ABSORPTION OF STEAM-VOLATILE FATTY ACIDS FROM THE RUMEN OF THE COW AS INFLUENCED BY DIET, BUFFERS, AND pH

1973 ◽  
Vol 53 (2) ◽  
pp. 279-288 ◽  
Author(s):  
S. O. THORLACIUS ◽  
G. A. LODGE
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Acid Concentration ◽  
Phosphate Buffer ◽  
Volatile Fatty Acids ◽  
Fatty Acid Concentration ◽  
Bicarbonate Buffer ◽  
Acid Absorption ◽  
Fatty Acid Absorption

Observations were made on the absorption of steam-volatile fatty acids from the temporarily isolated, washed ventral sac of the rumen of the conscious cow. At pH 7.0, absorption of fatty acids from a 50-mM bicarbonate buffer was similar to that obtained with a 40-mM phosphate buffer. With higher levels of phosphate (75 mM) and bicarbonate (90 mM) at pH 7.0, fatty acid absorption appeared to be lower from the bicarbonate buffer. When cows were fed a high concentrate diet, absorption of fatty acids was more rapid than when the diet had been all hay. Lowering the pH of experimental solutions increased fatty acid absorption. Clearance (amount absorbed divided by the fatty acid concentration) of fatty acids increased progressively with increasing chain length of the acids as the pH dropped below 7. Taking acetate clearance as 1.0, the clearance of propionate and butyrate, respectively, were 1.1 and 1.0 at pH 7.0; 1.2 and 1.4 at pH 6.5; and 1.6 and 2.4 at pH 5.5. Varying acetate and propionate concentrations did not influence the clearance of the fatty acids.

Effects of cell density on in vitro glucose metabolism by isolated adipocytes

1993 ◽  
Vol 264 (3) ◽  
pp. E361-E366 ◽  
Author(s):  
M. Digirolamo ◽  
S. V. Thacker ◽  
S. K. Fried
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Glucose Metabolism ◽  
Cell Density ◽  
Acid Concentration ◽  
Cell Concentration ◽  
Fatty Acid Concentration ◽  
Fat Cell ◽  
Cell Concentrations

We studied the effect of variable isolated fat cell concentrations (from 0.17 to 1.25 x 10(6) cells/ml) on rate and pattern of basal and insulin-stimulated glucose metabolism by rat epididymal fat cells. Cell concentration did not affect total glucose utilization, but high cell concentrations increased the absolute and relative conversion of glucose to CO2 and glyceride-fatty acids by two- to threefold and decreased the conversion to lactate, pyruvate, and glyceride-glycerol when compared with values observed at low cell concentration. When effects of adenosine deaminase (ADA) and N-6(2-phenylisopropyl)adenosine (PIA) were examined, addition of ADA to incubated cells produced no significant changes in the rate or pattern of adipocyte glucose metabolism; PIA had a slight and uniform effect on the conversion of glucose to its metabolic products and minimal effect on insulin-stimulated glucose metabolism. Medium free fatty acid concentration did not change during the incubation at various cell density, but intracellular free fatty acids were found to be inversely related to fat cell density in the medium. Thus a variable fat cell density influences the pattern of adipocyte glucose metabolism in vitro. This effect may be due to variable rates of lipolysis and resulting changes in intracellular fatty acid concentration rather than to adenosine per se. This work has practical implications in the need to define cell density when carrying out in vitro measurements of adipocyte glucose conversion to products.

scholarly journals Exploiting Compositionally Similar Grape Marc Samples to Achieve Gradients of Condensed Tannin and Fatty Acids for Modulating In Vitro Methanogenesis

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1793
Author(s):  
Josh Hixson ◽  
Zoey Durmic ◽  
Joy Vadhanabhuti ◽  
Philip Vercoe ◽  
Paul Smith ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Concentration ◽  
Methane Production ◽  
Condensed Tannin ◽  
Fatty Acid Concentration ◽  
Grape Marc ◽  
Volatile Fatty Acid Concentration ◽  
Tannin Concentration

