Effects of level of intake and urea supplementation of alkali-treated straw on protozoal and bacterial nitrogen synthesis in the rumen and partition of digestion in cattle

1988 ◽  
Vol 39 (6) ◽  
pp. 1181 ◽  
Author(s):  
BS Punia ◽  
J Leibholz ◽  
GJ Faichney

Six Friesian heifers (c. 300 kg) fitted with cannulas were given diets of wheat straw sprayed with NaOH (4.4 % wlw) and essential minerals either with or without urea (3% w/w). The total protozoal numbers in the rumen fluid were not significantly different between dietary trcatments (mean 6.2 X 104/ml). However, there were more holotrichs and medium-size entodiniomorph protozoa in the rumen fluid of the cattle given the HU and LU diets than the Hand L diets. Protozoal counts in the omasal fluid were 44% of those in rumen fluid. The apparent digestibilities of OM and neutral-detergent fibre (NDF) in the stomach and in the total tract were lower with high than low feed intakes. The urea supplement enhanced the digestibilities of OM and NDF in the stomach and in the total tract. The total nitrogen (N) and non-ammonia N (NAN) flowing to the omasum and to the duodenum per unit of N intake were significantly greater with the low than the high feed intakes and with urea supplementation of the diets than without urea supplementation. The proportions of total microbial N and bacterial N in omasal NAN were higher with the supplement of urea than the unsupplemented straw. The bacterial N in the NAN flowing to the omasum was lower for the high than the low intakes. Concentrations of ammonia-N and total volatile fatty acids in rumen fluid were higher for the ureasupplemented straw than the unsupplemented straw. The high level of feed intake was associated with higher water volume and solid contents in the rumen.

1968 ◽  
Vol 35 (2) ◽  
pp. 203-212 ◽  
Author(s):  
R. Waite ◽  
Agnes G. Wilson

SummaryThe effect on the chemical composition of rumen fluid of replacing oilcake nitrogen by either biuret or urea N in the concentrate part of the ration for cows has been investigated. The biuret treatment produced the highest concentrations of NPN and the lowest concentrations of ammonia N in the fluid, whereas the urea treatment gave rise to higher concentrations of NPN than did the oilcake treatment and the highest ammonia N concentrations of the 3 diets. It is unlikely, however, that the differences in either peak or mean ammonia concentrations between the biuret and urea diets, if they occurred in lactating cows receiving these diets, would be sufficient to affect milk production. The concentration of ammonia N in the rumen liquor of cows on the biuret diet increased progressively up to the 5th to 8th week of feeding this diet. The different dietary treatments did not result in any marked differences in the concentrations of total volatile fatty acids in the rumen fluids or in the proportions of acetic, propionic and butyric acids in the total fatty acids.


1987 ◽  
Vol 57 (1) ◽  
pp. 89-98 ◽  
Author(s):  
J. A. Rooke ◽  
N. H. Lee ◽  
D. G. Armstrong

1. In an incomplete 5 x 5 Latin square experiment, four cattle were given grass silage in two meals per d to satisfy 1.15 maintenance energy requirements. In addition, water or casein (21 g nitrogen and 0.17 kg organic matter (OM)/d) or urea (U; 28 g N/d) or a glucose syrup (G; 0.87 kg OM/d) or casein and glucose syrup (CG; 17 g N and 0.93 kg OM/d) were infused intraruminally at a constant rate.2. A 24 h collection of duodenal digesta was made using chromic oxide for flow estimation and 35S as a marker of microbial N entering the small intestine. Samples of rumen fluid were also taken for estimation of rumen pH, and concentrations of ammonia-N and volatile fatty acids.3. The intraruminal infusions had no significant effects on rumen pH, concentrations of volatile fatty acids or their molar proportions. Infusion of either C or U significantly (P < 0.05) increased rumen NH3-N concentrations whereas infusions of either G or CG lowered rumen NH3-N concentrations.4. Infusions of C or U had no significant effect on the quantities of OM, acid-detergent fibre (ADF) or N constituents which entered the small intestine.5. Infusions of G or CG increased the quantities of OM (G P < 0.05, CG P < 0.01), ADF (CG P < 0.05), non-NH3-N (G P < 0.05, CG P < 0.01), amino acid N (G P < 0.05, CG P < 0.01) and microbial N (G P < 0.05, CG P < 0.01) which entered the small intestine.6. The efficiency of rumen microbial N synthesis was unchanged by the infusion of C, U or G (P > 0.05) but increased significantly (P < 0.05) when CG were infused.


