Measurement in sheep of the quantity and composition of rumen digesta and of the fractional outflow rates of digesta constituents

1980 ◽  
Vol 31 (6) ◽  
pp. 1129 ◽  
Author(s):  
GJ Faichney
Keyword(s):  
Particulate Matter ◽  
Retention Time ◽  
Microbial Population ◽  
Quantitative Prediction ◽  
Representative Sampling ◽  
Mean Retention Time ◽  
Outflow Rate ◽  
Few Data ◽  
Specific Labelling

Knowledge of the fractional outflow rates of rumen digesta constituents is required for the quantitative prediction of rumen function. However, there are few data available for these parameters because of the problems associated with specific labelling of digesta constituents and with the need to ensure that samples are truly representative of rumen digesta. Methods are described here by which two markers can be used together to overcome the problem of representative sampling of the rumen, so eliminating the need for specific labelling, with 'ideal' markers, of digesta constituents. Thus, from the measurement of the amount and composition of true digesta in the rumen and the amount and composition of true digesta flowing from the abomasum, values for the fractional outflow rates (and its reciprocal, mean retention time) of rumen digesta constituents can be calculated. Appropriate application of these methods will allow the derivation of functions to predict fractional outflow rates. The results presented show that the fractional outflow rate of an adsorbable marker, 103Ru-P, was about half that of water but was about twice that of particulate matter; it was also greater than the net value for microbes. On the assumption that microbial material leaving the rumen is drawn from a free-floating microbial population and a population associated with particulate matter, it was calculated that 0.29 � SE 0.07 (range 0.09-0.49) of the rumen microbial population could have been free-floating.

Rates of passage of solutes, microbes and particulate matter through the gastro-intestinal tract of ewes fed at a constant rate throughout gestation

1988 ◽  
Vol 39 (3) ◽  
pp. 481
Author(s):  
GJ Faichney ◽  
GA White
Keyword(s):  
Particulate Matter ◽  
Intestinal Tract ◽  
Microbial Population ◽  
Activity Index ◽  
Ammonia Nitrogen ◽  
Peristaltic Activity ◽  
Constant Rate ◽  
Outflow Rate ◽  
The Mean ◽  
Gastro Intestinal Tract

The rates of passage of solutes, microbes and particulate matter were measured at different stages of gestation in multiparous Corriedale ewes. The mean retention times (MRT) of each of these constituents in the rumen decreased as gestation progressed. There was an increase in the MRT of digesta distal to the stomach which was sufficient to compensate for the decrease in solute MRT in the rumen. Thus, for the whole tract, only the MRT of particulate matter decreased during gestation. There were good relationships between the rate of passage from the rumen of microbes and of particulate matter and that of water, reflecting the importance of water as the vehicle for passage from the rumen. The fractional outflow rate of the particle-associated marker 103Ru-phen was greater than the net value for microbes, but was similar to the calculated value for non-microbial, non-ammonia nitrogen. The proportion of the rumen microbial population that was free-floating declined to a minimum of 0.18 as the fractional outflow rate of water increased. A peristaltic activity index showed a tendency to decline, particularly in the duodenum, as gestation progressed.

scholarly journals Passage through the rumen and the large intestine of sheep estimated from faecal marker excretion curves and slaughter trials

1998 ◽  
Vol 80 (4) ◽  
pp. 381-389 ◽  
Author(s):  
A. de Vega ◽  
J. Gasa ◽  
C. Castrillo ◽  
J. A. Guada
Keyword(s):  
Large Intestine ◽  
Retention Time ◽  
Solid Phase ◽  
Sampling Period ◽  
Mean Retention Time ◽  
Ewe Lambs ◽  
Pulse Dose ◽  
Outflow Rate ◽  
Accuracy Of Prediction ◽  
The Relationship

External digesta markers (Yb-labelled diets and Co-EDTA) were given orally as a pulse dose to four pairs of Rasa Aragonesa twin ewe lambs, fed on either chopped or ground and pelleted lucerne hay, in order to estimate slow (k1) and fast (k2) rates of passage of liquid and solid phase from faecal marker excretion curves. After the faecal sampling period daily doses of the same markers were infused continuously for 5 d and the animals slaughtered. Concentrations of markers in the different compartments of the gut were determined and used to calculate mean retention times. The results showed that the rumen and the large intestine were the two main mixing compartments of the gut, accounting for more than 95% of total mean retention time. Rates of passage estimated from faecal marker excretion did not accurately represent marker kinetics in the compartments of the gut derived from slaughter data. Accuracy in the estimation of fractional outflow rate from rumen (kR) by k1 was higher for low values of kR whereas k2consistently overestimated large intestine outflow rate (kLI), especially for high values of kR. The relationship between outflow rates from the main two mixing compartments was important in influencing the accuracy of prediction of faecal estimates.

