scholarly journals Characteristics of the rumen proteolysis of fraction I (18S) leaf protein from lucerne (Medicago sativa L)

1981 ◽  
Vol 46 (1) ◽  
pp. 39-58 ◽  
Author(s):  
J. H. A. Nugent ◽  
J. L. Mangan
Keyword(s):  
Medicago Sativa ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Maximum Velocity ◽  
Leaf Protein ◽  
Bacterial Cells ◽  
Fraction I Protein ◽  
Protein Nitrogen ◽  
Wide Range ◽  
Fraction I

1. The rate of proteolysis of fraction 1 (18S) leaf protein in the rumen of sheep and cattle was affected by diet and the rate on fresh lucerne (Medicago sativa L) was three to nine times the rate on a hay + concentrate diet.2. Simultaneous rumen fermentations in vivo and in an artificial rumen showed that the rates of proteolysis of fraction I in vitro was approximately 80% of the rates in sheep.3. Using 14C uniformly-labelled fraction I protein at low concentrations, proteolysis exhibited 1st-order kinetics. Over a wide range of protein concentrations the velocity v. substrate concentration curve showed Michaelis–Menten characteristics typical of an enzyme-catalysed reaction. With rumen fluid from a hay + concentrate-fed sheep the maximum velocity was 2.6 mg protein nitrogen/1 per min and the Michaelis constant was 75 mg nitrogen/1.4. Rapid adsorption of 14C-labelled fraction I protein onto bacterial cells preceded proteolysis.5. Sucrose-density-gradient analysis showed initial incorporation of 14C from protein into rumen bacteria followed by partial transfer to rumen protozoa.6. No peptides were detected during proteoiysis showing that the rate-limiting step occurred during the initial stages of proteolysis. Only small amounts of free amino acids were released except for leucine, isoleucine, valine and ornithine, which showed significantly increased levels.7. Volatile fatty acids were the main 14C-labelied end products and were rapidly produced in descending concentrations: acetate > propionate > 3-methyl + 2-methyl butyrate > butyrate > isobutyrate > valerate.

Effect of condensed tannins upon the performance of lambs grazing Lotus corniculatus and lucerne (Medicago sativa)

1996 ◽  
Vol 126 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Y. Wang ◽  
G. B. Douglas ◽  
G. C. Waghorn ◽  
T. N. Barry ◽  
A. G. Foote ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Condensed Tannins ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Lotus Corniculatus ◽  
Ammonia Concentration ◽  
Research Station ◽  
Oral Supplementation ◽  
Voluntary Feed Intake ◽  
Wool Growth

SUMMARYA grazing experiment, conducted for 22 weeks in 1992/93 at Aorangi Research Station, AgResearch Grasslands, Manawatu, New Zealand, compared the productivity of weaned lambs grazing Lotus corniculatus (birdsfoot trefoil) and lucerne (Medicago sativa). Effects of condensed tannins (CT) in lotus were evaluated by studying the responses of lambs to twice daily oral supplementation with polyethylene glycol (PEG). A rotational grazing system with restricted feed allowance was used. Measurements were made of pre- and post-grazing herbage mass, the composition of the feed on offer and diet selected, voluntary feed intake (VFI), liveweight gain (LWG), carcass growth, wool growth and the concentration of metabolites in rumen fluid. For both lotus and lucerne swards, the diet selected was mainly leaf. Lotus contained 34 g total CT/kg dry matter in the diet selected, whilst there were essentially no CT in lucerne. Compared to lambs grazing lucerne, lambs grazing lotus had slightly lower VFI, and higher LWG, carcass weight gain, carcass dressing-out percentage and wool growth. PEG supplementation had no effect on these measurements or upon the composition of rumen fluid in lambs grazing lucerne. However, in lambs grazing lotus, PEG supplementation reduced wool growth (10·9 ν. 12·1 g/day), slightly reduced LWG (188 ν. 203 g/day), increased rumen ammonia concentration, and increased the molar proportions of /.so-butyric, isovaleric and n-valeric acids and protozoa numbers in rumen fluid. PEG supplementation did not affect carcass gain, carcass fatness or the molar proportion of rumen acetic, propionic or n-butyric acids in lambs grazing lotus. It was concluded that the principal effect of CT in growing lambs grazing lotus was to increase wool growth without affecting VFI, thereby increasing the efficiency of wool production, that the greater rate of carcass gain of lambs grazing lotus than those grazing lucerne was mainly caused by factors other than CT and that CT did not affect the rumen fermentation of carbohydrate to major volatile fatty acids.

