad Bata ◽  
Setya Agus Santosa

Products of rumen fermentation and protein microbial of dairy cattle feed with rice bran ammonization and some feedstuffs as an energy sourcesABSTRACT. This study aims to examine the energy sources of feed ingredients that can increase the production of Volatile Fatty Acids (VFA), N-NH3, microbial protein synthesis, total gas production and metabolic energy. The material used is as a source of rumen fluid inoculum from Frisian Holstein cows (FH) females, amoniasi rice straw, salt, mineral mix brand "Ultra Minerals' production Eka Farma Semarang, onggok wet and dry, corn, and rice bran. Observed variable is the concentration of (VFA), N-NH3, rumen microbial protein synthesis, and total gas production. Based on the analysis of diversity seen any significant effect (P0.05) on total VFA concentration, N-NH3 and total gas but had no effect (P0.05) on microbial protein synthesis. Conclusion of research is the provision of energy sources with rice bran treatment, onggok wet and dry corn flour can be used as fermentable carbohydrates on feed hay amoniasi in vitro.


2014 ◽  
Vol 59 (No. 10) ◽  
pp. 450-459 ◽  
Author(s):  
M. Gunal ◽  
A. Ishlak ◽  
A.A. AbuGhazaleh ◽  
W. Khattab

The effects of adding essential oils (EO) at different levels (125, 250, 500 mg/l) on rumen fermentation and biohydrogenation were examined in a rumen batch culture study. Treatments were: control without EO (CON), control with anise oil (ANO), cedar wood oil (CWO), cinnamon oil (CNO), eucalyptus oil (EUO), and tea tree oil (TEO). Essential oils, each dissolved in 1 ml of ethanol, were added to the culture flask containing 40 ml of buffer solution, 2 ml of reduction solution, 10 ml of rumen fluid, 25 mg of soybean oil, and 0.5 g of the diet. After 24 h of incubation in a water batch at 39°C, three samples were collected from each flask and analyzed for ammonia-N, volatile fatty acids (VFA), and fatty acids (FA). Expect for CNO, the proportions of acetate, propionate, and acetate to propionate ratios were not affected (P > 0.05) by EO addition. Addition of CWO, CNO, and TEO reduced total VFA concentrations (P < 0.05) regardless of dose level. The ammonia-N concentration was greater in cultures incubated with EO regardless of dose level. Compared with the CON, the concentrations of C18:0 and trans C18:1 were reduced (P < 0.05) with EO addition regardless of dose level. Compared with the CON, the concentration of linoleic acid was greater (P < 0.05) when EO were added at 500 mg/l. EO tested in this study had no effects on VFA profile but significantly reduced the formation of biohydrogenation products (C18:0 and trans C18:1).


1957 ◽  
Vol 8 (6) ◽  
pp. 691 ◽  
Author(s):  
RL Reid ◽  
JP Hogan ◽  
PK Briggs

Detailed data are presented on changes in the proportions of acetic, propionic, and butyric acids in the rumen after feeding on various diets. Pre-feeding proportions were constant on each diet but varied from a mixture of 72-76 per cent. acetic, 14-16 per cent. propionic, and 10-12 per cent. butyric acid on all-roughage diets to one of 63-65 per cent. acetic, 18-20 per cent. propionic, and 16-18 per cent. butyric acid on a diet containing 70 per cent. wheat grain. On all diets the proportion of propionic acid increased after feeding and reached a peak which coincided with the maximum level of total volatile fatty acids. The response of butyric acid was variable, low levels being recorded on a diet of lucerne chaff and on one containing a high proportion of cracked maize. The proportion of acetic acid always declined after feeding. These responses were modified in experiments on rations containing high proportions of wheaten starch, in which rumen pH fell below 5.0 as a result of lactic acid accumulation. When animals were first fed on such diets, a decline in rumen pH below 5.0-5.5 after feeding was always associated with a pronounced decline in the proportions of propionic and butyric acids, to levels as low as 8 and 5 per cent. respectively. Continued feeding of such diets did not affect the response of butyric acid, but there was evidence of a change in propionic acid production in response to low pH conditions, both in respect to short-term change during experiments in which low rumen pH levels were maintained for considerable periods and to long-term change when such diets were fed intermittently over considerable periods. The implications of these findings are discussed with respect to the effects of pH on individual volatile fatty acid production in the rumen, and on the qualitative nature of the microbial population and on their metabolic patterns.