Corrigendum - Rates of passage of solutes, microbes and particulate matter through the gastro-intestinal tract of ewes fed at a constant rate throughout gestation

1988 ◽  
Vol 39 (3) ◽  
pp. 481
Author(s):  
GJ Faichney ◽  
GA White
Keyword(s):  
Particulate Matter ◽  
Intestinal Tract ◽  
Microbial Population ◽  
Activity Index ◽  
Ammonia Nitrogen ◽  
Peristaltic Activity ◽  
Constant Rate ◽  
Outflow Rate ◽  
The Mean ◽  
Gastro Intestinal Tract

The rates of passage of solutes, microbes and particulate matter were measured at different stages of gestation in multiparous Corriedale ewes. The mean retention times (MRT) of each of these constituents in the rumen decreased as gestation progressed. There was an increase in the MRT of digesta distal to the stomach which was sufficient to compensate for the decrease in solute MRT in the rumen. Thus, for the whole tract, only the MRT of particulate matter decreased during gestation. There were good relationships between the rate of passage from the rumen of microbes and of particulate matter and that of water, reflecting the importance of water as the vehicle for passage from the rumen. The fractional outflow rate of the particle-associated marker 103Ru-phen was greater than the net value for microbes, but was similar to the calculated value for non-microbial, non-ammonia nitrogen. The proportion of the rumen microbial population that was free-floating declined to a minimum of 0.18 as the fractional outflow rate of water increased. A peristaltic activity index showed a tendency to decline, particularly in the duodenum, as gestation progressed.

Effects of particle size on digestion of hay by sheep

1987 ◽  
Vol 109 (3) ◽  
pp. 551-561 ◽  
Author(s):  
B. Fadlalla ◽  
R. N. B. Kay ◽  
E. D. Goodall
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Retention Time ◽  
Terminal Ileum ◽  
Dry Matter ◽  
Degradation Rate ◽  
Apparent Digestibility ◽  
Mean Retention Time ◽  
Rumen Ph ◽  
Significant Difference

SummaryThe digestion and retention times of milled hay diets were first studied in three sheep fitted with rumen and abomasal cannulae. The hay was milled through 5, 20 or 40 mm screens. Solubility of dry matter (D.M.) in water and rate of loss of D.M. from hay in nylon bags suspended in the rumen increased with fineness of grinding. Apparent digestibility of D.M. within the gut tended to fall with fineness of grinding, as did mean retention time (MRT) of a particulate marker, [103Ru]phenanthroline ([103Ru]phen), within the gut and of [103Ru]phen and a liquid marker, [51Cr]EDTA, within the rumen. Dry-sieved abomasal particles were much smaller than particles of any of the hay preparations, most passing through a 0·6 mm screen.A second experiment was made on four other sheep, fitted with rumen cannulae and given a similar hay, chopped to 50 mm or milled through 2, 5 or 20 mm screens. Apparent digestibility of D.M. within the gut fell significantly with fineness of grinding, from 55% with the chopped hay to 46% with the 2 mm hay, as did MRT, from 45 to 40 h respectively. Rumen pH at 1 h after feeding decreased with fineness of grinding.In a third experiment, using the four sheep given chopped or 2 mm hay, retention times of particulate matter and of fluid in the reticulo-rumen and in the caecum-colon were measured. [103Ru]phen and [51Cr]EDTA were dosed together into either the rumen or the terminal ileum, and the rates of decline of marker concentration in rumen samples or faeces respectively were used to calculate the appropriate half times(t½). In the rumen particulate and fluid markers showed significantly shorter t½ values with the 2 mm hay (20·8 and 12·4 h, respectively) than with the chopped hay (25·9 and 15·6 h, respectively) without a significant difference in rumen outflow (0·437 and 0·492 l/h, respectively). In the caecum-colon the corresponding t½ values were 6·4 and 6·3 h, and 7·1 and 6·6 h, there being no significant difference either between markers or between diets.Samples of chopped hay and of 20, 5 and 2 mm hays were suspended in bags in the rumen of sheep given either chopped or 2 mm hay to eat. The fine hays lost D.M. more rapidly than the coarse hays but D.M. loss was slower when the sheep's diet was 2 mm hay that when it was chopped hay.It is concluded that three factors accounted for the effect of milling on digestibility: retention time in the reticulo-rumen, D.M. degradation rate in the rumen, and the potential digestibility of the hay preparation (asymptotic D.M. loss as measured in the rumen bag studies). It appeared that fine grinding reduced the digestibility of the hay because the effects of shortened MRT in reducing duration of digestion and of lowered rumen pH in depressing cellulolysis outweighed the effects of grinding in accelerating digestion and increasing potential digestibility within the rumen.

