scholarly journals Effects of ammonia concentration and microbial population on in vitro degradation of 14C-labelled dietary proteins

1991 ◽  
Vol 71 (1) ◽  
pp. 125-133
Author(s):  
M. K. Song ◽  
J. J. Kennelly
Keyword(s):  
Protein Degradation ◽  
Microbial Population ◽  
Rumen Fluid ◽  
Protein Solubility ◽  
Ammonia Concentration ◽  
Barley Grain ◽  
Minor Role ◽  
Reductive Methylation ◽  
Ruminal Fluid

Rumen fluid from two nonlactating cows fed barley silage and rolled barley grain based concentrates (75:25 on a dry matter basis) was incubated for 0.5, 1, 2, 3, and 4 h with 14C-labelled soybean meal (SBM), fish meal (FM) and corn gluten meal (CGM) to examine the effects of ammonia concentration and protein solubility on rate and extent of protein degradation by total mixed ruminal microorganisms (TMM) or mixed ruminal bacteria (MB). Proteins were labelled by reductive methylation. Ammonia concentration in control ruminal fluid was 4.0 mg dL−1; graded levels of 1 M (NH4)2SO4 were added to achieve ammonia concentrations of 10, 20, and 30 mg dL−1 ruminal fluid. Soluble protein was extracted with borate-phosphate buffer (pH 7.8). Removal of protozoa reduced the extent of protein degradation. However, relative to bacteria, protozoa appeared to play a minor role in protein degradation. Rate and extent of protein degradation was not influenced by ammonia concentration, but was highly correlated with protein solubility. Therefore, it is concluded that ammonia concentration is not the primary factor regulating proteolytic activity of rumen microorganisms, rather their activities may depend upon the solubility and physico-chemical properties of proteins. Key words: In vitro, ammonia concentration, protein degradation, microbial population

scholarly journals Rumen protein degradation and biosynthesis

1983 ◽  
Vol 50 (3) ◽  
pp. 569-582 ◽  
Author(s):  
L. Raab ◽  
B. Cafantaris ◽  
T. Jilg ◽  
K. H. Menke
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
Gas Production ◽  
Total N ◽  
Fluid Medium ◽  
The Difference ◽  
Fermentable Carbohydrates

1. A method is described for the determination of protein degradation based on measurements of ammonia concentration and gas production (Menke et al. 1979) when a feedingstuff was incubated with rumen fluid in vitro.2. NH3 liberated during incubation is in part used for microbial protein synthesis. Production of carbon dioxide and methane can be regarded as a measure of energy available for protein synthesis. The ratio, gas production: incorporation of NH3-nitrogen was estimated by addition of starch to the substrate. The response in gas production was linear in the range 0–200 mg starch, when starch was added to 0–200mg feedingstuff dry matter and 30 ml rumen fluid-medium mixture.3. Linear regression between NH3-N concentration (y, mg) and gas production (x, ml) yielded an intercept (b0) representing that amountof NH3-N which would be released when no fermentable carbohydrates were available and consequently no bacterial protein synthesis took place.4. The difference between this intercept b0 and NH3-N content in the blank (rumen fluid without substrate added) indicated the amount of NH3 liberated from protein and other N-containing compounds of the feedingstuff incubated. In vitro-degradable N (IVDN) was calculated as a proportion of total N by the equation:

The ability of the ficin enzyme technique to predict the in situ degradability of lucerne N

1999 ◽  
Vol 1999 ◽  
pp. 156-156
Author(s):  
G. Gizzi ◽  
E.R. Deaville ◽  
D.I. Givens
Keyword(s):  
Protein Degradation ◽  
Microbial Population ◽  
Reasonable Accuracy ◽  
Complex Process ◽  
Ruminal Protein Degradability ◽  
Protein Degradability

The assessment of protein degradability in the rumen is a complex process. The infinite combination of interaction between the rumen microbial population and the nature of the protein fed to the animal makes the estimation of ruminal protein degradability very arduous. At present the in situ technique is the most popular means of predicting ruminal nitrogen (N) degradation. However this procedure is slow, expensive and relies on the use of numerous surgically prepared animals. A number of studies (Assoumani et al., 1992; Aufrère and Cartailler, 1988) have shown that the use of in vitro methods using proteases can predict with reasonable accuracy the extent of protein degradation. The objective of this experiment was to examine the possibility of replacing the in situ technique with an in vitro procedure based on the use of the ficin protease to predict the extent of N degradation.

