Effect of dietary ergot on the mean transit time of digesta in the small intestine of sheep

1991 ◽  
Vol 71 (3) ◽  
pp. 767-771
Author(s):  
R. G. Rotter ◽  
G. D. Phillips
Keyword(s):  
Small Intestine ◽  
Transit Time ◽  
Mean Transit Time ◽  
Ergot Alkaloids ◽  
Latin Square ◽  
Repeated Measurements ◽  
Design Experiment ◽  
Transit Times ◽  
The Mean ◽  
Treatment Concentration

Ergot (Claviceps purpurea) causes serious deleterious effects in animals which ingest it, and it may also affect the rate of passage of digesta through the intestine. In a Latin square design experiment with repeated measurements, the mean transit times (MTT) of digesta in the small intestine were determined in four intact rams fed ergot (0.0, 0.05, 0.10 and 0.15% of the diet) with their daily feed allotments. Although there was a very slight indication of an effect as the ergot treatment concentration increased, the values were not significantly different (P > 0.05). Despite possible differences in the effects of individual constituent ergot alkaloids, there was no affect on the MTT in the small intestine of sheep. Key words: Ergot, rate of passage, sheep, mean transit time

The digestion by cattle of silage and barley diets containing increasing quantities of fishmeal

1987 ◽  
Vol 109 (2) ◽  
pp. 261-272 ◽  
Author(s):  
J. A. Rooke ◽  
D. G. Armstrong
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Synthetic Fibre ◽  
Latin Square ◽  
Basal Diet ◽  
Design Experiment ◽  
The Mean ◽  
Daily Intakes ◽  
Feeding Diets ◽  
Microbial N

SummaryA 4 × 4 latin-square design experiment was carried out to determine the effects of increasing nitrogen (N) intake by feeding diets containing increasing amounts of fishmeal upon the digestion of organic matter (OM) and N by cattle equipped with rumen and duodenal cannulae. A basal diet (B) containing 600 g silage and 400 g ground barley/kg diet and three diets (BF1, BF2 and BF3) in which increasing amounts of the silage and barley basal diet were proportionately replaced by fishmeal were fed. The mean daily intakes of OM and N when each diet was fed were 4·29, 4·28, 4·22 and 4·20 kg OM and 90, 108, 125 and 143 g N for diets B, BF1, BF2 and BF3 respectively.Neither the amounts of OM entering the small intestine nor those voided in the faeces were altered by the diets fed. Thus mean apparent OM digestibility for all the diets fed was 0·74 ± 0·007 and the proportion of digestible OM intake apparently digested in the rumen was 0·83±0·011.Mean daily concentrations of ammonia N in the rumen were significantly(P <0·01) increased from 85 mg N/l (diet B) to 129 mg N/1 (diet BF3) as fishmeal intake increased.The quantities of non-ammonia N (P<0·05) and of amino acid N (P<0·001) entering the small intestine were significantly increased as more fishmeal was added to the diets fed. As fishmeal intake increased apparent N digestibility was significantly (P<0·001) increased.Neither the quantities of microbial N entering the small intestine daily nor the apparent efficiency of microbial N synthesis within the rumen were increased by the diets fed. The quantities of feed N entering the small intestine daily were significantly (P<0·01) increased as fishmeal intake increased; thus apparent feed N degradability in the rumen was significantly (P<0·05) decreased from 0·84 (diet B) to 0·73 (diet BF3) as fishmeal intake increased. Similarly, the rates of disappearance of N from each of the four barley or barley and fishmeal concentrates when incubated in the rumens of the cattle in porous synthetic fibre bags were decreased as the proportion of fishmeal in the concentrates increased. Thus, the rumen N degradability of the diets fed, when calculated from the rates of disappearance of N from porous synthetic fibre bags placed in the rumen, decreased as fishmeal intake increased.As fishmeal intake increased the amino acid composition of duodenal digesta (expressed as g/kg determined amino acids) changed such that the content of arginine increased (P<0·01) and the content of isoleucine decreased (P<0·01). The concentrations of arginine (P<0·01), leucine and lysine (P<0·05) in blood plasma increased as fishmeal intake increased.