2005 ◽  
Vol 45 (12) ◽  
pp. 1529 ◽  
Author(s):  
Y. J. Williams ◽  
P. T. Doyle ◽  
A. R. Egan ◽  
C. R. Stockdale

An experiment was conducted to investigate the hypothesis that increasing the intake of Persian clover (Trifolium resupinatum L.) would decrease rumen fluid pH and the rate of loss of neutral detergent fibre from nylon bags. It was further hypothesised that the reduction in the rate of disappearance of neutral detergent fibre with increased intake would be less in highly digestible clover than in highly digestible ryegrass or pasture hay. Sixteen rumen fistulated cows, in late lactation, were used in a completely randomised, split-plot design for 33 days. There were 4 pasture allowance treatments (9, 16, 32 and 53 kg dry matter (DM)/cow.day of Persian clover) with 4 cows per treatment. Cows grazed in individual plots, pasture intakes were measured, and rumen fluid and in sacco measurements were undertaken. Pasture DM intake increased asymptotically as pasture allowance increased from 9 to 53 kg DM. Cows grazing at the 9 kg pasture allowance spent less time grazing than cows at higher allowances (294 v. 368, 421 and 414 min, P<0.05). Cows grazing at the 2 lower allowances spent less time grazing at night than cows at the 2 higher allowances. There was no effect (P>0.05) of pasture allowance on time spent ruminating, which averaged 236 min. Estimated rates of intake increased (P<0.05) with pasture allowance. Average daily rumen fluid pH decreased linearly (P<0.05) with pasture intake, with the averages for the pasture allowance treatments being 6.03, 5.95, 5.83 and 5.79 as pasture allowance increased. The patterns of rumen fluid pH over 24 h indicated that it was only late in the night that treatment differences were detected, with the lower pasture allowance treatments recording higher rumen fluid pH values than the higher pasture allowance treatments. There was no effect of pasture allowance on average daily rumen fluid ammonia-N concentrations (25 mg/100 mL). Total volatile fatty acids concentrations averaged 139, 152, 163 and 168 mmol/L as pasture allowance increased from 9 to 53 kg DM/cow.day. The proportion of acetate in total volatile fatty acids generally declined (71.4, 70.4, 67.4 and 69.2%; s.e.d. = 1.14) and the proportion of propionate generally increased (15.2, 15.5, 17.6 and 17.0%; s.e.d. = 0.77) as pasture allowance increased from 9 to 53 kg DM/cow, respectively. Rate of neutral detergent fibre loss from nylon bags was highest in clover, and lowest in hay, and was higher in cows grazing at 9 and 16 kg allowances compared with cows at 32 and 53 kg (P<0.05). There was a linear relationship (P<0.05) between rate of neutral detergent fibre loss and rumen fluid pH for clover and ryegrass, but not hay (P>0.05). There were no differences (P>0.05) in total rumen contents (75.6 kg; s.e.d. = 6.95), or DM (7.3 kg; s.e.d. = 0.73) and neutral detergent fibre (2.7 kg; s.e.d. = 0.32) pools, of cows grazing at different allowances. Offering cows increasing allowances of Persian clover pasture reduced rumen digesta retention times, as rumen pool sizes did not change. Average daily pH fell with increasing allowance due to differences in daily intake and pH patterns, and increasing pasture allowance decreased the rate of disappearance of neutral detergent fibre. It is suggested that increased outflow rates, driven by differences in daily pH patterns and changes in substrate composition, were responsible for the decline in disappearance of neutral detergent fibre from nylon bags, but the effects of the factors cannot be separated.


2017 ◽  
Vol 86 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Leoš Pavlata ◽  
Ondřej Šťastník ◽  
Štěpánka Křivová ◽  
Hana Dočkalová ◽  
Lenka Sedláková ◽  
...  

The aim of the study was to determine the effect of different physical forms of starter feed on rumen fermentation indicators of calves after weaning and their weight gain. The experiment was performed with Czech Fleckvieh calves after weaning. The calves were fed ad libitum completely pelleted starter feed or texturized starter feed with chopped straw. The rumen fluid samples were collected after a month of feeding the starter feeds. The calves were weighed monthly. The pH, total acidity, total volatile fatty acids, acetate, propionate, butyrate, lactic acid, ammonia and the number of rumen ciliate protozoa were determined in the rumen fluid samples. The calves receiving the starter feed with straw showed significantly higher rumen pH (6.24 ± 0.51 vs. 5.58 ± 0.30), total volatile fatty acids (98.02 ± 20.46 vs. 61.40 ± 26.51 mmol/l), molar proportion of acetate (61.20 ± 4.87 vs. 50.53 ± 4.66%), and the acetate:propionate ratio (2.38 ± 0.53 vs. 1.34 ± 0.18) and lower molar proportion of propionate (26.55 ± 4.48 vs. 37.92 ± 3.58%) compared with the calves receiving pelleted starter feed. Average daily gain of the calves did not differ significantly. The feeding of starter feed with chopped straw compared with the pelleted starter feed led to better development of the rumen fermentation evaluated by rumen pH, by total volatile fatty acids production, and by the proportion and ratio of acetic and propionic acids. The feeding of starter feed with chopped straw reduced the occurrence of subacute ruminal acidosis in the weaned calves.