Goats fed with non-protein nitrogen: ruminal bacterial community and ruminal fermentation, intake, digestibility and nitrogen balance

2021 ◽  
pp. 1-10
Author(s):  
A.S.M. Lopes ◽  
J.S. de Oliveira ◽  
E.M. Santos ◽  
A.N. Medeiros ◽  
P.E.N. Givisiez ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Nitrogen Balance ◽  
Nutrient Intake ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Nutrient Digestibility ◽  
Nitrogen Excretion ◽  
Ruminal Fermentation ◽  
Protein Nitrogen ◽  
Buffel Grass

Abstract The current study assessed ruminal fermentation parameters and bacterial community, nutrient intake, nutrient digestibility and nitrogen balance of goats fed diets containing buffel grass hay and ruminal ammonia nitrogen (N-NH3). Five rumen-cannulated mixed-breed castrated adult goats (45 ± 2.3 kg) were used in a 5 × 5 Latin square design represented by five N-NH3 levels (3.43, 9.95, 17.2, 23.0 and 33.7 mg/dl). Control animals were fed hay exclusively. Other treatments were represented by ruminal infusion composed of a mixture containing urea, ammonium sulphate and casein. The increasing N-NH3 concentrations did not affect rumen fluid pH, which averaged 6.43. Rumen ammoniacal nitrogen increased linearly in response to N-NH3. Volatile fatty acids were not affected by increasing N-NH3 concentrations. A higher abundance of Ruminococcaceae (Ruminococcus 1, Ruminococcaceae UCG-014 and Ruminococcaceae NK4A214 group) was observed in the rumen of goats infused with higher concentrations of N-NH3 (17.2 and 33.7 mg/dl N-NH3). There was a quadratic effect (P < 0.050) of N-NH3 levels on neutral detergent fibre intake with maximum values estimated at 13.7 mg/dl N-NH3. Nutrient intake, nitrogen excretion and nitrogen balance presented a positive linear effect (P < 0.050). In conclusion, 3.43 mg/dl of N-NH3 is the minimum level to maintain microbial activity, whereas the recommended level to optimize the microbial community is 14.5 mg/dl of N-NH3 in the rumen of goats fed buffel grass.

Effect of feeding frequency on the diurnal changes in microbial protein, volatile fatty acids and ammonia contents of the rumen of sheep

1979 ◽  
Vol 93 (1) ◽  
pp. 67-70 ◽  
Author(s):  
T. Michałowski
Keyword(s):  
Fatty Acids ◽  
Total Protein ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
Diurnal Changes ◽  
Microbial Protein ◽  
Feeding Frequency ◽  
Protein Nitrogen ◽  
Effect Of Feeding

SUMMARYDiurnal variations in microbial protein nitrogen, total volatile fatty acids and ammonia were examined in two wethers fed once and twice daily with 0·4 kg of concentrateand 0·4 kg hay/day. The total protein nitrogen varied during the day from 76·9 to 130·2 mg/100 ml of rumen fluid. The greatest amount of protein nitrogen was noted immediately before feeding and the smallest 4 h after feeding. The protein nitrogen of rumen protozoa formed about 39·8–53·4% of total protein nitrogen in rumen fluid. Volatile fatty acids varied from 74·0 to 130·5 m-mol/1 of rumen fluid and ammonia from 187·0 to 305·6 mg/1. The higher concentration of total and protozoal protein nitrogen and of VFA was observed when animals were fed twice daily. The changing of feeding frequency from once to twice daily caused an increase of ammonia concentration in the rumen of only one wether. The results obtained are discussed.

EFFECT OF TANNIN CONTENT IN TWO ISOSYNTHETIC STRAINS OF BIRDSFOOT TREFOIL (Lotus corniculatus L.) ON FEED DIGESTIBILITY AND RUMEN FLUID COMPOSITION IN SHEEP

1989 ◽  
Vol 69 (4) ◽  
pp. 1031-1039 ◽  
Author(s):  
J. CHIQUETTE ◽  
K.-J. CHENG ◽  
L. M. RODE ◽  
L. P. MILLIGAN
Keyword(s):  
Crude Protein ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Lotus Corniculatus ◽  
Ammonia Nitrogen ◽  
Birdsfoot Trefoil ◽  
Fluid Composition ◽  
Protein Nitrogen ◽  
Ruminal Ph ◽  
Feed Digestibility