scholarly journals Dating of streamwater using tritium in a post-bomb world: continuous variation of mean transit time with streamflow

2010 ◽  
Vol 7 (4) ◽  
pp. 4731-4760 ◽  
Author(s):  
U. Morgenstern ◽  
M. K. Stewart ◽  
R. Stenger
Keyword(s):  
New Zealand ◽  
Transit Time ◽  
Time Series Data ◽  
Stream Water ◽  
Mean Transit Time ◽  
Low Flow ◽  
Series Data ◽  
Transit Times ◽  
Bomb Test ◽  
The Mean

Abstract. Tritium measurements of streamwater draining the Toenepi catchment, a small dairy farming area in Waikato, New Zealand, have shown that the mean transit time of the water varies with the flow of the stream. Mean transit times through the catchment are 2–5 years during high baseflow conditions (in winter), becoming older as streamflow decreases (in summer), and then quite dramatically older during drought conditions, with ages of more than 100 years. Older water seems to be gained in the lower reaches of the stream, compared to younger water in the headwater catchment. The groundwater store supplying baseflow was estimated from the mean transit time and average baseflow to be 15.4×106 m3 of water, about 1 m water equivalent over the catchment and 2.3 times total annual streamflow. Nitrate from recent intensified land use is relatively high at normal streamflow, but is low at times of low flow with old water. This reflects both lower nitrate loading in the catchment several decades ago, and active denitrification processes in older groundwater. Silica, leached from the aquifer material and accumulating in the water in proportion to contact time, is high at times of low streamflow. There was a good correlation between silica and streamwater age, which potentially allows silica concentrations to be used as a proxy for age when calibrated by tritium measurements. This study shows that tritium dating of stream water is possible with single tritium measurements now that bomb-test tritium has effectively disappeared from hydrological systems in New Zealand, without the need for time-series data.

scholarly journals Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow

2010 ◽  
Vol 14 (11) ◽  
pp. 2289-2301 ◽  
Author(s):  
U. Morgenstern ◽  
M. K. Stewart ◽  
R. Stenger
Keyword(s):  
New Zealand ◽  
Transit Time ◽  
Time Series Data ◽  
Stream Water ◽  
Mean Transit Time ◽  
Dairy Farming ◽  
Low Flow ◽  
Series Data ◽  
Transit Times ◽  
The Mean

Abstract. Tritium measurements of streamwater draining the Toenepi catchment, a small dairy farming area in Waikato, New Zealand, have shown that the mean transit time of the water varies with the flow rate of the stream. Mean transit times through the catchment are 2–5 years during high baseflow conditions in winter, increasing to 30–40 years as baseflow decreases in summer, and then dramatically older water during drought conditions with mean transit time of more than 100 years. Older water is gained in the lower reaches of the stream, compared to younger water in the headwater catchment. The groundwater store supplying baseflow was estimated from the mean transit time and average baseflow to be 15.4 × 106 m3 of water, about 1 m water equivalent over the catchment and 2.3 times total annual streamflow. Nitrate is relatively high at higher flow rates in winter, but is low at times of low flow with old water. This reflects both lower nitrate loading in the catchment several decades ago as compared to current intensive dairy farming, and denitrification processes occurring in the older groundwater. Silica, leached from the aquifer material and accumulating in the water in proportion to contact time, is high at times of low streamflow with old water. There was a good correlation between silica concentration and streamwater age, which potentially allows silica concentrations to be used as a proxy for age when calibrated by tritium measurements. This study shows that tritium dating of stream water is possible with single tritium measurements now that bomb-test tritium has effectively disappeared from hydrological systems in New Zealand, without the need for time-series data.