2019 ◽  
Vol 64 (No. 8) ◽  
pp. 352-360
Author(s):  
Jiu Yuan ◽  
Xinjie Wan

The associative effects (AE) between concentrate (C), peanut shell (P) and alfalfa (A) were investigated by means of an automated gas production (GP) system. The C, P and A were incubated alone or as 40 : 60 : 0, 40 : 45 : 15, 40 : 30 : 30, 40 : 15 : 45, 40 : 0 : 60 and 30 : 70 : 0, 30 : 55 : 15, 30 : 40 : 30, 30 : 25 : 45, 30 : 10 : 60, 30 : 0 : 70 mixtures where the C : roughage (R) ratios were 40 : 60 and 30 : 70. Samples (0.2000 ± 0.0010 g) of single feeds or mixtures were incubated for 96 h in individual bottles (100 ml) with 30 ml of buffered rumen fluid. GP parameters were analysed using a single exponential equation. After incubation, the residues were used to determine pH, dry matter digestibility (DMD), organic matter digestibility (OMD), volatile fatty acids (VFA) and ammonia nitrogen (NH<sub>3</sub>-N) of the incubation fluid, and their single factor AE indices (SFAEI) and multiple-factors AE indices (MFAEI) were determined. The results showed that group of 30 peanut shell had higher SFAEI of GP<sub>48 h</sub>, DMD, OMD and total volatile fatty acids (p &lt; 0.05) and MFAEI (p &lt; 0.05) than groups 60, 45 and 0 when C : R was 40 : 60. The group of 10 peanut shell showed higher SFAEI of GP<sub>48 h</sub>, DMD and OMD (p &lt; 0.05) than groups 70, 55 and 40 and MFAEI (p &lt; 0.01) when C : R was 30 : 70. It is concluded that optimal SFAEI and MFAEI were obtained when the C : P : A ratios were 40 : 30 : 30 and 30 : 10 : 60.


1998 ◽  
Vol 1998 ◽  
pp. 168-168 ◽  
Author(s):  
A. Hussain ◽  
E. L. Miller

Inclusion of lactose in dairy cow rations increases dry matter intake (DMI) and milk yield (Garnsworthy 1996). This may be due to the relatively slow rate of lactose fermentation ( Hussain and Miller, 1998) sustaining better regulation of rumen pH and also possible consequence for microbial protein synthesis (Chamberlain et al., 1993).This experiment was conducted to study the changes in rumen environment over the adaptation period and effect of these changes on the fermentation of lactose itself.Three Suffolk wethers (b.wt 56± 7.36 kg) maintained on hay and concentrate (600:400) were offered 50g lactose per day for 16 days. Rumen liquor collected on dayO (before offering lactose), 4, 8, 12 and 16 was used to measure gas production from sucrose and lactose ( Menke et al., 1979). On these days rumen samples were collected at 0, 1, 2, 4, 6 and 8 hrs after the morning feed. Rumen pH, ammonia N (NH3N) and volatile fatty acids (VFA) were measured. At 8 hrs time rumen samples were also taken for protozoa enumeration. Data obtained were analysed using ANOVA procedure of Genstat 5.


2010 ◽  
Vol 50 (6) ◽  
pp. 449 ◽  
Author(s):  
P. G. Hutton ◽  
Z. Durmic ◽  
P. E. Vercoe

The Australian native plant Eremophila glabra was tested as a potential agent for preventing lactic acidosis in sheep after it was observed to be effective against acidosis in vitro. Ruminally fistulated wethers were infused via rumen cannula with single doses of kibbled wheat (14 g/kg bodyweight) and either virginiamycin (Eskalin500; AB, 80 mg/kg of wheat plus 100 g milled oaten hay/kg of wheat, n = 6), E. glabra (EG, 100 g freeze-dried and milled leaf material per kg of wheat, n = 10) or milled oaten hay (Control, 100 g milled oaten hay/kg of wheat, n = 16). Rumen samples were collected immediately before infusion and then 2, 4, 6, 8, 12, 16 and 24 h after the infusion. The samples were analysed for pH, D-lactate, volatile fatty acids (VFA) and osmolality. Rumen pH and D-lactate values indicative of acidosis were detected in the Control and EG groups. The pH nadir of the rumen was 12 h after the wheat infusion, at which time the values in the EG (pH = 4.87) and Control (pH = 5.09) groups were lower (P < 0.05) than in the AB group (pH = 5.63) and the D-lactate concentrations were higher (P < 0.05) in the EG and Control groups (24 mmol/L and 15 mmol/L, respectively) than in the AB group (0.9 mmol/L). At the same time, total VFA concentration was higher (P < 0.05) in the AB group (102 mmol/L) than in the Control (65 mmol/L) and the EG (14 mmol/L) groups. Rumen osmolality did not differ between groups. Virginiamycin was effective at preventing lactic acidosis. However, the inclusion of dried leaves from E. glabra at a similar level that was effective in vitro did not prevent lactic acidosis in vivo, and the reasons behind this remain unclear. The study demonstrates the difficulty in converting in vitro results to in vivo and highlights the need to test the plant at higher doses in vivo.