In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium

2002 ◽  
Vol 82 (2) ◽  
pp. 233-239 ◽  
Author(s):  
A. Machmüller ◽  
C. R. Soliva ◽  
M. Kreuzer
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Lauric Acid ◽  
Rumen Fluid ◽  
Fatty Acid Pattern ◽  
Coconut Oil ◽  
Bacterial Count ◽  
Ammonia Concentration ◽  
Fiber Fermentation

The effect of Ca supplementation on the methane-suppressing effect of lauric acid was investigated in an experiment based on a 2 × 2-factorial arrangement using the in vitro system Rusitec. Additional Ca was supplemented at 1 g kg-1 diet in the form of compounds of relatively low solubility in rumen fluid. Lauric acid (C12:0), the predominant effective medium-chain fatty acid in coconut oil, was added at a level of 50 g kg-1. Adding C12:0 did not affect bacterial count, but eliminated ciliate protozoa from fermenters. Ammonia concentration in fermentation mixture declined and volatile fatty acid pattern changed with C12:0. The apparent degradation rate of total organic matter was not altered by C12:0, but fiber fermentation was depressed (P < 0.001). Effects of Ca on microbial counts and fermentation characteristics remained low. Without additional Ca, C12:0 reduced the average daily methane release (mmol g-1 organic matter degraded) by 76%. In comparison, C12:0 only reduced methane production by 47% when additional Ca was included in the diet (interaction of C12:0 and Ca, P < 0.05). The present results suggest that the dietary content of soap-forming Ca has to be kept low in order to achieve a high methane-suppressing effect of lauric acid. Key words: Methane, lauric acid, lipids, calcium, Rusitec, ruminants

Relative efficacy of inocula from rumen fluid or faecal solution for determining in vitro digestibility and gas production

1998 ◽  
Vol 78 (4) ◽  
pp. 673-679 ◽  
Author(s):  
A. El-Meadaway ◽  
Z. Mir ◽  
P. S. Mir ◽  
M. S. Zaman ◽  
L. J. Yanke
Keyword(s):  
Rumen Fluid ◽  
Relative Size ◽  
Barley Grain ◽  
Gas Production ◽  
Barley Straw ◽  
In Vitro Digestibility ◽  
Production Values ◽  
Cattle Faeces ◽  
Faecal Suspension

Three experiments were conducted to study the effects of substituting rumen fluid (RF) with faecal suspension (FS) as an inoculum for determination of in vitro dry matter digestibility (IVDMD, experiment 1) and gas production (exp. 2). Barley grain (BG), Persian clover (PC), alfalfa (ALF), bromegrass (BR) and barley straw (BS) were used to evaluate the efficacy of the two inocula. In exp. 1, IVDMD was determined using RF or FS containing 3, 6 and 9% fresh cattle faeces as inocula. Except for BS, IVDMD values obtained with either RF or FS containing 3% faeces were not different (P > 0.05). In contrast, FS containing 6 or 9% faeces resulted in lower (P < 0.05) IVDMD than those obtained with RF. Total VFA, butyric and valeric acids of in vitro supernatant were higher (P < 0.05) in RF than FS incubated buffers. Molar proportions of acetic and propionic acids were variable among feeds. Mean acetic:propionic ratio was similar (except for BG) for RF or FS. In exp. 2, substitution of RF with FS containing 6, 11 or 16% cattle faeces as inoculum generally resulted in an increased lag time for four feeds (PC was not included). The rate of gas production was lower when FS was used instead of RF for ALF and BR. For BG however, use of FS resulted in a higher (P < 0.05) rate of gas production than when RF was used. Total gas production values were similar within all the feeds regardless of the source of inoculum. In experiment 3, the relative size of the total and cellulolytic populations were higher for RF than for FS, with a greater diversity of genera of bacteria isolated from RF. Results from this study indicate that FS has the potential to be used instead of RF to obtain IVDMD and gas production for BG and forage hay but not for poor quality roughages such as BS. However, more research with FS is required to confirm these findings. Key words: IVDMD, gas production, rumen fluid, faecal suspension

