scholarly journals Time of rumen fluid collection relative to feeding alters in vitro fermentation volatile fatty acid production

2018 ◽  
Vol 2 (suppl_1) ◽  
pp. S98-S98
Author(s):  
L A Pless ◽  
A N Brewster ◽  
D J McLean ◽  
S A Armstrong

Abstract The objective of this study was to determine the effect of time of rumen fluid collection relative to feeding on volatile fatty acid (VFA) production for in vitro rumen fermentation. Three ruminally cannulated Holstein heifers were used as rumen fluid donors. Feed was removed from heifers 12 h prior to feeding, rumen fluid was collected from each heifer before feeding (0 h), and at 2, 4, and 6 h after feeding, repeated on three separate incubation days. Buffered rumen fluid (100 mL) was incubated in 250-mL bottles containing 1.4 g of dried TMR, in duplicate for each heifer at each collection time. All bottles were incubated for 24 h at 39°C and constant agitation (60 rpm), and capped with monitors to capture temperature and pressure every 15 min (RF1, Ankom Technology, Macedon, NY). At the end of incubation, final pH and a sample of rumen fluid were collected for VFA and ammonia nitrogen. Data were analyzed using PROC GLIMMIX of SAS, with donor as the experimental unit and day as the random blocking factor; significance is defined as P ≤ 0.05. Time of rumen fluid collection significantly affected acetate (mmol/liter; P = 0.0004), propionate (mmol/liter; P = 0.02), isobutyrate (mmol/liter; P < 0.0001), valerate (mmol/liter; P = 0.004), isovalerate (mmol/liter; P < 0.00001), and total VFA concentrations (mmol/liter; P = 0.004). All VFA relative proportions were altered due to time of rumen fluid collection (P < 0.02). VFA production was highest when rumen fluid was collected 4-h post-feeding. There was little to no effect on pH. Our findings suggest that VFA production is maximized when rumen fluid is collected between 2 and 4 h after feeding.

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.


2015 ◽  
pp. 4884-4894 ◽  
Author(s):  
Ahmet Tekeli ◽  
Gültekin Yıldız ◽  
Winfried Drochner ◽  
Herbert Steingass

ABSTRACTObjective. Determine the effect of some plant extract supplementation to Total Mixed Ration (TMR), concentrate and hay on volatile fatty acid (VFA) production at 8 and 24 hours (h) using in vitro gas production technique in cattle. Material and methods. Three fistulated Holstein dairy cows were used for rumen fluid collection for application of in vitro gas production technique. Four essence oils (T. vulgaris, O. vulgare, S. aromaticum, Z. officinale) were used as plant extracts. Results. Essence oil supplementations to the examined feed groups had significant effect only on C2/C3 VFA level at 8 h in all feed groups (p<0.05). C2/C3 VFA level at 8 h significantly increased in the groups with Oregano 25 ppm supplementation for TMR and concentrate and in the groups with Thymol 25 ppm supplementation for hay. C3 VFA level at 8 h significantly increased in the group that received Syzygium 200 ppm supplementation for hay. Different plant extracts supplemented to TMR, concentrate and hay significantly affected C2, C3, IC4, IC5, C5 and C2/C3 VFA levels at 24 h (p<0.05). Conclusions. The findings of the study indicate that moderate doses of plant extracts result in increased VFA levels in ruminants while higher doses demonstrate the opposite effect.


1972 ◽  
Vol 34 (4) ◽  
pp. 636-641 ◽  
Author(s):  
K. M. Barth ◽  
P. E. Shumway ◽  
N. T. Kazzal ◽  
D. I. Davis ◽  
C. S. Hobbs

2018 ◽  
Vol 39 (4) ◽  
pp. 1749
Author(s):  
João Alexandrino Alves Neto ◽  
Ivanna Moraes de Oliveira ◽  
Matheus Henrique Moretti ◽  
Paloma Helena Gonçalves ◽  
Michele Aparecida Prado Alves ◽  
...  