Regional pulmonary transit times in humans

1989 ◽  
Vol 66 (2) ◽  
pp. 844-850 ◽  
Author(s):  
W. MacNee ◽  
B. A. Martin ◽  
B. R. Wiggs ◽  
A. S. Belzberg ◽  
J. C. Hogg
Keyword(s):  
Transit Time ◽  
Human Subjects ◽  
Mean Transit Time ◽  
Normal Subjects ◽  
Time Activity ◽  
Human Lungs ◽  
Transit Times ◽  
Lower Slice ◽  
The Mean ◽  
Deconvolution Techniques

We measured the frequency distribution of erythrocyte (RBC) transit times in resected lobes of lungs in eight human subjects undergoing thoracotomy for peripheral lung tumors. RBC transit times were measured by the injection of radiolabeled blood flow and volume markers, which were counted in samples from the resected lung. In five of these subjects, the measurements from the resected lung were compared with preoperative measurements of the transit times of radiolabeled RBCs with a gamma camera-computer system. Time-activity curves from the cardiac chambers and the lung or its regions were obtained from which transit times were calculated by the centroid and deconvolution techniques. The reproducibility of transit times measured by this technique was assessed in another eight normal subjects, after sequential bolus injections of radiolabeled cells. The mean transit time of the upper lung region was longer (5.1 +/- 0.5 s) than that of the lower (4.1 +/- 0.6 s, P less than 0.05) in the preoperative study. Similarly, the mean transit time of the upper lung slice was longer (5.5 +/- 0.3 s) than that of the lower slice (3.8 +/- 0.3 s, P less than 0.05) in the resected lung specimens. We conclude that there was good agreement between these techniques and that there are long transit times in the upper regions of human lungs.

scholarly journals An evaluation of the use of chromic oxide, polyethylene glycol and Cr-EDTA as markers for digestive studies along the small intestine of ruminants.

1981 ◽  
Vol 29 (3) ◽  
pp. 151-162
Author(s):  
J. van Bruchem ◽  
J. Wiersma ◽  
P.W.M. van Adrichem
Keyword(s):  
Small Intestine ◽  
Polyethylene Glycol ◽  
Transit Time ◽  
Mean Transit Time ◽  
Chromic Oxide ◽  
Flow Rates ◽  
The Mean ◽  
Infusion Tube

In cows, fitted with a T-shaped cannula in the duodenum and with a re-entrant cannula in the ileum, ileal recoveries were determined of Cr2O3, from impregnated paper and polyethylene glycol (PEG), introduced into the duodenum. The length of the collection periods of digesta was important. The mean transit time of both markers along the small intestine did not differ. In sheep, fitted with an infusion tube into the abomasum and with an ileal re-entrant cannula, PEG was recovered quantitatively over 10-h collection periods. In sheep, fitted with an infusion tube into the abomasum and with 4 T-shaped cannulae along the small intestine, flow rates of digesta in jejenum and ileum estimated with PEG and Cr-EDTA were similar. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Reabsorption kinetics of albumin from pleural space of dogs

1988 ◽  
Vol 255 (2) ◽  
pp. H375-H385 ◽  
Author(s):  
M. Miniati ◽  
J. C. Parker ◽  
M. Pistolesi ◽  
J. T. Cartledge ◽  
D. J. Martin ◽  
...  
Keyword(s):  
Control Mechanism ◽  
Mean Transit Time ◽  
Input Function ◽  
Pleural Space ◽  
Frequency Function ◽  
Liquid Pressure ◽  
Physiological Conditions ◽  
Transit Times ◽  
The Mean ◽  
Kinetics Of

The reabsorption of albumin from the pleural space was measured in eight dogs receiving 0.5 ml intrapleural injection of 131I-labeled albumin and a simultaneous intravenous injection of 125I-labeled albumin. Plasma curves for both tracers were obtained over 24 h. The 125I-albumin curve served as input function of albumin for interstitial spaces, including pleura, whereas the 131I-albumin curve represented the output function from pleural space. The frequency function of albumin transit times from pleural space to plasma was obtained by deconvolution of input-output plasma curves. Plasma recovery of 131I-albumin was complete by 24 h, and the mean transit time from pleura to plasma averaged 7.95 +/- 1.57 (SD) h. Albumin reabsorption occurred mainly via lymphatics as indicated by experiments in 16 additional dogs in which their right lymph ducts or thoracic ducts were ligated before intrapleural injection. A pleural lymph flow of 0.020 +/- 0.003 (SD) ml.kg-1.h-1 was estimated, which is balanced by a comparable filtration of fluid into the pleural space. This suggests that, under physiological conditions, the subpleural lymphatics represent an important control mechanism of pleural liquid pressure.