Low tannin (LT) and high tannin (HT) isosynthetic strains of birdsfoot trefoil containing 1 and 3% condensed tannins on a dry matter (DM) basis were cut fresh daily and fed to eight ruminally cannulated Suffolk wethers. Rumen fluid samples were collected before feeding and 3 and 6 h after feeding for pH, chlorophyll, supernatant protein nitrogen (N), ammonia nitrogen (NH3-N) and volatile fatty acids (VFA) determinations, and protozoa counts. Daily samples of the forage fed to the animals, and of feces, were analyzed for crude protein (CP) content, acid detergent fiber (ADF) and organic matter (OM). Results from rumen fluid analyses indicated that sheep receiving the HT strain had lower (P < 0.01) supernatant protein N and NH3-N concentrations, and consistently but not significantly lower VFA and chlorophyll concentrations. Animals fed HT showed higher (P < 0.05) protozoa counts than LT-fed animals, but only in the samples taken 3 h postfeeding. Ruminal pH was similar on LT and HT diets. Apparent digestibility of CP was 9% less (P < 0.05) in sheep fed the HT strain. However, apparent digestibilities of DM, OM and ADF were not affected by the tannin level. Key words: Lotus corniculatus L., birdsfoot trefoil, tannin, digestibility, rumen, sheep

Uromol as a source of dietary nitrogen for ruminants: metabolic and rumen fermentation studies on buffalo calves

1978 ◽  
Vol 91 (2) ◽  
pp. 309-316 ◽  
Author(s):  
N. S. Malik ◽  
P. N. Langar ◽  
A. K. Chopra
Keyword(s):  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Rumen Fluid ◽  
Nitrogen Retention ◽  
Buffalo Calves ◽  
Crude Fibre ◽  
Protein Nitrogen ◽  
Total N ◽  
Groundnut Meal

SUMMARYThe nutritive value of uromol, a heated product of urea and molasses, was compared with raw urea–molasses and groundnut meal in three metabolic trials on buffalo calves. The non-protein nitrogen (NPN) as urea or uromol contributed about 65, 48 and 30% of the nitrogen in the experimental concentrate mixtures, replacing partially or completely the groundnut meal of the control diets. The results showed that at 65% nitrogen replacement, the crude fibre and cellulose digestibilities and the nitrogen retention of the uromol diet was similar to that of the control but was significantly (P < 0·05) higher than the urea–molasses diet. At 48% nitrogen replacement the nitrogen retention in the uromol-fed animals was still significantly (P < 0·05) higher than the urea–molasses fed group. At 30% nitrogen replacement, the differences between the control, urea–molasses and uromol groups were not significant.In vivo rumen studies with the diets containing 50% NPN replacement showed lower but sustained ammonia-N with uromol than the urea–molasses diet. The total volatile fatty acids (TVFA) in rumen fluid, though initially higher in the control and uromol groups, were not significantly different from the urea–molasses group. Abomasal studies with diets containing 65% N as urea or uromol indicated a higher total nitrogen content in the abomasal fluid of the control and uromol-fed animals than the urea-fed animals. The 24 h abomasal passage of total-N/100 g nitrogen consumed was 95·5, 93·5 and 77·9 g in control, uromol and urea groups, respectively. The TCA-precipitatable-N (TCA-N) was also higher in the first two groups. These studies suggest that uromol is safer and has a better feeding value than urea–molasses at high rates of nitrogen replacement.

scholarly journals Rates of proteolysis in the rumen of the soluble proteins casein, Fraction I (18S) leaf protein, bovine serum albumin and bovine submaxillary mucoprotein

1983 ◽  
Vol 50 (2) ◽  
pp. 357-368 ◽  
Author(s):  
J. H. A. Nugent ◽  
W. T. Jones ◽  
D. J. Jordan ◽  
J. L. Mangan
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Similar Rate ◽  
Leaf Protein ◽  
Protein Chain ◽  
Protein Nitrogen ◽  
The Individual ◽  
Fraction I ◽  
Protein Bovine Serum Albumin

1. The rate of proteolysis in the rumen was dependent on the soluble protein used. With a sheep on a hay + concentrate diet the rates (approximately Vmax) for casein, Fraction I leaf protein and bovine serum albumin were 16·5, 3·4 and 0·9 mg protein nitrogen/l per min respectively.2. Change of diet from hay + concentrate to fresh lucerne (Medicago sativa) increased the proteolytic rates for all three proteins.3. Bovine submaxillary mucoprotein degraded extremely slowly in the rumen at approximately 0·5–0·6 mg N/l per min and its sialic acid component was degraded at a similar rate to that of the protein chain.4. Uniformly14C-labelled Fraction I leaf protein was used to demonstrate that in the presence of a second protein, competition for enzymic sites occurred. In Fraction I and bovine serum albumin mixtures, reduced rates for the individual proteins of the mixture were observed compared with the proteins treated separately.5. Treatment of bovine serum albumin with dithiothreitol (0·2 g/l) to cleave disulphide bridges increased the rates of proteolysis by as much as 8·5-fold.