There are no studies evaluating the virginiamycin (VM) doses under tropical conditions. So, the present study was conducted to evaluate the optimal dose of VM for growing Nellore bulls on tropical pasture. Two experiments were conducted. The first experiment, one hundred and two Nellore bulls (307 ± 25 kg body weight [BW]; 22 months) were used. Animal performance was evaluated using a randomized block design, with group as experimental unit (n = 8; 12 animals each). The second experiment, a double 4 × 4 Latin square, eight animals were used to evaluate the ruminal parameters. Four doses were evaluated: 0, 35, 55, and 75 mg VM per 100 kg BW. The average daily gain (P = 0.08) and carcass gain (P = 0.05) exhibited a trend of quadratic behavior. An increased dose of VM did not affect supplement intake (P = 0.64), rumen pH (P = 0.96), acetate: propionate ratio (P = 0.73), or the total concentration of volatile fatty acid (P = 0.63). The concentration of rumen ammonia nitrogen exhibited a quadratic effect (P = 0.01). A quadratic behavior was found for volatile fatty acid, except for propionate (P < 0.01). In conclusion, the dose of 47 mg VM per 100 kg BW is recommend for growing Nellore bulls on tropical pasture.


2019 ◽  
Vol 97 (8) ◽  
pp. 3550-3561 ◽  
Author(s):  
Jocelyn R Johnson ◽  
Gordon E Carstens ◽  
Wimberly K Krueger ◽  
Phillip A Lancaster ◽  
Erin G Brown ◽  
...  

Abstract The objectives of this study were to examine the relationship between residual feed intake (RFI) and DM and nutrient digestibility, in vitro methane production, and volatile fatty acid (VFA) concentrations in growing beef cattle. Residual feed intake was measured in growing Santa Gertrudis steers (Study 1; n = 57; initial BW = 291.1 ± 33.8 kg) and Brangus heifers (Study 2; n = 468; initial BW = 271.4 ± 26.1 kg) fed a high-roughage-based diet (ME = 2.1 Mcal/kg DM) for 70 d in a Calan-gate feeding barn. Animals were ranked by RFI based on performance and feed intake measured from day 0 to 70 (Study 1) or day 56 (Study 2) of the trial, and 20 animals with the lowest and highest RFI were identified for subsequent collections of fecal and feed refusal samples for DM and nutrient digestibility analysis. In Study 2, rumen fluid and feces were collected for in vitro methane-producing activity (MPA) and VFA analysis in trials 2, 3, and 4. Residual feed intake classification did not affect BW or BW gain (P &gt; 0.05), but low-RFI steers and heifers both consumed 19% less (P &lt; 0.01) DMI compared with high-RFI animals. Steers with low RFI tended (P &lt; 0.1) to have higher DM digestibility (DMD) compared with high-RFI steers (70.3 vs. 66.5 ± 1.6% DM). Heifers with low RFI had 4% higher DMD (76.3 vs. 73.3 ± 1.0% DM) and 4 to 5% higher (P &lt; 0.01) CP, NDF, and ADF digestibility compared with heifers with high RFI. Low-RFI heifers emitted 14% less (P &lt; 0.01) methane (% GE intake; GEI) calculated according to Blaxter and Clapperton (1965) as modified by Wilkerson et al. (1995), and tended (P = 0.09) to have a higher rumen acetate:propionate ratio than heifers with high RFI (GEI = 5.58 vs. 6.51 ± 0.08%; A:P ratio = 5.02 vs. 4.82 ± 0.14%). Stepwise regression analysis revealed that apparent nutrient digestibilities (DMD and NDF digestibility) for Study 1 and Study 2 accounted for an additional 8 and 6%, respectively, of the variation in intake unaccounted for by ADG and mid-test BW0.75. When DMD, NDF digestibility, and total ruminal VFA were added to the base model for Study 2, trials 2, 3, and 4, the R2 increased from 0.33 to 0.47, explaining an additional 15% of the variation in DMI unrelated to growth and body size. On the basis of the results of these studies, differences in observed phenotypic RFI in growing beef animals may be a result of inter-animal variation in apparent nutrient digestibility and ruminal VFA concentrations.


1990 ◽  
Vol 115 (3) ◽  
pp. 389-392 ◽  
Author(s):  
M. Marounek ◽  
O. Petr ◽  
L. Machañová

SUMMARYContents of the caecum and the colon of four steers and four cows fed concentrate-plus-roughage diets were obtained at an abattoir, transferred to the laboratory and incubated anaerobically with maize starch in the presence (10mg/l) or absence of monensin. Samples taken at the end of incubation were assayed for fermentation acids and methane production.Monensin significantly increased the molar percentage of propionate and decreased that of butyrate. Acetate percentage was not significantly influence by the addition of monensin. There was no consistent effect of monensin on total volatile fatty acid concentrations. Monensin decreased methanogenesis in all incubations. The production of methane was small, only 1 mmol/13–50 mmol of volatile fatty acid.


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