Ruminants produce large amounts of the greenhouse gas, methane, which can be reduced by supplementing feed with products that contain anti-methanogenic compounds, such as the solid winemaking by-product, grape marc. The aim of this study was to exploit compositional differences in grape marc to better understand the roles of condensed tannin and fatty acids in altering methanogenesis in a ruminant system. Grape marc samples varying in tannin extractability, tannin size and subunit composition, and fatty acid or tannin concentrations were selected and incubated in rumen fluid using an in vitro batch fermentation approach with a concentrate-based control. Four distinct experiments were designed to investigate the effects on overall fermentation and methane production. Generally, fatty acid concentration in grape marc was associated with decreased total gas volumes and volatile fatty acid concentration, whereas increased condensed tannin concentration tended to decrease methane percentage. Smaller, extractable tannin was more effective at reducing methane production, without decreasing overall gas production. In conclusion, fatty acids and tannin concentration, and tannin structure in grape marc play a significant role in the anti-methanogenic effect of this by-product when studied in vitro. These results should be considered when developing strategies to reduce methane in ruminants by feeding grape marc.

scholarly journals Extracellular fatty acids are not utilized directly for the synthesis of very-low-density lipoprotein in primary cultures of rat hepatocytes

1992 ◽  
Vol 287 (3) ◽  
pp. 749-753 ◽  
Author(s):  
G F Gibbons ◽  
S M Bartlett ◽  
C E Sparks ◽  
J D Sparks
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Concentration ◽  
Low Density Lipoprotein ◽  
Primary Cultures ◽  
Density Lipoprotein ◽  
Fatty Acid Concentration ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Extracellular Fatty Acid

In hepatocytes cultured in the presence of oleate (initial concn. 0.75 mM), the secretion of very-low-density lipoprotein (VLDL) triacylglycerol and, to a lesser extent, apoprotein B (apoB) increased with time, whereas there was a large decline in the extracellular concentration of fatty acid. There was thus no synchronous relationship between the extracellular fatty acid concentration and the secretion of VLDL. Rather, the appearance of VLDL in the medium was dependent on the intracellular triacylglycerol concentration. At a given concentration of extracellular fatty acid, cells depleted of triacylglycerol secreted less VLDL triacylglycerol and apoB than did control cells. A similar pattern was observed for triacylglycerol newly synthesized from extracellular [3H]oleate. By contrast, the synthesis and output of ketone bodies were directly dependent on the fatty acid concentration of the medium. These results suggest that, at least for oleic acid, extracellular fatty acids are not utilized directly for VLDL assembly, but first enter a temporary intracellular storage pool of triacylglycerol, which is the immediate precursor of secreted triacylglycerol. The size of this pool then determines the rate of secretion of VLDL triacylglycerol apoB. Ketogenesis, on the other hand, relies mainly on the direct utilization of extracellular fatty acids.

Metabolic studies on daily and weekly feeding of ruminants given all-wheat diets. 2. Concentrations of metabolites in blood and ruminal fluid

1975 ◽  
Vol 26 (5) ◽  
pp. 885 ◽  
Author(s):  
MJ Watson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Acid Concentration ◽  
Volatile Fatty Acid ◽  
Feed Consumption ◽  
Fatty Acid Concentration ◽  
Ruminal Fluid ◽  
Whole Wheat ◽  
Volatile Fatty Acid Concentration