EFFECT OF BARLEY SUPPLEMENT TO THE RATION OF DONOR ANIMALS USED IN IN VITRO DIGESTIBILITY DETERMINATION

1970 ◽  
Vol 50 (2) ◽  
pp. 265-267 ◽  
Author(s):  
F. W. CALDER
Keyword(s):  
Hordeum Vulgare ◽  
Dry Matter ◽  
Rumen Fluid ◽  
Barley Grain ◽  
In Vitro Digestibility ◽  
Hordeum Vulgare L ◽  
Alfalfa Hay ◽  
Medicago Sativa L ◽  
Ad Libitum

Rumen fluid from two sheep was used to determine in vitro dry matter digestibilities of 25 samples each from alfalfa hay (Medicago sativa L.) and barley grain (Hordeum vulgare L.). The sheep were fed either a good quality hay ad libitum and 1 kg rolled barley per day, or only the hay ad libitum, in a switchback design. The in vitro dry matter digestibilities of both alfalfa hay and barley were lower (P < 0.01) when the donor animal was fed hay and barley than when fed only hay.

Potential of walnut (Juglans regia) leave ethanolic extract to modify ruminal fermentation, microbial populations and mitigate methane emission

2020 ◽  
Vol 60 (9) ◽  
pp. 1189
Author(s):  
M. Sahebi Ala ◽  
R. Pirmohammadi ◽  
H. Khalilvandi-Behroozyar ◽  
E. Anassori
Keyword(s):  
Methane Emission ◽  
Rumen Fluid ◽  
Juglans Regia ◽  
Ethanolic Extract ◽  
Barley Grain ◽  
Gas Production ◽  
Microbial Populations ◽  
In Vitro Digestibility ◽  
Ruminal Fermentation

Series of in vitro trials were conducted to evaluate dose–response effects of walnut leaf ethanolic extract (WLEE) on ruminal fermentation, microbial populations, mitigation of methane emission and acidosis prevention. The treatments were conducted according to a 5 × 3 factorial arrangement in a completely randomised design formulated to contain corn (corn-based diet, CBD) and barley grain (barley-based diet, BBD), or equal amounts of barley and corn (barley and corn diet, BCD), consisting of either basal diets alone (0) or basal diets with 250, 500, 750 or 1000 µL of WLEE (W0, W250, W500, W750 and W1000 respectively) per litre of buffered rumen fluid. Three fistulated cows fed diets containing alfalfa hay and concentrate mixes (same as the control diet) plus minerals and vitamins were used for collection of ruminal fluid. The asymptote of gas production and methane emission was decreased and lag time increased in a linear and quadratic manner with an increasing dose of WLEE (P &lt; 0.001). However, gas production rate reduced linearly as WLEE dose increased (P &lt; 0.001). Methane production was significantly reduced linearly (L) and quadratically (Q) when walnut ethanolic extract was increased from 250 to 1000 μL/L (L and Q; P &lt; 0.001). The addition of WLEE significantly altered the volatile fatty acid profile in comparison to control, reducing the molar proportion of acetate and increasing that of propionate (P &lt; 0.001), and also decreased the ammonia-N concentration (L, P &lt; 0.001). Dry-matter and organic-matter in vitro digestibility coefficients were negatively affected by WLEE supplementation (L and Q; P &lt; 0.001). Although anti-acidosis potential of WLEE was significantly lower than that of monensin, W1000 increased medium culture pH compared with uncontrolled acidosis and the lower doses of WLEE. The populations of Fibrobacter succinogenes, Ruminococcus flavefaciens and R. albus were significantly reduced by WLEE, although to different magnitudes, depending on the corn and barley grain proportions in the diet. Results of the present study indicated that increasing addition levels of WLEE have noticeable effects on rumen microbial population and fermentation characteristics. It can be concluded that WLEE can potentially be used to manipulate ruminal fermentation patterns.