scholarly journals Aggregation in environmental systems: seasonal tracer cycles quantify young water fractions, but not mean transit times, in spatially heterogeneous catchments

2015 ◽  
Vol 12 (3) ◽  
pp. 3059-3103 ◽  
Author(s):  
J. W. Kirchner
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Strong Nonlinearity ◽  
Isotopic Tracers ◽  
Water Fraction ◽  
Benchmark Tests ◽  
Environmental Systems ◽  
Transit Times ◽  
Event Based ◽  
The Relationship

Abstract. Environmental heterogeneity is ubiquitous, but environmental systems are often analyzed as if they were homogeneous instead, resulting in aggregation errors that are rarely explored and almost never quantified. Here I use simple benchmark tests to explore this general problem in one specific context: the use of seasonal cycles in chemical or isotopic tracers (such as Cl−, δ18O, or δ2H) to estimate timescales of storage in catchments. Timescales of catchment storage are typically quantified by the mean transit time, meaning the average time that elapses between parcels of water entering as precipitation and leaving again as streamflow. Longer mean transit times imply greater damping of seasonal tracer cycles. Thus, the amplitudes of tracer cycles in precipitation and streamflow are commonly used to calculate catchment mean transit times. Here I show that these calculations will typically be wrong by several hundred percent, when applied to catchments with realistic degrees of spatial heterogeneity. This aggregation bias arises from the strong nonlinearity in the relationship between tracer cycle amplitude and mean travel time. I propose an alternative storage metric, the young water fraction in streamflow, defined as the fraction of runoff with transit times of less than roughly 0.2 years. I show that this young water fraction (not to be confused with event-based "new water" in hydrograph separations) is accurately predicted by seasonal tracer cycles within a precision of a few percent, across the entire range of mean transit times from almost zero to almost infinity. Importantly, this relationship is also virtually free from aggregation error. That is, seasonal tracer cycles also accurately predict the young water fraction in runoff from highly heterogeneous mixtures of subcatchments with strongly contrasting transit time distributions. Thus, although tracer cycle amplitudes yield biased and unreliable estimates of catchment mean travel times in heterogeneous catchments, they can be used reliably to estimate the fraction of young water in runoff.

scholarly journals Use of the mean transit time of an intravascular contrast agent as an exchange-insensitive index of myocardial perfusion

1999 ◽  
Vol 9 (3) ◽  
pp. 402-408 ◽  
Author(s):  
Massimo Lombardi ◽  
Richard A. Jones ◽  
J�rgen Westby ◽  
Geir Torheim ◽  
Timothy E. Southon ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Contrast Agent ◽  
Transit Time ◽  
Mean Transit Time ◽  
Intravascular Contrast Agent ◽  
The Mean

Lung water measurements with the mean transit time approach

1985 ◽  
Vol 59 (3) ◽  
pp. 673-683 ◽  
Author(s):  
R. M. Effros
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Tissue Perfusion ◽  
Time Data ◽  
Lung Water ◽  
Thermal Signal ◽  
The Mean ◽  
Points Of View ◽  
Vascular Obstruction ◽  
Pulmonary Vascular Obstruction

The potential usefulness and limitations of the double-indicator mean transit time approach for measuring lung water are evaluated from both theoretical and empirical points of view. It is concluded that poor tissue perfusion is the most serious factor that can compromise the reliability of this approach. Replacement of the conventional water isotopes with a thermal signal enhances indicator delivery to ischemic areas but the diffusion of heat is not sufficiently rapid to permit measurements of water in macroscopic collections of fluid which remain unperfused. The frequency of pulmonary vascular obstruction in patients with pulmonary edema related to lung injury suggests that interpretation of transit time data will be complicated by uncertainties concerning perfusion. Thermal-dye measurements of lung water may prove more helpful in situations where pulmonary blood flow remains relatively uniform.

Sign in / Sign up

Export Citation Format

Share Document