Protection of leaf protein of lucerne (Medicago sativa L.) against degradation in the rumen by treatment with formaldehyde and glutaraldehyde

1980 ◽  
Vol 95 (3) ◽  
pp. 603-617 ◽  
Author(s):  
J. L. Mangan ◽  
D. J. Jordan ◽  
Janet West ◽  
P. J. Webb
Keyword(s):  
Medicago Sativa ◽  
Rumen Fluid ◽  
Major Effect ◽  
Toxic Effects ◽  
Leaf Protein ◽  
Tween 20 ◽  
Total N ◽  
Mean Values ◽  
Soluble Leaf Protein ◽  
Micro Organisms

SUMMARYAqueous glutaraldehyde, in the presence of wetting agents Tween-20 or Haemosol, reacted with fresh cut lucerne (Medicago sativa L.), complete reaction being obtained with about 7·2 g (72 mmol)/kg herbage, or 18g/100g crude protein. Reaction with 25% w/v aqueous glutaraldehyde sprayed on to fresh lucerne was rapid, and at the rate of 66 mmol/kg lucerne, all aldehyde had reacted in 3 h and about 60% of the soluble leaf protein became insoluble. Formaldehyde at twice the molar concentration of glutaraldehyde was absorbed rapidly, but a longer time, up to 24 h, was required for the protein to become insoluble. Treatments with 22, 44 and 66 mmol glutaraldehyde/kg lucerne, and 44, 88 and 132 mmol formaldehyde/kg showed that reaction with leaf protein was approximately proportional to the amount of aldehyde. A major effect on the leaf cells was the fixation of chloroplasts, and intact fixed chloroplasts were isolated from treated lucerne with high protein: chlorophyll ratios of 5·8:1 to 9·5:1.Two varieties of lucerne, Kabul and Europe, pot-grown in a controlled environment cabinet, reacted rapidly when sprayed with glutaraldehyde and in 3 h soluble leaf protein was reduced from 30 to 16–17% of the total N. The plants rapidly lost water and the dry matter of the leaves rose to 42% for Kabul and 45% for Europe in 24 h. Stems showed little effect. Field spraying of lucerne with glutaraldehyde similarly fixed soluble leaf protein and caused desiccation of the leaves, rising to 47–50% D. M. in 3 days. The stems were little affected and subsequent regrowth of the plants was not inhibited.Feeding glutaraldehyde- and formaldehyde-sprayed lucerne to rumen-fistulated cattle showed that release of soluble leaf protein into the rumen fluid was greatly reduced, mean values being 40 and 43% respectively of the values obtained when control lucerne was fed. Mean ammonia concentrations were similarly reduced to 49 and 33% of the control values. Formaldehyde-treated lucerne, even after reaction for several days, frequently showed toxic effects on rumen micro-organisms, particularly protozoa. Glutaraldehyde reacted more rapidly with herbage and no toxic effects were observed. Both glutaraldehyde- and formaldehyde-treated lucerne were highly palatable to cattle.

scholarly journals Identification of the Potential Role of the Rumen Microbiome in Milk Protein and Fat Synthesis in Dairy Cows Using Metagenomic Sequencing

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Xin Wu ◽  
Shuai Huang ◽  
Jinfeng Huang ◽  
Peng Peng ◽  
Yanan Liu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Amino Acid ◽  
Milk Fat ◽  
Milk Protein ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Abundant Species ◽  
Metagenomic Sequencing ◽  
Amino Acid Synthesis ◽  
Prevotella Species

The rumen contains abundant microorganisms that aid in the digestion of lignocellulosic feed and are associated with host phenotype traits. Cows with extremely high milk protein and fat percentages (HPF; n = 3) and low milk protein and fat percentages (LPF; n = 3) were selected from 4000 lactating Holstein cows under the same nutritional and management conditions. We found that the total concentration of volatile fatty acids, acetate, butyrate, and propionate in the rumen fluid was significantly higher in the HPF group than in the LPF group. Moreover, we identified 38 most abundant species displaying differential richness between the two groups, in which Prevotella accounted for 68.8% of the species, with the highest abundance in the HPF group. Functional annotation based on the Kyoto Encyclopedia of Gene and Genome (KEGG), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG), and Carbohydrate-Active enzymes (CAZy) databases showed that the significantly more abundant species in the HPF group are enriched in carbohydrate, amino acid, pyruvate, insulin, and lipid metabolism and transportation. Furthermore, Spearman’s rank correlation analysis revealed that specific microbial taxa (mainly the Prevotella species and Neocallimastix californiae) are positively correlated with total volatile fatty acids (VFA). Collectively, we found that the HPF group was enriched with several Prevotella species related to the total VFA, acetate, and amino acid synthesis. Thereby, these fulfilled the host’s needs for energy, fat, and rumen microbial protein, which can be used for increased biosynthesis of milk fat and milk protein. Our findings provide novel information for elucidation of the regulatory mechanism of the rumen in the formation of milk composition.

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