Assessment of the heterogeneous ruminal fiber pool and development of a mathematical approach for predicting the mean retention time of feeds in goats1

2014 ◽  
Vol 92 (3) ◽  
pp. 1099-1109 ◽  
Author(s):  
J. G. L. Regadas Filho ◽  
L. O. Tedeschi ◽  
R. A. M. Vieira ◽  
M. T. Rodrigues
Keyword(s):  
Retention Time ◽  
Mathematical Approach ◽  
Mean Retention Time ◽  
The Mean

Digestion and retention time of stained food in sheep

1987 ◽  
Vol 109 (3) ◽  
pp. 545-549 ◽  
Author(s):  
B. Fadlalla ◽  
R. N. B. Kay
Keyword(s):  
Retention Time ◽  
Brilliant Green ◽  
Mean Retention Time ◽  
The Mean ◽  
Oat Husk

SummaryThe suitability of stained food and [103Ru]phenanthroline-treated food as markers for measuring dietary retention time was examined in sheep. The digestibility of oat husk, assessed by incubation of samples contained in nylon bags in the rumen, was greatly depressed by staining with brilliant green, and slightly depressed by basic fuschsin. The latter effect appeared largely to be due to boiling rather than the stain itself.When milled hay treated with both basic fuschsin and [103Ru]phenanthroline was introduced into the rumen, the mean retention time estimated with the stain was about 40% longer than that estimated with [103Ru]phenanthroline.

A study on consistency of differences between cows in rumen outflow rate of fibrous particles and other substrates and consequences for digestibility and intake of roughages

1988 ◽  
Vol 47 (1) ◽  
pp. 45-51 ◽  
Author(s):  
E. R. Ørskov ◽  
I. Ojwang ◽  
G. W. Reid
Keyword(s):  
Retention Time ◽  
Fish Meal ◽  
Apparent Digestibility ◽  
Fresh Weight ◽  
Small Particles ◽  
Outflow Rate ◽  
Ad Libitum ◽  
Practical Implications

AbstractIn 22 cows given complete diets of 500 g straw and 500 g concentrates per kg fresh weight the outflow rate of small fibrous particles was determined on two occasions to investigate the consistency of this measurement and its association with apparent digestibility. The correlation between the outflow rates on the two occasions werer= +0·90 and the correlation with apparent digestibility wasr= −0·80.In a second experiment, the outflow rates of long and small particles were determined together with rumen retention time. There was no difference between outflow rate of long and small particles but rumen retention times were greater with the long particles. The correlation between the two estimates of outflow rate wasr= +0·84. The outflow rate of fish meal was found to be 0·070 while that of short fibrous particles was 0·031 per h. The average liquid outflow rate was 0·146 per h.The three cows with the highest outflow rate and the three with the lowest outflow rate from experiment 2 were selected for experiment 3. While voluntary food intakes of the two groups were similar, the differences in outflow rates between the cows persisted both withad libitumand restricted intakes of both a high and a low roughage diet. The differences were reflected in significant differences between the two groups in apparent digestibility of the diets. The practical implications for breeding and selection are discussed.

scholarly journals Retention time of chromium-labelled feed particles and of water in the gut of sheep given hay and concentrate at maintenance

1985 ◽  
Vol 53 (3) ◽  
pp. 559-567 ◽  
Author(s):  
J. E. Lindberg
Keyword(s):  
Pisum Sativum ◽  
Cottonseed Meal ◽  
Retention Time ◽  
Rapeseed Meal ◽  
Mean Retention Time ◽  
Faecal Samples ◽  
Grass Hay ◽  
The Mean ◽  
Chopped Grass

1. Sheep were given a diet of 400 g chopped grass hay/d and 500 g crushed barley/d in three equal meals. The mean retention time in the whole gut (MRT) and the rumen retention time (RRT) of chromium-labelled feed particles and of water were estimated from marker concentrations in faecal samples.2. MRT of Cr-labelled hay (Cr-H), barley hulls (Cr-Bh), crushed peas (Pisum sativum) (Cr-CP) and rapeseed meal (Cr-RSM) were 53.5, 52.3, 44.3 and 37.0 h respectively when estimated from total faecal collections. The estimates obtained from spot samples of faeces were almost identical.3. RRT of Cr-H, Cr-Bh, Cr-CP, Cr-RSM (Expts 1, 2 and 3) and Cr-labelled cottonseed meal (Cr-CSM) was 35.9, 36.7, 25.3, 18.8, 19.8, 22.8 and 25.3 h respectively.4. The Cr-labelled feed particles showed marked variations in density in water (Dω). However, both MRT and RRT were closely related to Dω, (r—0.88 and —0.95 respectively).5. Rumen outflow rates of Cr-RSM in individual animals were related to the rumen outflow rates of water (r 0.76).

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