INFLUENCE OF IONOPHORE ADDITION TO ROUGHAGE AND HIGH-CONCENTRATE DIETS ON PORTAL BLOOD FLOW AND NET NUTRIENT FLUX IN CATTLE

1988 ◽  
Vol 68 (2) ◽  
pp. 419-429 ◽  
Author(s):  
D. L. HARMON ◽  
T. B. AVERY ◽  
G. B. HUNTINGTON ◽  
P. J. REYNOLDS
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Latin Square ◽  
Portal Blood Flow ◽  
Nutrient Flux ◽  
Portal Blood ◽  
Beef Steers ◽  
Beef Heifers ◽  
Net Flux ◽  
Hepatic Portal

Two experiments using cattle with chronic hepatic-portal and arterial catheters were conducted to investigate effects of ionophore addition to roughage and high-concentrate diets on net nutrient flux across portal-drained viscera. Monensin and salinomycin added to a high-concentrate diet fed to three beef heifers in a Latin square design (exp. 1) increased the net portal flux of propionate (P < 0.05) and glutamate (P < 0.05) with a tendency for increased portal blood flow. Two beef steers (exp. 2) were fed alfalfa with monensin (300 mg d−1) for 22 d prior to dietary monensin and samples were taken on days −3, 0, 1,2, 4, 9, 16, 32, and 35 relative to monensin removal. Portal blood flow and gut oxygen consumption decreased (P < 0.05) following monensin removal until day 9, then remained relatively constant. Use of glucose by portal-drained viscera decreased (P < 0.05) until day 16, then returned towards initial values, while net appearance of L-lactate decreased linearly (P < 0.05). After monensin removal from the diet, the net portal flux of L-lactate, ammonia-N, acetate, propionate, isobutyrate, and 3-methylbutyrate were reduced (P < 0.05). These reductions were largely the result of decreased portal blood flow. In both experiments, dietary ionophores affected net flux across portal-drained viscera for several metabolites. These changes may differ, however, with roughage level and ionophore fed. Key words: Bovine, ionophore, absorption, blood flow

Enhanced hepatic portal blood flow induced by prostaglandin E1 following liver transplantation in pigs

Surgery Today ◽  
1994 ◽  
Vol 24 (7) ◽  
pp. 621-626 ◽  
Author(s):  
Kazuhiro Tsukada ◽  
Takeo Sakaguchi ◽  
Takemi Tomiyama ◽  
Katsuyuki Uchida ◽  
Yoshinobu Sato ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Blood Flow ◽  
Prostaglandin E1 ◽  
Portal Blood Flow ◽  
Portal Blood ◽  
Hepatic Portal

Transit time ultrasound measurement of portal blood flow in cattle

1996 ◽  
Vol 1996 ◽  
pp. 239-239
Author(s):  
ARG Wylie ◽  
JD McEvoy ◽  
P McGrattan ◽  
DJ Devlin
Keyword(s):  
Blood Flow ◽  
Transit Time ◽  
Portal Blood Flow ◽  
Nutrient Flux ◽  
Portal Blood ◽  
Ultrasound Measurement ◽  
Once Daily ◽  
Dietary Nutrient ◽  
Frequent Feeding ◽  
Quantitative Characterisation

Portal blood flow (PF) is central to the quantitative characterisation of dietary nutrient uptake. Dilution of PAH (p-aminohippurate) is unsuited to rapidly changing flow and visceral studies often use frequent-feeding to encourage “steady-state” digestion and absorption and minimise postprandial PF variation. Such data is of limited value to understanding nutrient flux and visceral responses to conventional feeding (once/twice daily) eg. insulin levels did not differ on similar ME intakes of frequently-fed (12x2h) forage or concentrates (Reynolds and Tyrrell, 1991) whereas in steers fed once daily, insulin was higher (P<0.10) postprandially on a concentrate diet (Thorp et al., 1996). Transit-time ultrasound (TTU) gives real-time, continuous flow but the steer portal vein was regarded as anatomically unsuitable for TTU (Huntington et al., 1990) with PF of less than half those by PAH (20 vs 42ml/min/kg LW). The current study was initiated to monitor temporal PF changes by TTU in steers fed once-daily.