Nitrogen metabolism in the ovine stomach: 2. Factors influencing ruminal ammonia levels in sheep maintained on different diets

1974 ◽  
Vol 82 (3) ◽  
pp. 409-417 ◽  
Author(s):  
C. J. F. Harrop
Keyword(s):  
Nitrogen Metabolism ◽  
Urease Activity ◽  
Ammonia Concentration ◽  
Maximum Activity ◽  
Ammonia Production ◽  
Cellulolytic Bacteria ◽  
Ruminal Fluid ◽  
Factors Influencing

SUMMARYFactors which could be expected to influence levels of ammonia in the rumen were compared in sheep maintained on diets providing 11·4 or 20·7 g N/day.The ruminal fluid volume in sheep given the lower-N ration was 78% of that in sheep maintained on the higher-N diet. The effect of this in diluting rumen ammonia from recycled urea is discussed.Ruminal urease activity was higher in sheep given the lower-N diet, and was confined to the particulate fraction of rumen liquor in animals given either diet. At least 95% of the maximum activity occurred in the range of pH 5·4–7·05, and pH 6·0–7·25 in sheep maintained on the lower- and higher-N diets respectively. Small variations in activity were observed between the morning and evening meals.In vitro rates of net ammonia production in samples of rumen liquor were similar in sheep given either diet; a positive correlation with the initial ammonia concentration was evident. Net utilization of ammonia was detected in some experiments in samples from sheep maintained on the lower-N diet. Starvation for 1 day was associated with increased rates of production and initial concentrations of ammonia.Cellulose, as cotton thread, was digested at similar rates in vivo in sheep given the different diets. This is discussed in relation to the demand for ammonia by cellulolytic bacteria.

scholarly journals The degradation and utilization of formaldehyde-treated urea by rumen microbes in vitro

1982 ◽  
Vol 54 (1) ◽  
pp. 15-24
Author(s):  
Jouko Setälä ◽  
Liisa Syrjälä-Qvist
Keyword(s):  
Organic Matter ◽  
Rumen Fluid ◽  
Total Yield ◽  
Ammonia Concentration ◽  
Tungstic Acid ◽  
Treatment Level ◽  
Microbial Protein ◽  
Buffer Solution ◽  
Rumen Microbes

Urea was treated with different levels of formaldehyde (HCHO). The HCHO percentages, on a weight basis, were 0(F0), 0.25 (F0.25) 0.50 (F0.50), 0.75 (F0.75), 1.0 (F1.0), 1.5 (F1.5), 2.0 (F2.0), 3.0 (F3.0) and 5.0(F5.0). Twenty milligrams of urea was incubated for 5 hours in 40 ml of sheep rumen fluid-buffer solution (1:1) together with 1.5 grams of substrate. The substrate consisted of vacuum-dried and milled feeds: barley (25 %), molassed beet pulp (25 %) and NaOH-treated straw (50 %). The feeds and urea were used in the same proportions as in the diet of the sheep which yielded the rumen fluid for incubation. Treatment with HCHO decreased hydrolysis of urea to ammonia. The ammonia concentration in contents offer mentors 2 hours after the start of incubation had a highly significant (P < 0.001) negative correlation (r = -0.976, n = 72) with the HCHO treatment level. Microbial protein synthesis was calculated from tungstic acid - sulphuric acid precipitation. Synthesis of protein, expressed as grams of nitrogen per 100 grams fermented organic matter was highest when F1.5-F3.0 urea was used. Treatment with more than 3 % of HCHO decreased the number of protozoa and the general activity of the microbes, thus decreasing fermentation of organic matter and lowering the yield of microbial protein. When F1.5 urea was used, the total yield (mg protein/hr) was significantly higher than with untreated urea, but the results obtained with F1.5 urea did not differ significantly from those with F0.75 or F2.0 urea.

