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PubMedDate not supplied

Effect of adding sugar beet fibre and wheat bran to a starch diet on the absorption kinetics of glucose, amino-nitrogen and volatile fatty acids in the pig.

The purpose of this study with the pig was to analyse the influence of the type of dietary fibre on quantitative kinetics of the absorption of nutrients deriving from enzymatic digestion in the small intestine and that of volatile fatty acids (VFA) deriving from microbial digestion in the hindgut influenced by the length of adaptation to the diet. Two groups of four pigs were fitted with a device for measuring absorption by simultaneous analysis of the differences in the porto-arterial concentrations of nutrients and metabolites and of the portal blood flow rate. They received successively two diets containing fish- and heat-treated potato flour, balanced in vitamins and minerals, and only differing in the type of fibre added at the inclusion level of 10%: wheat bran (S) or sugar beet fibre (P). Following an adaptation period of 30 d (C) or 5 d (A) to each of these diets, and after the last experimental meal of 800 g, the animals were subjected for 12 h to blood samplings every 30-60 min for the analysis of glucose, amino-nitrogen and volatile fatty acids (VFA) with a simultaneous recording of the portal blood flow-rate. The type of dietary fibre did not modify nutrient absorption (glucose and amino-nitrogen) but affected the amounts of VFA appearing in the portal blood. These amounts were higher (P < 0.001) after ingestion of the sugar beet fibre-rich diet (group PC + PA: 766 mmol/12 h) than after that of the wheat bran-rich diet (group SC + SA: 477 mmol/12 h). The proportion of acetic acid in the absorbed mixture rose (PC + PA 63.6% versus SC + SA 58.5%, P < 0.01) at the expense of propionic acid (PC + PA 27.4% versus SC + SA 31.0%, P < 0.01). Prolongation of the adaptation period from 5 to 30 d led to a decrease in the absorption of nutrients deriving from enzymatic digestion in the small intestine (glucose g/12 h: SA + PA 341.8 versus SC + PC 244.5, P < 0.01; amino-nitrogen g/12 h: SA + PA 29.4 versus SC + PC 21.0, P < 0.001) without any subsequent change in the absorption of the volatile fatty acids.

Absorption↗
PubMed1985

Effects of wheat bran and porridge oats on hepatic portal venous volatile fatty acids in the pig.

Adult male pigs (40-60 kg of body weight) of the Kangaroo Island strain were surgically implanted with chronic indwelling hepatic portal venous cannulae. After a 24-hour fast the animals were given meals containing 500 g of either wheat bran or porridge oats and 200 g of sucrose and 2 litres of milk. With both cereal preparations plasma volatile fatty acids rose in the hepatic portal vein but the increase was significantly greater with wheat bran. Omission of sucrose and milk did not alter the response to porridge oats but diminished the response to wheat bran. These changes in plasma volatile fatty acids were unaffected by prior cooking of the cereals with hot water. With all test meals acetate and propionate were the major acids found, with butyrate contributing less than 8% of the total. This compositional profile was also found when the pigs were fed a commercial ration. The absence of butyrate differed from observations in the rat and reflected low concentrations of this acid in large bowel digesta. The difference in the response of the concentration of volatile fatty acids to feeding porridge oats and wheat bran in the pig was also the reverse of that found in the rat. These species differences may be of significance in relation to the choice of animal models for human fibre metabolism.

Animals↗
PubMed1976

The measurement of production rates of volatile fatty acids in the caecum of the conscious rabbit.

1. The decrease in specific radioactivity of individual volatile fatty acids (VFA) after a single injection of tracer was monitored. The results obtained indicated the occurrence of a first-order process. 2. Regression analysis indicated the high flux of VFA through the caecal pool, equivalent to 30% of the maintenance energy requirement of the animal. 3. Interconversion of VFA was monitored, and results indicated substantial synthesis of butyric acid from acetic acid. 4. Results were obtained from animals on two dietary regimens, and these were compared with results reported for the other species.

Acetates↗
PubMed1993

Effect of level of input of different proportions of volatile fatty acids on energy utilization in growing ruminants.