1967 ◽  
Vol 18 (1) ◽  
pp. 107 ◽  
Author(s):  
RA Weller ◽  
FV Gray ◽  
AF Pilgrim ◽  
GB Jones

(1) In sheep fed at 12-hr intervals on roughage diets (lucerne and wheaten hay) total volatile fatty acid production in the rumen has been measured by an isotope dilution procedure based on the infusion of a single 14C-labelled volatile fatty acid. (2) Total and individual acid production has been measured through the infusion of a mixture of 14C-labelled acids in which the proportions of individual acids were such that transfers of 14C by interconversions between the acids were balanced. (3) The findings support the view that the mixture of acids produced in the rumen is similar in composition to that present in the rumen fluid throughout the feeding cycle. Consequently it was possible to determine the production of individual acids by a relatively simple procedure requiring only the infusion of a single 14C-labelled acid and measurement of the concentration of 14C in a composite sample of the acids in the rumen fluid collected throughout the feeding cycle. This procedure is considered suitable for routine use; automatic sampling of rumen fluid still further reduces the work involved. (4) The infusion of certain mixtures of 14C-labelled fatty acids showed that the composition of the acid initially formed in the rumen was acetic 77–83%, propionic 15–18%, and butyric 1–7% according to the diet given and the time elapsed after feeding. From 50 to 80% of the butyric acid in the final volatile acid product was formed from acetic acid. Degradation of 14C-labelled butyrate formed from [1-14C] acetate in the rumen showed 93% of the 14C to be nearly evenly divided between carbon atoms C1 and C3.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Xin Wu ◽  
Shuai Huang ◽  
Jinfeng Huang ◽  
Peng Peng ◽  
Yanan Liu ◽  
...  

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.


1971 ◽  
Vol 51 (3) ◽  
pp. 721-727 ◽  
Author(s):  
L. J. FISHER ◽  
J. D. ERFLE ◽  
F. D. SAUER

Glutamate, succinate, propylene glycol, or glycerol were added to a basic concentrate at 3.3% of air-dry feed. Each concentrate was fed both ad libitum and in restricted amounts to four cows in early lactation. Dietary intake, milk yield and composition, molar proportions of rumen volatile fatty acids and blood glucose, ketones and plasma free fatty acids were used as criteria of effect of these supplements. Propylene glycol in the diet resulted in a lower intake of concentrate compared with glycerol (11.44 versus 14.30 kg/day) and significantly decreased (P < 0.05) rumen butyrate and plasma beta-hydroxybutyrate. Glutamate supplementation prevented the fall in milk fat content which occurred when the other three supplemented concentrates were fed ad libitum, and this effect may have been related to the constancy in the ratio of acetate to propionate in the rumen fluid.


2018 ◽  
Vol 39 (6) ◽  
pp. 2621
Author(s):  
Ludmila Couto Gomes ◽  
Claudete Regina Alcalde ◽  
Julio Cesar Damasceno ◽  
Luiz Paulo Rigolon ◽  
Ana Paula Silva Possamai ◽  
...  

Feeding goats with calcium salts of fatty acids (CSFA) can supply ruminants with lipids, with minimal effects on ruminal fermentation and fiber digestibility. However, there is a shortage of information on the effect of CSFA on characteristics of rumen fermentation in grassland goats. Thus, the present study aimed to assess the addition of CSFA to concentrate on the parameters of rumen fermentation of grazing goats. Five rumen cannulated goats were distributed in a Latin square 5x5 design (treatments: 0%, 1.5%, 3.0%, 4.5% and 6.0% CSFA. The pH, ammonia N and volatile fatty acids (VFA) content were analyzed in the ruminal fluid at 0, 2, 4, 6 and 8 hours after concentrate supplementation. The pH and ammonia N concentration showed a linear effect with the addition of CSFA. There was no effect observed for the VFA molar concentration after grazing goats were fed with the experimental diet. In conclusion, further research is needed to investigate the addition of CSFA to goat diets because there is evidence that CSFA increases ruminal pH and decreases excess ruminal ammonia without changing the VFA concentration in the rumen fluid.


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