In Vitro Conversion of ß-Carotene to Retinal in Bovine Rumen Fluid by a Recombinant ß-Carotene- 15, 15’-Monooxygenase

2012 ◽  
Vol 82 (2) ◽  
pp. 94-103 ◽  
Author(s):  
García-López ◽  
González-Gallardo ◽  
Antaramián ◽  
L. González-Dávalos ◽  
Shimada ◽  
...  
Keyword(s):  
Rumen Fluid ◽  
Meat Products ◽  
Beta Carotene ◽  
Future Research ◽  
In Vitro Digestibility ◽  
Optimum Conditions ◽  
Recombinant Bacteria ◽  
Ruminal Fluid ◽  
E Coli

Pasture-fed cattle yield carcasses with yellow fat; consumers often reject the resulting meat products because they assume they come from old and/or culled animals. Recombinant bacteria expressing beta-carotene 15, 15’-monooxygenase, introduced into the rumen of the animal, might help to reduce the coloration since this enzyme converts carotene to retinal, thereby eliminating the source of yellowness. The goal of this work was to evaluate the effect of a recombinant beta-carotene 15, 15’-monooxygenase (BCMO1) from Gallus gallus, expressed in Escherichia coli. The genetically modified microbe was introduced into ruminal fluid, and carotene conversion to retinal was measured. Under optimum conditions the enzyme produced 6.8 nmol of retinal per 1 mg of protein in 1 hour at 37 °C. The data on in vitro digestibility in ruminal fluid showed no differences in beta-carotene breakdown or in retinal production (p > 0.1) between E. coli with pBAD vector alone and E. coli with pBAD/BCMO1. The pBAD/BCMO1 plasmid was stable in E. coli for 750 generations. These results indicate that the protein did not break beta-carotene into retinal in ruminal fluid, perhaps due to its location in the periplasmic space in E. coli. Future research must consider strategies to release the enzyme into the rumen environment.

scholarly journals Nutritional assessment of waste of cassava starch extraction dried in cattle feed

2016 ◽  
Vol 37 (4Supl1) ◽  
pp. 2653
Author(s):  
Tatiane Fernandes ◽  
Maximiliane Alavarse Zambom ◽  
Deise Dalazen Castagnara ◽  
Rodrigo Cezar dos Reis Tinini ◽  
Eduardo Augusto da Cruz ◽  
...  
Keyword(s):  
Nutrient Intake ◽  
Nutritional Assessment ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
Cassava Starch ◽  
In Vitro Digestibility ◽  
Cattle Feed

This study aimed to evaluate the digestive power of waste of cassava starch extraction dried (WCSEd) and corn, in addition to determining the appropriate level of WCSEd to replace corn in the diet of cattle. Studies to evaluate the in vitro digestibility and in situ degradability were performed. The study used four cattle with rumen cannula, individually fed with diets containing increasing levels (0, 33, 66 and 100%) of WCSEd to replace corn, to evaluate the dry matter and nutrient intake and digestibility, pH and ammonia concentration of rumen fluid. The WCSEd showed differences in the in vitro digestibility of DM, OM and NDF (P &lt; 0.05) compared to corn, but did not change the NDT and in situ degradability. As for in vivo reviews, the DM and nutrient intake was influenced by treatments in decreasing order, resulting in changes in the digestibility of DM, OM and NDT of diet, and a decreased concentration of N-NH3, but the pH was not affected. The residue from the extraction of cassava starch showed lower in vitro digestibility; however, ruminal degradability did not differ from corn. Their use in ruminant feed reduces the intake and degradation of feed, but improves the use of N-NH3 in the rumen.

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