2017 ◽  
Vol 48 (2) ◽  
pp. 63-69
Author(s):  
M. Joch ◽  
V. Kudrna ◽  
B. Hučko

AbstractThe objective of this study was to determine the effects of geraniol and camphene at three dosages (300, 600, and 900 mg l-1) on rumen microbial fermentation and methane emission in in vitro batch culture of rumen fluid supplied with a 60 : 40 forage : concentrate substrate (16.2% crude protein, 33.1% neutral detergent fibre). The ionophore antibiotic monensin (8 mg/l) was used as positive control. Compared to control, geraniol significantly (P < 0.05) reduced methane production with increasing doses, with reductions by 10.2, 66.9, and 97.9%. However, total volatile fatty acids (VFA) production and in vitro dry matter digestibility were also reduced (P < 0.05) by all doses of geraniol. Camphene demonstrated weak and unpromising effects on rumen fermentation. Camphene did not decrease (P > 0.05) methane production and slightly decreased (P < 0.05) VFA production. Due to the strong antimethanogenic effect of geraniol a careful selection of dose and combination with other antimethanogenic compounds may be effective in mitigating methane emission from ruminants. However, if a reduction in total VFA production and dry matter digestibility persisted in vivo, geraniol would have a negative effect on animal productivity.


1972 ◽  
Vol 27 (2) ◽  
pp. 425-437 ◽  
Author(s):  
F. G. Whitelaw ◽  
J. Margaret Eadie ◽  
S. O. Mann ◽  
R. S. Reid

1. Two pairs of Friesian steers were changed fromad lib.to restricted intake of a pelleted barley diet and were maintained on this latter intake for periods of 18 or 25 weeks. The restricted level of intake was 70 g/kg0.73and was adjusted weekly according to individual live weights. The daily allowance was given in three equal feeds during day-time.2. After an initial period of 9 weeks on the restricted diet, during which all four animals were kept free of rumen ciliate protozoa, one member of each pair was given an inoculum of rumen ciliates. Eight weeks later, the ciliate-free member of the younger pair of steers was similarly inoculated. Observations were made on the rumen bacterial and protozoal populations and on changes in rumen pH and volatile fatty acids (VFA) throughout each treatment period. The concentrations of urea and haemoglobin in blood and of glucose and amino acids in plasma were examined on one occasion in each animal.3. In the absence of ciliates, restriction of intake resulted in rumen pH values and molar proportions of VFA similar to those normally encountered on anad lib.intake of a barley diet. A decrease in bacterial numbers and certain minor changes in bacterial types were observed on changing fromad lib.to restricted intake but the resultant population under ciliate-free conditions was basically the same as that found later in the faunated animals. In culture, organisms of the genusBacteroideswere predominant.4. Large populations of rumen ciliates were established in each animal inoculated. Relative to the ciliate-free periods, the presence of ciliates resulted in an increase in rumen pH, a reduction in total VFA concentration and a decrease in the ratio of propionic to butyric acid in rumen fluid. It is concluded that these changes are a direct effect of ciliate activity.5. Conditions within the rumen remained more stable from day to day when large ciliate populations were present than when ciliates were absent. In one animal, spontaneous fluctuations in ciliate number were accompanied by corresponding changes in rumen pH and VFA proportions.6. Significant differences were observed between faunated and ciliate-free animals in the concentration urea in blood and of glucose in plasma; only minor differences were noted in blood haemoglobin and plasma amino acid concentrations.


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