Transit time ultrasound measurement of portal blood flow in cattle

1996 ◽  
Vol 1996 ◽  
pp. 239-239
Author(s):  
ARG Wylie ◽  
JD McEvoy ◽  
P McGrattan ◽  
DJ Devlin
Keyword(s):  
Blood Flow ◽  
Transit Time ◽  
Portal Blood Flow ◽  
Nutrient Flux ◽  
Portal Blood ◽  
Ultrasound Measurement ◽  
Once Daily ◽  
Dietary Nutrient ◽  
Frequent Feeding ◽  
Quantitative Characterisation

Portal blood flow (PF) is central to the quantitative characterisation of dietary nutrient uptake. Dilution of PAH (p-aminohippurate) is unsuited to rapidly changing flow and visceral studies often use frequent-feeding to encourage “steady-state” digestion and absorption and minimise postprandial PF variation. Such data is of limited value to understanding nutrient flux and visceral responses to conventional feeding (once/twice daily) eg. insulin levels did not differ on similar ME intakes of frequently-fed (12x2h) forage or concentrates (Reynolds and Tyrrell, 1991) whereas in steers fed once daily, insulin was higher (P<0.10) postprandially on a concentrate diet (Thorp et al., 1996). Transit-time ultrasound (TTU) gives real-time, continuous flow but the steer portal vein was regarded as anatomically unsuitable for TTU (Huntington et al., 1990) with PF of less than half those by PAH (20 vs 42ml/min/kg LW). The current study was initiated to monitor temporal PF changes by TTU in steers fed once-daily.

scholarly journals The influence of food intake on portal blood flow and heat production in the digestive tract of sheep

1975 ◽  
Vol 34 (1) ◽  
pp. 125-139 ◽  
Author(s):  
A. J. F. Webster ◽  
P. O. Osuji ◽  
F. White ◽  
J. F. Ingram
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Food Intake ◽  
Digestive Tract ◽  
Heat Production ◽  
Portal Blood Flow ◽  
Total Heat ◽  
Portal Blood ◽  
Heat Increment

1. Measurements were made of portal blood flow, heat production and oxygen consumption in the digestive tract of sheep either fasted or given the following diets: chopped, dried grass; pelleted, dried grass; chopped, dried lucerne; pelleted, dried lucerne; or a pelleted baley diet.2. For sheep that had been fasted for 48 h, portal blood flow was 1.84 1/min, total visceral heat production was 62.3 kJ/kg body-weight0.75 per 24 h and aerobic heat production, estimated from oxygen consumption, was 62.1 kJ/kg body-weight0.75 per 24 h.3. Portal blood flow was markedly influenced by food intake, increasing from 1.8 1/min for starved sheep to 2.4 and 4 1/min for sheep fed at maintenance and 2.5 × maintenance levels of intake respectively. Variations in the quality and physical form of the diets had no apparent effect on portal blood flow.4. There was a curvilinear relationship between total heat production in the gut and metabolizable energy (ME) intake. The increase obtained for levels of intake below maintenance was greatest with lucerne diets, and least with pelleted, dried grass or pelleted barley diets. Above maintenance levels of intake the rate of increase in heat production, with all diets, was about 150 kJ/MJ ME intake.5. The heat of fermentation, estimated from the difference between total visceral metabolism and the aerobic metabolism of the tissues of the gut wall, was 76, 60 and 22 kJ/MJ digestible energy intake for the dried grass, lucerne and barley diets respectively.6. The contribution of fermentation heat and the aerobic metabolism of the gut to the total heat increment of feeding in sheep was assessed. It was concluded that about half the heat increment must be derived from tissues outside the digestive tract.

The effect of diet asynchrony on portal-drained viscera metabolism

1997 ◽  
Vol 1997 ◽  
pp. 1-1
Author(s):  
N.D. Scollan ◽  
E.J. Kim ◽  
M.S. Dhanoa ◽  
J.M. Gooden ◽  
M.A. Neville ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Portal Blood Flow ◽  
Portal Blood ◽  
Dietary Energy ◽  
Microbial Protein ◽  
Nutrient Use ◽  
Net Flux ◽  
The Impact ◽  
Arterial Insulin

Synchronising the rate of rumen breakdown and availability of dietary energy and nitrogenous components can improve the capture of rumen degradable nitrogen and improve the amount and efficiency of rumen microbial protein synthesis. It is not clear what influence rumen synchrony has on nutrient use by the portal-drained viscera (PDV). This experiment has examined the impact of feeding two diets formulated to be asynchronous or synchronous with respect to the potential hourly supply of energy and nitrogen to the microbial fraction of the rumen on portal blood flow, net flux of ammonia and urea across the PDV and arterial insulin concentrations.

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