Four steers were maintained wholly by intragastric infusion of volatile fatty acids (VFA) and protein, together with a mineral-vitamin supplement. The infusion was given at three levels of energy, namely 450, 675 and 900 kJ/kg live weight0.75, calculated to supply energy at 1.0, 1.5 or 2.0 times that required for maintenance. The VFA provided 0.837 and the protein 0.163 of the energy infused. The molar proportions of individual VFA were varied so that the infusate contained 0.36-0.91 of acetic acid, 0.56-0.01 of propionic acid and a constant 0.08 of butyric acid. Heat production was measured in respiration chambers. Urine was analysed for N, urea, beta-hydroxybutyrate and VFA. Blood plasma was analysed for beta-hydroxybutyrate, free fatty acids, insulin and glucose. As the proportion of acetic acid was increased, and propionic acid reduced, there was no change in blood or urine metabolites or in heat production until acetic acid exceeded a proportion of about 0.75. At higher proportions beta-hydroxybutyrate increased in plasma and urine, blood glucose and insulin tended to fall and urinary N excretion rose. At a proportion of acetic acid of > 0.80, acetate appeared in the urine and at > 0.86 heat production declined. The effect of level of infusion on the molar proportion at which plasma and urine metabolites changed was less clear. There was a tendency for the increase in beta-hydroxybutyrate to occur at a slightly lower proportion of acetic acid at the highest level of infusion. It is concluded that differences in heat production that are observed between diets are probably not caused by differences in rumen VFA proportions.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1986

Characterization of Flavobacterium species by analysis of volatile fatty acid production.

Seventy-four Flavobacterium strains were characterized by gas-liquid chromatographic analysis of volatile fatty acids produced in the culture medium. Principal components analysis permitted the graphic representation of the relative positions of the different strains, and aggregation according to the variance enabled a hierarchical classification to be established. The study revealed three subgroups each for F. meningosepticum and F. odoratum. Our F. breve, Flavobacterium sp. group IIb and F. multivorum strains appeared to be homogeneous. These results tallied with those of previous studies on DNA base composition and reassociation, electrophoretic protein profiles and cellular fatty acid composition.

Butyrates↗
PubMed1985

Supplementation of dairy cow diets with ammonium salts of volatile fatty acids.

The objective was to determine the efficacy of a blend of ammonium salts of the volatile fatty acids, isobutyric, 2-methylbutyric, isovaleric, and valeric as a supplement to diets for dairy cows. Treatments of 0 (control) or 120 (supplemented) g/cow of the blend were fed daily from approximately 3 wk prepartum through a complete lactation. Five trials were conducted concurrently with a total of 116 multiparous Holstein cows. Dietary ingredients or combinations of ingredients differed in each of the trials. Diets contained either 1) corn gluten meal and urea, 2) soybean meal, or 3) cottonseed meal as the primary grain source of crude protein. The forage portion of the diets contained corn silage in combination with one or more of the following: alfalfa hay, alfalfa haylage, or wheat silage. Cows fed the supplement produced more milk and fat-corrected milk than the control cows for the 305-d lactation on four of the five diets, resulting in an average increase of 1.7 kg/d or 7%. Feed intake of cows on the supplemented diet was generally similar or lower than intake of the control cows throughout lactation, indicating that increased milk yield was associated with improved feed utilization. Percent milk fat was similar for cows on the supplemented diet, but fat yield was higher. Percent milk protein was lower for supplemented cows, but protein yield was about the same for both treatments because of higher milk yield. Health and reproduction were similar for all cows.

Animal Feed↗
PubMed1999

Analysis of volatile fatty acids in wastewater collected from a pig farm by a solid phase microextraction method.

The main purpose of this study is to develop a reliable Solid Phase Microextraction (SPME) method for monitoring the concentration of volatile fatty acid (VFA) in the wastewater collected from pig farms. Ten volatile fatty acid species were spiked in 2 ml of swine wastewater and extracted with a carbowax coated extraction fiber to evaluate the accuracy and precision of the method. The fiber was introduced into a gas chromatography system by thermal desorption and detected by a mass spectrometer detector. The estimated method detection limits ranged from 11.5 mM/L for formic acid to 0.03 mM/L for heptanoic acid. The method is more sensitive than the sample direct injection method. The percentage recovery of analytes ranged from 77.3 for propanoic acid to 114.1 for formic acid at the spike level of 19.09 mM/L. The compound absorption rate varied significantly with the fiber absorption time for n-Valeric, isocaproic, n-caproic and heptanoic acids. An SPME method with twenty minutes fiber absorption and three minutes thermal desorption was tested in this study and resulted in good reproducibility for analyzing VFAs in swine wastewater. The method may be applied for scanning a wide spectrum of polar organic compounds in environmental samples.

Acrylic Resins↗