The respective effects of giving sheep 300 g whole wheat once each day or 2100 g once each week on the products of digestion in the rumen and the concentrations of several metabolites in the blood have been studied. Some studies were also made on cattle offered either daily or weekly rations of whole wheat. Related to the differing patterns of feed consumption on the two regimens, the fluctuations in ruminal fluid parameters were much greater for sheep and cattle fed weekly than on the daily feeding regimens. In sheep the mean total volatile fatty acid concentration and pH in ruminal fluid were similar on the two regimens, while when cattle were fed weekly, the volatile fatty acid concentration was higher (not significantly) and the pH lower. Weekly-fed sheep had lower rumen ammonia and branched-chain volatile fatty acid concentrations, whereas in cattle there was no difference between regimens. The rumen concentration of valeric acid was higher in both sheep and cattle fed weekly. In daily-fed sheep there was no diurnal variation in the concentrations of blood metabolites with the exception of free fatty acids. In contrast in weekly-fed sheep, the large changes in concentration of D(-)-glucose, L(+)-lactate, 3-hydroxybutyrate, urea and free fatty acids indicated phases of protein synthesis and lipogenesis following feeding, and protein and lipid mobilization at the end of the feeding cycle. It was concluded that in weekly-fed sheep there was a shift in the site of digestion from the rumen to the small intestine, but in cattle there was no evidence that the sites of digestion differed substantially between the two regimens.

Genotypic and environmental effects on saturated fatty acid concentration of canola grown in Manitoba

2004 ◽  
Vol 84 (3) ◽  
pp. 749-756 ◽  
Author(s):  
C. A. McCartney ◽  
R. Scarth ◽  
P. B. E. McVetty ◽  
J. K. Daun
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Saturated Fatty Acid ◽  
Acid Concentration ◽  
Protein Concentration ◽  
Saturated Fatty Acids ◽  
Fatty Acid Concentration ◽  
Oil Concentration ◽  
Main Effects

The low saturated fatty acid concentration of canola oil relative to other vegetable oils has resulted in a favourable market share for canola. Understanding the effects of genotype and environment on saturated fatty acid concentration will facilitate Brassica napus breeding efforts aimed at maintaining or reducing saturate levels in the seed oil. Canola-quality B. napus samples from the Manitoba Crop Variety Evaluation Team (MCVET) trials in 1999, 2000 and 2001 were tested for fatty acid composition, oil concentration and protein concentration. Weather data were obtained from nearby weather stations. The majority of the variation in total saturates for the cultivars studied was attributed to variation in palmitic acid (C16:0) due to the genotype main effect and variation in stearic acid (C18:0) due to the genotype and environment main effects. The variation due to the genotype × environment interaction was small relative to the main effects for the individual saturated fatty acids. C18:0 and arachidic (C20:0) acid concentrations were correlated between genotypes, suggesting pleiotropy or that these traits are controlled by linked genes in the cultivars tested. The data also suggested that C16:0 and C18:0 acid concentrations are controlled by different genes. C18:0, C20:0 and behenic (C22:0) acid concentrations were correlated across environments, but did not correlate with C16:0 concentration. Relationships between weather variables and fatty acid composition, oil concentration and protein concentration were not established. Additive Main effects and Multiplicative Interaction (AMMI) analysis revealed that some canola cultivars were more stable than others with regard to total saturates over environments. Key words: Genotype, environment, seed quality, saturated fatty acids, canola, Brassica napus

scholarly journals Absorption of Volatile Fatty Acids From the Reticulo-Rumen and Abomasum of Sheep

1968 ◽  
Vol 21 (1) ◽  
pp. 89 ◽  
Author(s):  
VJ Williams ◽  
TR Hutchings ◽  
KA Archer
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Solution ◽  
Acid Concentration ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Total Volatile ◽  
Volatile Fatty Acid Concentration ◽  
The Individual ◽  
Total Volatile Fatty Acid

Ten acute experiments were performed on sheep to study the relative rates of absorption of volatile fatty acids in acid solution from the reticulo-rumen and abomasum. When the solutions in the two organs were approximately the same in initial tonicity, pH, and volatile fatty acid concentration, the total volatile fatty acid was absorbed at about equal rates from both the reticulo-rumen and the abomasum. The individual volatile fatty acids were absorbed from the abomasum at different rates; the rate was faster the greater the number of carbon atoms in the molecule. Ammonia in acid solution was not absorbed from the reticulo-rumen or from the abomasum.

Sign in / Sign up

Export Citation Format

Share Document